Investigation on microstructural and compressive strength characteristics of a novel bio-admixture comprising Cassava Starch-Xanthan gum with cement mortar for building application

ABSTRACT

Developing high-performing bio adhesives for enhancing the bonding strength of cement-based materials is highly desirable as they improve workability, corrosion resistance and durability of the concrete. The present effort aims at stemming a novel bio admixture comprising agricultural products Cassava starch and Xanthan gum as well examines the effect of incorporation of it into the cement. The composition of xanthan gum is varied in the starch mixture systematically in the ratios namely 1:0.25, 1:0.5 and 1:0.75. As-prepared bio admixtures are characterized through Fourier Transform Infra-Red spectroscopy, X-Ray Diffraction, Thermo Gravimetric Analysis, contact angle and Scanning Electron Microscopy-Energy Dispersive X-ray studies. These results demonstrated that presence of optimal amount of xanthan gum facilitates the binding nature of starch and promotes better bond strength as it significantly improved the bonding capacity as well as hydrophilic nature of starch thereby augmenting the bonding strength when used in cement mortar. The bio admixture filler material occupied the voids between the mortar matrix, thus reducing the porosity. The beneficial effect of as-prepared bio admixture has been reflected in the compressive strength that has been enhanced by 16.6% when optimized quantity (1.5 wt.%) of the bio admixture is added to the mortar.

Keywords
Biopolymers; Bio-Based Admixture; Starch; Xanthan Gum; Natural Adhesive; Improved Mechanical Strength