Effects of water-cement ratio and superplasticizer dosage on mechanical and microstructure formation of styrene-butyl acrylate copolymer concrete

Abstract

The interaction between nanoparticles of Styrene-Butyl Acrylate latex and cement particles with various water-cement and superplasticizers-cement ratios during the hydration process has been investigated to achieve the best chemical combination of the materials for enhancing the mechanical properties and workability of the concrete. Analyses and experimental results have shown that the adhesive properties of Styrene Butyl Acrylate (SBA) copolymer latex along with an appropriate percentage of superplasticizers promote the performances of interlayer bonding of concrete. The compressive, splitting, and flexural strengths of specimens have been studied and the formations of the microstructures by the implementation of FESEM, EDX, XRD, FTIR, TEM, and DLS, have been analyzed. The obtained results show the considerable enhancement in the structural behavior of the copolymer-modified concrete in comparison with the control samples by creating cohesive microstructures in the presence of the copolymer. Appropriate water-cement ratio and superplasticizers were selected to study the efficient distribution of the copolymer nanoparticles throughout the cement matrix by the implementation of the FESEM and EDX analyses. The constructed polymer bridges and films between layers of Ca(OH)2 crystals have yielded to the formation of an internal cohesive strong microstructure. Also, XRD and FTIR results indicate that the stability and formation of ettringite have been enhanced by the development of calcium aluminate reaction with SBA copolymer. In the cement pore solution, the chemical interaction between nanoparticles, and Ca2+, the copolymer nanoparticles adsorption on cement paste were applied and the enhanced microstructure of the concrete was obtained.