Response of self-consolidating cement paste systems containing Acacia Nilotica Gum as an organic admixture

•Acacia Nilotica Gum increases the viscosity of SCPs, improving their stability.•AG improves thermal conductivity by entraining/entrapping air in SCPs.•AG degrades strength of SCPs, which is offset by cement replacement with SRMs.•AG modified systems can be used to avoid early buildup of heat of hydration.•AG improves the insulation properties and possibly freeze-thaw resistance of SCPs.

This research characterizes the gum obtained as a natural organic ooze-out from Acacia Nilotica trees, indigenously known as “Keekar”, through Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR) experimental techniques. It reports the response of self-consolidating paste systems (SCPs) containing Acacia Nilotica Gum (AG) in powdered form in ratios of 0.33%, 0.66% and 1% by weight of cement. The results are of interest to construction and civil engineering professionals and showed that AG enhanced the viscosity of SCPs which in turn improves their stability. Also, AG addition increased the water demand, setting times and early age expansion of SCPs while the heat of hydration, density and compressive strength got reduced. Reduction in density is attributed to incorporation of air voids and this may be exploited in energy efficient infills of buildings and possible improved freeze-thaw resistance. Most of the lost compressive strength due to AG incorporation was regained with the addition of Secondary Raw Materials (SRMs) including fly ash (FA) and limestone powder (LSP).