摘要
活性粉末混凝土(reactive powder concrete,RPC)作为一种具有高强度、良好耐久性的新型水泥基复合材料,具有广泛的应用前景。为了研究原材料选取、养护制度及养护龄期等因素对RPC立方体力学性能的影响,进行了这3个影响因素的交叉对照试验。试验结果表明:选用粒径为2 mm左右的石英砂更有利于提高RPC的密实度;选用低C 3A(铝酸三钙)含量的水泥有利于提升混凝土的抗压强度及抗折强度;直径为12μm,长为4 mm的PVA纤维(即白色絮状聚乙烯醇纤维,white flocculant polyvinyl alcohol fiber)体积掺量为1%时,能有效提高RPC的基本力学性能;80℃的热水养护能增强混凝土中粉煤灰活性,提高早期水化程度,使RPC抗压及抗折强度在3 d龄期内快速提升;RPC强度与养护龄期呈正相关。该研究结果为后续RPC的相关研究和RPC的优化提供了一定的参考。
RPC(reactive powder concrete)as a new type of cement matrix composite material with ultra-high strength and high durability,boasts a widespread application prospect.In order to study the effects of raw material selection,curing system and curing age on the mechanical properties of RPC cube,cross-control tests were conducted for these three influencing factors.The experimental results show that the quartz sand with particle size of about 2 mm is more conducive to RPC compaction;the cement with low C 3A(tricalcium aluminate)content is beneficial to improve the compressive and bending strength of concrete;when the fiber volume content of PVA(i.e.white flocculant polyvinyl alcohol fiber)with 12μm in diameter and 4 mm in length being 1%,the basic mechanical properties of RPC could be effectively improved;the hot-water curing of 80℃can enhance the activity of fly ash in concrete,improve the hydration degree at the early stage,and facilitate the rapid growth of RPC compressive and bending strength within 3 d age;RPC strength is positively correlated with curing age.The results of this study provide a certain reference value for the follow-up research and RPC optimization.
作者
徐锦超
薛文
周文建
卢凯
XU Jinchao;XUE Wen;ZHOU Wenjian;LU Kai(School of Civil Engineering and Architecture,Zhejiang University ofScience and Technology,Hangzhou 310023,Zhejiang,China)
出处
《浙江科技学院学报》
CAS
2020年第6期578-582,共5页
Journal of Zhejiang University of Science and Technology
基金
国家自然科学基金项目(51608484)。
