隧道路面聚合物水泥砂浆抗滑表层材料研究

发布时间：2018-04-08 12:12

本文选题：隧道水泥路面　切入点：抗滑表层　出处：《长安大学》2017年博士论文

【摘要】：隧道水泥混凝土路面在行车荷载的作用下易被磨光,逐渐失去抗滑性能而引发交通事故。水泥砂浆可作为抗滑表层对隧道水泥路面进行养护和修补,有效恢复水泥路面的路表功能。但普通水泥砂浆存在脆性大、韧性不足的缺陷,与旧路面粘结效果较差,且在荷载作用及隧道复杂环境中抗滑性能发生快速衰减,导致养护工作失败,因而开发应用耐久性能良好的新型隧道水泥路面抗滑表层材料己成为公路行业的当务之急。本文针对公路隧道特殊的酸性、油污及潮湿环境,对现有聚醋酸乙烯酯(PVAc)进行改性,制备出耐水性能优良的改性聚醋酸乙烯酯(P(BA-VAc))乳液,并将其用于水泥砂浆改性,研究了P(BA-VAc)乳液对水泥砂浆物理及力学特性的影响;开发了一种三轮加速磨耗仪,可模拟汽车轮胎与抗滑表层的磨损行为;提出了以“抗滑耐久性、粘结性、耐化学腐蚀性”为组成的隧道路面聚合物水泥抗滑砂浆的耐久性能评价体系,主要研究内容如下:采用具有耐水基团的丙烯酸丁酯(BA)对PVAc进行改性,制备了单体转化率超过97%的P(BA-VAc)乳液,通过乳液粒径分布、乳液稳定性、胶膜耐水性等评价了改性乳液的综合性能,并通过红外光谱分析、透射电镜分析等表征了聚合物的微观结构,结果表明改性单体BA与VAc相容性较好,且能够改善聚合物胶膜的耐水性和柔韧性。采用P(BA-VAc)、苯丙、丁苯、氯丁等乳液制备了聚合物改性水泥砂浆,并通过流动度、凝结时间、保水率、吸水率及干缩率等评价了聚合物改性砂浆的物理性能;通过抗折性能、抗压性能及抗拉性能评价了聚合物改性砂浆的力学特性;通过扫描电镜(SEM)观测了聚合物改性砂浆的微观形貌。研究发现P(BA-VAc)乳液可有效改善水泥砂浆的物理性能与力学特性,且在P(BA-VAc)掺量为10%~15%时整体性能较佳;SEM测试结果表明P(BA-VAc)胶膜可有效填充水泥砂浆的内部孔隙,在水化产物与集料之间起到桥接作用,使水泥石结构致密。采用摆式摩擦系数测试仪及动态摩擦系数测试仪(DFT)评价了聚合物砂浆的抗滑性能,采用水泥胶砂耐磨试验仪、湿轮磨耗试验仪及自主开发的三轮加速磨耗仪评价了水泥砂浆抗滑表层的耐磨性能,并对磨耗前后的试件进行抗滑性能对比研究,提出了聚合物改性砂浆加铺层的抗滑耐久性评价方法。研究结果表明,P(BA-VAc)乳液可有效改善水泥砂浆的抗滑性能,砂浆的抗滑系数随着聚合物掺量增加变化不明显,但耐磨性能随乳液增加而得到明显改善;不同聚合物对水泥砂浆抗滑耐久性能改善效果不同,其中P(BA-VAc)、苯丙及丁苯乳液对可有效改善砂浆的抗滑耐久性;而氯丁、VAE乳液对砂浆的抗滑耐久性改善效果不明显。采用抗折粘结试验、“8”字模拉伸粘结试验及Positest粘结力试验评价了聚合物水泥砂浆与旧水泥试件间的粘结性能,并推荐了三种测试方法的适用环境;分别研究了不同界面处理方式、界面剂类型及养护制度对粘结性能的影响,确定了最佳的处理方案;此外,采用SEM观测了新旧试件界面间的粘结状况,通过X射线光电子能谱(XPS)分析聚合物水泥砂浆中各组成材料间存在的化学反应情况。研究发现:P(BA-VAc)乳液可显著改善水泥砂浆的粘结强度,改性砂浆与旧水泥试件间的粘结强度随P(BA-VAc)掺量的增加而增加;建议室内试验采用抗折粘结试验和Positest粘结试验测试结果联合使用,室外检测可采用Positest粘结试验;建议对旧试件进行凿毛洁净处理,且选择与其配比相同的聚合物水泥浆作为界面剂,试件脱模后前期采用90%湿度养护,后期采用60%湿度养护;水泥净浆试样表面存在气孔,P(BA-VAc)乳液会渗入孔内,形成一定的嵌入深度,并紧密地粘附在水泥净浆的表面,而石英岩表面结构致密,聚合物乳液较难渗入其内部形成嵌入结构,仅仅附着在石英岩表面;P(BA-VAc)乳液与石英砂及水泥石中的Ca(OH)2在界面上均发生了化学反应,其与Ca(OH)2的化学位移效应高于石英砂。研究了P(BA-VAc)改性砂浆经硫酸、硝酸、氢氧化钠、硫酸钠和汽油腐蚀后的强度残留比,并通过扫描电镜(SEM)观测了砂浆的微观形貌,采用X射线衍射仪(XRD)分析了经腐蚀后砂浆的物质组成,结果表明:水泥砂浆耐硫酸、硝酸腐蚀性能较差,但P(BA-VAc)乳液可有效改善砂浆的耐酸腐蚀性能;P(BA-VAc)乳液可一定程度改善水泥砂浆的耐硫酸盐酸腐蚀性能;高含量PVAc改性砂浆可应用于碱性环境;油污对普通水泥砂浆和聚合物水泥砂浆腐蚀效果均不明显;P(BA-VAc)胶膜可填充水泥砂浆的内部孔隙,有效阻塞了腐蚀介质进入,P(BA-VAc)胶膜同时具有弹性,可吸收膨胀应力,降低了膨胀破坏发生,从而改善砂浆的耐腐蚀性能。
[Abstract]:Cement concrete pavement in tunnel traffic loads to be polished, losing skid resistance caused by traffic accidents. Cement mortar can be used as anti slide surface of maintenance and repair of tunnel cement concrete pavement, cement pavement effectively restore function. But the ordinary cement mortar has high brittleness, low toughness and poor defects. The old pavement bonding effect, and the loads in the tunnel and the complex environment anti sliding performance rapid attenuation, resulting in failure of maintenance work, thus the development of new tunnel cement concrete pavement application of good durability anti slide surface material has become a pressing matter of the moment of the highway industry. Aiming at the highway tunnel special acidic oil and humid environment, the existing polyvinyl acetate (PVAc) was modified to prepare excellent waterproof properties of modified polyvinyl acetate emulsion (P (BA-VAc)), which are used