聚合物改性水泥基粘结复合材料的粘结性能研究

发布时间：2018-01-28 23:30

本文关键词： 聚合物水泥复合材料粘结强度粘结性能粘结机理薄弱幅度薄弱指数粘结界面模型　出处：《湖南大学》2014年博士论文　论文类型：学位论文

【摘要】：聚合物乳液或胶粉掺入新拌和普通混凝土、砂浆或水泥净浆,亦可复掺外加剂或矿物掺合料,可使普通混凝土、砂浆或水泥净浆性质较大地改变,性能显著地改善,其制成的复合材料用作粘结材料,称为聚合物改性水泥基粘结复合材料(Polymer-modified cement-based bonding composite,简称PCBC)。本文以丁苯PCBC为重点,对几类PCBC粘结性能进行系统的试验研究和理论分析,其主要内容和创新成果如下： 1.基于系统的配比试验,提出了聚合物改性水泥基粘结砂浆(Polymer-modified cement-based bonding mortar,简称PCBM)较适宜的配比,研究几类PCBM短期粘结性能。通过试验和理论分析可得：(1)聚灰比、水灰比、胶砂比等聚合物砂浆配合比的变化明显地改变包括粘结强度在内的砂浆强度；高效减水剂等外加剂的复合改性,显著地改善部分聚合物砂浆早期粘结性能；UEA和SF等矿物掺合料对聚合物砂浆早期粘结性能的改性作用效果不明显；混用外加剂FDN及矿物掺合料SF和UEA对各种聚合物砂浆粘结改善作用差异较大。(2)几乎所有试验涉及的PCBM,硬化前的拌合物都有特殊的性质和特点,硬化后的也有独特的力学性能,明显地区别于普通砂浆,在选用适当的配比和保持良好的养护环境等条件下,可以显著改善早期粘结性能。 2.将聚合物砂浆的拌合物稠度和密度、粘结养护制度、配比、外加剂、矿物掺合料、粘结强度、本体抗压和抗折强度以及户外5a龄期粘结,有机地融入聚合物改性水泥基粘结复合材料短期和长期粘结性能研究中,形成了较系统的粘结性能研究体系,得到如下新型粘结材料：粘结性能优良的丁苯砂浆,不同粘结性能的丙烯酸、纯丙和氯丁砂浆,潮湿环境及水中可固化的液态环氧树脂,没有缓凝现象且本体强度不降低的NP砂浆。 3.通过试验研究了丁苯改性水泥基材料长期粘结性能复杂的作用机理。结果表明：丁苯水泥净浆斜剪、直剪、抗弯、轴向拉伸及丁苯混凝土劈裂强度性能优越,其抵抗大面积、大体积混凝土修补加固所产生的复杂应力系统破坏的能力突出；丁苯砂浆的长期水泥水化程度较高和其特有的、有益的水泥水化规律相关；丁苯砂浆受热和干缩变形规律不损害其长期粘结性能,有些变形甚至对长期粘结性能有益；丁苯砂浆的粘结界面电镜照片和显微硬度试验结果显示其粘结效果良好,与其宏观良好的长期粘结性能相一致。提出并运用了薄弱幅度和薄弱指数两个性能参数,对丁苯砂浆粘结界面显微硬度试验结果进行分析,进一步证实丁苯砂浆具有良好的长期界面粘结质量,推证了其粘结界面过渡区具有自我完善的功能,动态地解释了其长期粘结性能机理。提出并运用了丁苯砂浆粘结界面模型。
[Abstract]:The properties of ordinary concrete, mortar or cement paste can be changed greatly by adding polymer emulsion or rubber powder into new mixing ordinary concrete, mortar or cement paste, or by adding admixture or mineral admixture. The properties of the composites were significantly improved and the composites were used as bonding materials. It is called Polymer modified cement-based bonding composite. In this paper, the bond properties of several kinds of PCBC are systematically studied and theoretically analyzed, focusing on the butylbenzene PCBC. The main contents and innovative results are as follows: 1. The proportion test based on the system. Polymer-modified cement-based bonding mortar was proposed. In this paper, the short term bond properties of several kinds of PCBM are studied. Through the experiment and theoretical analysis, the ratio of polymer to cement and water to cement can be obtained. The change of polymer mortar mixture ratio, such as cement-sand ratio, obviously changes the strength of mortar, including the bond strength. The composite modification of superplasticizer and other admixtures significantly improved the early bonding property of some polymer mortar. The effect of mineral admixtures such as UEA and SF on the early adhesive properties of polymer mortar is not obvious. The effect of mixed admixture FDN and mineral admixture SF and UEA on the bond improvement of various polymer mortar is quite different. The mixture before hardening has special properties and characteristics, and after hardening, it also has unique mechanical properties, which is obviously different from ordinary mortar, under the conditions of choosing proper proportion and maintaining good maintenance environment and so on. The early bonding property can be significantly improved. 2. Consistency and density of polymer mortar, curing system, ratio, admixture, mineral admixture, bond strength, bulk compressive and flexural strength, and outdoor 5a age bond. Organically incorporated into the short-term and long-term bond properties of polymer modified cement based bonded composites, a more systematic bond performance research system has been formed. The following new adhesive materials were obtained: butadiene mortar with good bond properties acrylic acid with different bond properties pure propylene and chloroprene mortar liquid epoxy resin which can be cured in wet environment and water. NP mortar with no retarding phenomenon and no decrease in bulk strength. 3. The mechanism of complex long-term bond properties of SBR modified cement-based materials was studied. The results showed that the slanting shear, direct shear and bending resistance of butadiene cement paste were studied. Axial tensile and butadiene-butadiene concrete have excellent strength properties, and its ability to resist the failure of complex stress system caused by large area and mass concrete repair and reinforcement is outstanding. The degree of long-term cement hydration of benzene butadiene mortar is higher than that of benzene butadiene mortar, which is related to its unique and beneficial cement hydration law. The behavior of thermal and dry shrinkage deformation of butadiene mortar does not damage its long-term bond performance, and some deformation is even beneficial to the long-term bond property. The results of SEM and microhardness test show that the bonding effect of SBR mortar is good. The results of microhardness test on the bond interface of benzene butadiene mortar were analyzed by using two performance parameters, the weak range and the weak index. It is further proved that butadiene mortar has good long-term interfacial bond quality, and the self-improvement function of the bond interface transition zone is inferred. The mechanism of long-term bond performance is explained dynamically. A model of the bond interface of butadiene mortar is proposed and applied.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU528

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