Lightweight aggregate concrete with an open structure and a porous matrix with an improved ratio of compressive strength to dry density

摘要

In this study the combination of foam concrete and lightweight aggregates was investigated in order to develop a lightweight aggregate concrete with open structure and porous matrix (LACPM). For this purpose the recipe of a foam concrete was combined with the following lightweight aggregates: pumice, expanded glass, foam glass, expanded clay, and expanded perlite. The successfully produced concretes showed a homogenous microscopic structure and arrangement of the aggregates. A nanoscale view on the texture of the aggregates helped to understand the different embedding in the foamed cement paste matrix and their interaction at the interface. The best embedding was shown by pumice, expanded perlite and expanded clay. The ratio between compressive strength and dry density as well as the ratio between compressive strength and thermal conductivity has been improved respectively. Compared to conventional foam concrete an improvement of the compressive strength by almost 40 % was measured. The same applied for the drying shrinkage, the change in length was reduced by the addition of the aggregates to almost 80 %. (C) 2020 Elsevier Ltd. All rights reserved.