Title: Self-Consolidating Paste Systems Containing Acacia Nilotica Gum Powder
Author(s): Syed Ali Rizwan, Sana Gul, and Thomas A. Bier
Publication: Materials Journal
Appears on pages(s): 5-14
Keywords: acacia nilotica gum powder; characterization; self-consolidating paste systems
The authors have used different types of acacia gum powders in self-consolidating paste systems. The response of self-consolidating paste (SCP) systems modified with a natural organic admixture—acacia nilotica gum (AN) powder—in varying dosages at a constant water-binder ratio (w/b) of 27% is reported to address missing links and provides in-depth information to readers. Some comparative information with a similar, previously published work using a typical AN gum powder content of 0.66% at its water demand of 32.5% in SCP systems is also given to explain the role of mixing water content on various properties of self-consolidating cementitious
systems (SCCs). Five SCP formulations at varying dosages of AN gum powder were prepared, with or without cement replacement by secondary raw materials (SRMs) including fly ash and limestone powder. These formulations were tested in both fresh and hardened states for parameters such as high-range water-reducing admixture (HRWRA) demand, flow characteristics, compressive strengths, total linear early shrinkage, thermal conductivity, washout mass loss, density, and air content of the SCP systems. The role of mixing-water content was found to be very significant in terms of fresh and hardened properties of SCPs. The results revealed retarding behavior of SCP systems containing AN gum powder, slight offset able reduction in compressive strength at maximum recommended dose of AN gum powder, reduced thermal conductivity, reduced washout mass loss, and increased viscosity. Self-consolidating cementitious systems (SCCs) incorporating the recommended AN gum powder content can be used in situations such as mass concrete works, hot weather concrete, freezing-and-thawing environments, and to create energy-efficient buildings with reduced shrinkage.