Experimental studies on durability performances of ultra-lightweight low-carbon LC3 cement composites against chloride ingression and carbonation

Abstract

<p>This study aims to experimentally evaluate the durability performances of a novel ultra-lightweight low-carbon calcined clay cement composite (ULCC-LC³) for use in sustainable concrete. The durability performances of ULCC-LC3 were characterized by conducting rapid chloride migration tests, accelerated carbonation tests, MIP and <a href="https://www.sciencedirect.com/topics/materials-science/thermogravimetric-analysis" title="Learn more about TGA from ScienceDirect's AI-generated Topic Pages">TGA</a> tests. Results indicate that using LC³ is beneficial for improving chloride resistance of ULCC-LC³ due to refined pore structure while the carbonation resistance performance can be reduced due to less content of cement and pozzolanic reaction. The MIP tests showed the effect of using LC³ on microstructure of ULCC without carbonation was reducing the volume of porosity coarser than gel pores while increasing the volume of gel pores. The <a href="https://www.sciencedirect.com/topics/engineering/cementitious-matrix" title="Learn more about cementitious matrix from ScienceDirect's AI-generated Topic Pages">cementitious matrix</a> of mixes with LC³ was significantly densified by carbonation. The carbon emission and energy consumption were significantly decreased by 41.9% and 26.7% respectively by replacing cement with calcined clay and limestone. However, it was noted that the use of superplasticizer increased the energy consumption especially for the mix with LC3.<br></p>