【作者】 杨玉辉；

【导师】 周明凯；

【作者基本信息】 武汉理工大学 ， 建筑材料与工程， 2007， 硕士

【摘要】 细集料的特性对混凝土性能影响较为明显，特别是对于高强高性能混凝土，细集料的级配、细度模数和种类等对其和易性、力学性能等性质有较大影响，作为替代河砂配制高强高性能混凝土的机制砂，其级配相对较差，细度模数偏大，存在较多0.075mm以下的石粉，其表面粗糙，粒形尖锐，综合以上特点，有必要对C80机制砂混凝土的配合比设计进行研究，并针对机制砂含有石粉的特点，研究石粉对混凝土性能的影响。本文以C80机制砂混凝土的配制和性能测试为基础，确定了C80机制砂混凝土配合比的基本参数，研究了机制砂的特性对混凝土工作性及强度的影响，研究了石粉对混凝土工作性、力学性能、变形性能、抗渗性以及流变性能的影响，并探讨了机制砂中的石粉作混凝土掺合料的可行性。试验结果表明：(1)采用聚羧酸系高效减水剂可以配制出与河砂混凝土性能同样优异的C80机制砂混凝土；(2)C80机制砂混凝土与河砂混凝土相比具有强度高、弹模大、氯离子渗透系数低的特点，干缩略大于河砂混凝土。(3)机制砂中一定量的石粉对混凝土无不利影响，在MB值＜1.4时，石粉含量可放宽至7％；(4)从强度与工作性方面考虑，在保证胶凝材料用量的情况下，石粉可以取代粉煤灰作为混凝土掺合料；(5)机制砂中石粉含量在5％以下时，对C80机制砂混凝无不利的影响，此时的塑性粘度和屈服应力较小；与混凝土拌和物试验相比，流变学试验可以更好的定量描述混凝土的工作性。更多还原

【Abstract】 It is comparatively obvious that the characteristic of fine aggregate influences the performance of concrete , especially for high strength high-performance concrete, the nature , modulus of fineness and kind of the material ,etc. have greater influence of the workability, mechanical property of concrete. The manufactured sand of substituting the river sand for mixing high-performance concrete, have many characteristic, such as relatively bad grade, simply big modulus, many less than 0.075mm stone powder, and the surface is coarseness, the shape is sharp. Synthesize above characteristic, it is necessary to research to the mix ratio of the C80 concrete with machine-made sand, research the stone powder impact on performance of concrete.Based on the preparation and performance test of C80 manufactured sand concrete, the text confirmed the basic parameter of C80 manufactured sand concrete. Studied the characteristic of machine-made sand to the workability and strength of concrete, the stone powder to the workability, mechanical property, shrinkage property, anti-permeate and rheological performance, and discussed the feasibility of stone powder substituting fraction of mineral admixture.The result shows: (1) the C80 manufactured sand concrete can prepared using poly carboxylic acid water reducing agent as good performance as river sand concrete; (2) Compared with river sand concrete, the manufactured sand concrete has high strength, elastic modulus, low of diffusion coefficient of Cl~-, dry shrinkage is less higher than sand concrete; (3) certain amount of Stone powder didn’t has bad influence to concrete, as MB<1.4, content of stone powder can broaden 7%; (4) Under the situation of enough cementitious material, the stone powder can replace fly ash as mineral admixtures; (5) The stone powder of a certain amount is favorable for concrete to increase the rheology performance of manufactured sand concrete , the plastic viscidity at this moment and stress of surrendering are relatively small; compare with the fresh concrete test, rheology test can be better reflect the workability of concrete.更多还原