水泥细度对混凝土早期性能的建材专业大学生毕业论文（设计）.doc

重庆大学本科学生毕业设计（论文） 水泥细度对混凝土早期性能的影响 学 生：高阳 学 号指导教师：贾兴文 专 业：无机非金属材料工程 重庆大学材料科学与工程学院 二O一O年六月  Graduation Design(Thesis) of Chongqing University Reasearch of the effect of cement fineness on the early properties of concrete Undergraduate: Gaoyang Supervisor: Dr. Jia Xingwen Major: Inorganic non-metallic materials engineering College of Material Science and Engineering Chongqing University June 2010   摘 要 应用于大跨度预应力桥梁的水泥，由于施工要求早期强度，加之国家标准没有规定细度上限，因此越磨越细。过高的细度已经开始对混凝土的各方面性能产生影响。基于这个原因，针对用于桥梁工程的混凝土，作了细度对混凝土早期力学性能影响的实验研究。 通过采用统一配合比，改变水泥细度的方法成型混凝土试件，研究了细度对混凝土早期强度增长规律的影响，以及掺合料和减水剂的用量对混凝土强度与水泥细度相关规律的影响。 测定了不同细度水泥的标准稠度用水量，凝结时间，胶砂扩展度。 结果表明，混凝土的早期抗压强度随细度增大而增大，增长曲线逐渐平缓；早期抗拉强度也随细度增大而增加，但变化不明显，并且在水泥比表面积超过400㎡/kg 减水剂和少量矿物掺合料的掺入对比表面积350~400㎡/kg 水泥的标准稠度用水量随细度增加而增加，增幅不大，比表面积400㎡/kg 关键词：水泥细度，早期强度，标准稠度用水量，凝结时间，胶砂扩展度  ABSTRACT As the demand of the early strength of concrete grows, while the national standards hasnt fixed a fineness limit, the fineness of cement used in long-span prestressed concrete bridge increases without control. Excessive fineness begins to affect the performance of all aspects of concrete. For that reason, in this paper the affect of cement fineness on the early properties of concrete is studied. The results show that early compressive strength of concrete increases with the fineness，and growth curve turns from steep to flatEarly tensile strength of concrete increases with the fineness, and the growth is modest. Tensile strength decreases when surface area reaches 400；Standard consistency water grows slowly with the fineness.Setting time gradually shortened with increasing fineness.The addition of superplasticizer and mineral admixtures improves the strength of concrete which uses fine cement better. According to the experimental results,the author recommends to use fine cement whose surface area ranges between 350 and 400 in structures which has the demand of early strength. Key words： cement fineness , early strength , standard water