High density and high strength cement-based mortar by modification with epoxy resin emulsion

摘要

The HDHS (high dense and high strength) cement-based paste and mortar were designed based on the densest packing model determined by Dinger-Funk equation. The HDHS cement-based paste was modified by adding different contents of epoxy resin emulsion (ERE) and curing agent (CA). The influences of the degree of packing densification on the pore structure and mechanical strength of the HDHS cement-based paste were investigated. The hydration process of the modified HDHS cement-based paste, pore structure and mechanical properties of the modified HDHS cement-based mortar were researched. The results show that the compressive strength of the HDHS cement-based paste firstly increases and then decreases with the decrease of the Euclidean distance. The compressive strength reaches the maximum value of 123.4 MPa while the porosity is 10.15% at the Euclidean distance of 64.30. It is also found that the hydration of the modified HDHS cement-based paste can be divided into four stages based on the normalized heat flow. The influence of the polymer (ERE and CA) on the hydration is different at every stage. The adding of polymer reduces the compressive and flexural strength but increases the bonding strength of modified HDHS cement-based mortar. When the P/C (polymer/cement-based powders, wt.%) ratio is 12.5% and the CA/ERE ratio (wt.%) is 0.5, the compressive strength is still above 75 MPa and the bonding strength obtains the maximum of 2.65 MPa while the porosity is just 7.74%. (C) 2018 Elsevier Ltd. All rights reserved.