纖維增強(qiáng)高韌性水泥基材料設(shè)計(jì)與性能研究
發(fā)布時(shí)間：2018-09-15 06:09
【摘要】：現(xiàn)代建筑對建筑材料性能的要求越來越高,傳統(tǒng)混凝土的發(fā)展由于其脆性大、韌性差的原因受到了很大的限制,混凝土的服役壽命和安全性問題日益突出。因此,研究高韌性水泥基材料,提高混凝土的柔韌性和彎曲變形能力,對于提高現(xiàn)代建筑結(jié)構(gòu)的服役壽命和服役安全性具有重要的意義。本論文針對傳統(tǒng)混凝土剛度大、柔韌性差的問題,開展丁苯乳液改性鋼纖維混凝土、PVA纖維增強(qiáng)高韌性水泥基材料的制備技術(shù)、材料設(shè)計(jì)和性能研究。通過丁苯乳液、鋼纖維的復(fù)合摻入來達(dá)到同時(shí)增加傳統(tǒng)混凝土基體柔性、混凝土開裂后鋼纖維與混凝土粘結(jié)強(qiáng)度的效果來達(dá)到增強(qiáng)混凝土韌性的目的,并通過掃描電鏡、孔隙率測試等微觀測試技術(shù)解釋增韌原理;并從試驗(yàn)原材料性質(zhì)出發(fā),通過對原材料的預(yù)先處理、混合料攪拌工藝的選取,制備具有較高彎曲變形能力、能產(chǎn)生多縫開裂現(xiàn)象的PVA纖維增強(qiáng)高韌性水泥基材料,并評價(jià)不同配比水泥基材薄板和梁的彎曲韌性指數(shù),觀察裂紋的開裂形式;最后試驗(yàn)了兩種高韌性水泥基材料復(fù)合使用的狀態(tài)。得出以下結(jié)論:1、丁苯乳液能改善新拌混凝土、新拌鋼纖維混凝土的工作性能;混凝土的抗壓強(qiáng)度隨著丁苯乳液摻量的增加而顯著降低,但其抗折強(qiáng)度隨著丁苯乳液的增加而提高;15%的丁苯乳液與1%的鋼纖維復(fù)摻,能明顯提高混凝土的抗折強(qiáng)度、抗沖擊韌性以及彎曲韌性。2、顯微硬度分析儀顯示:15%的丁苯乳液改善了養(yǎng)護(hù)28d混凝土集料-漿體界面過渡區(qū)顯微硬度;利用掃描電子顯微鏡觀察了聚合物混凝土的微觀結(jié)構(gòu),以及鋼纖維從普通混凝土、聚合物混凝土中拔出后其表面形貌以及凹槽區(qū)微觀形貌,結(jié)果表明:丁苯乳液在混凝土中交織成膜,增加了漿體、漿體-集料的致密性,增強(qiáng)了鋼纖維與混凝土之間的界面粘結(jié)強(qiáng)度。3、丁苯乳液使混凝土分級進(jìn)汞量波峰左移;在孔徑為100nm-1000nm范圍內(nèi)的孔隙率提高;連續(xù)的聚合物網(wǎng)狀膜結(jié)構(gòu)連通較大的毛細(xì)孔,使大孔分割成封閉的小孔,在孔徑大小10nm的凝膠孔區(qū)域范圍內(nèi)的凝膠孔孔隙率增大;空氣養(yǎng)護(hù)下,由于干燥收縮出現(xiàn)大量裂紋,在大毛細(xì)孔即孔徑100nm區(qū)域范圍內(nèi),孔隙數(shù)量相對于標(biāo)準(zhǔn)養(yǎng)護(hù)時(shí)明顯增加。4、選取粉煤灰做礦物摻合料,PVA纖維表面用硅油處理、纖維預(yù)分散處理的水泥基薄板能達(dá)到10.7mm的彎曲變形量,有明顯的裂縫展開階段,纖維的滑移是水泥基材獲得變形能力的重要原因;摻入丁苯乳液的水泥基材料彎曲性能降低,板材厚度是決定彎曲變形量和裂縫形態(tài)的主要因素。5、PVA高韌性水泥基材料保護(hù)層能將內(nèi)部普通混凝土的裂縫分散成許多微小的裂縫,兩種材料復(fù)合使用具有良好的應(yīng)用前景。
[Abstract]:Modern buildings require higher and higher performance of building materials. The development of traditional concrete is restricted because of its high brittleness and poor toughness. The service life and safety of concrete are becoming more and more serious. Therefore, it is of great significance to study high toughness cement-based materials and improve the flexibility and flexural deformation ability of concrete for improving the service life and safety of modern building structures. Aiming at the problems of high stiffness and poor flexibility of traditional concrete, the preparation technology, material design and properties of the modified steel fiber reinforced concrete (PVA) fiber reinforced by SBR emulsion were studied in this paper. The toughness of concrete was enhanced by adding the composite of steel fiber and butadiene emulsion to increase the flexibility of traditional concrete matrix and the bond strength of steel fiber and concrete after concrete cracking, and the toughness of concrete was enhanced by scanning electron microscope (SEM). The microcosmic testing techniques such as porosity test explain the toughening principle, and from the properties of the experimental raw materials, through the pre-treatment of the raw materials and the selection of the mixture mixing process, the preparation has the higher bending deformation ability. The PVA fiber reinforced high toughness cement-based material which can produce multi-joint cracking phenomenon was used to evaluate the flexural toughness index of the sheet and beam of cement base material with different proportions and to observe the crack form. Finally, two kinds of high toughness cement-based materials were tested. The following conclusions can be drawn: 1, butadiene emulsion can improve the working performance of fresh concrete and fresh steel fiber reinforced concrete, and the compressive strength of the concrete decreases significantly with the increase of the content of styrene butadiene emulsion. However, with the increase of butadiene-butadiene emulsion, the flexural strength of concrete is increased by 15% of butadiene emulsion and 1% of steel fiber, and the flexural strength of concrete can be improved obviously. The impact toughness and flexural toughness. 2. The microhardness analyzer showed that the microhardness of the transition zone between aggregate and slurry was improved by using 1: 15% butadiene emulsion, and the microstructure of polymer concrete was observed by scanning electron microscope (SEM). As well as the surface morphology of steel fiber extracted from ordinary concrete and polymer concrete, and the micro-morphology of grooves. The results show that butadiene emulsion interweaves into film in concrete, which increases the compactness of slurry, paste and aggregate. The interfacial bond strength between steel fiber and concrete is strengthened. 3. The styrene butadiene emulsion shifts the peak of mercury content in concrete to the left; the porosity increases in the range of pore size 100nm-1000nm; and the continuous polymer reticular membrane structure connects the larger capillary, The large pore is divided into a closed pore, and the porosity of the gel pore increases in the range of the gel pore area of the pore size 10nm. Under air curing, a large number of cracks occur due to the drying shrinkage, and in the large capillary area, that is, in the 100nm region of pore size, Compared with the standard curing condition, the number of pores is obviously increased .4.The surface of PVA fiber is treated with silicon oil by using fly ash as mineral admixture. The cement base sheet treated by fiber pre-dispersion can reach the bending deformation of 10.7mm and has obvious crack development stage. The slippage of the fiber is the important reason for the deformation ability of the cement substrate, and the flexural property of the cement-based material mixed with the butadiene emulsion is decreased. The thickness of plate is the main factor that determines the amount of bending deformation and the shape of crack. The protective layer of PVA high toughness cement-based material can disperse the cracks of common concrete into many tiny cracks. The composite use of the two kinds of materials has a good application prospect.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU528
