膨胀剂对自密实钢管核心混凝土变形的影响  

Effect of expansive agent on core concrete shrinkage of self- compacting concrete filled steel tube

作　　者：方爱斌 叶燕华[1,2] 姚荣[1,3] 杜艳静[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京211800 [2]江苏省绿色建筑工程技术研究中心,江苏南京210009 [3]扬州科技学院,江苏扬州225009

出　　处：《混凝土》2016年第6期77-79,83,共4页Concrete

基　　金：国家自然科学基金项目(51178218)

摘　　要：为满足工程中钢管混凝土施工技术和经济效益的需要,将绿色高性能的自密实混凝土取代普通混凝土应用到钢管混凝土中。钢管中核心混凝土的收缩关系到整体的受力性能,为研究钢管混凝土中核心混凝土的收缩特性,制作了8个圆钢管自密实混凝土试件来进行收缩试验,探讨分析了膨胀剂掺量对试件收缩的影响。研究结果表明：钢管自密实混凝土中核心混凝土的收缩变形要远小于普通混凝土的收缩变形;掺入膨胀剂可以减小钢管混凝土的早期纵横向变形;适量掺入膨胀剂可以减小核心混凝土的收缩变形和钢管壁的环向变形,但过量掺入膨胀剂会增大钢管壁的环向膨胀率;对于钢管自密实混凝土,膨胀剂的最佳掺量在5%~10%之间,而膨胀剂的掺入量与收缩之间的关系十分敏感,建议实际应用中最佳掺量尽量精确到1%。In order to meet the needs of engineering in steel pipe concrete construction technology and economic benefits,will use the green high performance self compacting concrete replace ordinary concrete applied in concrete filled steel tubes.Shrinkage of concrete filled steel tubes are related to the overall mechanical performance,in order to study the shrinkage of core concrete in steel tube,the 8 round of self compacting concrete filled steel tubes contraction test was carried out, the essay discusses the effect of shrinkage of its expan- sive agent.The results show that the core concrete of steel tube in shrinkage deformation is far less than ordinary concrete shrinkage defor- mation.Expansive admixture can reduce the steel tubes self compacting concrete early vertical deformation.The right amount of expansion agent can reduce the shrinkage and circumferential deformation of the core concrete, but excessive expansive admixture will increase steel pipe wall circumferential expansion rate.For self compacting concrete filled steel tube ,the best dosage of expansive agent in 5%-10% ,re- lations between the incorporation of expansion agent and the shrinkage is very sensitive, suggestions for practical application the best dosage as accurate to 1%.

关 键 词：钢管自密实混凝土 收缩特性 膨胀剂掺量 环向膨胀率 

分 类 号：TU528.042.4[建筑科学—建筑技术科学]