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 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.
1) The document describes the process for Marshall stability test and mix design for bituminous concrete. Key steps include selecting aggregates based on strength and gradation, determining aggregate proportions, preparing specimens, and testing stability and flow.
2) Aggregate proportions are determined using an analytical method solving equations for the required gradation. Specimens are compacted and tested for stability (maximum load) and flow (deformation) at varying bitumen contents to determine the optimum mix.
3) Stability and flow values are measured using a Marshall test machine and calculations are done to determine density, voids, and other properties of the mix. The process is repeated to get the optimum bitumen content for the mix design.
Bitumen is a complex mixture of organic compounds that is primarily used for road construction. It originates from petroleum and naturally occurring deposits. Bitumen ages over time through oxidation and loss of volatile components, resulting in properties like decreased penetration and increased hardness. The rate of aging depends on factors like temperature, oxygen levels, and filler content. Standard tests like thin film oven testing and pressure aging vessel testing are used to simulate short and long-term aging. Rejuvenation and fillers can help combat the effects of aging and extend pavement lifespan.
This document provides an overview of the IRC method for designing flexible pavements according to IRC: 37-2012. It discusses the key considerations and calculations involved, including design traffic, subgrade properties like CBR and resilient modulus, material properties, and traffic data collection. The goal is to design a flexible pavement for a new four-lane divided national highway using the IRC guidelines and given traffic and material property data.
This document provides information on flexible pavement design and theory. It discusses the typical layers of a flexible pavement including the surface course, base course, and subgrade. It also outlines several factors that affect pavement design such as wheel load, climate, and material characteristics. Additionally, the document examines failures like fatigue cracking and rutting that pavement design aims to prevent. It provides guidance on mechanistic-empirical design as prescribed by the Indian Roads Congress.
The document discusses different approaches to flexible pavement design, including empirical, mechanistic, and mechanistic-empirical approaches. It provides details on each approach, such as the empirical approach using the 1993 AASHTO Guide equation relating pavement characteristics to performance, and the mechanistic approach modeling the pavement as layers and calculating stress/strain. The mechanistic-empirical approach combines both, using mechanics to calculate stresses/strains and empirical data to define failure criteria. Road tests like the AASHO and Maryland tests helped develop the empirical relationships used in design methods.
This document discusses viscosity testing for bitumen used in road pavements. It defines viscosity as the resistance to flow and explains that viscosity testing determines the consistency and strength of bitumen at different temperatures. The document outlines different types of viscometers used to measure the time required for bitumen to flow through an orifice at standardized temperatures, and how the results are interpreted to select bitumen with an appropriate viscosity for use in road construction and maintenance.
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 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.
1) The document describes the process for Marshall stability test and mix design for bituminous concrete. Key steps include selecting aggregates based on strength and gradation, determining aggregate proportions, preparing specimens, and testing stability and flow.
2) Aggregate proportions are determined using an analytical method solving equations for the required gradation. Specimens are compacted and tested for stability (maximum load) and flow (deformation) at varying bitumen contents to determine the optimum mix.
3) Stability and flow values are measured using a Marshall test machine and calculations are done to determine density, voids, and other properties of the mix. The process is repeated to get the optimum bitumen content for the mix design.
Bitumen is a complex mixture of organic compounds that is primarily used for road construction. It originates from petroleum and naturally occurring deposits. Bitumen ages over time through oxidation and loss of volatile components, resulting in properties like decreased penetration and increased hardness. The rate of aging depends on factors like temperature, oxygen levels, and filler content. Standard tests like thin film oven testing and pressure aging vessel testing are used to simulate short and long-term aging. Rejuvenation and fillers can help combat the effects of aging and extend pavement lifespan.
This document provides an overview of the IRC method for designing flexible pavements according to IRC: 37-2012. It discusses the key considerations and calculations involved, including design traffic, subgrade properties like CBR and resilient modulus, material properties, and traffic data collection. The goal is to design a flexible pavement for a new four-lane divided national highway using the IRC guidelines and given traffic and material property data.
This document provides information on flexible pavement design and theory. It discusses the typical layers of a flexible pavement including the surface course, base course, and subgrade. It also outlines several factors that affect pavement design such as wheel load, climate, and material characteristics. Additionally, the document examines failures like fatigue cracking and rutting that pavement design aims to prevent. It provides guidance on mechanistic-empirical design as prescribed by the Indian Roads Congress.
The document discusses different approaches to flexible pavement design, including empirical, mechanistic, and mechanistic-empirical approaches. It provides details on each approach, such as the empirical approach using the 1993 AASHTO Guide equation relating pavement characteristics to performance, and the mechanistic approach modeling the pavement as layers and calculating stress/strain. The mechanistic-empirical approach combines both, using mechanics to calculate stresses/strains and empirical data to define failure criteria. Road tests like the AASHO and Maryland tests helped develop the empirical relationships used in design methods.
This document discusses viscosity testing for bitumen used in road pavements. It defines viscosity as the resistance to flow and explains that viscosity testing determines the consistency and strength of bitumen at different temperatures. The document outlines different types of viscometers used to measure the time required for bitumen to flow through an orifice at standardized temperatures, and how the results are interpreted to select bitumen with an appropriate viscosity for use in road construction and maintenance.
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.
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 provides information on testing procedures for road aggregates. It discusses the importance of aggregate testing and outlines various tests performed on aggregates including sieve analysis, aggregate crushing value test, aggregate impact test, abrasion test, soundness test, specific gravity and water absorption tests, and shape tests. For each test type, the document describes the significance, test setup, procedure, observations, and specifications. The goal of the testing is to evaluate aggregates' properties like gradation, strength, shape, durability and suitability for use in pavement construction.
This document discusses different methods for soil stabilization, including mechanical, physical, chemical, and bituminous stabilization. Mechanical stabilization involves compacting soil to increase density and strength. Physical stabilization involves blending soils or adding admixtures to improve properties. Chemical stabilization uses lime, cement, or other chemicals like calcium chloride to react with soils and modify their characteristics. Bituminous stabilization involves adding bitumen or asphalt to seal soil pores and increase cohesion between particles. The document provides details on appropriate soil types, required quantities, and construction methods for each stabilization technique.
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 different types of pavements, including flexible, rigid, and semi-rigid pavements. It describes key design factors for both flexible and rigid pavements such as traffic load, pavement materials, subgrade strength assessed by CBR value, and design life. The document emphasizes the importance of pavement design, noting it accounts for nearly half the road construction cost. Good pavements are important as they can easily bear and transmit loads.
