Sustainable cementitious composites with 30% porosity and a compressive strength of 30 MPa

Abstract

Many researchers have tried to increase the porosity of cement-based materials for different applications, but a limitation of the existing technology is that it is difficult to achieve more than 30 MPa compressive strength for materials that have a porosity of more than 30%. To overcome the decrease in compressive strength, some studies have developed fly ash-based foam geopolymers with silica fume as the foaming agent. However, this material requires heat curing and has a rapid setting problem. Therefore, the present study aimed to develop a material that can maintain compressive strength above 30 MPa while increasing the porosity to 30%, solving the curing problem, and extending the setting time. This study proposes a sustainable material design based on the concept of limestone calcined clay cement (LC3) and a fly ash–based foamed geopolymer. The results show that the proposed material can generate porosity of more than 30% and maintain a compressive strength above 30 MPa while the rapid setting and curing limitation problems are solved. Moreover, the developed cementitious composite was proven to reduce CO2 emissions by 31.91% compared to conventional construction materials, which highlights that the newly developed material can be classified as a low carbon construction material.