再生骨料混凝土力学性能与盐冻耐久性研究

发布时间：2018-09-03 18:29

【摘要】：城市化建设用到的大量混凝土，将使人类面临着废弃物处理与矿产资源短缺的问题，人类从循环再生利用废弃混凝土方面着手相关研究，以求解决废弃物处理过程中引起的环境问题和缓解混凝土骨料供求矛盾；研究再生骨料混凝土的基本性能，，有利于推动再生骨料混凝土的商品化生产，最终达到解决环境恶化和资源短缺问题。本文在理论与试验相结合的基础上，采用数据统计的方法分析得到了以下结果：（1）级配和粒径基本相同的条件下，天然骨料的物理性能优于再生骨料；（2）由于再生骨料吸水率大的性质，再生骨料混凝土拌合物坍落度低于普通混凝土；（3）再生骨料混凝土与普通混凝土抗压破坏形态类似，再生骨料混凝土的抗压强度高于普通混凝土，但是其弹性模量、劈裂抗拉强度、抗折强度都低于普通混凝土；（4）再生骨料混凝土的盐冻性能在试验初期优于普通混凝土，但是当冻融循环次数超过某值（16次左右）时，普通混凝土抗冻性能优于再生骨料混凝土。再生骨料混凝土与普通混凝土工作性能、力学性能和抗冻性能主要由再生骨料与天然骨料的物理性质决定；通过研究再生骨料混凝土力学性能与盐冻性能，能够得出再生骨料混凝土可以应用于工程实际中，同时提出再生骨料的最佳取代率为50%。本文仅对再生骨料混凝土抗冻性能进行研究，以后可以在抗硫酸盐侵蚀、收缩和抗碳化等方面进行试验研究；同时可以在工程实际中进行试验观测，以便得到更符合实际的参考数据。
[Abstract]:A large number of concrete used in the construction of urbanization will make people face the problem of waste disposal and shortage of mineral resources. In order to solve the environmental problems caused by waste treatment and alleviate the contradiction between supply and demand of concrete aggregate, the basic performance of recycled aggregate concrete is studied, which is helpful to promote the commercial production of recycled aggregate concrete. Finally, the problem of environmental deterioration and shortage of resources can be solved. Based on the combination of theory and experiment, the following results are obtained by statistical analysis: (1) the physical properties of natural aggregate are superior to those of recycled aggregate under the condition of similar gradation and particle size; (2) because of the high water absorption of recycled aggregate, the slump of recycled aggregate concrete is lower than that of ordinary concrete; (3) the compressive failure of recycled aggregate concrete is similar to that of ordinary concrete. The compressive strength of recycled aggregate concrete is higher than that of ordinary concrete, but the elastic modulus, splitting tensile strength and flexural strength of recycled aggregate concrete are lower than that of ordinary concrete. (4) the salt freezing property of recycled aggregate concrete is better than that of ordinary concrete at the beginning of test. But when the number of freeze-thaw cycles exceeds a certain value (about 16 times), the frost resistance of ordinary concrete is better than that of recycled aggregate concrete. The working properties of recycled aggregate concrete and ordinary concrete are mainly determined by the physical properties of recycled aggregate and natural aggregate, and the mechanical properties and salt freezing properties of recycled aggregate concrete are studied. It can be concluded that recycled aggregate concrete can be used in engineering practice, and the optimum replacement rate of recycled aggregate is 50%. In this paper, the frost resistance of recycled aggregate concrete is studied, which can be studied in the aspects of sulfate resistance, shrinkage and carbonation resistance, and can be observed in engineering practice. In order to obtain more realistic reference data.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

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