Asphalt mixtures are made up of aggregates, binder and air voids. In order to make a economic and satisfactory performing asphalt mixture the quantity of these individual constituent is required. Mixture design is a tool to determine these optimum quantities.
Vibro replacement stone columns are a ground improvement technique to improve the load bearing capacity and reduce the settlement of the soil. On many occasions, it is noted that the local soil is, by nature, unable to bear the proposed structure, so the use of ground improvement techniques may be necessary. Use of stone columns is one such technique. The stone column consists of crushed coarse aggregates of various sizes. The ratio in which the stones of different sizes will be mixed is decided by design criteria
This document discusses the construction and maintenance of bituminous roads. It describes the different types of pavements including flexible and rigid pavements. For bituminous construction, it explains the procedures for subgrade preparation, application of tack coats and prime coats, and construction of different layers using techniques like penetration macadam, bituminous macadam, and seal coating. It also discusses the use of hot mix and cold mix methods using emulsions and cutbacks for construction and maintenance of bituminous roads.
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.
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.
A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. The pavement structure should be able to provide a surface of acceptable riding quality, adequate skid resistance, favorable light reflecting characteristics, and low noise pollution.
The document provides information on pavement design, including different types of pavement structures and methods for designing asphalt and rigid pavements. It discusses asphalt pavement design using the AASHTO 1993 method, which involves determining the structural number required based on factors like traffic loading, material properties, and desired service life. It also outlines the rigid pavement design method, touching on considerations like soil properties, material selection, thickness design, drainage, and reinforcement.
Principles and design concepts of reinforced soil wallsPrakash Ravindran
Reinforced soil walls are cost-effective retaining structures that can tolerate large settlements. They consist of layers of soil reinforced with tensile inclusions like geogrids or geotextiles. The reinforcement improves the soil strength allowing near-vertical faces to be constructed. Key advantages include flexibility, rapid construction, and ability to absorb movements. The document discusses design principles like external stability checks against sliding and bearing capacity failure. Internal stability checks reinforcement rupture and pullout capacity. Settlements, seismic design, and typical failures are also covered.
1) The document discusses ground improvement techniques of preloading and vertical drainage. Preloading involves applying a surcharge load to improve soil strength and reduce settlements before construction.
2) Vertical drains are often used with preloading to accelerate consolidation by shortening the drainage path. Common types are sand drains and prefabricated vertical drains.
3) Vacuum preloading is described as an alternative to conventional preloading using surcharge loads, applying atmospheric pressure via a membrane system instead. This requires an effective drainage and vacuum maintenance system.
This document provides a profile summary of Dr. Ashik Bellary Amie, an assistant professor at KLS VDIT in Karnataka, India. It lists his qualifications and experience including being a reviewer for several international journals and conferences on transportation engineering topics. It also outlines his educational background and awards received. The document then provides an outline for a presentation on bituminous mix design, covering the need for mix design, desirable mix properties, common design methods, and basic design steps from aggregate selection to determining the optimum binder content. References for further information on mix design are listed at the end.
The document provides information on bitumen mixes used for road construction. It discusses the constituents of bitumen mixes, which include aggregates, filler, and binders like bitumen. It describes different types of mixes like dense graded, stone matrix, and open graded mixes. It also covers characteristics of materials used in mixes and production methods for both hot and cold bitumen mixes. Cold mixes use bitumen emulsions and avoid heating of aggregates and binders.
Types of Pavements, Layers present in the pavements, Stresses on the rigid pavements, wheel load, repetitions etc.. and Indian Standard Method of design of Rigid Pavements.
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
The document discusses ground improvement techniques. It begins by introducing the topic and providing context about the location and author. It then discusses various soil conditions from problematic to ideal and different ground improvement methods. The key ground improvement mechanisms are described along with factors to consider when selecting a method. Examples are provided to estimate costs for improving loose sand and stabilizing soft clay using different techniques. The document provides an overview of ground improvement and considerations for selecting appropriate techniques.
A sample lab report on Marshall method of mix design for bituminous mixtures with all calculations.
Please request with your mail ID if you want to download this document.
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 provides information on testing procedures for road aggregates. It discusses the importance of aggregate testing and outlines various tests performed on aggregates including sieve analysis, aggregate crushing value test, aggregate impact test, abrasion test, soundness test, specific gravity and water absorption tests, and shape tests. For each test type, the document describes the significance, test setup, procedure, observations, and specifications. The goal of the testing is to evaluate aggregates' properties like gradation, strength, shape, durability and suitability for use in pavement construction.
This document discusses different methods for soil stabilization, including mechanical, physical, chemical, and bituminous stabilization. Mechanical stabilization involves compacting soil to increase density and strength. Physical stabilization involves blending soils or adding admixtures to improve properties. Chemical stabilization uses lime, cement, or other chemicals like calcium chloride to react with soils and modify their characteristics. Bituminous stabilization involves adding bitumen or asphalt to seal soil pores and increase cohesion between particles. The document provides details on appropriate soil types, required quantities, and construction methods for each stabilization technique.
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 different types of pavements, including flexible, rigid, and semi-rigid pavements. It describes key design factors for both flexible and rigid pavements such as traffic load, pavement materials, subgrade strength assessed by CBR value, and design life. The document emphasizes the importance of pavement design, noting it accounts for nearly half the road construction cost. Good pavements are important as they can easily bear and transmit loads.
Asphalt mixtures are made up of aggregates, binder and air voids. In order to make a economic and satisfactory performing asphalt mixture the quantity of these individual constituent is required. Mixture design is a tool to determine these optimum quantities.
Vibro replacement stone columns are a ground improvement technique to improve the load bearing capacity and reduce the settlement of the soil. On many occasions, it is noted that the local soil is, by nature, unable to bear the proposed structure, so the use of ground improvement techniques may be necessary. Use of stone columns is one such technique. The stone column consists of crushed coarse aggregates of various sizes. The ratio in which the stones of different sizes will be mixed is decided by design criteria
This document discusses the construction and maintenance of bituminous roads. It describes the different types of pavements including flexible and rigid pavements. For bituminous construction, it explains the procedures for subgrade preparation, application of tack coats and prime coats, and construction of different layers using techniques like penetration macadam, bituminous macadam, and seal coating. It also discusses the use of hot mix and cold mix methods using emulsions and cutbacks for construction and maintenance of bituminous roads.
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.
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.
A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. The pavement structure should be able to provide a surface of acceptable riding quality, adequate skid resistance, favorable light reflecting characteristics, and low noise pollution.
