The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method. The stability portion of the test measures the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute. Load is applied to the specimen till failure, and the maximum load is designated as stability. During the loading, an attached dial gauge measures the specimen's plastic flow (deformation) due to the loading. The flow value is recorded in 0.25 mm (0.01 inch) increments at the same time when the maximum load is recorded.
This document discusses different types of interface treatments used in pavement construction. It begins by defining an interface treatment as applying a thin layer of bituminous binder to the surface of an existing pavement layer before constructing a new bituminous layer. It then discusses prime coats, tack coats, and seal coats. For prime coats, it describes the purpose and materials used. It discusses best practices for application and important properties like penetration, curing time, strength and impermeability. For tack coats, it provides guidelines for surface preparation and application rates. Finally, it describes seal coats and the typical materials and process used to lay them down.
The document discusses Superpave mix design, which is a performance-based method for designing asphalt concrete mixtures. Some key points:
- Superpave uses the gyratory compactor to simulate field compaction of mixtures, allowing for evaluation of density during the design process.
- The design process involves 4 steps: selecting materials based on traffic and climate conditions, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture susceptibility.
- Key evaluation points on the gyratory compaction curve are Ninitial, Ndesign, and Nmax, which control compactability, expected field density, and maximum allowed density.
- Design traffic level determines the number
This document discusses different methods for grading bituminous binders, including penetration grading, viscosity grading, and performance grading. Penetration grading uses the penetration test results at 25°C to specify grades. Viscosity grading specifies grades based on viscosity measurements at 60°C and 135°C. Performance grading assigns grades based on the temperature ranges where the binder is expected to perform satisfactorily against rutting, fatigue cracking, and low-temperature cracking. The document also covers specifications, advantages and disadvantages of each grading method, and definitions and measurement of viscosity and its importance in characterizing bitumen properties.
The document provides information on different types of bitumen and bitumen modification. It discusses natural bitumen, artificial bitumen including straight run bitumen and blown bitumen. It also describes cut back bitumen, emulsions, and modified bitumens including crumb rubber modified bitumen, natural rubber modified bitumen, and polymer modified bitumen. The document lists the advantages of modified bitumens and guidelines for their use. It provides details on consistency tests, performance tests, and grades of different modified bitumens.
This document discusses using crumb rubber from waste tires in asphalt pavement. It begins with an introduction that notes the large volume of waste tires produced globally each year and the environmental issues with current disposal methods. The objectives are then stated as utilizing waste rubber in flexible pavement construction to reduce costs and natural resource usage. Various materials used are described, including aggregates, asphalt, and crumb rubber. Testing conducted on the materials is summarized. A literature review covers several papers on using crumb rubber in asphalt mixes. The methodology section outlines the test specimens prepared with different percentages of crumb rubber added. Marshall stability tests are then used to evaluate the mixtures and determine the optimal crumb rubber content.
The document provides details about a summer internship project report submitted by Ritwiz Kumar for a vocational training program at the Road Construction Division of the Bihar Public Works Department. The report includes an index and sections on types of roads, types of pavements, an introduction to bitumen and bituminous roads, bituminous road layers, and equipment used for road construction. It provides information about the internship dates and organization and acknowledges those who supported the training experience.
The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method. The stability portion of the test measures the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute. Load is applied to the specimen till failure, and the maximum load is designated as stability. During the loading, an attached dial gauge measures the specimen's plastic flow (deformation) due to the loading. The flow value is recorded in 0.25 mm (0.01 inch) increments at the same time when the maximum load is recorded.
This document discusses different types of interface treatments used in pavement construction. It begins by defining an interface treatment as applying a thin layer of bituminous binder to the surface of an existing pavement layer before constructing a new bituminous layer. It then discusses prime coats, tack coats, and seal coats. For prime coats, it describes the purpose and materials used. It discusses best practices for application and important properties like penetration, curing time, strength and impermeability. For tack coats, it provides guidelines for surface preparation and application rates. Finally, it describes seal coats and the typical materials and process used to lay them down.
The document discusses Superpave mix design, which is a performance-based method for designing asphalt concrete mixtures. Some key points:
- Superpave uses the gyratory compactor to simulate field compaction of mixtures, allowing for evaluation of density during the design process.
- The design process involves 4 steps: selecting materials based on traffic and climate conditions, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture susceptibility.
- Key evaluation points on the gyratory compaction curve are Ninitial, Ndesign, and Nmax, which control compactability, expected field density, and maximum allowed density.
- Design traffic level determines the number
This document discusses different methods for grading bituminous binders, including penetration grading, viscosity grading, and performance grading. Penetration grading uses the penetration test results at 25°C to specify grades. Viscosity grading specifies grades based on viscosity measurements at 60°C and 135°C. Performance grading assigns grades based on the temperature ranges where the binder is expected to perform satisfactorily against rutting, fatigue cracking, and low-temperature cracking. The document also covers specifications, advantages and disadvantages of each grading method, and definitions and measurement of viscosity and its importance in characterizing bitumen properties.
The document provides information on different types of bitumen and bitumen modification. It discusses natural bitumen, artificial bitumen including straight run bitumen and blown bitumen. It also describes cut back bitumen, emulsions, and modified bitumens including crumb rubber modified bitumen, natural rubber modified bitumen, and polymer modified bitumen. The document lists the advantages of modified bitumens and guidelines for their use. It provides details on consistency tests, performance tests, and grades of different modified bitumens.
This document discusses using crumb rubber from waste tires in asphalt pavement. It begins with an introduction that notes the large volume of waste tires produced globally each year and the environmental issues with current disposal methods. The objectives are then stated as utilizing waste rubber in flexible pavement construction to reduce costs and natural resource usage. Various materials used are described, including aggregates, asphalt, and crumb rubber. Testing conducted on the materials is summarized. A literature review covers several papers on using crumb rubber in asphalt mixes. The methodology section outlines the test specimens prepared with different percentages of crumb rubber added. Marshall stability tests are then used to evaluate the mixtures and determine the optimal crumb rubber content.
The document provides details about a summer internship project report submitted by Ritwiz Kumar for a vocational training program at the Road Construction Division of the Bihar Public Works Department. The report includes an index and sections on types of roads, types of pavements, an introduction to bitumen and bituminous roads, bituminous road layers, and equipment used for road construction. It provides information about the internship dates and organization and acknowledges those who supported the training experience.
The document discusses different types of pavements used for highways. It describes flexible pavements which transmit wheel loads through grain-to-grain contact and consist of multiple layers including the surface course, binder course, base course, and sub-base course. Rigid pavements have sufficient strength to distribute loads over a wider area and typically consist of concrete over a single granular or stabilized layer. The document also covers pavement materials like soils, aggregates, and asphalt concrete and tests used to evaluate soil strength properties important for pavement design like the California Bearing Ratio test.
This document discusses highway engineering and construction. It covers the classification of highways, materials used like asphalt and aggregates, machinery used for construction and maintenance like compactors and pavers, and rehabilitation methods like replacing damaged layers with thin hot or cold pavement layers. Highway engineering aims to provide efficient transportation routes, and involves building different road types to connect locations while using appropriate construction methods and machinery.
Rigid pavements are concrete slabs that distribute vehicle loads through beam action. They have high flexural strength and small deflections compared to flexible pavements. The presentation discusses the types of rigid pavements including jointed plain concrete, jointed reinforced concrete, and continuously reinforced concrete pavements. It also covers the design factors for rigid pavements such as traffic loading, subgrade strength, environmental conditions, and material properties. Rigid pavements are designed to last 30 years with minimal maintenance required over the design life.
This document discusses materials used in highway construction. It outlines seven major materials: bituminous materials, soil, aggregates, Portland cement concrete, admixtures, pavement marking materials, and structural steel. For each material, it provides details on composition, properties, and relevant tests used for evaluation and quality control of the material. Key tests discussed include moisture content value, California bearing ratio, Los Angeles abrasion value, and specific gravity and water absorption.
Aggregates blending, blending aggregates by graphical method, concrete mix design, concrete technology, what is aggregates blending, what is blending, methods of blending, how to blend aggregates, civil engineering
The document describes the components and operation of an asphalt batch mix plant. The plant uses aggregates that are fed into bins then dried and heated. The heated aggregates are mixed with asphalt in a mixing chamber. Additional components include asphalt tanks, mineral filler units, and load out conveyors. Controls and monitoring are centralized in a control panel. Batch mix plants generally cost between 60-75 lacs depending on capacity. Major manufacturers of batch mix plants in India are listed.
The document describes the layers of a concrete road, including:
1) A filling or cutting layer for leveling the ground
2) A 300mm thick subgrade murrum layer underneath
3) A granular sub-base layer made of crushed stone 0-40mm aggregate
4) A dry lean concrete layer used as a base with a higher aggregate to cement ratio
5) A top pavement quality concrete layer made with 32mm aggregate designed for heavy traffic.
This document discusses various methods and standards for measuring pavement surface characteristics like skid resistance and texture. It covers topics like factors that influence skid resistance, methods for measuring micro-texture and macro-texture, standards for measuring polished stone value, and devices for measuring skid resistance at different speeds. The summary provides an overview of the key methods and standards discussed in the document.
Crumb Rubber Modified Bitumen (CRMB) is hydrocarbon binder obtained through physical and chemical interaction of crumb rubber (produced by recycling of used tyres) with bitumen and some specific additives.
Mix design practice (bituminous mix) ce 463abhay mishra
The document discusses various methods for designing bituminous mixes, including the Marshall, Hveem, and Modified Hubbard-Field methods. The objective of bituminous mix design is to determine an optimal blend of aggregates and bitumen that provides sufficient bitumen for durability while maintaining stability, voids, and other properties to meet traffic and weather demands. Key steps involve preparing trial mixtures, testing stability and voids, and analyzing results to select the design bitumen content.
The document discusses different types of pavements. It describes flexible pavements as having multiple layers that distribute loads through aggregate interlock. Rigid pavements distribute loads through the beam strength of concrete slabs. Flexible pavements are composed of surface, base, and sub-base layers over a subgrade, while rigid pavements typically only require a concrete surface layer. Both pavement types are designed to reduce loads from vehicles to prevent damage to the subgrade. The document compares advantages and disadvantages of flexible and rigid pavements.
