水泥混凝土路面快速修补用聚合物改性水泥基材料的研究

发布时间：2018-03-07 04:02

本文选题：水泥混凝土路面　切入点：快速修补材料　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：水泥混凝土路面因具有强度高、承载能力强、耐久性好等优点，在各级公路中被广泛采用，但由于施工不当、超载等原因，水泥混凝土路面出现了严重受损，妨碍了正常的交通通行。传统的水泥基修补材料一方面因养生期长，严重影响了开放交通的时间；另一方面则因粘结强度低、耐久性差，导致修补后的水泥混凝土路面短时间就遭到破坏。本文通过碱激发矿渣水泥、P.O和R-SAC复配两条技术路线，研究了超早强基体性能，并采用聚合物乳液进一步改性，研制出了早强性能突出、粘结性能优良、凝结时间适中的水泥混凝土路面快速修补材料，并对早强基体的水化及聚合物改性的机理进行了探索，对快速修补材料的工程应用性能进行了一系列测试。研究结果表明： 1、碱激发矿渣水泥砂浆早期强度高，能满足6h开放交通的要求，但是由于碱激发胶凝体系碱性过强，聚合物发生严重破乳，不适合应用于聚合物改性；P.O和R-SAC复配水泥砂浆早期强度相对更高，更能满足6h开放交通的要求，且聚合物乳液在复配胶凝体系中，性能稳定，适合应用于聚合物改性。 2、不同减水剂对P.O和R-SAC复配胶凝体系的流动度、流动度经时损失、早期强度有显著影响，其中奈系减水剂FDN最为理想。 3、P.O和R-SAC不同的复配比例对复配水泥砂浆早期强度、凝结时间的影响显著，当P.O和R-SAC的复配比例为60%:40%时，复配水泥砂浆的6h力学强度最高，而且后期力学强度稳定发展，凝结时间适中，配伍性能较好。聚合物乳液的加入延长了复配水泥砂浆的可操作时间，，提升了早期和后期的抗折强度及粘结强度，大大提升了复配水泥砂浆的折压比。 4、XRD和SEM微观测试结果表明，复配胶凝体系6h就生成了大量的针状钙矾石和C-S-H/AH3凝胶，而且随着龄期的延长，钙矾石稳定、凝胶体增多，因此不仅早期强度显著，而且后期强度稳定发展；聚合物乳液的加入有利于消除水泥浆体的微裂纹，起到填充微孔缺陷的作用，但并没有产生新的水化产物。 5、对优选快速修补砂浆的性能测试表明：快速修补水泥砂浆收缩小、耐磨性能好，均优于普通硅酸盐水泥砂浆；不同的养护条件对其力学性能影响较大。配制的早强混凝土早期强度高，能满足6h开放交通的要求。综合研究表明：其能满足水泥混凝土路面快速修补的要求。
[Abstract]:Cement concrete pavement is widely used in highway at all levels because of its advantages of high strength, strong bearing capacity and good durability. However, due to improper construction and overload, cement concrete pavement is seriously damaged. The traditional cement-based repair materials, on the one hand, have a long health period, which seriously affects the opening time of traffic; on the other hand, because of low bond strength and poor durability, The modified cement concrete pavement was destroyed in a short time. In this paper, the properties of super early strength matrix were studied by alkali activated slag cement P.O and R-SAC, and further modified by polymer emulsion. The cement concrete pavement repairing material with outstanding early strength, excellent bond property and moderate setting time was developed. The hydration of early strength matrix and the mechanism of polymer modification were explored. A series of tests have been carried out on the engineering application performance of the fast repairing materials. The results show that:. 1. The early strength of alkaline activated slag cement mortar is high, which can meet the requirement of opening traffic for 6 h. However, the polymer demulsification occurs because the alkali-activated cementing system is too alkaline. It is not suitable for polymer modified P.O and R-SAC cement mortar with higher early strength and more suitable for 6h open transportation. The polymer emulsion has stable properties in the compound cementing system and is suitable for polymer modification. 2. Different water reducers have a significant effect on the fluidity, flowability loss and early strength of P.O and R-SAC composite gelling systems, among which FDN is the most ideal. (3) different blending ratios of P.O and R-SAC have a significant effect on the early strength and setting time of composite cement mortar. When the ratio of P.O and R-SAC is 60: 40%, the mechanical strength of the compound cement mortar is the highest in 6 hours, and the mechanical strength of the cement mortar develops steadily in the later stage. The addition of polymer emulsion prolonged the operating time of the composite cement mortar, increased the early and late flexural strength and bond strength, and greatly increased the compression ratio of the composite cement mortar. The results of X-ray diffraction and SEM microanalysis showed that a large number of acicular ettringite and C-S-H / AH3 gels were formed at 6 h after the compound gelling system was prepared, and with the increase of age, ettringite stabilized and the gel increased, so not only the early strength was remarkable. The addition of polymer emulsion can eliminate the microcracks of cement paste and fill the micropore defects, but no new hydration products are produced. 5. The performance test of the high quality and fast repairing mortar shows that the quick repairing cement mortar has the advantages of small shrinkage and good wear resistance, which is superior to the ordinary Portland cement mortar. Different curing conditions have great influence on its mechanical properties. The early-strength concrete prepared has high early strength and can meet the requirement of 6h open traffic. The comprehensive study shows that it can meet the requirement of rapid repair of cement concrete pavement.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U414;U418.6

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