新老混凝土界面粘结材料及强度的研究

【作者】 农金龙；

【导师】 彭勃；

【作者基本信息】 湖南大学 ， 材料学， 2003， 硕士

【摘要】 实际工程中的新老砂浆或新老混凝土粘结，往往受诸多因素共同影响。界面是新老砂浆或新老混凝土中最薄弱的区域，通常情况下，界面粘结强度低，很少达到本体的相应强度。新老混凝土界面粘结材料和处理方法有多种，粘结效果差异较大，且都不甚理想。 针对这一问题，本文在大量实验的基础上，对不同种类材料的界面粘结效果和影响因素进行了实验研究，对其粘结及改性机理进行了初步探讨；提出了不同界面粘结方法、不同养护制度下适宜的界面粘结材料及其较佳配比；对不同界面粘结材料在新老砂浆及新老混凝土中的粘结效果进行了对比，为其工程应用及界面粘结力学、耐久性能等的进一步研究奠定了基础。 本文的研究工作可主要分为以下两大方面： 1、新老砂浆界面粘结的研究 采用“8”字型新老砂浆粘结抗拉粘结强度的试验方法，研究了多种界面粘结材料在不同养护制度、不同粘结方法、不同龄期、不同配比条件下的粘结性能，并利用扫描电镜对界面微观结构进行了分析，对各种材料粘结改性机理进行初步探讨。研究中采用的界面粘结材料有普通水泥基材料、矿物掺合料改性水泥基材料、聚合物改性水泥基材料和环氧树脂，其中重点研究了聚合物改性水泥基材料，所用聚合物包括NP粉末、丁苯乳液、丙烯酸乳液、纯丙乳液、氯丁乳液、水乳环氧。 2、新老混凝土界面粘结的研究 采用新老混凝土劈裂粘结试验方法，对比研究了普通修补混凝土、丁苯改性混凝土、氯丁改性混凝土粘结性能。并通过新老混凝土钻芯拉拔粘结试验，研究了不同界面粘结材料的新老混凝土粘结效果，并与其砂浆粘结试验结果进行了对比，对实际工程应用中正确选用界面粘结材料及评价粘结效果具有一定的指导意义。更多还原

【Abstract】 The bond between new and old concretes or mortars in actual project is affected by many factors. Interface is the weakest region in new-to-old concretes or mortars. Usually, the interfacial bond strength is very low, and approach to the strength of substrate. There are many kinds of bond materials and methods of dealing with the interface, however. The effect varies remarkably and can’t meet the ideal demand.As to the problem above, explore to the interfacial bond and factors of various bond materials on the basis of a great deal of tests. Many experimental researches have been done and given preliminary discuss on the bond and mechanism. Meanwhile, proper bond materials and better proportion are offered, under the background of the difference interfacial bond methods and curing systems.This paper also makes a compare on the bond effect of various bond materials and given reference for the project application and the future research of bond mechanics and endurance.The research work can be divided into two parts:1. Research on the interfacial bond of new-to-old mortars.This paper has research on the bond performance under the conditions of different curing systems, bond method aging and proportion, by means of "8" mould and giving preliminary discuss on the mechanism of different materials by use of SEM.The paper adopts such materials as common cement materials, mineral modified cement-based materials, polymer modified cement-based materials and epoxy resin and places emphasis on the polymer modified cement-based materials. Polymers include NP powder, SBR latex, acrylic acid latex, pure acrylic acid latex, chlorobutyl latex and epoxy latex.2. Research on the bond of the new-to-old concretes.By means of the test of spitting bond between new and old concretes, the bond performance of different bond material is researched.The bond effect of various bond material is also researched by use of the test ofpored-drilled drawing bond between new and old concretes. This paper also makes a contrast with the effect of mortars’ bond, which offers a meaningful reference on how to choose bond materials and to appraise the bond effect.更多还原