Artificial lightweight aggregates

Artificial coarse aggregates These are mainly slag and expanded shale, and are frequently used to produce lightweight concrete. They are the by-product of other manufacturing processes, such as blast-furnace slag or expanded shale, or pumice for lightweight concrete. 

In ordinary concretes, Portland cement combined with sand and water is used as the matrix or the binder. The inclusions are composed of coarse aggregate made of natural stones with specially selected grain fractions. Under the term concrete-like composites falls a large group of materials which, with respect to ordinary concretes, all constituents may be replaced by other materials. Not only are Portland cements used as binders but also for other types of hydraulic cements, bitumens, polymers and resins. The natural stone grains are replaced by various kinds of artificial lightweight... 

Natural lightweight aggregates (LWA) are mostly obtained from volcanic rocks and their application is of local character. Artificial aggregates are produced in several countries for three main reasons ... 

Lightweight artificial aggregates including used paper... 

By mixing a large amount of fly-ash from coal fire electric power plants with a small quantity of Portland cement and water, Yamamoto et al. developed artificial aggregates (coal-ash sand) [1], [2], Various types of coal-ash sand can be made by changing the mix proportion, turning speed of the mixer and also adding some fibers. Lightweight... 

---