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The influence of superplasticizer (SP) on the early age drying shrinkage of cement paste with the same consistency was investigated. To conduct the test, which lasted for 72 hours, three paste mixtures were used for comparison. The 72 hours early age drying shrinkage staring from the initial setting time was measured by a clock gauge. The pore size distribution was measured by Mercury Intrusion Method. The surface tension of capillary simulation liquid and mass loss of paste were also measured. The experimental results showed that the addition of SP increased the early drying shrinkage greatly. The ratios of water evaporation and the total free water in mixtures added with SPs showed great differences. SPs fined the capillary pores of paste, and the volume of pore with diameter within 50 nm was well consistent with shrinkage rate. The addition of SPs did not raise the capillary liquid surface tension. It showed that with the volume of pore with diameter within 50 nm and the ratio of water evaporation and the total free water a tolerable shrinkage result of paste added with SP could be predicted, and the elastic modulus could have an influence on the early shrinkage. These results have never been proposed before.

参考文献

[1] M. Collepardi .Admixtures Used to Enhance Placing Characteristics of Concrete[J].Cement & concrete composites,1998(2/3):103-112.
[2] Ma Bao-guo;Wang Xin-gang;Liang Wen-quan .Study on early-age cracking of cement-based materials with superplasticizers[J].Construction and Building Materials,2007(11):2017-2022.
[3] Erika Holt .Contribution of mixture design to chemical and autogenous shrinkage of concrete at early ages[J].Cement and Concrete Research,2005(3):464-472.
[4] Etsuo Sakai;Takayuki Kasuga;Tomomi Sugiyama .Influence of superplasticizers on the hydration of cement and the pore structure of hardened cement[J].Cement and Concrete Research,2006(11):2049-2053.
[5] J. I. Escalante-Garcia .Nonevaporable water from neat OPC and replacement materials in composite cements hydrated at different temperatures[J].Cement and Concrete Research,2003(11):1883-1888.
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