掺C-S-H纳米晶核混凝土的早期强度与收缩性能  

Early Mechanical and Shrinkage Properties of C-S-H Nanocrystalline Nuclei-modified Concrete

作　　者：何羽乔 李鑫 周孝军[2] 刘明 丁庆军[4] HE Yu-qiao;LI Xin;ZHOU Xiao-jun;LIU Ming;DING Qing-jun(Chengdu Institute of Product Quality Inspection Co,Ltd,Chengdu 610100,China;School of Architecture and Civil Engineering,Xihua University,Chengdu 610039,China;China Construction West Construction Building Materials Research Institute Co,Ltd,Chengdu 610000,China;School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]成都产品质量检验研究院有限责任公司,成都610100 [2]西华大学建筑与土木工程学院,成都610039 [3]中建西部建设建材科学研究院有限公司,成都610000 [4]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《建材世界》2024年第3期38-41,45,共5页The World of Building Materials

基　　金：国家自然科学基金(U21A20149、52008340).

摘　　要：C-S-H纳米晶核可促进水泥水化,提升混凝土早期强度发展,有利于预应力混凝土结构提前进行预应力张拉。采用C-S-H纳米晶核早强剂制备早强低收缩混凝土,探究了C-S-H纳米晶核对混凝土早期强度、收缩变形性能及其发展规律的影响。结果表明:养护温度的提升有利于纳米晶核早强性能的发挥;混凝土早期强度随纳米晶核掺量增加呈先增加后稳定的趋势,当掺量为4%时混凝土的早强效果最佳,且不影响后期强度发展。纳米晶核的早强效果优于其他传统早强剂,传统早强剂6 h强度提升幅度为10%~20%,纳米晶核强度提升幅度可达105.2%,早强效果明显。同时,掺纳米晶核混凝土的体积变形与强度发展同步,主要集中在早期,前3 d收缩率占28 d龄期时收缩率的67%,且掺入纳米晶核试件的28 d收缩率为空白组的75%,体积稳定性好,可实现预应力提前张拉。C-S-H nanocrystalline nuclei can promote cement hydration,improve the early strength development of concrete,and help prestressed concrete structures to prestress tension in advance.The effects of C-S-H nanocrystalline nuclei on the early strength,shrinkage and deformation properties of concrete and its development were studied.The experimental results show that the increase of curing temperature is beneficial to the early strength performance of nanocrystalline nuclei.The early strength of concrete increases first and then stabilizes with the increase of nanocrystalline nucleus content.The early strength effect of concrete is the best when the content is 4%,and the later strength development is not affected.The early strength effect of nanocrystalline nucleus is better than that of other traditional early strength agents.The strength increase of traditional early strength agent 6 h is 10%~20%,and the strength increase of nanocrystalline nucleus can reach 105.2%,and the early strength effect is obvious.At the same time,the volume deformation and strength development of nanocrystalline core-doped concrete are synchronized,mainly concentrated in the early stage,the pre-3 d shrinkage rate accounts for 67%of the shrinkage rate at 28 d age,and the 28d shrinkage rate of the nanocrystalline core-doped specimen is 75%of the blank group,and the volume stability is good,and the prestressed tension can be realized.

关 键 词：纳米晶核 混凝土 早期强度 收缩变形 

分 类 号：TU528[建筑科学—建筑技术科学]