高性能再生骨料混凝土配合比设计方法试验研究

发布时间：2018-03-06 00:07

本文选题：高性能　切入点：再生骨料混凝土　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着建筑业的迅速发展,砂石等资源日益减少,而建筑废弃物却不断增多,再生骨料混凝土的研究与应用成为土木工程中一个重要的发展方向。目前国内对于再生骨料混凝土的研究主要停留在基本力学性能上,对高性能再生骨料混凝土配合比设计方法的研究还少见报道。由于再生粗骨料与天然粗骨料有着显著差异,所以再生骨料混凝土的配合比设计方法不能沿用普通混凝土的配合比设计方法。因此本文主要对再生骨料混凝土鲍罗米公式进行回归和修正,在保证稳定浆骨比的基础上提出适合高性能再生骨料混凝土的配合比设计方法。本文主要完成的工作如下：1、利用实验室废弃试块和道路废弃混凝土生产再生粗骨料,对不同来源的两种再生粗骨料和天然粗骨料进行基本性能试验。试验结果表明：两种再生粗骨料的各项性能都比天然骨料差,具体表现为再生粗骨料表面粗糙,表观密度和堆积密度低、空隙率高、吸水率大、压碎指标大。2、研究了不同压碎指标和不同再生粗骨料取代率对混凝土鲍罗米公式的影响。试验结果表明：不同压碎指标对骨料系数aα’的影响较小,而另一骨料系数ae’与压碎指标呈现良好的线性关系；不同的再生粗骨料取代率系数α。与再生粗骨料取代率也存在良好的线性关系。将再生骨料混凝土鲍罗米公式的计算值与试验实测值相比较发现,其数值误差在10%以内,说明考虑再生骨料压碎指标和再生粗骨料取代率下得到的再生骨料混凝土鲍罗米公式具有较高的可靠性。3、通过不同预处理方法和不同粉煤灰掺量对再生骨料混凝土强度影响的试验研究,对再生骨料混凝土的鲍罗米公式进行修正。结果表明：采用水泥外掺硅粉浆液、聚乙烯醇溶液预处理方法时,强化效果最好,再生骨料预处理影响系数av建议取1.1。粉煤灰影响系数γf与粉煤灰掺量也存在较好的线性关系。4、进行不同浆骨比的高性能再生骨料混凝土工作性能和基本力学性能试验研究。试验结果表明：当再生骨料混凝土浆骨比为37.5/62.5时,再生骨料混凝土的坍落度满足要求,经时变化小,立方体抗压强度、轴心抗压强度、弹性模量等力学性能都能达到较高值。5、通过参考普通混凝土配合比设计方法和高性能混凝土配合比设计方法,对再生骨料混凝土鲍罗米公式进行回归和修正,在稳定的高性能再生骨料混凝土浆骨比基础上,提出了适合高性能再生骨料混凝土的配合比设计方法
[Abstract]:With the rapid development of the construction industry, the resources such as sand and stone are decreasing day by day, but the construction waste is increasing. The research and application of recycled aggregate concrete has become an important development direction in civil engineering. The research on the design method of high performance recycled aggregate concrete mixture ratio is rarely reported, because there are significant differences between recycled coarse aggregate and natural coarse aggregate. Therefore, the proportion design method of recycled aggregate concrete can not be used in the ordinary concrete mix ratio design method. Therefore, this paper mainly regresses and modifies the Paulomi formula of recycled aggregate concrete. On the basis of ensuring stable slurry / bone ratio, the design method of mix ratio suitable for high performance recycled aggregate concrete is put forward. The main work of this paper is as follows: 1. The recycled coarse aggregate is produced from laboratory waste test blocks and road waste concrete. The basic properties of two kinds of recycled coarse aggregate and natural coarse aggregate from different sources were tested. The results showed that the properties of the two recycled coarse aggregates were worse than that of natural aggregate, and the surface of recycled coarse aggregate was rough. The apparent density and packing density are low, the porosity is high, and the water absorption is high. The influence of different crushing indexes and different replacement ratio of recycled coarse aggregate on the Baolomi formula of concrete is studied. The experimental results show that different crushing indexes have little effect on the aggregate coefficient a'. The other aggregate coefficient (ae') showed a good linear relationship with crushing index. There is also a good linear relationship between the coefficient of replacement rate of recycled coarse aggregate and the rate of replacement of recycled coarse aggregate. By comparing the calculated value of Baolomi formula of recycled aggregate concrete with the measured value, it is found that the numerical error is less than 10%. It is shown that the Baolomi formula of recycled aggregate concrete obtained by considering the crushing index of recycled aggregate and the replacement rate of recycled coarse aggregate has a high reliability. 3. Different pretreatment methods and different amount of fly ash are used to coagulate recycled aggregate. Experimental study on the influence of soil strength, The Boromi formula of recycled aggregate concrete is modified. The results show that the strengthening effect is the best when the cement is mixed with silica fume and polyvinyl alcohol solution is pretreated. The influence coefficient av of recycled aggregate pretreatment is recommended as 1.1. There is also a good linear relationship between the influence coefficient 纬 f of fly ash and the content of fly ash. 4. The working properties and basic mechanical properties of recycled recycled aggregate concrete with different ratio of slurry to bone are carried out. The experimental results show that when the ratio of recycled aggregate concrete to concrete is 37.5 / 62.5, The slump of recycled aggregate concrete meets the requirements, with little change in time, cube compressive strength, axial compressive strength, The mechanical properties such as modulus of elasticity can reach a higher value. By referring to the design method of ordinary concrete mix ratio and high performance concrete mix ratio design, the Baolomi formula of recycled aggregate concrete is regressed and revised. On the basis of stable ratio of high performance recycled aggregate concrete, the design method of mix ratio suitable for high performance recycled aggregate concrete is put forward.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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