掺聚丙烯纤维的水泥混凝土路面薄层快速修补材料性能研究

【作者】 代晓妮；

【导师】 尹健；

【作者基本信息】 中南大学 ， 土木工程材料， 2009， 硕士

【摘要】 近年来我国水泥混凝土路面破损日益严重,导致路面的修补工作量剧增,其抗冲击能力弱、耐磨性和承载能力差是破损的重要因素。鉴于此,本文通过掺聚丙烯纤维配制水泥混凝土路面薄层快速修补材料,来提高修补混凝土的使用性能,主要研究内容与结论如下:1、对薄层快速修补胶凝材料的配伍进行了深入研究,研究结果表明:当普通硅酸盐水泥与SAC、UFA以合适比例复配,胶砂比为1:1时,砂浆凝结时间、工作性能均能较好地满足现场施工要求。其2h抗折、抗压强度分别达到了4.1MPa、16.9MPa,能够满足2h开放交通的要求(抗折强度3.15MPa,抗压强度12.0MPa),1d抗折强度为7.4MPa,完全达到设计强度(4.5MPa)的要求,且后期强度稳步增加,28d抗折、抗压强度达到了16.2MPa、64.7MPa。掺入3%SF时,其28d抗压强度达到75.4MPa。2、在优化胶凝材料配伍的基础上,系统研究了砂率、复合胶凝材料配伍、聚丙烯纤维掺量等因素对薄层快速修补混凝土力学性能的影响,并优选出适宜的混凝土配比。试验结果表明:选用配伍合理的胶凝材料和适宜的水胶比、砂率、聚丙烯纤维掺量配制的薄层快速修补混凝土4h抗折、抗压强度达到了4.7MPa、18.4MPa,满足4h开放交通的要求,1d抗折强度达到设计强度的。后期强度稳步增加,90d抗折、抗压强度达到了16.4 MPa、85.0MPa。掺加5%SF时,其90d抗压强度达到85.8MPa。3、新老混凝土的粘结强度随着龄期的增加而增长。双掺聚丙烯纤维(0.9kg/m~3)和硅灰(5%),界面的粘结强度最大,28d粘结强度达到了4.0MPa,比未掺试件强度增长了25%。4、开展了掺聚丙烯纤维配制的薄层快速修补混凝土耐磨性能研究,探讨了砂率、复合胶凝材料配伍、聚丙烯纤维掺量等因素对薄层快速修补混凝土耐磨性能的影响。当选用配伍合理的胶凝材料和适宜的砂率、聚丙烯纤维掺量时,配制的薄层快速修补混凝土具有较好的早期耐磨性能。1d磨损量最小仅为3.224 kg/m~2,小于行业标准《水泥胶砂耐磨性试验方法》(JC/T421-2004)规定的最大磨损率3.600kg/m~2。5、通过掺入适量的聚丙烯纤维可以大幅度提高混凝土的抗冲击性能。当聚丙烯纤维掺量为0.9kg/m~3,混凝土抗冲击性能最好。4h、1d混凝土的破坏冲击韧性较未掺纤维的试件分别提高了1.6倍、1.7倍,初裂到破坏阶段所吸收的能量较未掺纤维试件分别提高了83%、100%。6、利用多元回归分析,对薄层快速修补混凝土的耐磨性能进行预测,除个别实测磨损量与模拟磨损量的相对误差较大外,其它的相对误差均较小,表明该模型预测精度良好,可用于薄层快速修补混凝土耐磨性能的预测。更多还原

【Abstract】 In recent years, the breakage of our country concrete road is increasingly serious, leading to sharp grow in concrete pavement repairing. An important factor were the poor abrasion resistance and weak impact resistance. In view of this, this paper taking the polypropylene fiber to prepare the thin rapid repairing material of Cement concrete pavement to improve the performance of repairing concrete. The main contents and conclusions of the study are as follows:1.Studies the compatibility of gelatinization materialof thin rapid repair material in depth. The results indicates: the time of setting and workability can satisfy construction require of job location, the flexural strength and the compression strength were 4.1MPa,16.9MPa respectively, can satisfy with the requirement of opening to traffic at 2 hours, flexural strength of 1d was 7.4MPa, have completely reached the designing strength, when P.O, SAC and UFA go together with suitable comparison and cement-sand ratio is 1 ’. 1. And later period strength will increase steadily, flexural strength and the compression strength of 28 day ages were 16.2 MPa、64.7MPa respectively. The incorporation of 3% SF, the compression strength of 28 day ages was 75.4MPa.2. Based on the optimized mixture proportion, this paper systematically studies the factors affecting the mechanical properties of rate of sand, different gelatinization compatibility, and the amount of polypropylene fiber. The results indicates: after casting, the flexural strength and the compression strength of 4 houe ages were 4.7MPa、18.4MPa respectively of the thin rapid repairing Concrete of Cement Concrete Pavement, when with due W/B, rate of sand, gelatinization compatibility and the amount of polypropylene fiber, which satisfied the requirement of opening to traffic at 4hours. Flexural strength of 1day ages reached 100% of designing strength. Later period strength increased steadily, flexural strength and the compression strength of 28 day ages were 16.4 MPa, 85.0MPa respectively. The incorporation of 5% SF, the compression strength of 90 day ages was 85.8 MPa. 3. The bond strength of new-old concrete enhances with the increasing of age. The incorporation both of polypropylene fiber(0.9kg/m~3) and SF(5%), the bond strength of new-old concrete of 28 day ages was the biggest, reached 4.0MPa, which increased 25% than the undoped.4. This paper studed on the abrasion resistance of the thin rapid repairing Concrete prepared by polypropylene fiber, mainly discussed the factors affecting the abrasion resistance of fast hardness and high early strength Concrete of Cement Concrete Pavemen of rate of sand, different gelatinization compatibility, and the amount of polypropylene fiber. The results indicates: after casting, with the appropriate mix proportion, the thin rapid repairing concrete can improve the abrasion resistance of the concrete at early stage, reduce the wear rate of unit surface area. 1 day ages of wear rate was only 3.224kg/m~2 , less than professional standard (JC/T421-2004) required 3.600kg/m~2.5. Polypropylene fiber can enhance impact resistance of Concrete greatly. The most suitable amout of polypropylene fiber is 0.9kg/m~3, impact toughness of 4 hour ages and 1day ages incressed by 1.6time, 1.7time than the undoped respectively, so as absorbing energy when cracking, incressed by 83%, 100%, than the undoped respectively.6. Establishing mathematical model for the thin rapid repairing Concrete to predict the abrasion resistance of concrete, except individual measurement of wear rate has big relative error to predictive value, the other relative errors were small, so the prediction modelof the abrasion resistance of Concrete has the good prediction accuracy, can be able be used for research on Predictionof the abrasion resistance of the thin rapid repairing Concrete.更多还原