Compressive Behavior of Concrete Incorporating Clay Brick Fines Added by Paste Replacement Method

Abstract

Urbanization in China has been producing a huge quantity of construction and demolition waste, of which clay brick waste accounts for a substantial proportion. For reducing waste disposal, the clay brick waste has been reutilized in concrete production by employing the aggregate replacement or cement replacement methods. However, with these methods, the clay brick waste tends to have an adverse effect on the mechanical performance of the concrete produced, especially at high replacement rate. Herein, a novel method, the paste replacement method (PRM), was applied, in which clay brick fines (CBF) were made by crushing and grinding clay brick waste and reused to partially replace the cementitious paste (water + cementitious materials). The compressive behavior of the concrete produced was tested. The results showed that the CBF added based on PRM increased compressive strength and elastic modulus, caused little change to Poisson’s ratio, and decreased the lateral dilation of the concrete. More importantly, it reduced the cement content by up to 29.4% and the cement factor (cement content to strength ratio) by up to 62.3%.