This paper deals with the effect of silica fume and styrene-butadiene latex (SBR) on the microstructure of the interfacial transition zone (ITZ) between Portland cement paste and lightweight aggregates (expanded clay). Scanning Electron Microscope (SEM) equipped with and energy dispersive X‑ray analysis system (EDS) was used to determine the interfacial transition zone thickness. In the plain concrete a marked ITZ around the aggregate particles (30mum) was observed, while in concretes with silica fume or latex SBR the ITZ was less pronounced (20-25mum). However, the better results were observed in concretes with silica fume and latex SBR (8-15mum).
Lightweight aggregate concrete; expanded clay; ITZ; silica fume; SBR latex; SEM
