發(fā)布時(shí)間：2019-03-16 20:50

【摘要】：隨著工業(yè)的發(fā)展,現(xiàn)代混凝土對(duì)尺寸穩(wěn)定性的要求越來越高,然而其早強(qiáng),高強(qiáng),低水膠比,高流動(dòng)性的特點(diǎn)卻加劇了收縮變形的發(fā)展,尤其是早期收縮變形,過大的早期收縮將會(huì)使混凝土開裂,降低結(jié)構(gòu)的耐久性和安全性。介于此,對(duì)混凝土早期收縮的研究是未來混凝土收縮變形研究的重點(diǎn)。同時(shí)鎂及鎂合金產(chǎn)業(yè)近年來的快速發(fā)展,相應(yīng)的產(chǎn)生了大量的還原廢料——鎂渣,這對(duì)周圍環(huán)境造成嚴(yán)重污染,已有研究發(fā)現(xiàn)鎂渣具有一定的水化活性和體積膨脹性。如果能利用鎂渣的體積膨脹性補(bǔ)償一部分混凝土的早期收縮,將對(duì)減少混凝土早期收縮具有積極意義。此外將鎂渣作為混凝土的摻和料,還可以提高混凝土的強(qiáng)度,同時(shí)達(dá)到降低工程成本,減少鎂渣對(duì)環(huán)境污染的目的,因此本課題具有較高的研究意義。以常用的C30混凝土為研究對(duì)象,以鎂渣摻量、粉煤灰摻量、等為主要因素,設(shè)計(jì)正交試驗(yàn)。應(yīng)用非接觸法,通過測定混凝土初凝后3d內(nèi)的早期收縮率,利用極差分析、方差分析等分析方法,探究混凝土早期收縮的特性,通過研究得出如下結(jié)論:(1)鎂渣、粉煤灰和礦粉對(duì)混凝土的早期自縮具有抑制效應(yīng),鎂渣和粉煤灰的抑制效應(yīng)很顯著,礦粉抑制效應(yīng)的顯著性一般。(2)混凝土的早期自縮主要發(fā)生在終凝前,12h完成早期自收縮總量的60.0%以上,24h完成早期自收縮總量的80.0%以上,之后發(fā)展變緩,但72h后仍有一定的增長趨勢(shì)。(3)鎂渣復(fù)合摻合料混凝土的早期自縮與時(shí)間呈相關(guān)性很好的雙曲線關(guān)系,其參數(shù)模型的顯著性水平高,與各因數(shù)的相關(guān)性好。(4)鎂渣與粉煤灰、礦粉的復(fù)摻效應(yīng)鎂渣與粉煤灰的復(fù)摻效應(yīng)鎂渣與礦粉的復(fù)摻效應(yīng)。
[Abstract]:With the development of industry, modern concrete requires more and more dimensional stability. However, the characteristics of early strength, high strength, low water-binder ratio and high fluidity aggravate the development of shrinkage deformation, especially the early shrinkage deformation. Excessive early shrinkage will make the concrete crack and reduce the durability and safety of the structure. In view of this, the research on early shrinkage of concrete is the focus of the future research on shrinkage and deformation of concrete. At the same time, with the rapid development of magnesium and magnesium alloy industry in recent years, a large amount of reduction waste-magnesium slag has been produced, which has caused serious pollution to the surrounding environment. It has been found that magnesium slag has certain hydration activity and volume expansibility. If the volume expansibility of magnesium slag can be used to compensate the early shrinkage of some concrete, it will be of positive significance to reduce the early shrinkage of concrete. In addition, using magnesium slag as admixture of concrete can also improve the strength of concrete, at the same time, it can reduce the engineering cost and reduce the environmental pollution of magnesium slag, so this subject has higher research significance. Taking C30 concrete as research object, taking magnesium slag content and fly ash content as main factors, the orthogonal test is designed. By means of non-contact method, the early shrinkage rate of concrete within 3 days after initial setting is measured, and the characteristics of early shrinkage of concrete are studied by means of analysis of extreme difference and variance analysis. The conclusions are as follows: (1) magnesium slag, The early self-shrinkage of concrete is inhibited by fly ash and mineral powder. The inhibition effect of magnesium slag and fly ash is remarkable. (2) the early self-shrinkage of concrete mainly occurs before final setting. More than 60.0% of the total early autogenous contraction was completed at 12h, over 80.0% of the early autogenous contraction was completed at 24h, and then the development slowed down. However, there is still a certain increasing trend after 72 hours. (3) the early self-shrinkage of magnesium slag composite admixture concrete has a good hyperbolic relationship with the time, and the significant level of its parameter model is high. (4) Co-doping effect of magnesium slag and fly ash, compound mixing effect of magnesium slag and fly ash, compound mixing effect of magnesium slag and ore powder.
【學(xué)位授予單位】：寧夏大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TU528

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 崔自治;李?yuàn)檴?張程;陳東東;;鎂渣復(fù)合摻合料混凝土的干燥收縮特性[J];四川大學(xué)學(xué)報(bào)(工程科學(xué)版);2016年02期

2 崔自治;王建峰;張程;陳東東;;鎂渣礦粉復(fù)合對(duì)混凝土早期抗裂的影響研究[J];科學(xué)技術(shù)與工程;2016年08期

3 崔自治;王建峰;陳東東;萬清琦;;鎂渣混凝土的早期抗裂[J];混凝土;2015年10期

4 崔自治;李?yuàn)檴?張程;陳東東;;鎂渣粉煤灰復(fù)合混凝土的干燥收縮特性[J];水力發(fā)電學(xué)報(bào);2015年10期

5 李崢;崔自治;;C30鎂渣混凝土的碳化特性試驗(yàn)研究[J];混凝土與水泥制品;2015年04期

6 方仁玉;車蜀濤;鄭江濤;張麗;李好新;但建明;王堆;羅勇;;鎂渣配料煅燒水泥熟料的性能研究[J];水泥;2014年11期

7 劉牧天;黎夢(mèng)圓;王強(qiáng);;等強(qiáng)度條件下石灰石粉對(duì)混凝土收縮和耐久性的影響[J];硅酸鹽通報(bào);2014年08期

8 李?yuàn)檴?崔自治;;鎂渣對(duì)C30混凝土干燥收縮的作用效應(yīng)研究[J];中國農(nóng)村水利水電;2014年06期

9 張華;吳和峰;;鎂渣對(duì)混凝土力學(xué)性能的影響[J];四川建材;2014年03期

10 崔自治;周康;李瀟;郭磊;;鎂渣細(xì)骨料混凝土的強(qiáng)度特性研究[J];混凝土;2013年06期

相關(guān)碩士學(xué)位論文 前1條

1 李?yuàn)檴?鎂渣混凝土的干燥收縮研究[D];寧夏大學(xué);2015年

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本文編號(hào)：2441948