高強高韌性橋面鋪裝混凝土制備及其性能研究
發(fā)布時間：2018-12-12 06:34
【摘要】：水泥混凝土由于原材料豐富、強度高、剛度大和性價比高等優(yōu)點而成為重要的橋面鋪裝材料之一。但水泥混凝土的抗拉強度低、脆性大，易開裂，因而在交通荷載、自然因素與收縮應(yīng)力等綜合作用下，較易出現(xiàn)裂縫和斷裂等病害，且病害一旦形成，修復(fù)難度較大，將嚴重影響橋梁的安全性和橋面鋪裝的耐久性。本文采用混雜纖維增強技術(shù)手段，綜合考慮混凝土工作性、力學(xué)性能和彎曲性能，從多尺度角度對混凝土進行了增強增韌設(shè)計，制備出了具有變形硬化特征的高強高韌性水泥混凝土橋面鋪裝材料，并對其性能進行了深入研究。 論文從單纖維增強混凝土入手，對聚乙烯纖維（PE）混凝土和聚丙烯粗合成纖維（CPP）混凝土的力學(xué)性能和彎曲性能進行了研究。結(jié)果表明，單纖維混凝土抗壓強度可達60MPa，單纖維混凝土的變形性能有所改善，混凝土荷載-撓度曲線由脆性破壞變?yōu)樽冃渭彼佘浕�，具有一定的裂后承載能力，但混凝土的彎曲韌性仍較差，單纖維增韌方式不能使混凝土獲得高韌性。 基于混凝土多相、多尺度層次的非均質(zhì)結(jié)構(gòu)特性，結(jié)合單纖維增韌的試驗結(jié)果，本文采用了兩種不同性質(zhì)和不同尺度的纖維混雜增強增韌體系——聚乙烯纖維與聚丙烯粗合成纖維混雜體系，對混凝土內(nèi)不同結(jié)構(gòu)和性能層次進行了逐級強化與增韌，制備出了高強高韌性混雜纖維混凝土，并通過抗壓強度試驗、四點彎曲試驗、纖維/基體界面改性試驗和耐磨性試驗對混雜纖維混凝土性能進行了全面研究。結(jié)果表明，混凝土抗壓強度超過60MPa，抗彎拉強度可達8MPa；混凝土彎曲性能顯著提高，，荷載-撓度曲線飽滿并具備變性硬化特征，裂后承載保持能力較強；混雜纖維混凝土的韌性指數(shù)與殘余強度系數(shù)明顯提高，均超過理想彈塑性材料，抗彎拉韌性水平多數(shù)為3，部分可達4；CPP纖維/基體界面改性后，粘結(jié)強度提高，界面區(qū)結(jié)構(gòu)更為密實，界面微結(jié)構(gòu)得以強化，在宏觀上可延緩大裂縫的擴展與混凝土的破壞，輔助細觀尺度的增韌，有效提高混凝土的彎曲韌性；材料耐磨性與抗?jié)B性隨粗集料體積水平提高而降低，因此粗集料水平不宜過高。
[Abstract]:Cement concrete has become one of the important bridge deck paving materials because of its rich raw materials, high strength, high stiffness and high cost performance. However, cement concrete has low tensile strength, high brittleness and easy cracking. Therefore, under the combined action of traffic load, natural factors and shrinkage stress, cracks and fractures are more likely to occur, and once the disease is formed, it is difficult to repair. It will seriously affect the safety of bridge and the durability of deck pavement. In this paper, the reinforcement and toughening design of concrete is carried out from the angle of multi-scale by means of hybrid fiber reinforcement technology and considering the workability, mechanical properties and flexural properties of concrete. The high strength and high toughness cement concrete bridge deck pavement materials with deformation hardening characteristics were prepared and their properties were studied. In this paper, the mechanical properties and bending properties of polyethylene fiber (PE) concrete and polypropylene coarse synthetic fiber (CPP) concrete are studied from the point of view of single fiber reinforced concrete. The results show that the compressive strength of single fiber concrete can reach 60 MPA, the deformation performance of single fiber concrete has been improved, the load-deflection curve of concrete has changed from brittle failure to deformation and rapid softening, and it has certain post-crack bearing capacity. However, the flexural toughness of concrete is still poor, and the single fiber toughening method can not make concrete obtain high toughness. Based on the heterogeneous structure characteristics of concrete with multi-phase and multi-scale, combined with the test results of single fiber toughening, In this paper, two kinds of fiber hybrid toughening systems of different properties and different scales, polyethylene fiber and polypropylene coarse synthetic fiber hybrid system, are used to strengthen and toughen the different structures and properties of concrete step by step. High strength and high toughness hybrid fiber reinforced concrete was prepared. The properties of hybrid fiber reinforced concrete were studied by compressive strength test, four-point bending test, fiber / matrix interface modification test and wear resistance test. The results show that the compressive strength of concrete is more than 60 MPA and the flexural tensile strength is up to 8 MPA, the flexural property of concrete is improved significantly, the load-deflection curve is full and has the characteristics of denaturation and hardening, and the load-bearing capacity of the concrete after crack is relatively strong. The toughness index and residual strength coefficient of hybrid fiber reinforced concrete are higher than that of ideal elastoplastic material. The flexural and tensile toughness level of hybrid fiber reinforced concrete is mostly 3 and some of them can reach 4. After the modification of CPP fiber / matrix interface, the bond strength is increased, the structure of interface area is more dense, and the interface microstructure is strengthened, which can delay the propagation of large cracks and the destruction of concrete macroscopically, and assist in the toughening of meso-scale. Effectively improve the flexural toughness of concrete; The wear-resistance and impermeability of the materials decrease with the increase of the volume level of coarse aggregate, so the level of coarse aggregate should not be too high.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U444;U443.33
