The effect of superfine composite admixture on the mechanical properties,volume stability and pore structure of ce-ment-based cementing materials was studied by simulating the high ground temperature environment at high altitude in the labora-tory.The optimal dosage of superfine composite admixture at different temperatures was summarized and analyzed.The reaction mechanism of superfine composite admixture in cementing system at optimal yield was analyzed by combining microscopic means.The results show that the addition of superfine composite admixture can improve the mechanical properties of cement-based ce-menting materials.With the extension of curing age,the compressive strength of the optimal admixture can be increased by 10％～21％,and the strength increases slowly at high temperature.The shrinkage rate of the superfine composite admixture system is bet-ter than that of the pure cement system,and can keep the system stable under proper high temperature environment,but the volume shrinkage rate of the system will increase when the curing temperature is 80 ℃.The superfine composite admixture can reduce the average pore size of the system,improve the compactness,and generate more hydrated products such as ettringite and hydrated calci-um silicate.
关键词
高地温/超细复合掺合料/水泥基胶凝材料/力学性能/体积稳定性/微观形貌
Key words
high ground temperature/superfine composite admixture/cement-based cementing materials/mechanical properties/volume stability/micro-morphology
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