Enhancing sustainability in concrete production: A novel compression casting technique for optimizing cement usage

Abstract

Cement manufacturing is a major source of carbon dioxide (CO2) emissions. This study focuses on using the compression casting method to reduce the cement content in concrete manufacturing. No such work is present in the existing literature. For this purpose, five concrete mix designs of normal concrete (NC) and compression cast concrete (CCC), targeting compressive strengths of 50 MPa, 30 MPa, 25 MPa, 20 MPa, and 15 MPa, were considered. Moreover, considering the reduced cement content, five additional concrete mixes of NC and CCC were also prepared. All concrete specimens were tested in axial compression to study the stress-strain behavior. The findings reveal that CCC specimens exhibit higher stress-strain curves compared to NC specimens for the same mix design. The post-peak behavior of CCC specimens is observed to be more brittle than that of NC specimens. The reduction in density, compressive strength, and elastic modulus with the increase in the water-to-cement (w/c) ratio is more pronounced in NC specimens than in CCC specimens. The results indicate that the compression casting method allows for a reduction in cement content by approximately 25–50 % while achieving the desired compressive strengths, ranging from 30 to 50 MPa. A correlation is clearly demonstrated to determine the potential cement savings for specific concrete strengths. In summary, adopting compression casting technology effectively lowers cement requirements, leading to cost and carbon emission reductions in the construction sector and significantly enhancing the durability of concrete materials.