for modification of cement mortar, Study of P (BA-VAc) emulsion effect on physical and mechanical properties of cement mortar; developed a three accelerated wear tester, which can simulate the automobile tire and sliding wear behavior of the surface; put forward to the "anti slide durability, adhesion, durability evaluation system of chemical corrosion resistance for tunnel pavement polymer cement the composition of anti slide mortar, the main research contents are as follows: using butyl acrylate with water group (BA) modification of PVAc, the monomer conversion rate of more than 97% of the P (BA-VAc) was prepared by emulsion, emulsion particle size distribution, emulsion stability, film water resistance to evaluate the comprehensive performance of modified emulsion, and through infrared spectrum analysis, the microstructure of polymer was characterized by transmission electron microscopy analysis. The results showed that modified monomers BA and VAc had good compatibility, and can improve the polymer film water resistance and flexibility. Using P (BA-VAc), propyl benzene, Styrene butadiene emulsion was prepared, chlorine and other polymer modified cement mortar, and the fluidity, setting time, water retention rate, water absorption rate and dry shrinkage to evaluate the physical properties of polymer modified mortar; the flexural properties, tensile properties and compressive performance evaluation of mechanical properties of the polymer modified mortar by scanning; electron microscopy (SEM) observations of the morphology of polymer modified mortar. The study found that P (BA-VAc) emulsion can improve the physical properties and mechanical properties of cement mortar, and the P (BA-VAc) content is 10%~15% when the overall performance is better; SEM test results show that the P (BA-VAc) internal pore film can effectively filled with cement mortar, plays a bridging role between hydration products and aggregate, make the structure of cement stone density. Using the pendulum friction coefficient tester tester and dynamic friction coefficient (DFT) to evaluate the anti slide performance of polymer mortar, using cement mortar Abrasion tester, wet abrasion tester and self-developed three accelerated abrasion tester cement mortar anti sliding wear resistance and wear on the surface of the evaluation of the samples before and after comparison of the performance of anti slide, the polymer modified mortar and durability evaluation method of anti slip layer. The results showed that P (BA-VAc) emulsion can effectively improve the anti slide performance of cement mortar, sliding coefficient with polymer content did not change significantly increased resistance of mortar, but with the increase of wear resistance of emulsion was improved; different polymer cement mortar can improve the durability of anti slide effect, in which P (BA-VAc), styrene and butadiene the emulsion can effectively improve the durability of anti slip mortar; and neoprene, VAE