The document provides information on pavement design, including different types of pavement structures and methods for designing asphalt and rigid pavements. It discusses asphalt pavement design using the AASHTO 1993 method, which involves determining the structural number required based on factors like traffic loading, material properties, and desired service life. It also outlines the rigid pavement design method, touching on considerations like soil properties, material selection, thickness design, drainage, and reinforcement.
Principles and design concepts of reinforced soil wallsPrakash Ravindran
Reinforced soil walls are cost-effective retaining structures that can tolerate large settlements. They consist of layers of soil reinforced with tensile inclusions like geogrids or geotextiles. The reinforcement improves the soil strength allowing near-vertical faces to be constructed. Key advantages include flexibility, rapid construction, and ability to absorb movements. The document discusses design principles like external stability checks against sliding and bearing capacity failure. Internal stability checks reinforcement rupture and pullout capacity. Settlements, seismic design, and typical failures are also covered.
1) The document discusses ground improvement techniques of preloading and vertical drainage. Preloading involves applying a surcharge load to improve soil strength and reduce settlements before construction.
2) Vertical drains are often used with preloading to accelerate consolidation by shortening the drainage path. Common types are sand drains and prefabricated vertical drains.
3) Vacuum preloading is described as an alternative to conventional preloading using surcharge loads, applying atmospheric pressure via a membrane system instead. This requires an effective drainage and vacuum maintenance system.
This document provides a profile summary of Dr. Ashik Bellary Amie, an assistant professor at KLS VDIT in Karnataka, India. It lists his qualifications and experience including being a reviewer for several international journals and conferences on transportation engineering topics. It also outlines his educational background and awards received. The document then provides an outline for a presentation on bituminous mix design, covering the need for mix design, desirable mix properties, common design methods, and basic design steps from aggregate selection to determining the optimum binder content. References for further information on mix design are listed at the end.
The document provides information on bitumen mixes used for road construction. It discusses the constituents of bitumen mixes, which include aggregates, filler, and binders like bitumen. It describes different types of mixes like dense graded, stone matrix, and open graded mixes. It also covers characteristics of materials used in mixes and production methods for both hot and cold bitumen mixes. Cold mixes use bitumen emulsions and avoid heating of aggregates and binders.
Types of Pavements, Layers present in the pavements, Stresses on the rigid pavements, wheel load, repetitions etc.. and Indian Standard Method of design of Rigid Pavements.
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
The document discusses ground improvement techniques. It begins by introducing the topic and providing context about the location and author. It then discusses various soil conditions from problematic to ideal and different ground improvement methods. The key ground improvement mechanisms are described along with factors to consider when selecting a method. Examples are provided to estimate costs for improving loose sand and stabilizing soft clay using different techniques. The document provides an overview of ground improvement and considerations for selecting appropriate techniques.
A sample lab report on Marshall method of mix design for bituminous mixtures with all calculations.
Please request with your mail ID if you want to download this document.
The document discusses the Marshall mix design method for determining the optimum bitumen content for an asphalt mix. The Marshall stability and flow test is used to predict mix performance. Specimens are prepared with varying bitumen contents and tested for properties like stability, flow, air voids, specific gravities. Graphs of these properties against bitumen content are used to find the optimum content as the average of the contents for maximum stability, maximum density, and 4% air voids. Calculations of mix properties and an example are provided.
Dense Bituminous Macadam (DBM) is a binder course used for roads with more number of heavy commercial vehicles and a close-graded premix material having a voids content of 5-10 per cent.
The document discusses the history and methods of hot mix asphalt (HMA) mix designs. It describes the Marshall and Hveem mix design methods, which were developed in the 1930s-1940s to determine the optimal blend of aggregates and asphalt binders. The Marshall method uses compacted cylindrical specimens subjected to impact compaction and stability testing, while the Hveem method employs kneading compaction and a stabilometer to evaluate shear strength. Both aim to achieve sufficient stability, air voids, and workability within the mix. The Superpave gyratory compactor method was later introduced as a improved alternative.
This document is a summer internship project report submitted by Shubham Paliwal to the Department of Civil Engineering. It provides introductions and definitions related to bitumen and bituminous roads. It describes the different layers of a bituminous road, including the subgrade, sub-base, base, and wearing surface layers. It also discusses operations used in bituminous roads like seal coats, tack coats, and prime coats. References used in the project are listed at the end.
The document provides an overview of Superpave mix design methods for hot mix asphalt (HMA). It discusses the goals of using a gyratory compactor to simulate field compaction. The key steps of the Superpave mix design process are selecting materials, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture sensitivity. Sample preparation and determining volumetric properties are also summarized. The Superpave method aims to develop durable, stable HMA mixes through gyratory compaction testing.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
This document provides information on bitumen, which is used as a binding material in pavements. It discusses the types of bitumen including paving grade, modified, cutback and emulsion. Cutback bitumen has solvents added to increase fluidity while bitumen emulsion uses water. Modified bitumen has additives added to improve properties. The document also describes various tests conducted on bitumen like penetration, ductility, softening point and viscosity to determine hardness and grading. Bitumen requirements include adequate viscosity and adhesion properties. The grading of bitumen depends on the results of penetration tests.
The document discusses different types of bituminous pavement used in highway engineering. It describes how bituminous pavement is made by mixing heated aggregates like crushed stone with heated asphalt binders. It then lists various types of bituminous pavement like asphalt concrete and discusses their properties and appropriate uses based on traffic levels. The document also discusses factors that can lead to failures of bituminous concrete pavement like excessive loads beyond the pavement's strength.
This document outlines the aggregate property requirements for Superpave hot mix asphalt, including criteria for coarse aggregate angularity, flat and elongated particles, fine aggregate angularity, clay content, and aggregate gradation band limits. It provides tables specifying minimum property requirements based on expected traffic levels. Sample gradation band charts are given for various nominal maximum aggregate sizes used in Superpave mixes.
Presentation delivered at the CalAPA Spring Asphalt Pavement Conference April 9-10, 2014 in Ontario. Topic: New Superpave specification coming to California.
An orientation on changes to Caltrans asphalt pavement specifications to incorporate elements of the national "Superpave" standard. Presented by Joe Peterson, chief, Office of Roadway Materials Testing for Caltrans at the Dec. 3, 2014 CalAPA L.A. and High Desert Technical Committee meeting in Fontana.
production tests aging of bitumen and modified Bitumen Abhijeet Bhosale
This document provides information on bitumen through a presentation by several people. It defines bitumen as a viscous liquid or solid consisting of hydrocarbons that is soluble in trichloroethylene. Bitumen is black or brown in color and has waterproofing and adhesive properties. It is produced from crude oil through fractional distillation. Different types of bituminous materials include tar, pitch and asphalt. The document also describes various tests conducted on bitumen like penetration test, ductility test, softening point test, and viscosity test. It provides recommended values for different bitumen grades based on these tests.
