PMCC桥面铺装材料组成、性能与施工关键技术研究

发布时间：2018-07-10 17:05

本文选题：聚合物改性水泥混凝土 + 桥面铺装层　；参考：《武汉理工大学》2015年博士论文

【摘要】：聚合物改性水泥混凝土(Polymer Modified Cement Concrete,简称PMCC)具有刚柔相济的路用性能,是一种良好的桥面铺装材料。论文针对基于一次摊铺成型的PMCC材料组构关系与工艺关键参数的匹配问题,对PMCC桥面铺装材料与界面粘结材料的组成、性能与施工工艺展开研究。系统研究了丁苯聚合物乳液材料组成与稠度、聚灰比等对PMCC压实性能的影响规律,PMCC的稠度易控制在改进VC值5s,配合振动压实成型30s,搅拌60s,施工时间控制在1h以内完成。以PMCC弯曲韧性为核心指标,提出了基于一次摊铺成型的关键参数,包括稠度、水泥用量、聚灰比、纤维用量的合理取值范围,制备了路用性能良好的PMCC桥面铺装材料。对比研究了聚合物乳液、聚酯纤维及其复掺对PMCC的增韧作用,发现了聚合物乳液与聚酯纤维对提升水泥基材料的韧性具有协同效应,并揭示了其复合增韧机理。结果显示纤维复合改性PMCC的28天抗压强度相对同等水泥用量下的普通水泥混凝土虽然存在小幅度的降低,但抗弯拉强度、弯曲韧性、断裂韧性、断裂能分别提高44.2%、289.1%、397.0%、462.8%;抗冻等级由F150提高至F250;在失效概率为5%、应力水平为0.7时,弯曲疲劳寿命提高883.6%;弯拉弹性模量、磨损量和氯离子扩散系数分别降低43.1%、54.8%、64.1%。即使在180天较长龄期的条件下,聚合物乳液仍然能够发挥出对混凝土各项力学性能较好的改善作用。改性机理研究显示P/C为13%时,聚合物乳液虽然不能参与水泥的水化反应,且在前期延缓水泥的水化,但在后期聚合物膜良好的稳定性、保水性为水泥提供良好的水化环境,聚合物乳液改善了混凝土的孔隙结构,增强了混凝土各组分之间的粘结,并且聚合物水泥浆对纤维具有更强的握裹力,减少断裂过程中纤维被拔出的现象,使纤维对PMCC的增韧效果优于普通混凝土。优化了界面粘结层材料的组成、拌制及喷涂工艺,解决了聚合物水泥浆搅拌过程中容易结团的难题,提高了界面粘结强度,为PMCC优异的路用性能提供保障。
[Abstract]:Polymer modified cement concrete (PMCC) is a kind of good bridge deck pavement material because of its strong and flexible road performance. In this paper, the composition, performance and construction technology of PMCC bridge deck paving material and interfacial bonding material are studied in view of the matching between the fabric relationship of PMCC material and the key parameters of the process. The effects of composition and consistency of styrene-butadiene polymer emulsion on compaction properties of PMCC were systematically studied. The consistency of PMCC was easily controlled by improving VC value 5 s, compacting with vibration for 30 s, stirring for 60 s, and controlling the construction time within 1 h. Taking the bending toughness of PMCC as the core index, the key parameters based on primary paving molding, including consistency, cement content, cement ratio, fiber content and reasonable value range of PMCC bridge deck paving material with good road performance are proposed. The toughening effect of polymer emulsion, polyester fiber and its admixture on PMCC was studied. The synergistic effect of polymer emulsion and polyester fiber on the toughness of cement based materials was found, and the mechanism of composite toughening was revealed. The results showed that the 28 days compressive strength of fiber composite modified PMCC was lower than that of ordinary cement concrete with the same cement content, but the flexural tensile strength, flexural toughness and fracture toughness of the cement concrete were decreased by a small margin. The fracture energy is increased by 44.2and 289.1and by 397.0and 462.8; the frost resistance grade is raised from F150 to F250; when the failure probability is 5 and the stress level is 0.7, the flexural fatigue life is increased by 883.6; the flexural elastic modulus, wear and chloride diffusion coefficient are reduced by 43.1 and 64.1respectively. Even under the condition of 180 days, the polymer emulsion can improve the mechanical properties of concrete. The study of modification mechanism showed that polymer emulsion could not participate in the hydration reaction of cement and delay the hydration of cement in the early stage when P / C was 13%, but the polymer film had good stability in the later stage, and the water retention provided a good hydration environment for cement. Polymer emulsion improves the pore structure of concrete, enhances the bond between each component of concrete, and the polymer cement slurry has a stronger grip on the fiber and reduces the phenomenon of the fiber being pulled out during the fracture process. The toughening effect of fiber on PMCC is better than that of ordinary concrete. The composition, mixing and spraying process of interfacial bonding layer materials are optimized. The problem of easy agglomeration in the mixing process of polymer cement slurry is solved, the interfacial bond strength is improved, and the excellent road performance of PMCC is guaranteed.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U444;U445.4

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