建筑垃圾再生蒸压加气混凝土的试验研究
发布时间：2018-11-07 17:08
【摘要】：随着我国经济化建设进程加快,建筑行业迎来一个全速发展时期,伴随而来的就是建筑物大规模拆建,由此产生的数以亿计的建筑垃圾成为摆在人们面前的一道难题。大量的建筑垃圾无处安置,部分直接填埋,更多的直接露天堆放,占用耕地,造成环境污染。当前,建筑垃圾资源化处理备受社会各界关注,从质量与数量看,对处理建筑垃圾而言主要是回收利用废弃混凝土。因此,大部分研究集中在混凝土再生骨料应用,回收利用途径狭窄、效率低,对于废弃混凝土应用于新型建筑墙体材料的研究较少。本文主要对采用建筑垃圾废弃混凝土制备蒸压加气混凝土进行了可行性研究。为了实现废弃混凝土最大资源化利用,试验首先研究了废弃混凝土原材料的各种性能;其次研究废弃混凝土作为单一硅质原材料制备再生加气混凝土,以粉煤灰加气混凝土为对比,研究掺入不同比例的粉煤灰代替废弃混凝土制备蒸压加气混凝土制品,以获得建筑垃圾再生加气混凝土的配方;然后采用单因素试验方法研究水料比、石灰、水泥和铝粉掺量这四个因素在再生加气混凝土制备过程中对制品性能的影响,以及研究了球磨不同细度的废弃混凝土、高温煅烧废弃混凝土以及掺加化学药剂这三种技术手段对废弃混凝土的激发作用;最后对建筑垃圾再生蒸压加气混凝土的强度成型机理和效益进行了基本的分析。通过分析研究废弃混凝土的化学组分和力学性能,试验结果表明废弃混凝土成分中Si O2含量较高,XRD图谱中水化硅酸钙含量较高,废弃混凝土标准稠度用水量和凝结时间以及安定性都满足标准要求,而废弃混凝土掺入40%时制成的砂浆28d强度达到32.5水泥强度,说明废弃混凝土本身是具有一定活性的。废弃混凝土制备蒸压加气混凝土配合比试验结果表明,采用废弃混凝土作为单一硅质原料制备的产品强度太低,而在粉煤灰和废弃混凝土混掺的情况下成功地制出干密度为624.19 kg/m3、抗压强度为3.57MPa的制品。单因素试验结果表明,影响制品性能的因素水料比、石灰、水泥、铝粉掺量分别有一个最佳取值,当配方中水料比取0.6、石灰掺量取18%、水泥掺量取12%、铝粉掺量0.09%,各自试验条件下制品性能分别对应一个最佳值。当对废弃混凝土球磨55min时,对激发其活性最佳;废弃混凝土经高温煅烧,在一定程度上提高了活性,而且废弃混凝土活性随煅烧温度升高而增强,900℃时活性最好,制品强度最大;加入不同比例的Si O2粉后制品强度均有了一定程度提高。建筑垃圾再生蒸压加气混凝土强度成型机理和效益分析结果表明,制品SEM电镜扫描图像中含有较多结晶较好的片状托勃莫来石,水化产物形貌较好;单位体积再生加气混凝土产品制造能耗比一级普通烧结粘土砖节约0.39 kgce,生产成本98.29元,相当于市场价的一半,经济和社会效益显著。
[Abstract]:With the acceleration of economic construction in China, the construction industry ushered in a period of full speed development, accompanied by large-scale demolition and construction of buildings, resulting in hundreds of millions of construction waste has become a difficult problem in front of people. A large amount of construction waste has nowhere to be placed, part of the landfill is directly buried, and more directly stored in the open air, occupying cultivated land, resulting in environmental pollution. At present, construction waste resource treatment has been concerned by all walks of life. In terms of quality and quantity, it is mainly to recycle waste concrete to deal with construction waste. Therefore, most of the research is focused on the application of recycled concrete aggregate, the way of recycling is narrow, the efficiency is low, and the research on the application of abandoned concrete in new building wall materials is less. In this paper, the feasibility of autoclaved aerated concrete made from waste concrete of construction waste is studied. In order to realize the maximum utilization of waste concrete, the properties of raw materials of waste concrete are studied in the experiment. Secondly, waste concrete is used as a single silica raw material to produce recycled aerated concrete. Compared with fly ash aerated concrete, the autoclaved aerated concrete products are prepared with different proportion of fly ash instead of waste concrete. To obtain the formula of recycled aerated concrete for construction waste; Then the effects of water / material ratio, lime, cement and aluminum powder on the properties of recycled aerated concrete were studied by single factor test method, and the waste concrete with different fineness of ball milling was studied. The stimulation of waste concrete by calcining waste concrete at high temperature and adding chemical agent; Finally, the strength forming mechanism and benefit of recycled autoclaved aerated concrete are analyzed. The chemical composition and mechanical properties of the waste concrete were analyzed and studied. The results showed that the content of Si O 2 was higher and the content of calcium silicate hydrate in the XRD diagram was higher in the waste concrete. The standard consistency, setting time and stability of the waste concrete meet the standard requirements, while the 28d strength of the mortar made from the waste concrete mixed with 40 cycles reaches 32.5 cement strength, which indicates that the waste concrete itself has certain activity. The experimental results of mixture ratio of autoclaved aerated concrete made of waste concrete show that the strength of the product prepared by using waste concrete as a single siliceous material is too low. The products with a dry density of 624.19 kg/m3, and compressive strength of 3.57MPa were successfully prepared under the condition of mixing fly ash with waste concrete. The results of single factor test show that the water / material ratio, lime, cement and aluminum powder have the best value respectively. When the ratio of water to material is 0.6, the content of lime is 18 and the amount of cement is 12, the ratio of water to material is 0.6, the content of lime is 18, and the content of cement is 12. The content of aluminum powder is 0.09, and the properties of the products under each test condition are respectively an optimum value. When 55min is milled to waste concrete, it has the best activity to excite it. After high temperature calcination, the activity of waste concrete increases to a certain extent, and the activity of waste concrete increases with the increase of calcination temperature. The activity of waste concrete is the best at 900 鈩，