This document provides a project report on the design and analysis of a flexible pavement for a road on the SMS Institute of Technology campus in Lucknow, India. It includes chapters on the cross-section of a flexible pavement with different layers, surveying and leveling of the site, important tests for the pavement materials, the design approach and criteria, potential failures of flexible pavement, and machinery used in pavement construction. The report was submitted in partial fulfillment of requirements for a Bachelor of Technology degree in Civil Engineering.
The document discusses the components and requirements of an ideal permanent way for railways. It describes that the permanent way consists of rails fitted on sleepers which rest on ballast and a subgrade. The key requirements for an ideal permanent way are proper gauge, alignment, gradient, drainage and minimal resistance. It also discusses different types of rails, sleepers and fastenings used in railway track construction.
The document discusses the different layers of flexible pavement, including the granular sub-base, granular base course, and bituminous layers. It describes the materials, construction processes, and quality control tests for each layer. Specifically, it outlines the objectives and materials used for the granular sub-base layer, including crushed stone aggregates, gravel, coarse sand, and requirements for material passing sieves. It also discusses the compaction and testing requirements for constructing the granular sub-base layer.
This document provides an overview of various types of paving equipment used in asphalt road construction. It describes stabilizers/reclaimers, milling machines, graders, sweepers, batch plants, drum plants, dump trucks, material transfer vehicles, asphalt pavers, and compactors/rollers. For each type of equipment, it explains its purpose and functioning in the road paving process.
This document discusses the typical layers of a flexible pavement. It begins by describing seal coat, tack coat, and prime coat layers. It then outlines the layers of a carriageway from bottom to top: earth work, granular sub base, wet mix macadam, bituminous macadam, bituminous concrete. Details are provided on the materials and construction procedures for some of these layers. The document also discusses cement concrete pavements and their advantages over flexible pavements.
This document discusses the design, maintenance, and cost analysis of bituminous hot mix plants. It outlines the objectives of analyzing hot mix plants, including understanding their types and costs. It describes the key components of hot mix plants like drum and batch mixers, and the mixing procedures. It also discusses the necessary government permissions and certificates. Finally, it provides a cost analysis of establishing and operating a hot mix plant, including capital costs, operating expenses, production capacity, and expected profits.
Este documento discute la variabilidad en la construcción y comportamiento de pavimentos. Explica que hay variación en factores como el espesor de las capas, profundidad de armaduras y soporte del suelo durante la construcción. También hay diferencias en el comportamiento a lo largo del pavimento y entre proyectos similares. Esta variabilidad afecta la bondad del diseño y puede reducir la vida útil si causa fallas localizadas. El documento introduce conceptos de confiabilidad para cuantificar esta variabilidad e incorporarla en el diseño de
This document discusses the use of bitumen in road construction. It notes that bitumen has unique properties that make it suitable for use in flexible roads. There are four main types of bitumen: paving grade, modified, cutback, and emulsion. The document outlines several factors that influence how bitumen hardens over time when used in roads, including oxidation, loss of volatiles, and physical hardening. It lists some advantages as a smooth ride surface, quick repair ability, staged construction, lower life costs, and temperature resistance. Disadvantages include less durability, lower tensile strength compared to concrete, and higher construction costs during extreme temperatures.
The U.S. Environmental Protection Agency (EPA’s) Office of Air Quality Planning
and Standards (OAQPS) is compiling information on lime manufacturing plants as part of its
responsibility to develop National Emission Standards for Hazardous Air Pollutants
(NESHAP) under Section 112 of the 1990 Clean Air Act. The NESHAP is scheduled to be
proposed in 2000, and the Innovative Strategies and Economics Group is responsible for
developing an economic impact analysis (EIA) in support of the evaluation of impacts
associated with the regulatory options considered for this NESHAP. This industry profile of
the lime manufacturing industry provides information to be used to support the regulation.
This document provides an overview of biomass briquetting technology and practices. It discusses various agro-residues that can be used for briquetting, including rice husk, coffee husk, and groundnut shells. It describes the fundamental aspects and mechanisms of briquetting using screw press and piston press technologies. Key aspects covered include feed processing equipment, material and energy balances, the process for setting up a briquetting plant, and an economic analysis of briquetting. The document aims to familiarize readers with biomass briquetting and its potential to provide a cleaner fuel alternative while making productive use of agricultural residues.
The document discusses different types of pavements used for highways. It describes flexible pavements which transmit wheel loads through grain-to-grain contact and consist of multiple layers including the surface course, binder course, base course, and sub-base course. Rigid pavements have sufficient strength to distribute loads over a wider area and typically consist of concrete over a single granular or stabilized layer. The document also covers pavement materials like soils, aggregates, and asphalt concrete and tests used to evaluate soil strength properties important for pavement design like the California Bearing Ratio test.
This document discusses highway engineering and construction. It covers the classification of highways, materials used like asphalt and aggregates, machinery used for construction and maintenance like compactors and pavers, and rehabilitation methods like replacing damaged layers with thin hot or cold pavement layers. Highway engineering aims to provide efficient transportation routes, and involves building different road types to connect locations while using appropriate construction methods and machinery.
Rigid pavements are concrete slabs that distribute vehicle loads through beam action. They have high flexural strength and small deflections compared to flexible pavements. The presentation discusses the types of rigid pavements including jointed plain concrete, jointed reinforced concrete, and continuously reinforced concrete pavements. It also covers the design factors for rigid pavements such as traffic loading, subgrade strength, environmental conditions, and material properties. Rigid pavements are designed to last 30 years with minimal maintenance required over the design life.
This document discusses materials used in highway construction. It outlines seven major materials: bituminous materials, soil, aggregates, Portland cement concrete, admixtures, pavement marking materials, and structural steel. For each material, it provides details on composition, properties, and relevant tests used for evaluation and quality control of the material. Key tests discussed include moisture content value, California bearing ratio, Los Angeles abrasion value, and specific gravity and water absorption.
Aggregates blending, blending aggregates by graphical method, concrete mix design, concrete technology, what is aggregates blending, what is blending, methods of blending, how to blend aggregates, civil engineering
The document describes the components and operation of an asphalt batch mix plant. The plant uses aggregates that are fed into bins then dried and heated. The heated aggregates are mixed with asphalt in a mixing chamber. Additional components include asphalt tanks, mineral filler units, and load out conveyors. Controls and monitoring are centralized in a control panel. Batch mix plants generally cost between 60-75 lacs depending on capacity. Major manufacturers of batch mix plants in India are listed.
The document describes the layers of a concrete road, including:
1) A filling or cutting layer for leveling the ground
2) A 300mm thick subgrade murrum layer underneath
3) A granular sub-base layer made of crushed stone 0-40mm aggregate
4) A dry lean concrete layer used as a base with a higher aggregate to cement ratio
5) A top pavement quality concrete layer made with 32mm aggregate designed for heavy traffic.
This document discusses various methods and standards for measuring pavement surface characteristics like skid resistance and texture. It covers topics like factors that influence skid resistance, methods for measuring micro-texture and macro-texture, standards for measuring polished stone value, and devices for measuring skid resistance at different speeds. The summary provides an overview of the key methods and standards discussed in the document.
Crumb Rubber Modified Bitumen (CRMB) is hydrocarbon binder obtained through physical and chemical interaction of crumb rubber (produced by recycling of used tyres) with bitumen and some specific additives.
Mix design practice (bituminous mix) ce 463abhay mishra
The document discusses various methods for designing bituminous mixes, including the Marshall, Hveem, and Modified Hubbard-Field methods. The objective of bituminous mix design is to determine an optimal blend of aggregates and bitumen that provides sufficient bitumen for durability while maintaining stability, voids, and other properties to meet traffic and weather demands. Key steps involve preparing trial mixtures, testing stability and voids, and analyzing results to select the design bitumen content.
The document discusses different types of pavements. It describes flexible pavements as having multiple layers that distribute loads through aggregate interlock. Rigid pavements distribute loads through the beam strength of concrete slabs. Flexible pavements are composed of surface, base, and sub-base layers over a subgrade, while rigid pavements typically only require a concrete surface layer. Both pavement types are designed to reduce loads from vehicles to prevent damage to the subgrade. The document compares advantages and disadvantages of flexible and rigid pavements.
This document provides a project report on the design and analysis of a flexible pavement for a road on the SMS Institute of Technology campus in Lucknow, India. It includes chapters on the cross-section of a flexible pavement with different layers, surveying and leveling of the site, important tests for the pavement materials, the design approach and criteria, potential failures of flexible pavement, and machinery used in pavement construction. The report was submitted in partial fulfillment of requirements for a Bachelor of Technology degree in Civil Engineering.
The document discusses the components and requirements of an ideal permanent way for railways. It describes that the permanent way consists of rails fitted on sleepers which rest on ballast and a subgrade. The key requirements for an ideal permanent way are proper gauge, alignment, gradient, drainage and minimal resistance. It also discusses different types of rails, sleepers and fastenings used in railway track construction.
The document discusses the different layers of flexible pavement, including the granular sub-base, granular base course, and bituminous layers. It describes the materials, construction processes, and quality control tests for each layer. Specifically, it outlines the objectives and materials used for the granular sub-base layer, including crushed stone aggregates, gravel, coarse sand, and requirements for material passing sieves. It also discusses the compaction and testing requirements for constructing the granular sub-base layer.
This document provides an overview of various types of paving equipment used in asphalt road construction. It describes stabilizers/reclaimers, milling machines, graders, sweepers, batch plants, drum plants, dump trucks, material transfer vehicles, asphalt pavers, and compactors/rollers. For each type of equipment, it explains its purpose and functioning in the road paving process.
This document discusses the typical layers of a flexible pavement. It begins by describing seal coat, tack coat, and prime coat layers. It then outlines the layers of a carriageway from bottom to top: earth work, granular sub base, wet mix macadam, bituminous macadam, bituminous concrete. Details are provided on the materials and construction procedures for some of these layers. The document also discusses cement concrete pavements and their advantages over flexible pavements.
