The effects of reduced paste volume in Portland limestone cement concrete

Abstract

A high cementitious content in Portland cement concrete can cause early cracking of concrete. This study investigated the effects of minimized paste volume in structural concrete incorporating Portland limestone cement and Blended Aggregates (BA) Technique. Comparisons were made on the effects of different types of cement and paste volume of concrete. The results indicate that Type IL cement which contains 14% limestone powder has comparable performance as that of the concrete made with Type I/II cement. Based on the results of laboratory testing and numerical modeling, the performance of concrete with different paste volumes was evaluated. The paste volume of concrete could be reduced to around 27% without affecting its properties. The paste volume of concrete incorporating BA technique could be further reduced to 24%. The concrete mixes incorporating BA technique were noted to have better potential performance as the reference concrete. Using Type IL cement and BA technique can effectively reduce the initial cost and carbon dioxide emission in structural concrete without loss of performance of the concrete.