Influence of subsequent curing on water sorptivity and pore structure of steam-cured concrete  

作　　者：贺智敏 龙广成 谢友均 

机构地区：[1]School of Civil Engineering,Central South University [2]School of Civil Engineering,Ningbo University

出　　处：《Journal of Central South University》2012年第4期1155-1162,共8页中南大学学报（英文版）

基　　金：Project(2008G031-18) supported by the Ministry of Railway Science and Technology Research Foundation of China;Project(2010R50034) supported by the Key Science and Technology Innovation Team Program of Zhejiang Province, China;Project(2010QZZD018) supported by Leading-edge Research Program of Central South University,China

摘　　要：Steam-cured condition is found to cause larger porosity and worse properties of concrete compared with normal curing condition. For the sake of seeking effective measurements to eliminate this bad effect of steam-cured condition on concrete, the water sorptivity and pore structure of steam-cured concretes exposed to different subsequent curing conditions were investigated after steam-curing treatment. The capillary absorption coefficient and porosity of the corresponding concretes were analyzed, and their mechanisms were also discussed. The results indicate that water sorptivity and pore structure of steam-cured concrete are greatly influenced by the curing condition used in subsequent ages. Exposure steam-cured concrete to air condition has an obviously bad effect on its properties and microstructures. Adopting subsequent curing of immersing steam-cured concrete into about 20℃ water after steam curing period can significantly decrease its capillary absorption coefficient and porosity. Steam-cured concrete with 7 d water curing has minimum capillary absorption coefficient and total porosity. Its water sorptivity is decreased by 23% compared with standard curing concrete and the porosity is 9.6% lower. Moreover, the corresponding gradient of water sorptivity and porosity of steam-cured concrete both decrease, thus mictostructure of concrete becomes more homogeneous.Steam-cured condition is found to cause larger porosity and worse properties of concrete compared with normal curing condition.For the sake of seeking effective measurements to eliminate this bad effect of steam-cured condition on concrete,the water sorptivity and pore structure of steam-cured concretes exposed to different subsequent curing conditions were investigated after steam-curing treatment.The capillary absorption coefficient and porosity of the corresponding concretes were analyzed,and their mechanisms were also discussed.The results indicate that water sorptivity and pore structure of steam-cured concrete are greatly influenced by the curing condition used in subsequent ages.Exposure steam-cured concrete to air condition has an obviously bad effect on its properties and microstructures.Adopting subsequent curing of immersing steam-cured concrete into about 20 °C water after steam curing period can significantly decrease its capillary absorption coefficient and porosity.Steam-cured concrete with 7 d water curing has minimum capillary absorption coefficient and total porosity.Its water sorptivity is decreased by 23% compared with standard curing concrete and the porosity is 9.6% lower.Moreover,the corresponding gradient of water sorptivity and porosity of steam-cured concrete both decrease,thus microstructure of concrete becomes more homogeneous.

关 键 词：steam-cured concrete water sorptivity pore structure curing condition 

分 类 号：TU528[建筑科学—建筑技术科学]