The effect of different viscosity modifying additives on the mechanical and flow properties of self-compacting mortars

Abstract

Some requirements are needed in the rheology design of special concretes such as self-compacting concrete, underwater concrete, shotcrete. For example, in the design of the desired concrete flow, some viscosity modifying agents (VMA) are used with various plasticizer additives. However, studies are needed to determine which of these additives used to design flow parameters is more appropriate. Herein, the mechanical and rheological effects of two commercially used VMAs on self-compacting mortars were investigated. For this purpose, compressive-flexural strength tests and mini-slump, mini-V funnel tests were conducted to determine the effects of welan gum (WG), and xanthan gum (XG) included in the mixtures at various ratios (0.01-0.1%) by weight of cement. The study supported by FE-SEM analysis concluded that WS had a positive effect on mechanical behavior, while XG had a negative effect, but XG was more effective on flow properties than WG.