约束程度对外掺MgO混凝土变形及劈拉强度的影响  

Effect of restraint degree on the expansion and tensile splitting strength of concrete containing MgO-based expansive agent

作　　者：沈达[1] 邓敏[1] 莫立武[1] 

机构地区：[1]南京工业大学材料科学与工程学院材料化学工程国家重点实验室,江苏南京210009

出　　处：《混凝土》2012年第10期14-17,共4页Concrete

基　　金：国家科技支持计划项目(2011BAE27B01);国家重点基础研究发展计划(2009CB623105)

摘　　要：研究了约束程度对外掺MgO膨胀剂(MEA)混凝土变形及劈拉强度的影响,试模壁厚为5、7、10 mm,MEA活性指数为60、150 s,MEA掺量为0、6%和9%。试验结果表明:相同约束条件下MEA混凝土的应变随MEA膨胀剂掺量的增加而增大,养护温度越高,应变越大。30℃时,掺6%MEA-60的混凝土在壁厚为5 mm的试模约束下,28 d时的应变为11.8×10-6,大于在壁厚为10 mm的试模约束下混凝土的应变,但在壁厚为10 mm的试模约束下,其劈拉强度比在壁厚为5 mm试模约束下高13%。Effect of restraint degree on the expansion and tensile splitting strength of concrete containing MgO-based expansive agent(MEA) were investigated.The wall thicknesses of the mold used to restrain the expansion of concrete specimen were 5,7,10 mm respectively.The activity values of MEA used were 60 s and 150 s,and the amount of MEA added in concrete were 0、6% and 9% respectively.Results showed that with increasing amount of MEA,the expansion of concrete increased correspondingly.Furthermore,higher curing temperature caused larger expansion strain of the concrete.The expansion strain of concrete containing 6% MEA-60 restrained by using 5mm-thick mold was 11.8×10-6 at 28 d when cured under 30 ℃,which was higher than that of the concrete restrained by using 10 mm-thick mold.and the tensile splitting strength of the latter,however,was increased by 13% in comparison to that of the former.

关 键 词：MEA膨胀剂 约束程度 应变 劈裂抗拉强度 

分 类 号：TU528.01[建筑科学—建筑技术科学]