This document discusses the design, maintenance, and cost analysis of bituminous hot mix plants. It outlines the objectives of analyzing hot mix plants, including understanding their types and costs. It describes the key components of hot mix plants like drum and batch mixers, and the mixing procedures. It also discusses the necessary government permissions and certificates. Finally, it provides a cost analysis of establishing and operating a hot mix plant, including capital costs, operating expenses, production capacity, and expected profits.
Este documento discute la variabilidad en la construcción y comportamiento de pavimentos. Explica que hay variación en factores como el espesor de las capas, profundidad de armaduras y soporte del suelo durante la construcción. También hay diferencias en el comportamiento a lo largo del pavimento y entre proyectos similares. Esta variabilidad afecta la bondad del diseño y puede reducir la vida útil si causa fallas localizadas. El documento introduce conceptos de confiabilidad para cuantificar esta variabilidad e incorporarla en el diseño de
This document discusses the use of bitumen in road construction. It notes that bitumen has unique properties that make it suitable for use in flexible roads. There are four main types of bitumen: paving grade, modified, cutback, and emulsion. The document outlines several factors that influence how bitumen hardens over time when used in roads, including oxidation, loss of volatiles, and physical hardening. It lists some advantages as a smooth ride surface, quick repair ability, staged construction, lower life costs, and temperature resistance. Disadvantages include less durability, lower tensile strength compared to concrete, and higher construction costs during extreme temperatures.
The U.S. Environmental Protection Agency (EPA’s) Office of Air Quality Planning
and Standards (OAQPS) is compiling information on lime manufacturing plants as part of its
responsibility to develop National Emission Standards for Hazardous Air Pollutants
(NESHAP) under Section 112 of the 1990 Clean Air Act. The NESHAP is scheduled to be
proposed in 2000, and the Innovative Strategies and Economics Group is responsible for
developing an economic impact analysis (EIA) in support of the evaluation of impacts
associated with the regulatory options considered for this NESHAP. This industry profile of
the lime manufacturing industry provides information to be used to support the regulation.
This document provides an overview of biomass briquetting technology and practices. It discusses various agro-residues that can be used for briquetting, including rice husk, coffee husk, and groundnut shells. It describes the fundamental aspects and mechanisms of briquetting using screw press and piston press technologies. Key aspects covered include feed processing equipment, material and energy balances, the process for setting up a briquetting plant, and an economic analysis of briquetting. The document aims to familiarize readers with biomass briquetting and its potential to provide a cleaner fuel alternative while making productive use of agricultural residues.
This document discusses biomass briquetting technology and practices. It provides an overview of potential agricultural residues for briquetting in Asia, fundamental aspects of briquetting including binding mechanisms and compaction characteristics. It also describes various briquetting technologies such as screw press and piston press. Key components of a briquetting plant and procedures for setting up a new plant are outlined. The document concludes with sections on economic analysis and applications of biomass briquettes.
This document provides a profile of the iron mining industry and a site visit report for LTV Steel. The profile describes the economic and environmental aspects of iron mining. Iron ore deposits are formed through sedimentary, igneous, and weathering processes. Extraction methods include open pit and underground mining. Beneficiation involves milling, magnetic separation, flotation, gravity concentration, thickening, filtering, and agglomeration to produce iron ore concentrates. Wastes include waste rock, tailings, and mine water. Management includes waste rock piles, tailings impoundments, and mine reclamation. The profile also discusses environmental effects and applicable regulations. The site visit report provides background on LTV Steel and describes its
This document provides an environmental assessment of the proposed Vasilikos Energy Centre project on Cyprus. It was prepared by Parsons Brinckerhoff Limited and Aeoliki Limited for M.W. Kellogg Limited. The assessment examines the legislative and policy framework, provides a description of the project, and assesses potential impacts and mitigation measures related to land use, geology/soils, water resources, ecology, landscape/visual, air quality, noise, traffic, waste, archaeology, and the marine environment. It includes tables summarizing emissions, discharge standards, baseline conditions, impact criteria, and proposed mitigation measures. Figures and appendices provide additional details.
Methods for Monitoring Pump-and-Treat PerformanceRenato Kumamoto
This document provides guidance on monitoring methods for evaluating the performance and effectiveness of pump-and-treat groundwater remediation systems. It discusses key objectives for hydraulic containment and aquifer restoration and constraints that can hinder achieving cleanup goals. A variety of field measurements are described to monitor hydraulic capture zones, groundwater flows, water levels, water quality parameters, pumping rates and effluent concentrations. The frequency of monitoring is also addressed. The guidance aims to help clearly define system objectives and ensure careful performance monitoring to determine if a pump-and-treat system is operating as intended.
This document provides guidance for volunteer weather observers in the National Weather Service Cooperative Observer Program. It details the types of weather observations collected, such as precipitation and temperature, and how to properly maintain observation equipment and record data. The Cooperative Observer Program is the oldest and largest network of weather observers, with over 11,000 volunteers collecting daily weather reports across the United States that are vital for climate monitoring, forecasting, and emergency preparedness.
Study Showing U.S. Shale Drilling will Create 1.6M Jobs & $245B in 10 YearsMarcellus Drilling News
American Clean Skies Foundation and ICF International published a new economic study looking at the statistics for the impact of shale gas drilling, state by state. The impact is huge: As much as 1.6 million new jobs and $245 billion in new economic activity from 2007 through 2017 - a ten-year period.
This document provides the standard test method for determining water and sediment content in crude oil using the centrifuge method in a laboratory setting. It describes the centrifuge procedure, apparatus needed, sampling methodology, calculation of results, and discusses precision and bias. The method is not considered fully accurate for water content determination and distillation or extraction methods are preferred when high accuracy is required. The document provides this method as an American National Standard and references other ASTM and API standards.
This document provides a final report for a proposed wind farm project on the Isle of Cumbrae in Scotland. It summarizes the key aspects of planning and designing the wind farm, including site selection based on environmental and wind analyses, choosing the Vestas-90 2MW turbine model, construction plans, quality management procedures, estimated energy production costs and profitability over 20 years, and permissions required. The project aims to provide renewable energy for the island in an environmentally friendly and financially viable manner.
This project was a part of the DTU course Wind Farm Planning and Development.
Greater Gabbard is an existing offshore wind farm of 504 MW located 23 km from the Suffolk coast in UK. In this Project, I colaborated with Guido Luis Grassi Gonzalez, Sam Nivin Deepa Rosaline and Spandan Das to investigate the optimization of the AEP of this wind farm by changing the type of turbines used while keeping the total installed capacity. Achieving this would lead to better space utilization, higher yield and lower global costs, reducing the return period of the investment.
This document provides guidance on sequencing batch reactor (SBR) design and operation. It was developed by the New England Interstate Water Pollution Control Commission based on a literature review and visits to five SBR facilities. The document aims to highlight design and operational enhancements that can improve wastewater treatment performance. It is intended to assist municipalities, engineers, regulators and operators working with SBR systems.
This document from the EPA discusses nitrogen oxides (NOx) and methods for controlling them. It finds that NOx is formed during high temperature combustion processes and is a precursor for ozone and particulate matter formation. It affects the environment by contributing to smog and acid rain. The document then outlines various methods for controlling NOx emissions from stationary sources, including pollution prevention approaches during combustion and add-on control technologies like selective catalytic reduction. It provides details on the costs and effectiveness of different approaches for various combustion source types. The document concludes that sufficient NOx control methods exist but that further reductions may be needed to meet air quality standards.
Marine transport is a critical means of moving people and goods around the littoral waters of Southeast
Alaska. Unfortunately, it also generates significant harmful emissions. Tidelines Institute, a Southeast
AK-based leader in environmental education and research, requires a more environmentally friendly
propulsion system for their vessel, Tara. This project designed a serial hybrid propulsion system for
Tara, furnishing Tidelines with a bill of materials, design documentation, implementation diagrams, CAD
drawings, operational analysis software, and a life cycle assessment. This design will take advantage of
the substantial hydro power resources in the region and help Tidelines be an agent of structural change.
This document provides guidelines for rainwater harvesting in Georgia. It discusses the purpose of rainwater harvesting systems and compliance with state and local codes. It also introduces the American Rainwater Catchment Systems Association (ARCSA), a key organization for information on rainwater harvesting best practices and standards. The introduction chapter provides background on water scarcity globally and the importance of rainwater harvesting for water conservation and management given population growth and climate change.
This document provides guidelines for rainwater harvesting in Georgia. It discusses the purpose of rainwater harvesting systems and compliance with state and local codes. It also introduces the American Rainwater Catchment Systems Association (ARCSA), a key organization for information on rainwater harvesting best practices and standards. The introduction chapter provides background on water scarcity globally and the importance of rainwater harvesting for water conservation and management given population growth and climate change.
This Phase 1 environmental site assessment evaluated the 12 acre property at 321 W. California Avenue in Ruston, LA for potential environmental concerns. The assessment identified 11 potential problems at the site including transformers lacking PCB labels, vehicle spillage in parking areas, an upstream fertilizer plant, and a past underground storage tank removal. Soil and groundwater sampling were recommended to test for contaminants around the transformers, in parking areas, along the on-site waterway, and at the former underground storage tank location. The report provided details on the assessment process, site features and history, and recommendations for addressing identified environmental issues.
AK: Anchorage: Low Impact Development Design Guidance ManualSotirakou964
This document provides guidance for designing low impact development (LID) elements like rain gardens, infiltration trenches, soak-away pits, and filter strips. It discusses evaluating sites for these elements based on soil infiltration rates, groundwater depth, and other factors. Design approaches are presented for each LID element, covering preliminary site evaluation and design considerations, pretreatment where needed, and final design details. Construction and maintenance guidelines are also provided. The overall aim is to help plan and implement LID techniques that reduce stormwater runoff impacts.
This document provides a user's guide for AERMAP, which is a terrain preprocessor for the AERMOD dispersion model. It describes the basic concepts and components of AERMAP, provides details on its input and output formats, and explains how to run the model. The guide includes examples of AERMAP input files and describes how AERMAP processes digital elevation data to determine source and receptor elevations for use in air quality simulations.
