ABSTRACT
The subject of this chapter is the aggregates. Aggregates are the skeleton of concrete. So, their effect on the properties of fresh and hardened concrete is very much. In the first part of this chapter, the most important natural rocks in the nature introduced and the probability of their usage as the aggregates for concrete are discussed. The production process of aggregates and natural or crushed aggregates and their properties are the next subjects mentioned in this chapter.
The next part is about the concrete density and the effect of aggregates type on the density of concrete. The production of normal weight, heavy weight and light weight concrete, and use of heavy weight and light weight aggregates are also mentioned.
The subject of aggregates size and the introduction of the coarse and fine aggregates is the next issue of this chapter. Choosing of the maximum size of coarse aggregates is the other important subject discussed.
The last part of this chapter is about the quality control of aggregates. The most important tests for the assurance of the quality of aggregates before using them in concrete production are described. Abrasion resistance test, sieve analysis test of coarse and fine aggregates, density and water absorption of aggregates, fillers and passing by sieve No. 200, and harmful materials in aggregates are the tests described in this chapter.