This document discusses bitumen, which is a black or dark brown material derived from petroleum that is used in civil engineering projects like roads and construction. It originates from natural asphalt deposits or is produced through refining crude oil, with the asphalt being the residue left over after distillation. The document outlines the basic refining process and lists some key engineering properties measured for bitumen like penetration value, softening point, and viscosity. It also provides details on common penetration grades available in India.
This document summarizes the construction of a 6.5 km private road located in Ranipur, Haridwar, India. It describes the various layers that make up the roadway, including earthwork, granular sub-base, wet mix macadam, bituminous macadam, bituminous concrete, and finishing touches like kerbs and shoulders. The layers are constructed in sequential order, with careful compaction and mixing of aggregates and binders at each stage to support vehicular traffic on the carriageway. Proper camber is built into the road surface to allow for water drainage off the sides of the paved area.
This document summarizes a project report on the construction of roads at the National Institute of Technology in Warangal, India. It was completed by five students under the guidance of a faculty member. The report discusses the importance of roads for economic development and transportation. It provides an overview of the types of roads in India and the current status of the national highway system. It also describes the phases of road construction, materials used, equipment involved, and project management tools applied to the road projects at NIT Warangal.
This document discusses bitumen hardening and its effects on pavement distresses. It summarizes various types of cracking that can result from bitumen hardening, including fatigue cracking, block cracking, longitudinal cracking, and transverse cracking. It then explains factors that can cause bitumen hardening at the production, construction, and in-service stages. These include oxidative hardening, loss of volatiles, physical hardening, exudative hardening, and hardening during storage, mixing, and when the pavement is in service. The document also discusses the importance of quality control and quality assurance practices to produce consistent bituminous mixtures and ensure the approved mixture is used for the road project.
The document discusses bituminous mix design which involves combining aggregates, bitumen, filler materials like cement or GGBS, shredded plastic, and an anti-stripping agent called Bitu-grip. It provides details on the materials used, testing procedures, results of mix designs for different types of mixes like BC, DBM, BM, and MSS. The use of shredded plastic and Bitu-grip can increase bonding between aggregate and bitumen while filler reduces voids and increases strength. GGBS can be used instead of cement, providing cost savings. Use of these additives results in reduced binder and bitumen content.
Performance evaluation of dense bituminous macadam mix a refusal density ap...eSAT Journals
Abstract
Secondary compaction is a state; where the pavement which is compacted with the conventional compaction has been further
compacted due to the movement of traffic and which corresponds to the ultimate density which can be attained on the bituminous
pavement called as “Refusal density” of the pavement. Secondary compaction has to be studied in detail and it is understood that the
75 blows of the Marshall test does not determine the actual field circumstances. The Marshall design actually in the field will not
simulate the field conditions hence there will be a reduction in the air voids at the refusal density. Then due to fineness of the mix, this
causes the plastic deformation on the pavement surfaces. Hence an attempt has been made to study the air void content at refusal
density. Also the Bulk Density, Air voids (Va), Voids in mineral aggregate (VMA),Voids filled with Bitumen (VFB) of the mix at the
refusal density are also studied. For the simulation of the field density in the laboratory a Hugo hammer is used. The usage of the
Polymer Modified Bitumen reduces the plastic deformation and other distresses of the pavement.
Keywords: Dense bituminous macadam (DBM), Refusal density, Hugo hammers.
Effect of air void on dense graded bituminous mixAvinash Bhosale
SEMINAR FOR effect of air voids on dense graded bituminous mix.
MATERIALS USE FOR NATIONAL HIGHWAY.
such as Dense bituminous macadam.
air voids in road pavement and how to analyse it.
This document provides information on dense bituminous macadam (DBM), which is a binder course used for road construction. It discusses the design criteria, materials, job mix formula, and construction process for DBM layers. DBM mixes are designed in the laboratory to meet specific stability and durability requirements. The design considers factors like aggregate type and gradation, binder content, and compaction parameters. DBM layers are constructed by preparing the base, mixing the materials, spreading the mix, compacting it with rollers, and then opening the road to traffic once cooled.
IRJET- Mix Design for Wearing Course of Flexible Road Pavement by Marshal...IRJET Journal
This document presents a mix design for the wearing course of a flexible road pavement using the Marshall method. Laboratory tests were conducted on aggregates, asphalt, and pavement mixtures. The results showed the aggregates met specifications and had properties suitable for use in a wearing course. The optimum asphalt content was determined to be 5.0% based on a variety of mix parameters measured at different asphalt contents, including density, air voids, voids in the mineral aggregate, voids filled with asphalt, stability, and flow. All mix parameters at the 5.0% asphalt content met the required specifications.
The document discusses the durability of bituminous mixes, which refers to the ability of the mixture to retain its original properties and resist load, abrasion, and moisture damage over time. Key factors that influence durability include adequate bitumen film thickness, proper void content, compatibility between the aggregate and bitumen, and sufficient asphalt content. The void content in mineral aggregate (VMA) is an important design property that helps ensure adequate film thickness.
Waterproofing roads prevents pothole formation and increases pavement lifespan. Materials used for waterproofing include calcium stearate, petroleum wax emulsions, rubber crumbs, and mastic asphalt polymers. Construction involves pre-treating surfaces, applying tack coats, and using specialized fabrics and seals between layers. Waterproofed roads have advantages like improved strength, reduced repairs and accidents, energy efficiency, and sustainability.
The document discusses various methods and materials used to waterproof roads, including calcium stearate, petroleum wax emulsion, rubber crumbs, mastic asphalt polymer, and paving fabrics. Waterproofing roads with these materials prevents water from entering cracks and weakening the road surface, thereby restricting pothole formation and increasing the lifespan of the road. The advantages of waterproof roads include increased strength and performance, improved structural durability, reduced repair works and costs, higher energy efficiency, and a reduction in accidents.
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1) Concrete mix proportioning determines the relative amounts of ingredients to achieve the desired properties in an economical way.
2) Factors like water-cement ratio, aggregate size and grading, cement content affect the strength, workability and durability of concrete.
3) Common mix design methods include ACI, IS, and trial batch methods. The general steps are selecting slump, aggregate size, water content, water-cement ratio, and calculating cement and aggregate
This document discusses methods for batching, mixing, transporting, and handling concrete. It describes the basic processes including batching ingredients by mass or volume, mixing concrete thoroughly in stationary or truck mixers, and transporting fresh concrete via dump trucks, pumps, conveyor belts, or chutes. The key considerations for choosing handling methods are the job scope and size, amount of concrete, placement locations (above or below ground), and schedule. Common equipment includes mixers, agitators, pumps, conveyors, chutes, and cranes to efficiently place concrete without segregation or delays.