emulsion to improve the durability of anti slide effect is not obvious. The mortar flexural bond test, "8" font tensile test and Positest adhesion force test The polymer cement mortar and cement bond performance between, and recommend the applicable environment of the three kinds of test methods; different interface processing methods were studied, effects of agent and curing system on the bonding properties of the interface, to determine the optimal processing scheme; in addition, using SEM observations of the old and new test piece bonding condition the interface between the X by X-ray photoelectron spectroscopy (XPS) analysis of the various components of the polymer cement mortar material between the presence of a chemical reaction. The study found: P (BA-VAc) emulsion can significantly improve the bonding strength of cement mortar, modified mortar and the bond strength between old cement test with P (BA-VAc) increased volume increased; indoor experiment using flexural bond test and Positest bond test results combined with the outdoor can be tested by Positest bond test; suggestions for cutting hair clean treatment on old specimens, and the selection and The ratio of the same polymer cement mortar as interfacial agent, the specimen after stripping early with 90% humidity curing, the 60% humidity curing; there are pores in cement sample surface, P (BA-VAc) emulsion will seep into the hole, forming a certain depth of embedding, and closely adhered on the surface of cement paste, and quartz rock compact surface structure, polymer emulsion is difficult to penetrate into the internal formation of embedded structure, only attached to the silica surface; P (BA-VAc) emulsion with quartz sand and cement stone in Ca (OH) 2 occurred at the interface of chemical reaction, and the Ca (OH) chemical shift effect 2 higher than that of quartz sand of P (BA-VAc) mortar modified by sulfuric acid, nitric acid, sodium hydroxide, sodium sulfate corrosion and gasoline after the residual strength ratio, and by scanning electron microscopy (SEM) morphology of mortar were measured by X ray diffraction (XRD) analysis of substances by the corrosion of mortar The results show that the cement mortar, resistance to sulfuric acid, nitric acid corrosion resistance is poor, but P (BA-VAc) emulsion can improve the corrosion resistance of mortar; P (BA-VAc) emulsion cement mortar can improve the resistance to corrosion of sulfuric acid and hydrochloric acid; high content of PVAc modified mortar can be used in alkaline environment; oil of Portland cement polymer mortar and cement mortar corrosion effects are not obvious; P (BA-VAc) internal pore film can be filled with cement mortar, effectively blocking the corrosion medium into the P (BA-VAc), the film also has elasticity, can absorb the expansion stress, reduces swelling damage occurred, so as to improve the corrosion resistance of the mortar.

【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ177.62

【相似文献】