Environmentally friendly viscosity-modifying agent for self-compacting mortar: Cladophora sp. cellulose nanofibres

Abstract

Admixtures such as viscosity modifying agents and mineral admixtures could be used to regulate the rheological behaviour of the self-compacting concrete mixture. Herein, cellulose nanofibres obtained from Cladophora sp., a bio-waste that pollutes water bodies and threatens the ecosystem, were used to provide appropriate plastic viscosity in self-compacting mortars instead of a traditional viscosity modifying agent known as Welan gum (WG). Within the scope of the study, mini-slump, mini-V funnel, viscosity tests, compressive-flexural strength tests and FE-SEM analyses were performed on the mortar and cement paste specimens prepared. According to the rheological results, increases of up to 93% in plastic viscosity and increases of up to 10 times in yield stress were observed in the CCF-used specimens. On the other hand, increases in yield stress up to seven times and in plastic viscosity up to 37% were determined in the specimens with WG added. Moreover, as a result of mechanical tests, increases of up to 15% in compressive strength and up to 7% increases in flexural strength were observed in the WG-added specimens. While the decreases of up to 4% in compressive strength were observed, increases of up to 12% in flexural strength were detected in the CCF-added specimens.