This document describes the Multiphase Flow Production Model (PROMOD1) software. It provides a theory and user's manual for the program, which was developed to model multiphase flow in wells. The program calculates production rates and pressure profiles based on reservoir properties and wellbore configuration. It uses various correlations to model flow in reservoirs, wellbores, chokes, and pipelines. The program matches reservoir inflow equations with wellbore flow equations to determine the production point.
Similar to Hot mix plant report - **HOT MIX ASPHALT PLANTS EMISSION ASSESSMENT REPORT** (20)
This document discusses pile foundations. It begins by listing the topics that will be covered, including types of piles, pile spacing, pile caps, load testing, and failures. It then defines a pile foundation as using slender structural members like steel, concrete or timber that are installed in the ground to transfer structural loads to deeper, stronger soil layers. The document goes on to classify piles based on their function, material, and installation method. It describes common pile types such as precast concrete, driven steel, and cast-in-place piles. The document provides details on pile uses, selection factors, and installation procedures.
The self purification of natural water systems is a complex process involving physical, chemical, and biological factors. Dissolved oxygen levels below 4-5 mg/L can reduce the forms of life that can survive. Several factors affect dissolved oxygen availability including dilution, dispersion, temperature, sunlight, oxidation rates, and reduction processes. When wastewater is discharged into a stream, it creates four zones: degradation, active decomposition, recovery, and clearer water as the stream restores to its natural condition.
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3. EPA 454/R-00-019
HOT MIX ASPHALT PLANTS
EMISSION ASSESSMENT REPORT
This document was prepared by:
Emissions Monitoring and Analysis Division
Office of Air Quality Planning and Standards
United States Environmental Protection Agency
Research Triangle Park, NC
and under contract, by:
Midwest Research Institute
Kansas City, MO and Cary, NC
EPA Contract Number 68D-98-027
and
Eastern Research Group, Inc.
1600 Perimeter Park
P.O. Box 2010
Moorisville, NC
EPA Contract Number 68-D7-0068
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
December 2000
5. DISCLAIMER
The information in this document has been funded by the Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency (EPA) under contract 68-D-98-027 to Midwest
Research Institute and under contract 68-D-70-068 to Eastern Research Group, Inc. The EPA has made
additions and revisions to the information submitted by the contractors. This final report has been subjected
to the Agency’s review, and it has been approved for publication as an EPA document. Mention of trade
names or commercial products is not intended to constitute endorsement or recommendation for use.
iii
6. Document Title
EPA Document
Number
Publication
Date
Hot Mix Asphalt Plants
Emission Assessment Report EPA 454/R-00-019 December 2000
Hot Mix Asphalt Plants
Kiln Dryer Stack Instrumental Methods Testing
Asphalt Plant A, Cary, North Carolina
EPA 454/R-00-020 April 2000
Hot Mix Asphalt Plants
Kiln Dryer Stack Manual Methods Testing
Asphalt Plant A, Cary, North Carolina
Volume 1 of 2
Volume 2 of 2
EPA 454/R-00-021a
EPA 454/R-00-021b
April 2000
April 2000
Hot Mix Asphalt Plants
Kiln Dryer Stack Instrumental Methods Testing
Asphalt Plant B, Clayton, North Carolina
EPA 454/R-00-022 April 2000
Hot Mix Asphalt Plants
Kiln Dryer Stack Manual Methods Testing
Asphalt Plant B, Clayton, North Carolina
Volume 1 of 2
Volume 2 of 2
EPA 454/R-00-023a
EPA 454/R-00-023b
April 2000
April 2000
Hot Mix Asphalt Plants
Truck Loading and Silo Filling Instrumental Methods Testing
Asphalt Plant C, Los Angeles, California
EPA 454/R-00-024 May 2000
Hot Mix Asphalt Plants
Truck Loading and Silo Filling Manual Methods Testing
Asphalt Plant C, Los Angeles, California
Volume 1 of 8
Volume 2 of 8
Volume 3 of 8
Volume 4 of 8
Volume 5 of 8
Volume 6 of 8
Volume 7 of 8
Volume 8 of 8
EPA 454/R-00-025a
EPA 454/R-00-025b
EPA 454/R-00-025c
EPA 454/R-00-025d
EPA 454/R-00-025e
EPA 454/R-00-025f
EPA 454/R-00-025g
EPA 454/R-00-025h
May 2000
May 2000
May 2000
May 2000
May 2000
May 2000
May 2000
May 2000
Hot Mix Asphalt Plants
Technical Systems Audit of Testing at Asphalt Plant C
Asphalt Plant C, Los Angeles, California
EPA 454/R-00-026 May 2000
PREFACE
This report was produced by the Source Measurement Technology Group of EPA’s Emissions
Measurement Center located in Research Triangle Park,NC. It is one of a series of twelve reports
prepared to document an EPA program to characterize emissions to the air from hot mix asphalt plants.
These twelve reports and their associated EPA document numbers and publication dates are:
iv
7. Document Title
EPA Document
Number
Publication
Date
Hot Mix Asphalt Plants
Truck Loading Instrumental Methods Testing
Asphalt Plant D, Barre,Massachusetts EPA 454/R-00-027 May 2000
Hot Mix Asphalt Plants
Truck Loading Manual Methods Testing
Asphalt Plant D, Barre,Massachusetts
EPA 454/R-00-028 May 2000
Hot Mix Asphalt Plants
Response to Comments on Testing Program for Asphalt Plants
C and D EPA 454/R-00-029 May 2000
Hot Mix Asphalt Plants
Stakeholders Opinions Report EPA 454/R-00-030
These documents, including this Emissions Assessment Report document, are available for downloading,
on CD-ROM and in paper.
Downloads can be made from:
http//www.epa.gov/ttn/emc/asphalt.html
Copies of the CD ROM can be requested by mail at:
Emission Measurement Center,MD-19
US Environmental Protection Agency
Research Triangle Park,NC 27711
Paper copies of the reports can be obtained from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone orders 1-800-553-6847 or (703) 605-6000; FAX orders (703) 605-6900
http://www.ntis.gov/products/environment.htm
v
8. ACKNOWLEDGMENTS
Many individuals contributed to the development of this report. Ron Myers of the Emission
Measurement Center’s Source Measurement Technology Group (SMTG), Brian Shrager, Scott Klamm,
Richard Marinshaw, and Amy Marshall of Midwest Research Institute (MRI), are the primary authors of
the report. Bob McConnell of EPA’s Region I office, David Mobley, Acting Director of EPA’s Emissions
Monitoring and Analysis Division, Bill Lamason, Mike Toney, Gary McAlister, and Candace Sorrell of
EPA’s Emission Measurement Center,Ron Ryan and Dennis Beauregard of EPA’s Emission Factor and
Inventory Group, Laura Autry of EPA’s Air Quality Trends Analysis Group, participated in the review.
We also acknowledge the contributions of numerous reviewers and advisors from PES,MRI and EPA.
vi
11. LIST OF ACRONYMS
ASTM
Btu
CH4
CO
CO2
EPA
HAP
HMA
NOx
PAH
PM
PM-10
PM-2.5
RAP
RTFOT
SCC
SO2
SOx
TOC
VOC
American Society of Testing and Materials
British thermal unit
methane
carbon monoxide (as measured by EPA Method 10)
carbon dioxide (as measured by EPA Method 3)
Environmental Protection Agency
hazardous air pollutant (listed in or pursuant to section 112(b) of the 1990 Clean Air Act
Amendments)
hot mix asphalt
nitrogen oxides (as measured by EPA Method 7)
polycyclic aromatic hydrocarbon (a class of HAPs)
particulate matter (as measured by EPA Methods 5 or 17)
particulate matter less than 10 microns in diameter
particulate matter less than 2.5 microns in diameter
reclaimed asphalt pavement
rolling thin film oven test (ASTM Method D2872-88)
source classification code
sulfur dioxide (as measured by EPA Methods 6 or 8)
sulfur oxides
total organic compounds (as measured by EPA Method 25A)
volatile organic compound (refer to 40 CFR 51.100); VOC is TOC plus formaldehyde, less
methane, ethane, acetone,and other chemicals listed as negligibly photochemically reactive.
ix
13. 1. EXECUTIVE SUMMARY
1.1 INTRODUCTION
This report presents an assessment of emissions from hot mix asphalt (HMA) manufacturing
facilities. Included in the report is a description of the manufacturing process and the emissions associated
with HMA production; the procedures for developing emission factors and emission inventories for the
HMA industry; and estimated annual emissions for typical HMA facilities.
1.2 OVERVIEW OF HMA INDUSTRY
Hot mix asphalt is used primarily as paving material and consists of a mixture of aggregate and
liquid asphalt cement, which are heated and mixed in measured quantities. Hot mix asphalt facilities can be
broadly classified as either drum mix plants or batch mix plants, according to the process by which the raw
materials are mixed. In a batch mix plant, the aggregate is dried first, then transferred to a mixer where it
is mixed with the liquid asphalt. In a drum mix plant, a rotary dryer serves to dry the aggregate and mix it
with the liquid asphalt cement. After mixing, the HMA generally is transferred to a storage bin or silo,
where it is stored temporarily. From the silo, the HMA is emptied into haul trucks, which transport the
material to the job site. Figure 1 presents a diagram of a typical batch mix HMA plant; a typical drum mix
HMA plant is depicted in Figure 2.
In 1996, approximately 500 million tons of HMA were produced at the 3,600 (estimated) active
asphalt plants in the United States. Of these 3,600 plants, approximately 2,300 are batch plants, and
1,300 are drum mix plants. The total 1996 HMA production from batch and drum mix plants is estimated
at about 240 million tons and 260 million tons, respectively. Based on these figures, an average batch mix
plant produces approximately 100,000 tons of HMA annually, and an average drum mix plant produces
about 200,000 tons of HMA per year. Naturalgas fuel is used to produce 70 to 90 percent of the HMA.
The remainder of the HMA is produced using oil, propane, waste oil, or other fuels.