本文编号：2317008
[Abstract]:With the acceleration of economic construction in China, the construction industry ushered in a period of full speed development, accompanied by large-scale demolition and construction of buildings, resulting in hundreds of millions of construction waste has become a difficult problem in front of people. A large amount of construction waste has nowhere to be placed, part of the landfill is directly buried, and more directly stored in the open air, occupying cultivated land, resulting in environmental pollution. At present, construction waste resource treatment has been concerned by all walks of life. In terms of quality and quantity, it is mainly to recycle waste concrete to deal with construction waste. Therefore, most of the research is focused on the application of recycled concrete aggregate, the way of recycling is narrow, the efficiency is low, and the research on the application of abandoned concrete in new building wall materials is less. In this paper, the feasibility of autoclaved aerated concrete made from waste concrete of construction waste is studied. In order to realize the maximum utilization of waste concrete, the properties of raw materials of waste concrete are studied in the experiment. Secondly, waste concrete is used as a single silica raw material to produce recycled aerated concrete. Compared with fly ash aerated concrete, the autoclaved aerated concrete products are prepared with different proportion of fly ash instead of waste concrete. To obtain the formula of recycled aerated concrete for construction waste; Then the effects of water / material ratio, lime, cement and aluminum powder on the properties of recycled aerated concrete were studied by single factor test method, and the waste concrete with different fineness of ball milling was studied. The stimulation of waste concrete by calcining waste concrete at high temperature and adding chemical agent; Finally, the strength forming mechanism and benefit of recycled autoclaved aerated concrete are analyzed. The chemical composition and mechanical properties of the waste concrete were analyzed and studied. The results showed that the content of Si O 2 was higher and the content of calcium silicate hydrate in the XRD diagram was higher in the waste concrete. The standard consistency, setting time and stability of the waste concrete meet the standard requirements, while the 28d strength of the mortar made from the waste concrete mixed with 40 cycles reaches 32.5 cement strength, which indicates that the waste concrete itself has certain activity. The experimental results of mixture ratio of autoclaved aerated concrete made of waste concrete show that the strength of the product prepared by using waste concrete as a single siliceous material is too low. The products with a dry density of 624.19 kg/m3, and compressive strength of 3.57MPa were successfully prepared under the condition of mixing fly ash with waste concrete. The results of single factor test show that the water / material ratio, lime, cement and aluminum powder have the best value respectively. When the ratio of water to material is 0.6, the content of lime is 18 and the amount of cement is 12, the ratio of water to material is 0.6, the content of lime is 18, and the content of cement is 12. The content of aluminum powder is 0.09, and the properties of the products under each test condition are respectively an optimum value. When 55min is milled to waste concrete, it has the best activity to excite it. After high temperature calcination, the activity of waste concrete increases to a certain extent, and the activity of waste concrete increases with the increase of calcination temperature. The activity of waste concrete is the best at 900 鈩，
本文编号：2317008
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