[Abstract]:Cement concrete has become one of the important bridge deck paving materials because of its rich raw materials, high strength, high stiffness and high cost performance. However, cement concrete has low tensile strength, high brittleness and easy cracking. Therefore, under the combined action of traffic load, natural factors and shrinkage stress, cracks and fractures are more likely to occur, and once the disease is formed, it is difficult to repair. It will seriously affect the safety of bridge and the durability of deck pavement. In this paper, the reinforcement and toughening design of concrete is carried out from the angle of multi-scale by means of hybrid fiber reinforcement technology and considering the workability, mechanical properties and flexural properties of concrete. The high strength and high toughness cement concrete bridge deck pavement materials with deformation hardening characteristics were prepared and their properties were studied. In this paper, the mechanical properties and bending properties of polyethylene fiber (PE) concrete and polypropylene coarse synthetic fiber (CPP) concrete are studied from the point of view of single fiber reinforced concrete. The results show that the compressive strength of single fiber concrete can reach 60 MPA, the deformation performance of single fiber concrete has been improved, the load-deflection curve of concrete has changed from brittle failure to deformation and rapid softening, and it has certain post-crack bearing capacity. However, the flexural toughness of concrete is still poor, and the single fiber toughening method can not make concrete obtain high toughness. Based on the heterogeneous structure characteristics of concrete with multi-phase and multi-scale, combined with the test results of single fiber toughening, In this paper, two kinds of fiber hybrid toughening systems of different properties and different scales, polyethylene fiber and polypropylene coarse synthetic fiber hybrid system, are used to strengthen and toughen the different structures and properties of concrete step by step. High strength and high toughness hybrid fiber reinforced concrete was prepared. The properties of hybrid fiber reinforced concrete were studied by compressive strength test, four-point bending test, fiber / matrix interface modification test and wear resistance test. The results show that the compressive strength of concrete is more than 60 MPA and the flexural tensile strength is up to 8 MPA, the flexural property of concrete is improved significantly, the load-deflection curve is full and has the characteristics of denaturation and hardening, and the load-bearing capacity of the concrete after crack is relatively strong. The toughness index and residual strength coefficient of hybrid fiber reinforced concrete are higher than that of ideal elastoplastic material. The flexural and tensile toughness level of hybrid fiber reinforced concrete is mostly 3 and some of them can reach 4. After the modification of CPP fiber / matrix interface, the bond strength is increased, the structure of interface area is more dense, and the interface microstructure is strengthened, which can delay the propagation of large cracks and the destruction of concrete macroscopically, and assist in the toughening of meso-scale. Effectively improve the flexural toughness of concrete; The wear-resistance and impermeability of the materials decrease with the increase of the volume level of coarse aggregate, so the level of coarse aggregate should not be too high.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U444;U443.33
【參考文獻】
相關(guān)期刊論文 前10條
1 翟紅俠,李美娟;高強輕集料混凝土的發(fā)展與分析[J];安徽建筑工業(yè)學(xué)院學(xué)報(自然科學(xué)版);1997年03期
2 季節(jié),徐世法,羅曉輝,馮治安,高建立;橋面鋪裝病害調(diào)查及成因分析[J];北京建筑工程學(xué)院學(xué)報;2000年03期
3 劉永光;曾慶敦;;鋼纖維混凝土橋面鋪裝層的細觀應(yīng)力破壞分析[J];東南大學(xué)學(xué)報(自然科學(xué)版);2006年05期
4 黃從運,王服人;聚合物改性水泥混凝土[J];房材與應(yīng)用;2002年05期
5 蔡向榮;徐世p
本文編號：2374096
本文鏈接：http://sikaile.net/kejilunwen/jiaotonggongchenglunwen/2374096.html
教材專著
