实际生产再生细骨料混凝土基本性能的试验研究

发布时间：2018-09-06 11:14

【摘要】：再生细骨料混凝土是一种新型绿色建筑材料,具有环保和经济价值。作为一种新材料,再生细骨料混凝土基本性能的优劣直接关系到混凝土结构的安全。对再生细骨料混凝土基本性能进行试验研究具有实用价值。针对实际生产中使用的再生细骨料,本文采用基于自由水灰比的配合比设计方法成功配制了再生细骨料混凝土,并按5种水灰比,6种再生细骨料取代率分别进行再生细骨料混凝土工作性能、力学性能和耐久性能试验,探讨了工程应用的可行性,取得的主要成果如下:1、着重分析了再生细骨料与天然砂的性能差异,并总结出再生细骨料的性能特点。试验结果显示,再生细骨料物理性能指标几乎只能达到规范Ⅲ类的要求,整体品质较差,性能不及天然砂。2、再生细骨料混凝土采用基于自由水灰比的配合比设计方法,把混凝土拌合用水分成自由水和吸附水两部分,解决了再生细骨料吸水率大对其坍落度构成不良影响这一难题,试验所配的再生细骨料混凝土的工作性能基本能满足要求。应用此方法配制再生细骨料混凝土,其工作性能满足工程使用要求。3、对不同水灰比而言,随着取代率不断增加,再生细骨料混凝土抗压强度、抗拉强度、抗折强度都有不同程度地降低。当取代率不大于20%时,水灰比0.7的再生细骨料混凝土的抗压强度、抗拉强度、抗折强度均不低于普通混凝土,说明该情况下混凝土中天然砂可由再生细骨料进行取代,但取代率不应超过20%。4、当取代率不大于20%时,再生细骨料混凝土的抗渗性能达到P6等级,其氯离子渗透性低,且其抗碳化性能较好,说明再生细骨料混凝土的耐久性符合工程一般要求。
[Abstract]:Recycled fine aggregate concrete is a new green building material with environmental protection and economic value. As a new material, the basic performance of recycled fine aggregate concrete is directly related to the safety of concrete structure. It is of practical value to study the basic properties of recycled fine aggregate concrete. Aiming at the recycled fine aggregate used in actual production, this paper has successfully prepared the recycled fine aggregate concrete by using the mix ratio design method based on free water cement ratio. At the same time, according to the replacement ratio of 5 kinds of water-cement ratio and 6 kinds of recycled fine aggregate, the working performance, mechanical property and durability of recycled fine aggregate concrete were tested, and the feasibility of engineering application was discussed. The main results are as follows: 1. The difference between recycled fine aggregate and natural sand is analyzed, and the characteristics of recycled fine aggregate are summarized. The test results show that the physical properties of recycled fine aggregate can almost meet the requirements of Class III of the Code, the overall quality is poor, and the performance is not as good as that of natural sand. The recycled fine aggregate concrete adopts the design method of mix ratio based on free water-cement ratio. The concrete mixing water is divided into two parts: free water and adsorbent water, which solves the problem that the high water absorption rate of recycled fine aggregate has a bad effect on its slump. The working performance of recycled fine aggregate concrete can basically meet the requirements. Using this method to prepare recycled fine aggregate concrete, its working performance meets the requirement of engineering application. For different water-cement ratio, with the increasing of replacement rate, the compressive strength and tensile strength of recycled fine aggregate concrete are obtained. The flexural strength is reduced to some extent. When the replacement ratio is less than 20, the compressive strength, tensile strength and flexural strength of recycled fine aggregate concrete with water-cement ratio 0.7 are not lower than that of ordinary concrete, which shows that the natural sand in concrete can be replaced by recycled fine aggregate in this case. But the substitution rate should not exceed 20. 4. When the substitution rate is not greater than 20, the impermeability of recycled fine aggregate concrete reaches P6 grade, its chloride ion permeability is low, and its carbonation resistance is better. The durability of recycled fine aggregate concrete meets the general engineering requirements.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

【参考文献】