Porous aggregate strength and its influence on lightweight concrete strength

The stress strength of structural concrete made from natural aggregates depends on strength and modulus of elasticity of aggregate grains, shape of grains, on curve of granularity and on hard-set cement paste strength. The compressive strength of lightweight structural concrete with porous aggregates depends not only on the hard-set binding agent strength but both on the aggregate grains strength and the aggregate its volume in concrete mixture. Lightweight porous aggregate aggloporite was used for experimental test. Aggloporite is an artificial porous aggregate made from fly ash, clay and coal dust. Porous surface of aggloporite grains enables the fine cement particles with the water to penetrate into the surface pores at mixing, which results in strengthening of aggloporite grain surface in the course of cement hydration. The results of experimental tests of the relations between the LWSC strength, aggloporite grain strength and the cohesion strength affected on porous surface of aggloporite grain with the products of hydrating cement paste is presented.