This document discusses concrete mix design and proportioning. The objective of mix design is to determine the most economical combination of materials to produce durable concrete of required strength under given conditions, using minimum cement and water. Factors considered include workability, strength, durability and economy. The principles are to use minimum cement and water while maintaining workability and quality. Concrete strength is directly related to the water-cement ratio, with lower ratios producing stronger, more durable concrete. Common mix design methods include the absolute volume method and ACI standards for different concrete types.
The document discusses bituminous mix design and the Marshall mix design method. It describes the objectives of mix design as developing an economical blend of aggregates and asphalt that meets design requirements such as sufficient asphalt, stability, air voids, and workability. The Marshall mix design procedure involves selecting and testing aggregates and asphalt, developing trial blends, compacting specimens, and evaluating properties according to criteria like stability, flow, air voids, and tensile strength ratio. Calculations are also required to determine properties like theoretical maximum density and voids in the mix.
This document discusses the process of concrete mix design. The goal of mix design is to produce concrete with the required strength, durability and workability at the lowest cost. It describes the factors that must be considered such as minimum strength, workability, water-cement ratio and aggregate size and grading. The different types of mixes are described as nominal, standard or design mixes. The key steps of mix design are outlined, including selecting the target strength, water-cement ratio, water content, cement content and aggregate volumes. Durability, aggregate properties and mix calculations are also summarized.
Laboratory Investigation of Conventional Asphalt Mix Using Shell Thiopave for...IJERA Editor
The characteristic performance of asphalt pavement always depends on the properties of bitumen, volumetric properties of asphalt mixtures. Bitumen is visco– elastic material where the temperature and rate of load application have a great influence on its behavior. There are different solutions to reduce the pavement distress such as using Thiopave (binder extender and asphalt mixture modifier) in the mix design. Thiopave can significantly alter the performance properties of the mix and it is helpful to extend the life span of pavement. In this study, investigating use of thiopave and the change in the performance properties is dependent both on the percentage of virgin binder using VG-30 bitumen that is substituted with thiopave with different percentages. The study indicated that 10%, 20%, 30% and 40% replacement of binder was done with thiopave. The most notable impact of the addition of thiopave to a bituminous mixture is an increase in the stiffness of the mixture for better resistance to fatigue cracking and rutting. Thiopave materials can have a positive impact on laboratory mixture performance. The addition of thiopave has been shown to significantly increase Marshall Stability. From this study it is observed that thiopave can be utilized up to 30% to 40% as replacement to bitumen.
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1) The document discusses methods for designing high-performance concrete mixes, including the limitations of existing methods like ACI 211-1 which are intended for normal concrete.
2) It proposes a new simplified method that involves selecting the water-to-binder ratio, water content, superplasticizer dosage, coarse aggregate content, and entrained air content in sequence.
3) The key aspects of high-performance concrete that make existing mix design methods inadequate include the ability to independently control slump and water content using superplasticizers, and the need to satisfy requirements like low permeability and high durability in addition to high strength.
This document discusses different types of admixtures used in concrete, including their uses and effects. It covers mineral admixtures like fly ash and silica fume that can reduce costs and improve properties. It also discusses chemical admixtures, specifically highlighting water reducers, superplasticizers, accelerators, and retarders. Water reducers and superplasticizers can lower the water-cement ratio while maintaining workability, leading to increased strength. Accelerators can reduce setting time while retarders have the opposite effect of delaying setting.
THIS PRESENTATION IS MAINLY OCCUPIED IN CE 6002 CONCRETE TECHNOLOGY UNIT NO.03......
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7. There are several guidelines for adjusting the trial mix but it may not necessarily apply in all cases Voids Low, Stability Low :- Voids may be increased in no. of ways As a general approach to obtaining higher voids in the mineral aggregate the aggregate grading should be adjusted by adding more coarse ore more fine aggregate It must be remembered, however, that lowering the bitumen content may decrease the durability of the pavement Too much reducing in bitumen content may lead to brittleness, accelerated oxidation, and increased permeability If the above adjustments do not produce a stable mix, the aggregate may have to be change Stability & void content of the mix may be increased by increasing the amount of crushed materials and / or decreasing the amount of material passing the 75µ
8. Voids Low, Stability Satisfactory:- Low void content may eventually result in instability due to plastic flow or flushing after the pavement has been exposed to traffic for a period of time because of particle re-orientation and additional compaction Insufficient void may also result because of inadequate bitumen content in finer mixes even though stability is initially satisfactory for specific traffic, however, durability will be affected For these reasons, mixes low in voids should be adjusted by increasing or decreasing coarse & fine aggregates
9. Voids Satisfactory, Stability Low:- Low stability when voids and aggregate grading are satisfactory may indicate some deficiencies in the aggregate Consideration should be given to improving the coarse particle shape by crushing or increasing the %age of coarse aggregate in the mixture, or possibly increasing the maximum aggregate size Aggregate particles with rougher texture and less rounded surfaces will exhibit more stability while maintaining or increasing the void content
10. Voids High, Stability Satisfactory:- High voids contents are frequently associated with the mixes found to have high permeability High permeability, by permitting circulation of air and water through the pavement may lead to premature hardening of the bitumen Even though stabilities are satisfactory, adjustment should be made to reduce the voids Small reduction may be accomplished by increasing the mineral dust content of the mix It may be necessary to select or combine aggregates to a gradation which is closer to the maximum density grading curve
11. Voids High, Stability Low:- Two steps may be necessary when the voids are high and stability is low First voids are adjusted by the method discussed above If this adjustment does not also improve the stability The second step should be a consideration of aggregate quality as discussed in first & second cases
12.
