This document discusses the components, classification, properties, workability, and strength testing of concrete. Concrete is made up of cement, coarse aggregate, fine aggregate, air, and water. It can be classified as hardened or fresh concrete. The properties of fresh concrete include workability, segregation, and bleeding, while hardened concrete properties include strength, impermeability, durability, and dimensional variations. Workability is tested using slump, compaction factor, and Vebe tests. Compressive strength of hardened concrete is tested using cube or cylinder tests.