Affect of lightweight aggregate to early age cracking in concrete

Abstract

Concrete is often sensitive to cracking, which could be the result of early age shrinkage. Cracks can cause the corrosion of steel reinforcements and reduce the lifetime of concrete structures. Altogether crack tendency of concrete can be influenced by many parameters in the concrete mixture. Laboratory tests have been carried out according to the Austrian FRC technical specification, in particular with regard to early age shrinkage cracking. Seven different, commonly used lightweight aggregate types were used made from expanded glass, expanded clay, expanded perlite, polystyrene and crushed brick. In this paper, the relationship between the water absorption capacity and early age shrinkage cracking tendency was tested. In the laboratory compressive strength was also tested. In case of every aggregate type, the relationship between the absorbed water and cracking tendency was linear.