13. PREPARATO OF TEST SPECIMENS At least 3 specimens for each combination of aggregates and bitumen content Preparation of aggregates Determination of mixing & compaction temperature Preparation of mixtures Packing the mold Compaction of specimens
14. BULK SPECIFIC GRAVITY DETERMINATION This test is performed according to ASTM D 1188 & ASTM D 2726 STABILITY & FLOW DENSITY & VOID ANALYSIS
16. DETERMINATION OF PRELIMINARY DESIGN BITUMEN CONTENT The design bitumen content of the bituminous mixture is selected by considering all of the design parameters As an initial starting point, choosing the bitumen content at the median of the present air voids limits, which is four percent All of the calculated and measured mix properties at this bitumen content should then be evaluated by comparing them to the mix design criteria as specified in MORT&H Cl. 500 If all of the design criteria are met, then this is the preliminary design bitumen content if not some adjustment is necessary or mix is redesign
17. SELECTION OF FINAL MIX DESIGN The final selected mix design is usually the most economical one that will satisfactorily meet all of the established criteria The design bitumen content should be a compromise selected to balance all of the properties. Normally, the mix design criteria will produce a narrow range of accept bitumen contents that pass all of the guidelines as shown by the example in Fig.5.6
19. EVALUATION OF VMA CURVE In many cases, the most difficult mix design property to achieve is a minimum amount of voids in the mineral aggregate The goal is to furnish enough space for the bitumen so it can provide adequate adhesion to bind the aggregate particles, but without bleeding when temperature rise and the bitumen expands Normally, the curve exhibits a flattened U-shape, decreasing to a minimum value and then increasing with increasing bitumen content shown in Fig. 5.7 (a) It is recommended that bitumen contents on the “wet” or right –hand increasing side of this VMA curve be avoided, even if the minimum air void and VMA criteria is met Design bitumen content in this range have a tendency to bleed and or exhibit plastic flow when placed in the field
21. Any amount of additional compaction from traffic leads to inadequate room for bitumen expansion, loss of aggregate –to-aggregate contact, and eventually, rutting and shoving in high traffic areas Ideally, the design bitumen content should be selected slightly to the left of the low point of the VMA curve, provided none of the other mixture criteria are violated When the bottom of the U-shaped curve falls below the minimum criteria level required for the nominal maximum aggregate size of the mix. This is an indication that changes to the job-mix-formula are necessary Specifically, the aggregate grading should be modified to provide additional VMA
24. EFFECT OF AIR VOIDS It should be emphasized that the design range of air voids (3 to 5%) is the level desired after several years of traffic The air voids after the construction is about 8% The bituminous mixtures that ultimately consolidate to less than 3% air voids can be expected to rut and shove, if placed in heavy traffic locations Problem can occur if the final air content is above 5% or if the pavement is constructed with over 8% air voids initially. Brittleness, premature cracking, raveling, and stripping are all possible under these conditions (Fig. 5.8)
26. EFFECT OF VOIDS FILLED WITH BITUMEN The main effect of the VFB criteria is to limit maximum levels of VMA and subsequently, maximum levels of bitumen content VFB also restricts the allowable air void content for mixes that are near the minimum VMA criteria Mix designed for lower traffic volumes will not pass the VFB criteria with a relatively high % air voids (5%) even though air void criteria range is met. The purpose is to avoid less durable mixes in light traffic situations. Mix designed for heavy traffic will not pass the VFB criteria with relatively low % air voids (less than 3.5%) even though that amount of air voids is within the acceptable range Because low air voids contents can be very critical in terms of permanent deformation The VFB criteria helps to avoid those mixes that would be susceptible to rutting
27. The VFB criteria helps to avoid those mixes that would be susceptible to rutting in heavy traffic situations The VFB criteria provide an additional factor of safety in the design and construction process in terms of performance
28.
29. (e) The number of blows needed for the larger specimen is 1.5 times (112 blows) that required of the smaller specimen (50 or 75 blows) to obtain equivalent compaction (f) The minimu stability should be 2.25 times and the range of flow values should be 1.5 times the same criteria for the normal-sized specimens (g) Similar to the normal procedure, these value should be used to convert the measure stability values to an equivalent value for a specimen with a 95.2 mm thickness, if the actual size varies, the following table should be used as C.F.
34. MODIFIED HUBBARD-FIELD METHOD OF BITUMINOUS MIX DESIGN This method was developed by P.Hubbard and F.C. Field This method was in fact intended to design sheet bituminous mix It was later modified for the design of bituminous mixes having coarse aggregate size up to 19 mm
37. PROCEDURES: Once the desired blend and gradation of the mineral aggregates is arrived Batch weights are worked out for producing specimens of compacted size, 152 mm dia. & ht. 70 to 76 mm These weighed aggregates and bitumen are heated to the temperature of approximately 140 0 C Then, this mix is placed in the preheated mould and tamped in two layers by 30 blows each with the specified tampers This specimen is tamped again on the reverse side by 30 blows by each of the two tampers
38. Then a static load of 4536 kg is applied on the specimen for two minutes After this, the specimen is cooled in water to temperature less than 37.8 0 C, maintaining the same compressive load Finally, the specimen is removed, weighed and measured This specimen is placed in the test mold assembly over the test ring of internal dia. of 146 mm and the plunger is loaded on the top of the specimen The entire assembly is kept in a water bath maintained at 60 0 C for atleast one hour in position under the compression machine
39. The compressive load is applied at a constant rate of deformation of 61 mm per minute and the maximum load in kg developed during the test is recorded as the stability value The average stability value of all the specimens tested using a particular mix is found A s in the case of Marshall method, the tests are repeated for other bitumen contents The value of specific gravity, percent voids in total mix and % aggregate voids are calculated
43. HVEEM METHOD OF BITUMINOUS MIX DESIGN (ASTM D 1560 & ASTM D 1561)
44. This method was developed by Francis N. Hveem who was materials & research engineer for the California Division of Highways EQUIPMENT & MATERIALS REQUIRED FOR DETERINING THE APPROX. BITUMEN CONTENT Kerosene – 4 liters Beakers – 1500 ml Filter papers – 55 mm dia Timer Oil – SAE No. 10 lubricating 4 liters etc. Centrifuge- hand operated capable of producing 400 times gravity
