Properties of Concrete with High-Volume Limestone Powder under Low Temperature Conditions

Abstract

This paper studies the effects of high-volume composite mineral admixture made of limestone powder and low-quality fly ash on the properties of concrete,and studies the form of attack of cement-based material made of limestone powder at low water-binder ratio under low-temperature sulfate environment.Through experiments, this paper makes clear the workability of fresh concrete and analyzes the law of strength development of concrete. The experimental results indicate that the concrete with high-volume limestone powder as composite mineral admixture has good fresh properties; due to low water consumption per unit volume, medium-and-high-strength concrete can be prepared. As new type concrete mineral admixture, the composite mineral admixture made of limestone powder and low-quality fly ash will play an active role in the sustainable development of concrete industry. After the specimen with the water-binder ratio of less than 0.4 and the limestone powder volume of greater than 20% is soaked in 10% magnesium sulfate solution at low temperature at the age of 200d, gypsum attack-led destruction is caused to the concrete test cube, without thaumasite sulfate attack.