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Abstract The change rule of water requirement of cement standard consistency, cement setting time, 28 d drying shrinkage of cement and mortar strength with different content of sulphoaluminate-based strength-promoting and shrinkage-reducing admixture (SP-SRA) in different kinds of cement such as P·I cement and P·O cement were studied. Effect of different content of SP-SRA on hydration heat, phase and micromorphology of hydration products of P·I cement were analyzed. The results showed that the setting time and 28 d drying shrinkage of cement have evidently decreased and both the strength and the early hydration rate were increased as increasing of content of SP-SRA. The results obtained from XRD and DSC have proven that SP-SRA accelerate the formation of AFt. The results of MIP showed that the quantity of little pores in cement mortar were increased, which indicates that the hydration products such as AFt filled the pore space of cement stone, which results in decreasing of the number of large pores and increasing of the number of little pores. The cement stone was denser, and its strength increased. The expansion of AFt compensates the partial shrinkage, so that the drying shrinkage of cement with SP-SRA was reduced.
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Published: 04 December 2018
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2018, Vol. 0 