45. The maximum size of aggregates used in the test mixes should not exceed 25 mm In this method, specimen of 102 mm dia. & 64 mm The principal features of the Hveem method of mix design are the surface capacity and Centrifuge Kerosene Equivalent (C.K.E.) test on the aggregates to estimate the bitumen requirements of the mix, followed by a stabilometer test, a cohesiometer test , swell test and a density voids analysis on test specimens of the compacted paving mixtures
46. The first step in the Hveem method of mix design is to determine the “approximate” bitumen content by the C.K.E. The gradation of the aggregate or blend of aggregates employed in the mix is used to calculate the surface area of the total aggregate Total % passing Max size 4.75 2.36 1.18 0.600 0.300 0.150 0.075 Surface area factor m 2 /kg 0.41 0.82 1.64 2.87 6.14 12.29 32.77
50. SURFACE CAPACITY TEST FOR COARSE AGGREGATE The capacity test for the larger aggregate involves these steps: Place exactly 100 g of dry aggregate which passes the 9.5 mm and Retained on the 4.75 mm into a metal funnel (this fraction is considered to be representative of the coarse aggregate in the mix) Immerse sample and funnel into a beaker containing SAE No. 10 lubricating oil at room temperature for 5 minute Allow to drain for 2 minutes Remove funnel and sample from oil and drain for 15 minutes at a temperature of 60 0 C Weigh the sample after draining and determining the amount of oil retained as a percent of the dry aggregate weight Necessary correction has to be made if the sp gravity of aggregate is greater than 2.70 or less than 2.60
51. Chart for determining surface constant for coarse material, Kc, from coarse aggregate absorption Fig. 6.3
52. Chart for determining Kf and Kc to determine surface constant for combined aggregate, Km
55. ESTIMATED DESIGN BITUMEN CONTENT Preliminary estimation of the design bitumen content Using the C.K.E. value obtained and the chart in Fig. 6.2, determine the value Kf (surface constant for fine material) Similarly, using the C.K.E. value and the chart in Fig. 6.3, determine the Kc (surface constant for coarse material) Using the values obtained for Kf and Kc and the chart Fig. 6.4, determine the value Km (surface constant for fine & coarse material combined) Km = Kf + correction to Kf The correction of Kf obtained from Fig. 6.4 is positive if (Kc-Kf) is positive and is negative if (Kc-Kf) is negative
56. With values obtained for Km, surface area, and average specific gravity, use case 2 procedure of the chart in Fig. 6.5 to determine the oil ratio Determine the bitumen content (bitumen ratio) for the mix using Fig. 6.6 corrected for the grade to be employed, using the surface area of the sample, the grade of the bitumen and the oil ratio from Fig 6.5
57. Specific gravity of coarse aggregate (bulk) = 2.45 Specific gravity of fine aggregate (apparent) = 2.64 Percent fine passing 4.75 mm sieve = 45 Then, Avg. sp. gr . = To demonstrate the use of the charts in Figs. 6.2 through 6.6 100 55 2.45 + 45 2.64 Surface area of aggregate grading = 6.6 m 2 /kg C.K.E. = 5.6 % oil retained, coarse = 1.9 (corrected for sp gr this values is 1.7 %
58. From Fig. 6.2 determine Kf as 1.25 From Fig. 6.3 determine Kc as 0.8 From Fig. 6.4 determine Km as 1.15 From Fig. 6.5 determine the oil ratio for liquid bitumen as 5.2 % From Fig. 6.6 determine design bitumen content (bitumen ratio) for AC-10 bitumen as 6.1% by weight of dry aggregate
59. PREPARATION OF TEST SPECIMENS A series of stabilometer test specimens is prepared for a range of bitumen contents both above and below the approximate design bitumen content indicated by the CKE procedure One specimen with the amount of bitumen as determined by the CKE Two specimens above the CKE amount in 0.5 increments, and one 0.5 % below the CKE amount For highly absorptive aggregates and non-critical mixes, increase the steps in bitumen content to 1.0% and use more specimens as necessary
60. PREPARATION OF BATCH WEIGHTS About 1200 g of dry aggregates of desired gradation is taken and filled the mold having 101.6 mm dia. & 63.5 mm ht. When the aggregates and bitumen have reached the desired mixing temperature, transfer the batch mix into a suitable flat pan and cure for 2 to 3 hrs at a temperature of 146 ± 3 0 C in a oven equipped with forced draft air circulation After curing is complete, place batch mix in heating oven and reheat mixture to 110 0 C Then the batch mix ready for compaction
61. COMPACTION The compaction of the test specimen is accomplished by means of the mechanical compactor that imparts a kneading action type of consolidation by a series of individual impressions made with a ram having a face shaped With each push of the ram, a pressure of 3.45 Mpa (500psi) is applied, subjecting the specimen to a kneading compression over an area of approximately 2000 mm 2 Each pressure is maintained for approximately 0.4 sec. Place the compaction mold in the mold holder and insert a 100 mm dia paper disk to cover the base plate. So the base plate will act as a free-fitting plunger during the compaction operation
62. Spread the prepared mixture uniformly on the preheated feeder trough Using a paddle that fits the shape of the trough, transfer approximately one-half of the mixture to the compaction mold Rod the portion of the mix in the mold 20 times in the centre of the mass and 20 times around the edge with the round-nose steel rod Transfer the remainder of the sample to the mold and repeat the rodding procedure Place the mold assembly into position on the mechanical compactor and apply approximately 20 tamping blows at 1.7 MPa to achieve semi-compacted
63. Condition of the mix so that it will not be unduly disturbed when the full load is applied The exact no. of blows to accomplish the semi-compaction shall be determined by observation The actual no. of blows may vary between 10 & 50, depending upon the type of material and it may not ne possible to accomplish the compaction in the mechanical compactor because of undue movement of the mixture under the compactor foot In such instances use 178 kN static load applied over the total specimen surface by the double plunger method, in which a free-fitting plunger is placed below & on top of the sample
64. Apply the load at the rate of 1.3 mm per minute and hold for 30 ± 5 seconds After the semi-compaction, remove the steel shim and release mold tightening screw sufficiently to allow free up-and –down movement of mold and about 3 mm side movement of mold To complete compaction in the mechanical compactor, increase compactor foot pressure to 3.45 Mpa and apply 150 tamping blows Place the mold and specimen in an oven at 60 0 C for 1 hour, after which a “leveling-off” load off 56 kN is applied by the “double-plunger” method and released immediately
65. SPECIMEN FOR SWELL TEST Prepare the compation mold by placing a paraffin-impregnated strip of ordinary wrapping paper 19 mm wide, around the inside of the mold 13 mm from the bottom to prevent water from escapping from between the specimen and the mold during the water immersion period of the test The paper strip is dipped in melted paraffin and applied while hot Compaction molds are not preheated for swell test specimens The remainder of the compaction procedure for swell test specimens is the same as for the stabilometer test specimens except for:
