Experimental investigation on the effect of incorporating nanomaterials on some properties of self-compacting cementitious mortar

Abstract

Currently, there is a need to reduce wastes as much as possible in order to develop the concept of sustainability. Self-compaction mortar is one of the most important materials that used in the repair and rehabilitation works of damaged concrete structures. The goal of this study was to investigate the influences of nano TiO2 and nano calcined clay as a sustainable material on fresh and hardened properties of self-compacting mortar. Investigations were carried out to assess the flowrate of self-compacting mortar using the mini flow table and mini-V-funnel tests. The hardened properties were: compressive strength, flexural strength, dry density, water absorption in addition to microstructural properties (as determined by Scanning Electron Microscopy; SEM). Results showed that the addition of nano TiO2 and nano calcined clay was of importance in all properties investigated, by increasing compressive strength by 13, 20 and 22 % for NCC, and by 16, 25 and 29 % for TiO2 respectively at 28-days. According to SEM micrographs, part of the new born CSH crystals was found to be diffused into the matrix pores and were found to densify the interfacial transition zones which caused tendencies toward increased the ultimate strength. So, black pores were filled with extra hydration products and hence, increasing the healing ability of microcracks associated with strength enhancement.