The primary emission sources associated with HMA production are the dryers, hot bins, and
mixers, which emit particulate matter (PM) and a variety of gaseous pollutants. Other emission sources
found at HMA plants include storage silos, which temporarily hold the HMA; truck load-out operations, in
which the HMA is loaded into trucks for hauling to the job site; liquid asphalt storage tanks; hot oil
heaters,which are used to heat the asphalt storage tanks; and yard emissions, which consist of fugitive
emissions from the HMA in truck beds. Emissions also result from vehicular traffic on paved and unpaved
roads, aggregate storage and handling operations, and vehicle exhaust.
The PM emissions associated with HMA production include the criteria pollutants PM-10 (PM
less than 10 micrometers in aerodynamic diameter) and PM-2.5, hazardous air pollutant (HAP) metals, and
HAP organic compounds. The gaseous emissions associated with HMA production include the criteria
pollutants sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic
compounds (VOC),as well as volatile HAP organic compounds.
1.3 DEVELOPMENT AND USE OF EMISSION FACTORS FOR HMA FACILITIES
An emission factor relates the quantity (weight) of pollutants emitted to a unit of activity of the
source. Emission factors for the HMA industry are generally determined in units of pounds of pollutant
emitted per ton of HMA produced. These emission factors typically are used to estimate area-wide
1
14. emissions for a large number of facilities and emissions for specific facilities where source-specific
emissions data are not available or where source testing is cost prohibitive.
To develop emission factors for the HMA industry, data from more than 390 emission test reports
and other documents on the industry were compiled and reviewed. Through a careful screening process,
the documents that were determined to be unusable for emission factor development were excluded from
further evaluation. The remaining reports were compiled by plant type, emission source, pollutant, and
emission control. For each emission test, emission factors were calculated by dividing the measured
emission rates by the HMA production rate measured at the time of the emission test. These emission
factors were then grouped by source,pollutant, and control device, and an average emission factor was
calculated for each group.
Emission factors can be used to estimate emissions from one or more HMA facilities by
multiplying the emission factor by the HMA production rate. For example, the emission factor for CO
emissions from a natural gas-fired drum mix dryer is 0.13 pounds per ton (lb/ton). If the dryer produces
200,000 tons per year (ton/yr), the estimated CO emissions during that period would be: 200,000 ton/yr ×
0.13 lb/ton = 26,000 lb/yr or 13 tons/yr.
1.4 ESTIMATED ANNUAL EMISSIONS FROM TYPICAL HMA FACILITIES
Annual emissions for a facility can be estimated by summing up the emissions from each emission
source over the course of a year. Annual emissions for a specific source can be estimated by multiplying
the annual throughput or production rate for that source by its corresponding emission factors. For an
HMA facility, annual emissions can be estimated by multiplying the annual HMA production rate by the
emission factors for each type of source at the facility. Table 1 summarizes annual emissions for a typical
HMA batch mix plant, and Table 2 summarizes annual emissions for a typical drum mix HMA plant. The
estimates presented in these tables account for all of the identified emission sources at each type of facility.
For both batch mix plants (Table 1) and drum mix plants (Table 2), the estimate includes emissions from
the dryer/mixer, load-out operations, asphalt storage, yard (fugitive emissions from loaded trucks), diesel
exhaust, paved and unpaved road dust, and aggregate processing (screening, conveyor transfer,and
reclaimed asphalt pavement [RAP] crushing). Additionally, for the drum mix plant (Table 2), the estimate
includes emissions from silo filling operations. Estimates are presented for criteria pollutants (pollutants
for which national ambient air quality standards have been developed) and hazardous air pollutants (HAPs,
as defined in section 112(b) of the 1990 Clean Air Act Amendments). Criteria pollutants include PM-10,
VOC,CO, SO2, and NOx. Emissions for three classes of HAPs are presented in Tables 1 and 2:
polycyclic aromatic hydrocarbons (PAHs),volatile organic HAPs,and metal HAPs. The emissions were
estimated using the emission factors developed for the HMA industry and the following assumptions:
·
·
·
·
·
·
Dryers are fueled with natural gas or No. 2 fuel oil (estimates are presented for both types). It
is estimated that between 70 and 90 percent of HMA plants use natural gas, although some
HMA plants use fuel oil as an alternative to natural gas.
Dryer emissions are controlled with fabric filters.
PM emissions from load-out and silo filling are entirely PM-10.
Annual HMA production rate for a typical batch mix plant is 100,000 ton/yr.
Annual HMA production rate for a typical drum mix plant is 200,000 ton/yr.
The typical HMA plant has two 18,000-gallon asphalt storage tanks.
As indicated in Table 1, a typical batch mix plant using a No. 2 fuel oil-fired dryer emits over
74,000 lb/yr of criteria pollutants, and a typical batch mix plant using a natural gas-fired dryer emits over
2
15. 56,000 lb/yr of criteria pollutants, of which approximately 41,000 lb/yr are CO and approximately
10,700 lb/yr are PM-10; emissions of other criteria pollutants range from about 500 to about 12,000 lb/yr.
The same plant would emit about 770 lb/yr of HAPs. A typical drum mix plant using a No. 2 fuel oil-fired
dryer emits about 83,000 lb/yr of criteria pollutants, and a typical drum mix plant using a natural gas-fired
dryer emits around 75,000 lb/yr of criteria pollutants, of which approximately 28,000 lb/yr are CO, about
10,000 lb/yr are VOC,and around 31,000 lb/yr are PM-10. A typical drum mix plant emits from 1,300 to
2,000 lb/yr of HAPs,depending on the fuel used in the dryer.
3
16. 4
Figure 1. General process flow diagram for batch mix asphalt plants (source classification codes in parentheses).
17. 5
Figure 2. General process flow diagram for counter-flow drum mix asphalt plants (source classification codes in parentheses).
18. Pollutant
Annual emissions by source, pounds peryear
Mobile
sources
(diesel
exhaust)
Material
handling
and road
dust
No. 2 fuel oil-
fired dryer,
hot screens,
b
and mixer
Natural gas-
fired dryer,
hot screens,
c
and mixer
Load-
d
out
Asphalt
e
Storage
f
Yard
g
Total
(oil-
fired)
g
Total
(gas-
fired)
Criteria air pollutants
Particulate matter less than
10 micrometers (PM-10)
Volatile organic compounds (VOC)
Carbon monoxide (CO)
Sulfur dioxide (SO2)
Nitrogen oxides (NOx)
46
100
700
22
380
7,900 2,700
820
40,000
8,800
12,000
2,700
820
40,000
460
2,500
52
391
135
32
3
110
35
10,700
1,500
41,000
8,800
12,400
10,700
1,500
41,000
480
2,900
Hazardous air pollutants (HAPs)
Polycyclic aromatic hydrocarbons
(PAHs)
Phenol
Volatile HAPs
Metal HAPs
g
Total HAPs
0.035
1.9
1.9
11
751
1.4
760
11
751
1.4
760
2.0
0.40
6.2
8.6
0.12
140
140
1.6
1.6
13
0.40
760
1.4
770
13
0.40
760
1.4
770
6
TABLE 1. ESTIMATED ANNUAL EMISSIONS FOR A TYPICAL BATCH MIXHMA FACILITYa
a
b
c
d
e
f
g
Based on an annualHMA production rate of 100,000 tons per year.
Between 10 and 30 percent of the HMA is produced using fuel oil.
Between 70 and 90 percent of the HMA is produced using natural gas.
Loading of HMA into haul trucks.
Includes emissions from oil-fired hot oil heaters.
Fugitive emissions from loaded trucks prior to departure to the job site.
Total expressed using two significant figures.
19. Pollutant
Annual emissions by source, pounds peryear
Mobile
sources
(diesel
exhaust)
Material
handling
and road
dust
No. 2
fuel oil-
fired
b
dryer
Natural
gas-fired
c
dryer
Load-
d
out
Silo
e
filling
Asphalt
f
storage
g
Yard
h
Total
(oil-
fired)
h
Total
(gas-
fired)
Criteria air pollutants
Particulate matter less than
10 micrometers (PM-10)
Volatile organic compounds (VOC)
Carbon monoxide (CO)
Sulfur dioxide (SO2)
Nitrogen oxides (NOx)
220
190
1,200
26
560
26,000 4,600
6,400
26,000
2,200
11,000
4,600
6,400
26,000
680
5,200
104
782
270
117
2,440
236
64
6
220
72
31,000
10,000
28,000
2,200
12,000
31,000
10,000
28,000
710
5,800
Hazardous air pollutants (HAPs)
Polycyclic aromatic hydrocarbons
(PAHs)
Phenol
Volatile HAPs
Metal HAPs
h
Total HAPs
0.13
6.6
6.7
176
1,560
19
1,800
37
1,020
16
1,100
4.0
0.80
12.4
17
5.8
31
37
0.12
140
140
3.3
3.3
190
0.80
1,800
19
2,000
50
0.80
1,200
16
1,300
7
TABLE 2. ESTIMATED ANNUAL EMISSIONS FOR A TYPICAL DRUM MIXHMA FACILITYa
a
b
c
d
e
f
g
h
Based on an annualHMA production rate of 200,000 tons per year.
Between 10 and 30 percent of the HMA is produced using fuel oil.
Between 70 and 90 percent of the HMA is produced using natural gas.
Loading of HMA into haul trucks
Filling of temporary storage silo prior to load-out.
Includes emissions from oil-fired hot oil heaters.
Fugitive emissions from loaded trucks prior to departure to the job site.
Total expressed using two significant figures.
21. 2. ASSESSMENT OF HOT MIX ASPHALT EMISSIONS
This section presents the results of an assessment of emissions from HMA manufacturing. An
overview of the HMA industry and process operations is provided first (Section 2.1). Section 2.2
summarizes the methodology used to develop emission factors for the HMA industry. Section 2.3 identifies
other sections of AP-42 that apply to HMA plants. An overview of the process for conducting an emission
inventory is presented in Section 2.4, and Section 2.5 presents estimates of annual emissions from typical
HMA facilities.
2.1 INDUSTRY OVERVIEW AND PROCESS DESCRIPTION1
Hot mix asphalt paving materials are a mixture of well-graded, high-quality aggregate and liquid
asphalt cement, which is heated and mixed in measured quantities. The aggregate often includes RAP.
