Sustainability on durability of self compacting concrete from C&D waste by improving porosity and hydrated compounds: A microstructural investigation

Abstract

This research article is on establishment of sustainability with reference to the durability properties of self compacted recycled aggregate concrete (SCRAC) by improving porosity and hydrated compounds in concrete. Partial replacement of fly ash by silica fume and virgin concrete aggregate (VCA) by recycled concrete aggregate (RCA) are taken for preparing the SCRAC by adopting suitable mix design method along with proposed two stage mixing approach (TSMAsfc). This two stage mixing approach makes significant improvement in durability properties as the slurry of cement and silica fume fills the pores and cracks and makes interfacial transition zones (ITZs) stronger. Microstructure analysis using the electron probe micro analyser (EPMA) is carried out to justify the reason of improvement of durability properties of SCRAC. Image analysis of backscattered secondary electron (BSE) images are carried out for the quantitative analysis of different compounds (C-S-H, UH, CH and pores) at the ITZ. Image analysis and EPMA analysis confirmed that the ITZ gets stronger by adopting two stage mixing approaches.