泥粉种类及含量对C60现浇梁混凝土性能的影响

Mud powder type and content on the properties of C60 concrete cast-in-place beam

对比研究了伊利土、黄黏土和蒙脱土对C60现浇梁混凝土坍落度、抗压强度、弹性模量和干燥收缩的影响规律。研究发现,在外加剂掺量一致的基础上,蒙脱土对混凝土坍落度影响最明显,黄黏土次之,伊利土最小。掺入蒙脱土后混凝土抗压强度和弹性模量降低最明显,黄黏土次之,伊利土最小。在保证混凝土性能满足施工要求的前提下,应将伊利土、黄黏土和蒙脱土的最大含量分别控制在4%、2%和1%以下。混凝土强度相当时,蒙脱土对混凝土电通量和干燥收缩的影响最明显,黄黏土次之,伊利土最小。SEM扫描结果显示,蒙脱土对混凝土界面过渡区劣化影响最明显,黄黏土次之,伊利土最小。MIP结果表明:泥粉会导致水泥浆体有害大孔比例显著增多,小孔比例减小,相对而言蒙脱土的影响最明显,黄土次之,伊利土最小。本研究揭示和分析了伊利土、黄黏土及蒙脱土对C60现浇梁混凝土性能的影响,并为项目工程建设提供了新线索。

The effects of illite,yellow clay and montmorillonite on slump,compressive strength,elastic modulus and dry shrinkage of C60 concrete were studied.It is found that the influence of montmorillonite on the slump of concrete is the most obvious,the yellow clay is the second,and the illite is the least.After adding montmorillonite,the compressive strength and elastic modulus of concrete decrease most obviously,the yellow clay is next,and the illite is the smallest.Under the premise of ensuring the concrete performance to meet the construction requirements,the maximum mixing amounts of illite,yellow clay and montmorillonite are 4%,2%and 1%respectively.When the concrete strength is equal,the influence of montmorillonite on the electric flux and drying shrinkage of concrete is the most obvious,the yellow clay is the second,and the illite is the least.SEM results show that the deterioration of the interfacial transition zone is the most obvious,followed by yellow clay and illite.The results of MIP show that the proportion of harmful macropore increases significantly,the proportion of small pore decreases,the effect of montmorillonite is the most obvious,loess is the second,illite is the least.It reveals and analyzes the effects of illite,yellow clay and montmorillonite on the properties of C60 concrete,and provides new clues for the project construction.