66. When compaction is completed in the mechanical compactor, remove mold and specimen from compactor, invert mold and push specimen to the opposite end of mold Apply a 56 kN static load [head speed 6 mm/min] with the original top surface supported on the lower platen of the testing press It is advisable to place a piece of heavy paper under the specimen to prevent damage to this lower platen
67. TESTS AND ANALYSES ARE NORMALLY PERFORMED IN THE ORDER LISTED Stabilometer Test Bulk Density Determination Swell Test Stabilometer Test Place the compacted specimens for stabilometer tests in oven at 60 ± 3 0 C for 3 to 4 hours Adjust compression machine for a head speed of 1.3 mm/min with no load applied Check displacement of stabilometer with a stailometer with a calibration cylinder and if necessary adjust to read 2.00 ± 0.05 turns
68. Stabilometer Test Adjust the stabilometer base so that the distance from the bottom of the upper tapered ring to the top of the base is 89 mm For specimens having overall ht. outside the range between 61 mm & 66 mm, stabilometer should be corrected as indicated in Fig. 6.14 Remove the mold with its specimen from the oven and place on top of stabilometer. Using the plunger, hand lever and fulcrum, force the specimen from the mold into the stabilometer Place follower on top of specimen and position the entire assembly in compression machine for testing
69. Stabilometer Test Using a displacement pump, raise the pressure in the stabilometer system until the gauge (horizotanl pressure) reads exactly 34.5 kPa (5psi) Close displacement pump valve, taking care not to disturb the 34.5 kPa initial pressure (This step is omitted on stabilometers that are not provided with the displacement pump valve Apply test loads with compression machine using a head speed of 1.3 mm/min Record readings of stabilometer test gauge at vertical test loads of 13.4, 22.3, and 26.7 kN
70. Stabilometer Test Immediately after recording the horizontal pressure reading under maximum vertical load 26.69 kN, reduce total load on specimen to 4.45 kN Open the displacement pump angle valve and by means of the displacement pump, adjust test gauge to 34.5 kPa (This will result in a reduction in the applied press load which is normal and no compensation is necessary) Adjust dial gauge on pump to zero by means of small thumbscrew
71. Stabilometer Test Turn displacement pump handle smoothly and rapidly (two turns per second) and to the right (clockwise) until a pressure of 690kPa is recorded on the test gauge During this operation the load registered on the testing press will increase and in some cases exceed the initial 4.45kN load. This change in load is normal and no adjustment is required Record the exact number of turns required to increase the test gauge reading from 34.5 kPa to 690 kPa as the displacement on specimen [2.5 mm dial reading is equivalent to one turn displacement]
72. Stabilometer Test After recording the displacement, first remove the test load and reduce pressure on the test gauge to zero by means of the displacement pump; then reverse the displacement pump and additional three turns and remove specimen from stabilometer chamber BULK DENSITY DETERMINATION After completion of the stabilometer tests, the specimens have cooled to room temperature The procedure for this test is presented in ASTM D 1188, ASTM D 2726
73. SWELL TEST Allow compacted swell test specimen to stand at room temperature for at least one hour (This is done to permit rebound rebound after compaction) Place the mold and specimen in 190 mm dia x 64 mm deep aluminum pan Place the perforated bronze disk on specimen, position the tripod with dial gauge on mold and set the adjustable stem to give a reading of 2.54 mm on the dial gauge Introduce 500 ml of water into the mold on top of the specimen and the measure distance from the top of the mold to the water surface with the graduated scale
74. SWELL TEST After 24 hours, read the dial gauge to the nearest 0.025 mm and record the change as well Also, measure the distance from the top of the mold to the water surface with the graduated scale and record the change as permeability or the amount of water in ml that percolates into and / or through the test specimen
75. … The stabilometer value is calculated as below: S = Ph D 22.2 Pv-Ph + 0.222 S = stabilometer value D = displacement on specimen Ph = horizontal pressure equal to stabilometer pressure gauge reading taken at the instant Pv is 2.76 Mpa [22.24 kN] total load Pv = Vertical pressure [typically 2.76 Mpa = 22.24 kN total load
76. Density & Voids Analysis Using the specific gravity of the test specimens and the maximum specific gravity of the paving mixture determine using ASTM D 2041 Compute the % air voids as Va = 100 x (Gmm-Gmb)/(Gmm) Where, Gmm = maximum sp gr of paving mixture = 100/ [(Ps/Gse or Gsb + Pb/Gb) Ps = aggregate content, % by total wt of mixture Gse = effective sp. gr of aggregate = (Pmm-Pb)/ [(Pmm/Gmm)- (Pb/Gb)]
77.
78. C = L W (0.2H+0.0176 H 2 ) Where, C = Cohesiometer value L = Weight of shots in gm W = Diameter or width of specimen in cm H = Height of specimen cm Using the specific gravity of the test specimens and the apparent specific gravity of aggregate the percent voids in the total mix is calculated
79. DESIGN CRITERIA BY HVEEM METHOD Light traffic = Design EAL < 10 4 Medium traffic = Design EAL b/w 10 4 and 10 6 Heavy traffic = Design EAL > 10 6 TEST VALUE CRITERIA LIGHT TRAFFIC MEDIUM TRAFFIC HEAVY TRAFFIC Stabilometer value, R > 30 > 35 > 37 Cohesiometer value, C > 50 > 50 > 50 Swell, mm < 0.762 < 0.762 < 0.762 Air void, % > 4 > 4 > 4
80.
81. Surface flushing is considered “heavy” (unacceptable) if there is sufficient free bitumen to cause surface pudding or specimen distortion after compaction (c) Select from step (2) the two highest bitumen contents that provide the specified minimum stabilometer value and enter them in step (3) (d) Select from step (3) the highest bitumen content that has at least 4.0% air voids and enter in step (4) (e) The bitumen content in step (4) is the design bitumen content. However, if the maximum bitumen content used in the design set step (1) is the bitumen content entered on step (4), additional specimens must be prpepared with increased bitumen content in 0.5% increments and a new design bitumen content determination should be made
82. PYRAMID USED IN DESIGN OF BITUMEN CONTENT Step 2 Specimens with no more than slight flushing Step 1 Design series Step 3 Specimens meeting minimum stability Step 4 maximum bitumen content with 4 or more % air voids
84. For evaluating the value of resistance value (R-value) of soil sugrade material, stabilometer is employed The compaction is done using a kneading compactor with 24.6 kg/cm 2 pressure, 100 times After the compaction, a load is applied at a rate of 907 kg/minute to record the exudation pressure required to force water out of the specimen Expansion pressure is also noted permitting the specimen to remain in water for 16 to 20 hours The stabilometer resistance R-value is determined by placing the specimen in the stabilometer and applying the lateral and vertical pressures as specified
85. The R-value of soil is calculated from the formula: R = 100 - 100 2.5 D 2 Pv Ph 1 1 Pv = vertical pressure applied (11.2 kg/cm 2 ) Ph = horizontal pressure transmitted at Pv = 11.2 kg/cm 2 D 2 = displacement of stabilometer fluid necessary to increase the horizontal pressure from 0.35 to 7 kg/cm 2 measured in number of revolutions of the calibrated pump handle