Aggregate and RAP (if used) constitute over 92 percent by weight of the total mixture. Aside from the
amount and grade of asphalt cement used, mix characteristics are determined by the relative amounts and
types of aggregate and RAP used. A certain percentage of fine aggregate (less than 74 micrometers [Fm] in
physical diameter) is required for the production of good quality HMA.
Hot mix asphalt plants can be classified by their mixing operation as one of the following:
(1) batch mix plants, (2) continuous mix (mix outside dryer drum) plants, (3) parallel flow drum mix
plants, and (4) counterflow drum mix plants. An HMA plant can be constructed as a permanent plant, a
skid-mounted (easily relocated) plant, or a portable plant. All plants can have RAP processing capabilities.
In 1996, approximately 500 million tons of HMA were produced at the 3,600 (estimated) active
asphalt plants in the United States. Of these 3,600 plants, approximately 2,300 are batch plants, 1,000 are
parallel flow drum mix plants, and 300 are counterflow drum mix plants. The total 1996 HMA production
from batch and drum mix plants is estimated at about 250 million tons and 260 million tons, respectively.
About 85 percent of new plants being constructed today are of the counterflow drum mix design, while
batch plants and parallel flow drum mix plants account for 10 percent and 5 percent respectively.
Continuous mix plants represent a very small fraction of the plants in use (#0.5 percent) and, therefore, are
not discussed further. While most HMA plants have the capability to use both fuel oil and natural gas, it is
estimated that between 70 and 90 percent of the HMA in the U. S. is produced using natural gas. The
process operations at typical batch mix and drum mix plants are described in the following paragraphs.
2.1.1 Batch Mix Plants2
Processing begins as the aggregate is hauled from onsite storage piles and is placed in the
appropriate hoppers of the cold feed unit. The material is metered from the hoppers onto a conveyer belt
and is transported into a rotary dryer (typically gas- or oil-fired). As the hot aggregate leaves the dryer, it
drops into a bucket elevator, is transferred to a set of vibrating screens,then separated into as many as four
different grades (sizes), and dropped into “hot” bins according to size. At newer facilities, RAP may be
transferred to a separate heated storage bin. At the same time, liquid asphalt cement is pumped from a
heated storage tank to an asphalt bucket, where it is weighed to achieve the desired aggregate-to-asphalt
cement ratio in the final mix. To control the aggregate size distribution in the final batch mix, the operator
transfers material from various hot bins (and RAP bins, if used) to a weigh hopper until the desired mix
1 See Appendix A, Section 11.1.1, and Appendix B, Section 2.1, for more detailed information.
2 See Appendix A, Section 11.1.1.1, and Appendix B, Section 2.2.1, for more detailed information.
9
22. and weight are obtained. The aggregate from the weigh hopper is dropped into the mixer (pug mill) and
dry-mixed for 6 to 10 seconds. The liquid asphalt is then dropped into the pug mill where it is mixed for an
additional period of time. At older plants, RAP typically is conveyed directly to the pug mill from a
storage hopper and combined with the hot aggregate. Total mixing time usually is less than 60 seconds.
Then, the hot mix is conveyed to a hot storage silo or is dropped directly into a truck and hauled to the job
site. Figure 1 depicts a typical batch mix plant.
2.1.2 Drum Mix Plants3
This process is a continuous mixing type process. The major difference between this process and
the batch process is that the dryer is used not only to dry the material but also to mix the heated and dried
aggregates with the liquid asphalt cement. In a parallel flow drum mixer, the aggregate is introduced to the
drum at the burner end. As the drum rotates, the aggregate, as well as the combustion products from the
burner, move toward the other end of the drum in parallel. Liquid asphalt cement is introduced in the
mixing zone midway down the drum in a lower temperature zone, along with any RAP and PM from
collectors. In a counterflow drum mixer, the material flow in the drum is opposite or counterflow to the
direction of exhaust gases. In addition, the liquid asphalt cement mixing zone is located behind the burner
flame zone so as to remove the materials from direct contact with hot exhaust gases. After mixing, the
mixture is discharged at the end of the drum and is conveyed to either a surge bin or HMA storage silos.
Figure 2 illustrates a counterflow drum mix plant.
In a parallel flow mixer, the exhaust gases also exit the end of the drum and pass on to the
collection system. Parallel flow drum mixers have an advantage, in that mixing in the discharge end of the
drum captures a substantial portion of the aggregate dust, therefore lowering the load on the downstream
PM collection equipment. For this reason,most parallel flow drum mixers are followed only by primary
collection equipment (usually a baghouse or venturi scrubber). However,because the mixing of aggregate
and liquid asphalt cement occurs in the hot combustion product flow, organic emissions (gaseous and liquid
aerosol) may be greater than in other processes.
Counterflow drum mix plants likely will have organic stack emissions (gaseous and liquid aerosol)
that are lower than parallel flow drum mix plants because the liquid asphalt cement, virgin aggregate,and
RAP are mixed in a zone removed from the exhaust gas stream. A counterflow drum mix plant normally
can process RAP at ratios up to 50 percent with little or no observed effect upon emissions.
2.1.3 Recycle Processes4
Reclaimed asphalt pavement significantly reduces the amount of new aggregate and asphalt cement
needed to produce HMA. In the reclamation process, old asphalt pavement is removed from the road base.
This material is then transported to the plant, and is crushed and screened to the appropriate size for further
processing. The paving material then is heated and mixed with new aggregate (if applicable), and the
proper amount of new asphalt cement is added to produce HMA that meets the quality requirements of the
customer.
3 See Appendix A, Sections 11.1.1.2 and 11.1.1.3, and Appendix B, Sections 2.2.2 and 2.2.3, for more
detailed information.
4 See Appendix A, Section 11.1.1.4, and Appendix B, Section 2.2.4, for more detailed information.
10
23. 2.1.4 Emissions and Controls5
Hot mix asphalt plants have two major categories of emissions: ducted sources (those vented to the
atmosphere through some type of stack, vent, or pipe), and fugitive sources (those not confined to ducts and
vents but emitted directly from the source to the ambient air). Dryers are the most significant ducted
sources of emissions from both batch mix and drum mix HMA plants. Emissions from these sources
consist of water (as steam evaporated from the aggregate); PM; products of combustion (carbon dioxide
[CO2], NOx, and sulfur oxides [SOx]); CO; and small amounts of organic compounds of various species
(including VOC,methane [CH4], and HAPs). The CO and organic compound emissions result from
incomplete combustion of the fuel and also are released from the heated asphalt.
At batch mix plants, other potential process sources include the hot-side conveying, classifying,
and mixing equipment, which are vented to either the primary dust collector (along with the dryer gas) or to
a separate dust collection system. These emissions are mostly aggregate dust, but they also may contain
gaseous organic compounds, CO, and a fine aerosol of condensed organic particles. This organic aerosol is
created by the condensation of gas into particles during cooling of organic vapors volatilized from the
asphalt cement in the mixer. The amount of organic aerosol produced depends to a large extent on the
temperature of the asphalt cement and aggregate entering the mixer. Organic vapor and its associated
aerosol also are emitted directly to the atmosphere as process fugitives during truck load-out, from the bed
of the truck itself during transport to the job site, and from the asphalt storage tank. Both the low
molecular weight organic compounds and the higher weight organic aerosol may contain small amounts of
HAP. The ducted emissions from the heated asphalt storage tanks may include gaseous and aerosol
organic compounds and combustion products from the tank heater.
At most HMA facilities, fabric filters are used to control emissions from dryers. Other controls
used include mechanical collectors and scrubbers. Emissions from aggregate handling and transfer
typically are controlled with fabric filters or scrubbers. Large diameter cyclones and settling chambers also
are used as product recovery devices. The material collected in those devices is recycled back into the
process.
There also are a number of fugitive dust sources associated with batch mix HMA plants, including
vehicular traffic generating fugitive dust on paved and unpaved roads, aggregate material handling, and
other aggregate processing operations.
2.2 EMISSION FACTOR DEVELOPMENT FOR AP-42 SECTION 11.1,HOT MIX ASPHALT
PLANTS
A detailed description of how the emission factors were developed for the HMA industry is
provided in Section 4 of Appendix B. The following paragraphs summarize the methodology used.
To develop emission factors for the HMA industry, data from about 390 emission test reports and
other documents on the industry were compiled and reviewed (a complete list of these references is
provided following Section 4 of Appendix B). The majority of these reports documented measurements of
emissions from batch plant dryer/mixers and drum plant dryers. Through a carefulscreening process,35
of the reports were determined to be unusable for emission factor development and were excluded from
further evaluation. About 350 reports remained and were compiled by plant type, emission source,
pollutant, and emission control. These emission factors were then grouped by source, pollutant, and
5 See Appendix A, Section 11.1.2, and Appendix B, Section 2.3, for more detailed information.
11
24. control device, and an average emission factor was calculated for each group. Table 3 presents a matrix of
all of the sources and pollutants for which emission factors are presented in AP-42 (Appendix A).
While the particulate, CO2, CO, and TOC emission factors are based on over 100 tests,most of
the remaining criteria pollutant emission factors are based on between 5 and 10 tests. A few HAP emission
factors are based on more than 5 tests, although the majority are based on between 2 and 5 tests.
Information on the supporting data for specific emission factors and the quality rating assigned to the
emission factor is included in the section or table in Appendices A and B as indicated in Table 4. Column
four of Table 4 references the tables in Appendix A that present the emission factors and quality ratings.
Column five of Table 4 references the paragraphs in Appendix B that discuss the basis for the emission
factors developed for all of the sources and pollutants. Column six of Table 4 references the tables in
Appendix B that present the emission factors and the individual data used to develop the emission factors.
Generally, the amount of supporting data is typical of many AP-42 sections. However,the amount of data
supporting the particulate, CO2, CO, and TOC emission factors is greater than most AP-42 sections. The
following paragraphs summarize the procedures followed to develop the emission factors for HMA
facilities.
