發(fā)布時(shí)間：2018-04-17 00:09

  本文選題：再生粗骨料取代率 + 高溫�。� 參考：《湘潭大學(xué)》2017年碩士論文

【摘要】：自然資源的維護(hù)與合理使用一直是人類發(fā)展的一個(gè)重要方向,聯(lián)合國(guó)在20世紀(jì)80年代提出了可持續(xù)發(fā)展戰(zhàn)略。再生混凝土技術(shù)符合建筑資源可持續(xù)發(fā)展戰(zhàn)略,已被國(guó)際認(rèn)可為是一種發(fā)展綠色生態(tài)混凝土的主要措施。越來越多的學(xué)者致力于研究再生混凝土的性能和應(yīng)用,但是在綜合考慮再生混凝土力學(xué)性能的尺寸效應(yīng)和再生混凝土高溫性能方面的研究還有待進(jìn)一步加強(qiáng)。研究高溫后再生混凝土的力學(xué)性能,能有效的提高再生混凝土的應(yīng)用。對(duì)高溫后再生混凝土的抗壓強(qiáng)度和再生混凝土受壓性能的尺寸效應(yīng)方面進(jìn)行了較系統(tǒng)的研究。研究的主要內(nèi)容有:首先對(duì)再生粗骨料進(jìn)行加工處理,經(jīng)過機(jī)械及人工加工處理后得到試驗(yàn)所需要的再生粗骨料,測(cè)試了再生粗骨料的基本性能。與天然骨料的研究對(duì)比發(fā)現(xiàn),再生粗骨料較天然骨料表觀密度提高了1.39%,堆積密度降低了11.4%,吸水率提高了4.07%,壓碎指標(biāo)值提高了6.18%。其次,對(duì)高溫后再生混凝土的抗壓性能進(jìn)行了系統(tǒng)的試驗(yàn)研究。由試驗(yàn)過程和結(jié)果分析發(fā)現(xiàn),再生混凝土試塊隨著溫度的不斷升高,試塊表觀變化經(jīng)歷了從青灰色—淺灰色—灰褐色—熏黑的過程,再生混凝土與普通混凝土的表觀顏色變化過程區(qū)別不大。隨著溫度的不斷升高,再生混凝土試塊的質(zhì)量逐漸減少,從20℃到400℃的質(zhì)量損失大于400℃到600℃。隨著溫度的逐漸升高,再生混凝土的抗壓強(qiáng)度逐漸降低,這一點(diǎn)和普通混凝土相似。以再生粗骨料取代率為100%的再生混凝土(RC100)為例,從20℃到200℃時(shí),殘余抗壓強(qiáng)度下降了4.58%,從200℃到400℃殘余抗壓強(qiáng)度下降了3.93%,400℃到600℃的殘余抗壓強(qiáng)度下降了9.06%�？梢钥闯鲭S著溫度的升高,再生混凝土的殘余抗壓強(qiáng)度下降值有所不同,其中400℃到600℃再生混凝土的殘余抗壓強(qiáng)度下降值最大。再次,研究了再生粗骨料取代率對(duì)高溫后再生混凝土抗壓強(qiáng)度的影響以及再生粗骨料取代率對(duì)再生混凝土抗壓強(qiáng)度尺寸效應(yīng)的影響。試驗(yàn)結(jié)果表明:再生粗骨料取代率的增加對(duì)再生混凝土的受壓性能尺寸效應(yīng)影響不大,而隨著再生粗骨料取代率的增加高溫后再生混凝土的殘余抗壓強(qiáng)度呈現(xiàn)出不斷降低的趨勢(shì)。最后,研究了再生混凝土抗壓強(qiáng)度的尺寸效應(yīng),對(duì)試驗(yàn)結(jié)果分析后可以得到:再生混凝土抗壓強(qiáng)度的尺寸效應(yīng)較為明顯,邊長(zhǎng)為100mm的立方體試件的抗壓強(qiáng)度值和邊長(zhǎng)為200mm的立方體試件的抗壓強(qiáng)度值相對(duì)于邊長(zhǎng)為150mm的立方體標(biāo)準(zhǔn)試件的抗壓強(qiáng)度值,其尺寸效應(yīng)系數(shù)分別在(0.98~0.94)和(1.13~1.03),取平均值為0.96和1.08。建立了不同截面尺寸之間再生混凝土立方體抗壓強(qiáng)度的相關(guān)關(guān)系。
[Abstract]:The maintenance and rational use of natural resources has always been an important direction of human development. The United Nations put forward the strategy of sustainable development in the 1980s.The recycled concrete technology is in line with the sustainable development strategy of building resources and has been recognized as a major measure for the development of green ecological concrete.More and more scholars devote themselves to study the properties and applications of recycled concrete, but the research on the dimension effect and high temperature performance of recycled concrete still needs to be further strengthened.Studying the mechanical properties of recycled concrete after high temperature can effectively improve the application of recycled concrete.The compressive strength of recycled concrete after high temperature and the size effect of compressive performance of recycled concrete are studied systematically.The main contents of the research are as follows: firstly, the recycled coarse aggregate is processed, and the recycled coarse aggregate is obtained after mechanical and manual processing, and the basic properties of the recycled coarse aggregate are tested.Compared with the natural aggregate, the apparent density of regenerated coarse aggregate increased by 1.39, the accumulation density decreased by 11.4 percent, the water absorption rate increased by 4.07, and the crushing index value increased by 6.18.Secondly, the compressive performance of recycled concrete after high temperature is studied systematically.According to the experimental process and the analysis of the results, it is found that the apparent change of the recycled concrete specimen goes through the process of green gray, light gray, grayish brown and black with the increasing of temperature.The process of apparent color change of recycled concrete and ordinary concrete is not different.With the increasing of temperature, the mass of recycled concrete samples decreases gradually, and the mass loss from 20 鈩，

本文編號(hào)：1761176