高品质再生骨料制备技术及其对再生混凝土性能的影响

发布时间：2018-02-04 00:26

本文关键词： 循环颗粒整形再生粗骨料再生混凝土力学性能耐久性能　出处：《青岛理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：城镇化建设以及旧城的拆迁改造产生了大量的城市垃圾和固体废弃物，其中废混凝土占了很大比重。利用废混凝土制备出高品质的再生骨料，，并将其用到混凝土中，不仅可以节省天然骨料资源，而且还可以减少废混凝土对环境的污染，符合可持续发展的国策，具有很好的经济效益和环境效益。本文提出循环颗粒整形技术，对简单破碎再生粗骨料进行了多次强化处理，获得高品质再生粗骨料，研究了经过循环颗粒整形后高品质再生粗骨料性能的变化，以及对再生混凝土性能的影响。重点分析了高品质再生粗骨料取代率（0%、20%、40%、60%、80%和100%）和胶凝材料用量（300kg/m~3、350kg/m~3、400kg/m~3、450kg/m~3和500kg/m~3）两种因素对再生混凝土工作性能、力学性能和渗透性能等耐久性能的影响。试验研究结果表明：循环颗粒整形技术可显著改善再生粗骨料的性能。循环颗粒整形后再生粗骨料的吸水率和压碎指标较未整形再生粗骨料显著降低，表观密度和堆积密度提高，含泥量和针片状颗粒含量显著降低；循环颗粒整形能更充分地去除再生骨料表面的水泥浆石，使骨料表面光滑无棱角，孔隙率降低，提高了再生混凝土的流动性，从而改善了再生混凝土的工作性能。当高品质再生粗骨料完全取代天然骨料时，再生混凝土28d抗压强度较天然骨料混凝土降低4.8%左右。高品质再生粗骨料混凝土减少了氯离子渗透的通道，使得氯离子扩散系数显著降低；高品质再生骨料混凝土的45d收缩量较天然骨料混凝土仅增加5%左右，其抗裂性能和抗碳化性能明显高于未整形再生粗骨料混凝土，接近于天然骨料混凝土。总的来说，高品质再生骨料的各项性能已经接近于天然骨料，可以制备高性能混凝土。
[Abstract]:The construction of urbanization and the demolition and reconstruction of the old city have produced a large amount of municipal garbage and solid waste, among which waste concrete accounts for a large proportion. High quality recycled aggregate is prepared from waste concrete. It can not only save the natural aggregate resources, but also reduce the pollution of waste concrete to the environment. It is in line with the national policy of sustainable development and has good economic and environmental benefits. In this paper, the technology of circulating particle shaping is put forward, and the simple crushed recycled coarse aggregate has been strengthened many times to obtain high quality recycled coarse aggregate. The change of the properties of high quality recycled coarse aggregate and its influence on the properties of recycled concrete were studied. The substitution rate of high quality recycled coarse aggregate was analyzed by 40% or 20%. And the amount of cementitious material was 300 kg / m / m ~ 3 / 3 ~ 350 kg / m ~ (-1) / 3 ~ 3 / 400 kg / m ~ (3) / m ~ (3). The effects of 450 kg / m3 and 500 kg / mm3) on the durability of recycled concrete, such as working performance, mechanical properties and permeability. The experimental results show that the properties of recycled coarse aggregate can be significantly improved by circulating particle shaping technology, and the water absorption rate and crushing index of recycled coarse aggregate after plastic treatment are significantly lower than that of non-plastic recycled coarse aggregate. The apparent density and stacking density increased, and the content of mud and needle particles decreased significantly. The recycled particle shaping can remove the cement paste more fully, make the aggregate surface smooth and angular free, reduce the porosity, and improve the flowability of recycled concrete. Thus, the working performance of recycled concrete is improved. When high quality recycled coarse aggregate completely replaces natural aggregate. The compressive strength of recycled concrete is about 4.8% lower than that of natural aggregate concrete for 28 days. The shrinkage of high quality recycled aggregate concrete in 45 days is only about 5% more than that of natural aggregate concrete. The crack resistance and carbonation resistance of high quality recycled aggregate concrete are obviously higher than that of unshaped recycled coarse aggregate concrete. In general, the properties of high quality recycled aggregate are close to that of natural aggregate and can be used to produce high performance concrete.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

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