發(fā)布時(shí)間：2018-03-21 00:05

  本文選題：天然輕骨料混凝土　切入點(diǎn)：三點(diǎn)彎曲試驗(yàn)　出處：《內(nèi)蒙古農(nóng)業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：內(nèi)蒙古地區(qū)天然浮石儲(chǔ)量豐富,天然輕骨料混凝土在工程上的應(yīng)用越來越廣泛。目前對(duì)輕骨料混凝土大都是耐久性、抗凍性等宏觀層次的研究,忽略了混凝土材料內(nèi)部復(fù)雜的細(xì)觀結(jié)構(gòu),難以揭示材料變形和破壞的物理破壞機(jī)理,基于這一點(diǎn),本文研究輕骨料混凝土的抗折性能,結(jié)合數(shù)字圖像處理技術(shù)和數(shù)值模擬對(duì)輕骨料混凝土的細(xì)觀力學(xué)性能進(jìn)行研究。本研究選取粉煤灰和偏高嶺土作為摻合料,采用已設(shè)計(jì)好的配合比和制備工藝制作尺寸為350mm × 300mm × 75mm的試塊,制備三種不同的輕骨料混凝土,分別為粉煤灰輕骨料混凝土、偏高嶺土輕骨料混凝土、普通輕骨料混凝土。用以上三組試件,養(yǎng)護(hù)28d后,用巖石切割機(jī)切割成350mm × 75mm × 75mm的小梁試件,共9塊,并用數(shù)碼相機(jī)拍攝切割面,用于之后的數(shù)字圖像處理。然后進(jìn)行小梁的三點(diǎn)彎曲試驗(yàn),研究其抗折性能以及其應(yīng)力應(yīng)變。將采集小梁試件的切割面的圖像進(jìn)行數(shù)字圖像處理,包括圖像增強(qiáng)、銳化、圖像分割、圖像二值化(圖中只含有輕骨料和水泥砂漿)、圖像矢量化等,使其成為能導(dǎo)入ABAQUS有限元軟件的DXF格式圖形。采用ABAQUS有限元軟件對(duì)基于數(shù)字圖像處理技術(shù)的輕骨料混凝土彎曲試驗(yàn)進(jìn)行有限元模擬,研究其應(yīng)力應(yīng)變分布情況,將其與室內(nèi)試驗(yàn)的數(shù)據(jù)進(jìn)行對(duì)比,驗(yàn)證數(shù)值模擬的可靠性與準(zhǔn)確性。并在此基礎(chǔ)上分別對(duì)骨料和水泥砂漿的應(yīng)力應(yīng)變情況進(jìn)行分析,研究其破壞機(jī)理。最后整理分析試驗(yàn)數(shù)據(jù)并對(duì)室內(nèi)試驗(yàn)和數(shù)值模擬的對(duì)比分析得出以下主要結(jié)論：三種輕骨料混凝土的抗折能力相差不大,加載時(shí),其內(nèi)部水泥砂漿的承擔(dān)的應(yīng)力要比浮石的應(yīng)力要大。數(shù)字圖像處理技術(shù)結(jié)合ABAQUS有限元軟件技術(shù)可以準(zhǔn)確地模擬輕骨料混凝土的力學(xué)性能,可以減少室內(nèi)試驗(yàn)的工作量,可以更好地對(duì)輕骨料混凝土的破壞機(jī)理在細(xì)觀層次進(jìn)行研究。
[Abstract]:There are abundant natural pumice in Inner Mongolia, and the application of natural lightweight aggregate concrete in engineering is more and more extensive. At present, most of the researches on lightweight aggregate concrete are at the macro level, such as durability, frost resistance, etc. It is difficult to reveal the physical failure mechanism of material deformation and failure by neglecting the complex mesoscopic structure of concrete material. Based on this point, the flexural properties of lightweight aggregate concrete are studied in this paper. Combined with digital image processing technology and numerical simulation, the meso-mechanical properties of lightweight aggregate concrete were studied. Fly ash and metakaolin were selected as admixtures in this study. Three different kinds of lightweight aggregate concrete, fly ash lightweight aggregate concrete and metakaolin lightweight aggregate concrete, were prepared by using the designed mix ratio and the preparation process of the test block with the size of 350 mm 脳 300 mm 脳 75 mm. Ordinary lightweight aggregate concrete. After 28 days of maintenance with the above three groups of specimens, the trabeculae were cut into 350mm 脳 75mm 脳 75mm trabeculae by rock cutting machine, 9 pieces of trabeculae were cut with digital camera. Then the three-point bending test of trabecular beam is carried out to study its flexural performance and stress and strain. The image of the cut surface of trabecular specimen is processed by digital image processing, including image enhancement and sharpening. Image segmentation, image binarization (image containing only lightweight aggregate and cement mortar, image vectorization, etc.). ABAQUS finite element software is used to simulate the bending test of lightweight aggregate concrete based on digital image processing technology, and the distribution of stress and strain is studied. The reliability and accuracy of the numerical simulation are verified by comparing it with the data of laboratory test. On this basis, the stress-strain situation of aggregate and cement mortar is analyzed respectively. The failure mechanism of the concrete is studied. Finally, the test data are analyzed and compared with the numerical simulation. The main conclusions are as follows: the flexural strength of the three lightweight aggregate concrete is not different from that of the other three kinds of lightweight aggregate concrete, when the concrete is loaded, The internal stress of cement mortar is greater than that of pumice. Digital image processing technology combined with ABAQUS finite element software technology can accurately simulate the mechanical properties of lightweight aggregate concrete and reduce the workload of laboratory test. The failure mechanism of lightweight aggregate concrete can be studied at meso level.
【學(xué)位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU528.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 秦淑芳;申向東;;偏高嶺土對(duì)天然輕骨料混凝土力學(xué)性能影響的研究[J];硅酸鹽通報(bào);2013年06期

相關(guān)碩士學(xué)位論文 前1條

1 倪文琛;膠粉改性瀝青混合料的力學(xué)性能研究[D];內(nèi)蒙古工業(yè)大學(xué);2011年

，

本文編號(hào)：1641386