【摘要】：隨著我國經(jīng)濟化建設進程加快,建筑行業(yè)迎來一個全速發(fā)展時期,伴隨而來的就是建筑物大規(guī)模拆建,由此產(chǎn)生的數(shù)以億計的建筑垃圾成為擺在人們面前的一道難題。大量的建筑垃圾無處安置,部分直接填埋,更多的直接露天堆放,占用耕地,造成環(huán)境污染。當前,建筑垃圾資源化處理備受社會各界關注,從質(zhì)量與數(shù)量看,對處理建筑垃圾而言主要是回收利用廢棄混凝土。因此,大部分研究集中在混凝土再生骨料應用,回收利用途徑狹窄、效率低,對于廢棄混凝土應用于新型建筑墻體材料的研究較少。本文主要對采用建筑垃圾廢棄混凝土制備蒸壓加氣混凝土進行了可行性研究。為了實現(xiàn)廢棄混凝土最大資源化利用,試驗首先研究了廢棄混凝土原材料的各種性能;其次研究廢棄混凝土作為單一硅質(zhì)原材料制備再生加氣混凝土,以粉煤灰加氣混凝土為對比,研究摻入不同比例的粉煤灰代替廢棄混凝土制備蒸壓加氣混凝土制品,以獲得建筑垃圾再生加氣混凝土的配方;然后采用單因素試驗方法研究水料比、石灰、水泥和鋁粉摻量這四個因素在再生加氣混凝土制備過程中對制品性能的影響,以及研究了球磨不同細度的廢棄混凝土、高溫煅燒廢棄混凝土以及摻加化學藥劑這三種技術手段對廢棄混凝土的激發(fā)作用;最后對建筑垃圾再生蒸壓加氣混凝土的強度成型機理和效益進行了基本的分析。通過分析研究廢棄混凝土的化學組分和力學性能,試驗結果表明廢棄混凝土成分中Si O2含量較高,XRD圖譜中水化硅酸鈣含量較高,廢棄混凝土標準稠度用水量和凝結時間以及安定性都滿足標準要求,而廢棄混凝土摻入40%時制成的砂漿28d強度達到32.5水泥強度,說明廢棄混凝土本身是具有一定活性的。廢棄混凝土制備蒸壓加氣混凝土配合比試驗結果表明,采用廢棄混凝土作為單一硅質(zhì)原料制備的產(chǎn)品強度太低,而在粉煤灰和廢棄混凝土混摻的情況下成功地制出干密度為624.19 kg/m3、抗壓強度為3.57MPa的制品。單因素試驗結果表明,影響制品性能的因素水料比、石灰、水泥、鋁粉摻量分別有一個最佳取值,當配方中水料比取0.6、石灰摻量取18%、水泥摻量取12%、鋁粉摻量0.09%,各自試驗條件下制品性能分別對應一個最佳值。當對廢棄混凝土球磨55min時,對激發(fā)其活性最佳;廢棄混凝土經(jīng)高溫煅燒,在一定程度上提高了活性,而且廢棄混凝土活性隨煅燒溫度升高而增強,900℃時活性最好,制品強度最大;加入不同比例的Si O2粉后制品強度均有了一定程度提高。建筑垃圾再生蒸壓加氣混凝土強度成型機理和效益分析結果表明,制品SEM電鏡掃描圖像中含有較多結晶較好的片狀托勃莫來石,水化產(chǎn)物形貌較好;單位體積再生加氣混凝土產(chǎn)品制造能耗比一級普通燒結粘土磚節(jié)約0.39 kgce,生產(chǎn)成本98.29元,相當于市場價的一半,經(jīng)濟和社會效益顯著。
[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，

本文編號：2317008