【作者】 刘健；

【导师】 赵国藩；

【作者基本信息】 大连理工大学 ， 结构工程， 2000， 博士

【摘要】 混凝土结构的修补加固已经成为一个重要的工程领域，加大截面法（新老混凝土整体式补强加固技术）是一种在修补加固中应用较广的方法，从而使得对新老混凝土的粘结问题的研究具有深远的现实意义。新老混凝土粘结性能的好坏具体表现在粘结面的抗力性能上，基于此，本文的工作对新老混凝土粘结的力学性能进行试验研究，主要集中在以下几个方面： 1．由劈裂抗拉试验得到的新老混凝土粘结劈拉强度，是对粘结抗拉强度的一种间接评估手段，与工程实际所要求知道的直接抗拉强度有一定的距离。本文由直接拉伸试验得到的粘结抗拉强度，同由劈裂抗拉试验得到的粘结劈拉强度比较分析，推出二者的换算关系公式，为工程实践提供指导，今后可以通过简便易行的劈拉试验来得到粘结直拉强度。 2．通过高压水处理可以得到较高的粘结强度，比较而言人工凿毛处理的粘结强度较低，对用这两种方法处理的新老混凝土粘结试件进行劈裂抗拉试验，分别得到粘结劈拉强度进行对比分析，从而对二者粘结性能的差异有了直观的认识。 3．对新老混凝土粘结试件加温200℃后，进行劈裂抗拉试验，与常温下粘结劈拉强度分析比较，并对高温作用引起粘结性能下降的原因作了分析。 4．选取影响粘结性能的三个主要因素：新混凝土的龄期、新混凝土的种类、粗糙度进行正交试验设计，通过劈裂抗拉试验，以粘结劈拉强度作为指标对影响因素方差分析，得到各因素对粘结性能的影响程度。 5．受老混凝土的约束不同种类的新混凝土的约束收缩情况是不同的，选取三种新混凝土：普通混凝土、钢纤维混凝土A（纤维掺量1％）、钢纤维混凝土B（纤维掺量1.5％），对三种新老混凝土粘结试件的收缩情况进行四个月的测量，得到在新混凝土的不同位置的约束收缩情况，建立了相应的约束收缩曲线。 6．新混凝土收缩受到老混凝土基层的约束，会在新混凝土内部产生拉应力，拉应力过大就会使新混凝土开裂，通过建立约束收缩的力学模 大连理工大学博士学位论文型，对新混凝土中的应力应变分布进行研究，与实际测量结果比较分析，证明模型的合理有效性。 7．进行新老混凝土立方体粘结试件的压剪、拉剪力学性能试验研究。分析压应力（拉应力）、粗糙度等因素对抗剪强度的影响，分别建立新老混凝土的粘结在压剪及拉剪复合受力状态下的破坏强度公式；对压剪、拉剪受力状态下新老混凝上结合面的剪切滑移性能进行了试验研究，得到结合面相应的剪切应力～滑移关系。 8．进行新老混凝上立方体粘结试件的压压剪、拉压剪力学性能试验研究。分析垂直压应力（垂直拉应力）、平行压应力、粗糙度等因素对抗剪强度的影响，分别建立新老混凝土的粘结在压压剪及拉压剪复合受力状态下的破坏强度公式；对压压剪、拉压剪受力状态下新老混凝土结合面的剪切滑移性能进行了试验研究，得到结合面相应的剪切应力～滑移关系。更多还原

【Abstract】 The repair and strengthening of concrete structure has become an important engineering domain. The enlarging section method (the reinforcement and strengthening technique of integral type of young on old concrete) is widely applied in the repair and strengthening of concrete structure. Therefore, the research of adherence of young on old concrete has profound significance. This paper studied the mechanics performance of adherence of young on old concrete. The main results are summarized as follows: 1. The adhesive splitting tensile test is an indirect method to evaluate the tensile strength. But the adhesive direct strength is required to know in engineering. This paper got the relation formula between them tbro ugh tests. So, through the portable adhesive splitting tensile test, the adhesive direct tensile strength can be achieved from the relation formula. 2. The higher adhesive strength can be gotten through the water-jet method. By comparison, the adhesive strength gotten by the method of chipping with hammers is lower. After used these two methods to treat the surfaces of old concrete, the adhesive splitting tensile tests are performed on the bonding specimens. From the test results, the difference of their adhesive performance is gotten. 3. The bonding specimens are heated up to 200 0C. After that, the adhesive splitting tensile strength is achieved by tests. Compared with the strength gotten in normal temperature, the reason of the difference resulted from the effect of high temperature is analyzed. 4. Three main factors affecting the adhesion performance are selected to make orthogonal design, which are the age of new concrete~. the variety of new concrete and the roughness. By adhesive splitting tensile strength as index mark to analyze variance, the degrees of effect of each factor are gotten. 5. The shrinkage of various new concrete restrained by old concrete is different. Three kinds of new concrete: ordinary concrete~ steel fiber ?Ill ? concrete (steel fiber 1%) and steel fiber concrete (steel fiber 1.5%) are selected to make the adhesion specimens. After measured the restrained shrinkage of the specimens in four months, the corresponding curves of restrained shrinkage on the sites of new concrete are concluded. 6. When the shrinkage of new concrete is restrained by old concrete, the tensile stresses can be created in the interior of new concrete. Through founded the mechanics model of restrained shrinkage, the stresses and strains in the new concrete are studied. Compared with the results of measurement, the model is proved to be approprite and effective. 7. By the tests of compression-shear and tension-shear, the effects of compressive stresses (or tensile stresses) and roughness to the adhesion performance are analyzed, the formulas of failure strength under combined stresses are founded, and the relations of shear stress-slip of the interface under combined stresses are Studied. 8. By the tests of compression-compression-shear and tension-compression- shear, the effects of vertical compressive stresses (or vertical tensile stresses)~. parallel compressive stresses and roughness to the adhesion performance are analyzed, the formulas of failure strength under such更多还原