2.2.1 Batch Mix and Drum Mix Dryers
The usable data on batch mix and drum mix plant dryer emissions were compiled according to
source type, emission control, and pollutant. Data on fuel types, the percentage of RAP used in the mix,
and the process operating rate (e.g.,dryer production rate) also were recorded. The quality of the emission
data was evaluated with respect to the level of documentation in the report, the test methods used, the
number of test runs, and any reported problems with the sampling procedures or the operation of the source
during the test period. On the basis of this evaluation, data ratings of A, B, C, or D were assigned to each
data set. Specific procedures used to evaluate the data are specified in Proceduresfor Preparing Emission
Factor Documents (EPA-454/R-95-015).
For each emission test, an emission factor also was calculated for each pollutant sampled. These
test-specific emission factors then were grouped according to source type, emission control device,
pollutant, and, in the case of combustion sources,fuel type. At this stage in the process,D-rated data sets
were discarded, provided there were higher quality data available for that particular group (i.e., that
specific combination of source, control, fuel, and pollutant). In addition, where there were data from
multiple tests on the same specific emission source, the test-specific emission factors were averaged to yield
a source-specific emission factor. In subsequent calculations, this source-specific emission factor was
used.
A statistical analysis of the data for batch and drum mix dryers was performed to determine the
effects of RAP content,fuel type, production rate on emissions of severalpollutants. The analysis showed
no strong correlation between these parameters and emission factors. Details on the statistical analysis can
be found in Section 4.3 of Appendix B.
To develop emission factors,the mean of the test-specific emission factors was calculated for each
of the emission factor groups discussed above. In some cases,the data for two or more groups were
combined and an overall mean emission factor was calculated. For example, if the data indicated that fuel
type had no apparent effect on emissions of a specific pollutant, fuel type was ignored and all of the data
for that source type and pollutant were combined. The final step in developing emission factors is to assign
a quality rating of A, B, C, D, or E. Quality ratings are a function primarily of the number of data points
12
25. from which a specific emission factor is calculated. Additional information on the rating system used is
discussed in Section 3 of Appendix B.
2.2.2 Hot Oil Heaters
For hot oil heaters,only a single test report for an oil-fired hot oil heater was available. The report
was reviewed and the emission factors compiled using the procedures described previously. Appendix B,
Section 4.2.4.2, provides a detailed description of how these emission factors were developed. It should be
noted that most hot oil heaters are gas-fired,and the emission factors developed from the available data
would not necessarily be representative of gas-fired heaters.
2.2.3 Truck Load-Out
Truck load-out emissions were developed from two emission tests sponsored by the U. S.
Environmental Protection Agency (EPA) (Appendix B References 355 and 356). In designing, performing
and evaluating these two tests, EPA was involved with a number of groups. The groups included citizens,
State and local health agencies, State and local air pollution control agencies,and industry associations.
These different groups provided input on the selection of facilities for emissions testing, the design of the
test program, reviewed the individual site-specific test plans, observed emissions testing, commented on the
draft test reports and provided suggestions for analysis of the data to develop emission factors. The
procedures used to develop emission factors generally were the same as those described above. However,
additional steps were taken to ensure the quality and consistency of the data and the representativeness and
universality of the emission factors developed from the data. For example, two quality assurance scientists
from Research Triangle Institute were employed to independently audit the test. These additional steps are
summarized below. Detailed explanations of the methodology used are provided in Section 4.4 of
Appendix B.
At one of the facilities the sampling area was enclosed but did not meet EPA requirements for a
total enclosure. Consequently, the capture efficiency was quantitatively estimated and the data were
corrected for capture efficiency.
At one facility, emissions due to diesel truck operation could not be segregated from emissions due
to truck load-out. Therefore,background concentrations also were sampled. To account for background
levels of various pollutants emitted from truck operation, the as-measured background concentrations were
subtracted from the capture efficiency corrected load-out emission concentrations. For the most part,
values were treated as zero if the background concentration exceeded the capture-efficiency-adjusted run
concentration.
Because the asphalt types and temperatures for the two facilities differed, adjustments also were
made to normalize the emission data. To account for differences in the volatility of the liquid asphalts
used, samples of asphalt were collected during the emission tests and analyzed by ASTM Method D 2872-
88, Effects of Heat and Air on a Moving Filmof Asphalt (Rolling Thin FilmOven Test - RTFOT) to
determine the “loss-on-heating” values for the asphalts. Additional loss-on-heating data also were obtained
from several State departments of transportation laboratories in order to determine a common RTFOT
value to use as a default in those situations where no historical information is available. Based upon the
RTFOT data collected and the desire to select a default which encourages the use of site-specific data, a
default of -0.5 percent was selected as a default value for use in the predictive emission factor equations
developed from the data.
13
26. To account for differences in the load-out temperatures of the two facilities the data were adjusted
using the Clausius-Clapeyron equation, which relates vapor pressure and temperature of a substance. This
equation and the asphalt laboratory data provide a mechanism to normalize the emissions to a temperature
of 325EF, which is the maximum midpoint load-out temperature recommended by the Asphalt Pavement
Environmental Council’s Best Practices Guide dated March 2000.
Using the adjusted data and the temperature and volatility relationship described above, separate
predictive emission factor equations were developed for emissions of total PM, organic PM, total organic
compounds (TOC), and CO from drum mix and batch mix load-out operations. Additionally, adjusted
data for a variety of HAP’s were used to develop ratios of the HAP pollutant to either organic PM or TOC
(speciation profiles). These speciation profiles are applicable to load-out emissions and yard emissions.
2.2.4 Silo Filling
Silo filling emission factors were developed from one of the emission tests described in the previous
paragraphs for load-out emissions (Appendix B Reference 355). These data also were collected and
evaluated with stakeholder involvement. Additionally, the same basic methodology described in the
previous paragraphs for load-out emissions was used to adjust the data on emissions from silo filling
operations. Predictive emission factor equations also were developed for total PM, organic PM, TOC, and
CO. A detailed explanation of the methodology used to develop these equations is provided in
Section 4.4.4 of Appendix B. Speciation profiles for silo filling emissions were also developed using the
methodology described for load-out emissions. The speciation profiles from silo filling are applicable to
asphalt storage tank emissions.
2.2.5 Asphalt Storage Tanks
To estimate emissions from heated organic liquid storage tanks, the methodologies described in
Chapter 7 of AP-42 and the TANKS software are generally used. The emissions from these types of tanks
depend on the contents of the tank, the volume of gas vented, and the operating temperature range of the
liquid in the tank. Emissions during the filling of these tanks (working loss) are governed by the saturation
concentration of the liquid stored in the tank and the volume of gas displaced by the addition of liquid to the
tank. Emissions during other periods (breathing losses) are governed by the saturation concentration of the
liquid stored in the tank and the changes in the volume of the gas caused by temperature variations.
Although vapor pressure information on paving asphalt is not available to allow the use of the TANKS
program without additional information, information was available from the silo filling test report to infer
emissions during the filling of the asphalt storage tank and, by extension, the vapor pressure characteristics
of paving asphalt at the typical operating temperatures. Using these data, input values for Antoine’s
equation and liquid and vapor molecular weight were developed for use with the TANKS program to
calculate working and breathing losses for asphalt storage tanks. A detailed explanation of the
methodology used to develop these values is presented in Section 4.4.5 of Appendix B.
2.2.6 Yard Emissions
At one of the EPA-sponsored emission tests described in the previous paragraphs for load-out
emissions (Appendix B Reference 355), data also were collected on fugitive emissions from loaded trucks
as they sat in the yard prior to departure for the job site. As with the other data from this reference,these
data were evaluated with stakeholder involvement. The data obtained were fitted to a power function in
order to develop an equation for these yard emissions as a function of time. A specific emission factor for
cumulative emissions over an 8-minute period (which represents the maximum time represented by the
14
27. data) was calculated using the power function equation developed from the emission data. A detailed
explanation of the methodology used to develop the equations and the emission factor is provided in Section
4.4.6 of Appendix B.
2.3 OTHER APPLICABLE AP-42 SECTIONS
Emission factors for other generic sources associated with HMA facilities can be found in other
sections of AP-42 (http://www.epa.gov/ttn/chief/ap42/index.html). As discussed above, methodologies for
estimating emissions from asphalt storage tanks can be found in Chapter 7 of AP-42. Methods for
estimating fugitive dust emissions from vehicular traffic are presented in AP-42 Chapter 13
(Sections 13.2.1 and 13.2.2). Material handling emissions and storage pile emissions are addressed in AP-
42 Chapter 11 (Section 11.19.2) and Chapter 13 (Section 13.2.4). Emission factors for truck exhaust are
provided in AP-42 Volume II: Mobile Sources (http://www.epa.gov/oms/ap42.htm).
To calculate the material handling and mobile source emission estimates presented in Tables 1 and
2 of this report, suitable emission factors for these material handling and mobile sources were determined.
The following paragraphs describe the basis for the emission factors that were used:
· Receipt of new aggregate – Used equation from AP-42 Section 13.2.4, assuming an average
moisture content of 1.5 percent and an average wind speed of 10 miles per hour (mph). The
resulting PM-10 emission factor is 0.0041 lb/ton of new aggregate. The resulting PM-2.5
emission factor is 0.0013 lb/ton of new aggregate.
· Transfer of aggregate from storage to conveyor belt or between conveyor belts – Used
controlled emission factor from AP-42 Section 11.19.2. The PM-10 emission factor is
0.000048 lb/ton of new aggregate.
· Screening of aggregate – Used controlled emission factor from AP-42 Section 11.19.2. PM-10
emission factor is 0.00084 lb/ton of new aggregate.
· RAP crushing – Used controlled tertiary crushing emission factor from AP-42 Section 11.19.2.
PM-10 emission factor is 0.00059 lb/ton of new aggregate.
· Paved road dust emissions – Used paved roads equation from AP-42 Section 13.2.1, assuming
an average vehicle weight of 22 tons and a road silt content of 3 grams per square meter. The
resulting PM-10 emission factor is 0.016 lb per vehicle mile traveled. The resulting PM-2.5
emission factor is 0.0040 lb per vehicle mile traveled.
