Concreto leve estrutural: influência da argila expandida na microestrutura da zona de transi??o pasta/agregado

摘要

This paper presents the results of a study on the effect of expanded clay on the microstructure of the interfacial transition zone (ITZ) between Portland cement paste and aggregates. A scanning electron microscope (SEM) equipped with an energy dispersive X-ray analysis system (EDX) was used to determine the ITZ thickness. In plain concrete a marked ITZ around the aggregate particles (55 ? m) was observed, while in concretes with expanded clay, the ITZ was less pronounced (30 ? m). It was also verified that the ITZ of concrete with expanded clay had lower levels of porosity and calcium hydroxide than that observed in plain concrete.