Investigating effects of comprehensive optimization of cementitious materials on early residual expansion deformation and long-term performance and microstructure of steam-cured concrete

This article primarily focuses on optimizing the composition of cementitious materials, such as fly ash, ground granulated blast furnace slag, nano-silica, silica fume, and superabsorbent polymers, to investigate their effectiveness in mitigating early residual expansion deformation in steam-cured concrete. Additionally, it evaluates the long-term performance of steam-cured concrete samples incorporating these cementitious materials. The article concluded that replacing 30% of the cement in the concrete mix with 20% fly ash and 10% slag, along with the additional inclusion of 0.2% super absorbent polymers, yields the best results in mitigating the above deformation and enhancing the performance of steam-cured concrete. The recommended mix proportion suggested in the article for 1 cubic meter of concrete includes 315 kg of cement, 90 kg of fly ash, 45 kg of slag, 0.9 kg of super absorbent polymer, 660 kg of sand, 1210 kg of limestone aggregate, 135 kg of water, and 4 kg of superplasticizer. This approach also prevents the reduction or insufficient development of the later-stage mechanical properties of steam-cured concrete and improves its pore structure. By focusing on optimizing the cementitious system of steam-cured concrete, this article provides theoretical and technical support for the preparation of high-performance prefabricated steam-cured concrete components.