· Unpaved road dust emissions – Used unpaved roads equation from AP-42 Section 13.2.2,
assuming an average vehicle weight of 6 tons, a road silt percentage of 10 percent, a surface
moisture content of 0.7 percent. The resulting PM-10 emission factor is 2.04 lb per vehicle
mile traveled. The resulting PM-2.5 emission factor is 0.29 lb per vehicle mile traveled.
· Diesel exhaust emissions – Used heavy duty diesel truck emission factors for idling and for an
average speed of 10 mph with a 250 brake horsepower engine. The diesel engines get 10 miles
per gallon at 10 mph and burn 1 gallon per hour (gal/hr) of fuel at idle. The sulfur content of
diesel fuel is 0.05 percent. At idle, the emissions factors for diesel engines are: VOC -
0.208 grams per minute (g/min) (0.00046 pound per minute [lb/min]), CO - 1.57 g/min
(0.0035 lb/min), NOx - 0.917 g/min (0.0020 lb/ min), SO2 - 0.157s pounds per gallon of fuel
(lb/gal) (where s is fuel sulfur content) and PM - 0.043 g/min (0.000095 lb/min). When
traveling at an average speed of 10 mph, the emission factors for diesel engines are:VOC -
3.18 grams per mile (g/mile) (0.0070 pounds per mile [lb/mile]), CO - 18.82 g/mile
(0.041 lb/mile), NOx - 8.50 g/mile (0.019 lb/mile), SO2 - 0.157s lb/gal fuel (where s is fuel
sulfur content), and PM - 0.1011 grams per brake horsepower hour (0.00022 pounds per
horsepower hour). For organic HAP emissions - Used medium duty diesel truck emission
15
28. factors from article by Schauer, et. al., in Environmental Science & Technology of May 15,
1999. The volatile HAP emission factors presented were 0.084 grams per kilometer (g/km)
(0.00030 lb/mile) and 0.0016 g/km (0.0000057 lb/mile) for PAHs.
The ducted and process fugitive emissions estimates presented in Tables 1, 2, 7, and 11 are based
on the following additional assumptions:
·
·
·
·
·
·
·
·
·
·
·
84,800 ton/yr of new aggregate for batch mix plant.
10,000 ton/yr of recycled pavement for batch plant.
1.25 million gallons (5,200 tons) of asphalt for batch plant.
150,900 ton/yr of new aggregate for drum mix plant.
40,000 ton/yr of recycled pavement for drum mix plant.
2.5 million gallons (10,400 tons) of asphalt for drum mix plant.
Two 18,000-gallon asphalt storage tanks.
Five open conveyor transfer points for new aggregate.
Front end loader travel over unpaved roads of 0.25 mile per ton of RAP used.
Vehicle travel over paved roads of 1.5 miles per 25 tons of HMA produced.
Vehicle idling time of 128,000 min (an average of 4 trucks in line during the average 8-minute
load-out time) for batch plant.
· Vehicle idling time of 72,000 min (an average of 6 trucks in line during the average 1.5-minute
load-out time) for drum mix plant.
2.4 EMISSION INVENTORY FOR TYPICAL HOT MIXASPHALT PLANTS
To perform an emission inventory for a typical HMA plant, the first step is to identify the types of
emission sources and to count the total number of each type of source. The next step is to identify the best
emission estimation tools, which include: (1) facility-specific emissions test data; (2) source-specific
emission factors; (3) other types of source-specific data, such as mass balance data; (4) emission factors
for similar sources; (5) emission factors for sources that are believed to be somewhat similar to the source
being considered; and (6) engineering estimates. After selecting appropriate emission estimation tools,
activity factors,such as production rates,should be determined for each source so that emissions can be
estimated for a specified period of time. The emissions over the specified period of time for each source
and pollutant then are summed to complete the emission inventory. Appendix C provides more detailed
information on procedures for performing an emission inventory at an HMA plant.
2.5 EMISSION ESTIMATES FOR TYPICAL HOT MIXASPHALT PLANTS
Tables 1 and 2 present annual estimates of emissions of criteria pollutants and HAPs for typical
batch mix and drum mix HMA plants, respectively. The estimates presented in these tables account for the
most significant emission sources at each type of facility. Tables 5 through 12 present more detailed
annual emission estimates for typical batch and drum mix HMA plants. Table 5 summarizes the estimated
emissions from a typical batch mix plant dryer, hot screens,and mixer. Included in the table are estimates
for criteria pollutants as well as specific PAHs,volatile HAPs,and metal HAPs for which emission factors
were developed. Estimated annual criteria pollutant, PAH and volatile HAP emissions from typical batch
mix plant load-out operations and asphalt storage tank are summarized in Tables 6 and 7. Tables 8, 9, 10,
and 11 summarize the estimated annual emissions from a typical drum mix plant dryer, load-out
operations, silo filling operations, and asphalt storage tank respectively. These tables includes estimates
for criteria pollutants, PAHs,volatile HAPs,and metal HAPs for which emission factors were developed.
Finally, Table 12 presents estimates of fugitive emissions from loaded trucks (yard emissions) for a typical
16
29. Plant type Source Criteria pollutants HAPs Other pollutants
Batch mix Dryer, hot
screens,and
mixer
PM-10, CO,
NOx,
VOCSO2,
24 organic HAPs
9 metal HAPs
CO2
4 other organics
3 other metals
Hot oil heaters 22 organic HAPs
Load-out PM, CO,VOC, 41 organic HAPs 3 other organics
Yard emissions VOC 19 organic HAPs
Drum mix Dryer PM-10, CO,
NOx,
VOCSO2,
58 organic HAPs
11 metal HAPs
CO2
15 other organics,
6 other metals
Hot oil heaters 22 organic HAPs
Load-out PM, CO,VOC 41 organic HAPs 3 other organics
Silo filling PM, CO,VOC 28 organic HAPs 3 other organics
Yard emissions VOC 19 organic HAPs
batch mix and drum mix plant. The emissions estimates presented in Tables 5 through 12 are based on the
emission factors developed for the HMA industry and the following assumptions:
·
·
·
·
·
·
Batch mix plant and drum mix plant dryers are fueled with either natural gas or fuel oil. It is
estimated that between 70 and 90 percent of HMA plants use natural gas, although some HMA
plants use fuel oil as an alternative to natural gas. As shown in Tables 5 and 8, fuel oil-fired
mixers and dryers have higher emissions of SO2, NOx, and some HAPs.
Batch mix plant dryer, hot screens,and mixer and drum mix plant dryer emissions are
controlled with fabric filters.
PM emissions from load-out and silo filling are entirely PM-10. (However,the organic portion
of these emissions also can be assumed to be PM-2.5. Information is available in AP-42
Appendix B.1, Particle Size Distribution Data and Sized Emission Factors for Selected
Sources, for categorizing the inorganic or filterable PM into PM-10 and PM-2.5 fractions.)
Average asphalt loss on heating is -0.5 percent (asphalt volatility).
Average HMA load-out temperature is 325°F.
The typical HMA plant has two asphalt storage tanks that are 50 feet long and 8 feet in
diameter. It is estimated that these storage tanks require a total heating capacity of about
200,000 Btu/hr, based on a heat loss of 60 Btu/ft2 of tank surface area. The asphalt storage
tanks are kept at 325°F continuously for the five months the HMA plant operates. As a result,
720 million Btu are used to maintain the temperature of the asphalt in the storage tank. For a
gas-fired hot oil heater, 720,000 ft3 of gas is combusted. For an oil-fired hot oil heater,
5,100 gallons of fuel oil are combusted. It should be noted that this fuel usage is about
3 percent of the fuel used in a typical batch mix plant and 1.6 percent of the fuel used in a
typical drum mix plant.
TABLE 3. MATRIXOF EMISSION FACTORS DEVELOPED FOR HMA SOURCES
17
43. APPENDIX C
Chapter 3:
Preferred and Alternative Methods for Estimating
Air Emissions from Hot Mix Asphalt Plants
Emission Inventory Improvement Program (EIIP)
July 1996
45. TECHNICAL REPORT DATA
(Please read Instructions on reverse before completing)
1. REPORT NO.
EPA-454/R-00-019
2. 3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Hot Mix Asphalt Plants
Emission Assessment Report
5. REPORT DATE
December 2000
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Ron Myers (EPA)
Brian Shrager (MRI)
Gary Brooks (ERG)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68D-98-027 (MRI)
68-D7-0068 (ERG)
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park,NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
16. ABST R A C T The United States Environmental Protection Agency (EPA) Emission Factors and Inventory Group (EFIG)
is investigating the Hot Mix Asphalt industry to identify and quantify criteria and hazardous air pollutants (HAP’s)
emitted from kiln stacks, transport truck loading and silo filling. EFIG obtained over 300 emission tests from kiln stacks
that characterize emissions of criteria pollutants and hazardous air pollutants’ emissions. EFIG requested that EPA’s
Emission Measurement Center (EMC) conduct the required testing of the transport truck and silo filling operations.
Under separate EPA contracts, Midwest Research Institute (MRI) and Pacific Environmental Services (PES) performed
two emissions tests. The primary objective of the testing program was to characterize uncontrolled emissions of the
criteria pollutants particulate matter (PM) and total hydrocarbons (THC) and emissions of volatile and semi-volatile
organic HAP’s including polycyclic organic matter, phenol, benzene, toluene, xylene, ethyl benzene, 2-butanone,
cumene, formaldehyde, hexane, isooctane and others. The results of the two test reports and responses to comments on
these test reports are covered in separate EPA reports (EPA 454/R-00-024, EPA 454/R-00-025 (a through h), EPA
454/R-00-026, EPA 454/R-00-027, EPA 454/R-00-028 and EPA 454/R-00-029). This document characterizes hot
mix asphalt plant operations, summarizes emissions from the typical batch mix and drum mix plants, presents emission
factors specifically developed for hot mix asphalt plants and presents analyses used to develop the emission factors
developed and presents information needed to inventory the emissions at hot mix asphalt plants.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b. IDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group
Air Pollution control
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (Report)
Unclassified
21. NO. OF PAGES
592
20. SECURITY CLASS (Page)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION IS OBSOLETE