典型悬浮添加剂对高水材料力学性质影响的试验研究

发布时间：2018-03-05 01:01

  本文选题：高水材料　切入点：改性　出处：《工程科学与技术》2017年S1期 　论文类型：期刊论文

【摘要】：针对高水材料强度相对偏低、成本相对较高的问题,选取粉煤灰和硅粉两种材料作为添加剂,对高水材料进行改性研究。设置添加剂掺量梯度为5%、10%、15%和20%,采用四川大学电子万能试验机和扫描电镜(SEM)两种试验设备,进行添加剂对高水材料力学性质影响试验,探究添加剂对高水材料力学性质及微观结构的影响。试验结果表明,添加剂对高水材料力学性质和微观结构均有较大的影响:1)掺20%粉煤灰和掺10%硅粉均可使高水材料的抗压强度提高到0.36 MPa,与未掺添加剂高水材料相比,强度提高了20%,且能有效提高残余强度。2)添加剂的掺入改变了高水材料钙矾石晶体的发育形貌、直径大小及空间网状结构的致密程度,主要包括以下两个方面:粉煤灰的掺入使晶体形貌由短棒状发展为针棒状,大直径晶体数量增多,绒球状的水化硅酸钙及未反应完的残留物填充在晶体结构孔隙中,使晶体空间结构更为致密;硅粉的掺入使晶体形貌发展为枝网状,水化硅酸钙数量增加,起到了充填孔隙和增加晶体交错搭接牢固性的作用,枝网状的晶体和绒球状的硅酸钙共同形成了致密的网状结构。3)证明了抗压强度的大小是由晶体形貌、直径大小、晶体结构的搭接方式及网状结构的致密性共同影响的。
[Abstract]:Aiming at the problem that the strength of high water material is relatively low and the cost is relatively high, two kinds of materials, fly ash and silica fume, are selected as additives. The modification of high water materials was studied. The effect of additives on the mechanical properties of high water materials was tested by means of electronic universal testing machine of Sichuan University and scanning electron microscope (SEM). The effects of additives on the mechanical properties and microstructure of high water materials were investigated. The addition of 20% fly ash and 10% silica fume can increase the compressive strength of the high water material to 0.36 MPA, compared with the high water material without additive, the additive has great influence on the mechanical properties and microstructure of the high water material, and the addition of 20% fly ash and 10% silica fume can increase the compressive strength of the high water material to 0.36 MPA. The strength of ettringite crystal was increased by 20%, and the residual strength. 2) the addition of additives changed the morphology of ettringite crystal, the diameter of ettringite crystal and the density of space network structure. It mainly includes the following two aspects: the crystal morphology of fly ash is changed from short rod to needle rod, the number of large diameter crystals increases, the suede calcium silicate hydrate and unreacted residue are filled in the pore of crystal structure. With the addition of silica fume, the crystal morphology developed into a branch network, and the amount of calcium silicate hydrate increased, which played the role of filling the pores and increasing the fastness of the crystal staggered and overlapped. It is proved that the compressive strength is influenced by the morphology of the crystal, the diameter of the crystal, the overlap mode of the crystal structure and the density of the mesh structure.
【作者单位】： 四川大学水力学与山区河流开发保护国家重点实验室;四川大学水利水电学院;
【基金】：国家自然科学基金煤炭联合基金重点资助项目(51134018;51369001)
【分类号】：TV41
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本文编号：1568047