Effect of pore modifiers on physical and mechanical properties of high-performance cement mortar

Abstract

Two different pore modifiers (PM), artificial pozzolan (AP) and modified aluminum salt (MA), were introduced into the composition of a High Performance Cement Mortar (HPCM). The chemical compositions of raw materials, ordinary Portland cement (OPC), sea sand, AP, and MA were identified by X-Ray Fluorescence spectrometry (XRF). The hydration kinetics resulting from each PM added to the HPCM was investigated by the relevance of hydration temperature. The mechanical properties such as compressive strength, dynamic modulus of rupture, and dynamic modulus of elasticity were measured as well as water absorption and density. Additionally, Scanning Electron Microscope (SEM) and Brunauer-Emmett-Teller (BET) were used to reveal the beneficial effects of appropriate PM through the microstructure, pore size distribution and specific surface area. Experimental results showed that the PM increased the hydration temperature, resulting in the generation of stress at early stages throughout the HPCM structure. This stress caused the formation of micropores, which increased water absorption, decreased density, and enhanced the structural integrity