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混凝土;修补材料;丙烯酸类修补砂浆;水泥基类修补砂浆;力学性能;收缩性能
concrete;repair materials;acrylic repair mortar;cement-based repair mortar;mechanical properties;shrinkage performance
为评价有机修补砂浆与无机修补砂浆之间的性能差异,选择2种丙烯酸类有机修补材料与1种水泥基类无机修补材料分别制备砂浆,测试各砂浆试件的抗压强度、抗折强度、界面弯拉强度、正拉黏接强度和干缩率等指标,并从微观孔隙方面分析性能差异的机理,探讨砂的类型及胶砂比对丙烯酸类有机修补砂浆性能的影响.结果表明,与水泥基类修补砂浆相比,丙烯酸类有机修补砂浆的2 h抗压和抗折强度较高,均能达到28 d抗压与抗折强度的70%以上,同时具有更优异的黏接强度和韧性,但收缩率较大.连续级配机制砂取代石英砂,可显著降低丙烯酸类有机修补砂浆内部气泡量,提高抗压强度、抗折强度、界面弯拉强度和正拉黏接强度,且胶砂比为0.4时力学性能最高.此外,界面弯拉强度与正拉黏接强度具有良好的相关性,在评价修补砂浆黏接性能方面具有一定的可替代性.研究成果可为在役混凝土设施和混凝土预制构件的修复提供借鉴.
To evaluate the performance differences between organic and inorganic repair mortar, two types of acrylic organic repair materials and one cement-based inorganic repair material were selected to prepare mortars, and their compressive strength, flexural strength, interfacial flexural-tensile strength, tensile bond strength, dry shrinkage rate were tested. The mechanisms underlying the performance differences were explored from the perspective of micropore structure, and the effects of sand type and cementto-sand ratio on the performance of acrylic organic repair mortar were also examined. Results show that, compared with cement-based repair mortars, acrylic organic repair mortars exhibit significantly higher compressive and flexural strength at 2 hours, reaching more than 70% of the 28-day compressive and flexural strength. They also demonstrate superior bonding strength and toughness, although a higher shrinkage rate. Replacing quartz sand with continuously graded manufactured sand notably reduces the amount of air bubbles within the acrylic organic repair mortar, and improves the compressive strength, flexural strength, interfacial flexural-tensile strength, tensile bond strength. Optimal mechanical performance is achieved when the cement sand ratio is 0.4. Furthermore, there is a strong correlation between the interfacial flexural-tensile strength and the tensile bond strength, which has potential interchangeability in evaluating the bonding performance of repair mortars. This research provides valuable technical references for repairing peeling and block defects in in-service concrete structures and precast concrete components.
1
试验
1.1 原材料
1.2 配合比设计
表1 修补砂浆配合比
Table 1 Mix proportion of repair mortar
1.3 试验方法
2
结果与分析
2.1 抗压强度与抗折强度
3
结论
来源:深圳大学学报理工版
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