摘要
为避免混凝土结构后浇带产生不规则裂缝,总结分析了混凝土结构热传导方程及变形计算理论,并在此基础上,对某建设工程地下室顶板后浇带温升变化及裂缝控制展开研究。结果表明:考虑水泥、粉煤灰及膨胀剂对混凝土水化热的影响,C40微膨胀混凝土引起的水化温升为59.4℃,温度应变为3.43×10^(-4);后浇带留置30d后,既有混凝土的残余应变为1.51×10^(-4),约占总收缩的74%,占比较大,在地下室顶板后浇带裂缝分析时,需要考虑既有混凝土残余收缩应变的影响;C40微膨胀混凝土封闭后浇带能够较好地抵消混凝土结构内部温度应变和收缩应变,改善后浇混凝土抗裂性能,考虑后浇带混凝土限制膨胀作用后的内部约束应变仅为9.6×10^(-4),小于C40微膨胀混凝土的极限拉伸应变。
To avoid irregular cracks in the post pouring strip of concrete structures,the heat conduction equation and deformation calculation theory of concrete structures were summarized and analyzed.Based on this,a study was conducted on the temperature rise changes and crack control of the post pouring strip of the basement roof of a certain construction project.The results show that considering the effects of cement,fly ash,and expansion agent on the hydration heat of concrete.The hydration temperature rise caused by C40 micro expansion concrete is 59.4℃,and the temperature strain is 3.43×10^(-4).After leaving the post pouring strip for 30 days,the residual strain of the existing concrete is 1.51×10^(-4),accounting for about 74%of the total shrinkage,which is relatively large.When analyzing the cracks in the post pouring strip of the basement roof,the influence of the residual shrinkage strain of the existing concrete needs to be considered.The C40 micro expansion concrete enclosed pouring strip can effectively counteract the internal temperature strain and shrinkage strain of the concrete structure,improve the crack resistance of the poured concrete,and consider that the internal constraint strain of the post pouring strip concrete after limiting the expansion effect is only 9.6×10^(-4),which is less than the ultimate tensile strain of C40 micro expansion concrete.
作者
黄光荣
HUANG Guangrong(Fuzhou Zhengsheng Chuangfu Industrial Co.,Ltd.)
出处
《广东建材》
2025年第8期125-128,共4页
Guangdong Building Materials
关键词
混凝土结构后浇带
温度分析
裂缝控制
温度应变
收缩应变
Post pouring strip of concrete structure
Temperature analysis
Crack control
Temperature strain
Shrinkage strain