[Abstract]:Modern buildings require higher and higher performance of building materials. The development of traditional concrete is restricted because of its high brittleness and poor toughness. The service life and safety of concrete are becoming more and more serious. Therefore, it is of great significance to study high toughness cement-based materials and improve the flexibility and flexural deformation ability of concrete for improving the service life and safety of modern building structures. Aiming at the problems of high stiffness and poor flexibility of traditional concrete, the preparation technology, material design and properties of the modified steel fiber reinforced concrete (PVA) fiber reinforced by SBR emulsion were studied in this paper. The toughness of concrete was enhanced by adding the composite of steel fiber and butadiene emulsion to increase the flexibility of traditional concrete matrix and the bond strength of steel fiber and concrete after concrete cracking, and the toughness of concrete was enhanced by scanning electron microscope (SEM). The microcosmic testing techniques such as porosity test explain the toughening principle, and from the properties of the experimental raw materials, through the pre-treatment of the raw materials and the selection of the mixture mixing process, the preparation has the higher bending deformation ability. The PVA fiber reinforced high toughness cement-based material which can produce multi-joint cracking phenomenon was used to evaluate the flexural toughness index of the sheet and beam of cement base material with different proportions and to observe the crack form. Finally, two kinds of high toughness cement-based materials were tested. The following conclusions can be drawn: 1, butadiene emulsion can improve the working performance of fresh concrete and fresh steel fiber reinforced concrete, and the compressive strength of the concrete decreases significantly with the increase of the content of styrene butadiene emulsion. However, with the increase of butadiene-butadiene emulsion, the flexural strength of concrete is increased by 15% of butadiene emulsion and 1% of steel fiber, and the flexural strength of concrete can be improved obviously. The impact toughness and flexural toughness. 2. The microhardness analyzer showed that the microhardness of the transition zone between aggregate and slurry was improved by using 1: 15% butadiene emulsion, and the microstructure of polymer concrete was observed by scanning electron microscope (SEM). As well as the surface morphology of steel fiber extracted from ordinary concrete and polymer concrete, and the micro-morphology of grooves. The results show that butadiene emulsion interweaves into film in concrete, which increases the compactness of slurry, paste and aggregate. The interfacial bond strength between steel fiber and concrete is strengthened. 3. The styrene butadiene emulsion shifts the peak of mercury content in concrete to the left; the porosity increases in the range of pore size 100nm-1000nm; and the continuous polymer reticular membrane structure connects the larger capillary, The large pore is divided into a closed pore, and the porosity of the gel pore increases in the range of the gel pore area of the pore size 10nm. Under air curing, a large number of cracks occur due to the drying shrinkage, and in the large capillary area, that is, in the 100nm region of pore size, Compared with the standard curing condition, the number of pores is obviously increased .4.The surface of PVA fiber is treated with silicon oil by using fly ash as mineral admixture. The cement base sheet treated by fiber pre-dispersion can reach the bending deformation of 10.7mm and has obvious crack development stage. The slippage of the fiber is the important reason for the deformation ability of the cement substrate, and the flexural property of the cement-based material mixed with the butadiene emulsion is decreased. The thickness of plate is the main factor that determines the amount of bending deformation and the shape of crack. The protective layer of PVA high toughness cement-based material can disperse the cracks of common concrete into many tiny cracks. The composite use of the two kinds of materials has a good application prospect.
【學(xué)位授予單位】：武漢理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU528
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