钢筋套筒连接用灌浆料新旧结合面抗折强度试验研究

EXPERIMENTAL RESEARCH ON THE FLEXURAL STRENGTH OF THE OLD AND NEW JOINT SURFACE OF GROUTING MATERIALS FOR STEEL SLEEVE CONNECTION

为研究套筒灌浆饱满度缺陷补灌修复后新旧灌浆料结合面的粘结性能,考虑原材料种类和配比的影响,选择5个品牌7种型号灌浆料制作新旧灌浆料粘结试件进行抗折强度试验研究。结果表明:尽管新旧结合面是粘结试件的薄弱部位,但实际破断位置并非都发生在结合面上,表明新旧结合面的粘结强度有时大于灌浆料的本体强度,其原因与结合面的凹凸不平有关;粘结试件的抗折强度和刚度均低于一次成型的灌浆料试件,抗折强度降低50%~70%;粘结试件的抗折性能受新旧灌浆料力学性能差异程度的影响,使用强度接近的灌浆料制作的粘结试件,其抗折强度和刚度均优于其他工况的粘结试件;灌浆料的抗压强度与抗折强度呈负相关关系,随着灌浆料的抗压强度提高,其抗折强度降低。研究结果可为钢筋套筒灌浆连接补灌修复时选择补灌材料提供参考。

In order to study the bonding performance of the joint surface between old and new grouting materials after regrouting and repairing the defects of sleeve grouting fullness,5 brands and 7 types of grouting materials are selected to make new and old grouting material bonded-test-pieces so as to carry out the experimental research of the flexural strength on the basis of considering the affection of types and proportions of raw materials.Results showed:Although the old and new joint surface is the weak part of bonded test pieces,not all the actual fractures occur on the joint surface,which indicates that the bonding strength of the old and new joint surface is sometimes greater than the self-strength of the grouting material,of which the reason is connected with the unevenness of the joint surface;the flexural strength and rigidity of the bonded test pieces are all lower than those of the one-step molded grouting material test pieces,among which the flexural strength is reduced by 50%~70%;the flexural properties of bolded test pieces are affected by the difference in the mechanical properties of new and old grouting materials,while the flexural strength and rigidity of the bolded test pieces made of similar strength grouting materials are all better than those of the bolded test pieces in other working conditions;the compressive strength and the flexural strength of grouting materials present the negative related relation,that is,the higher the compressive strength of the grouting material is,the lower the flexural strength becomes.The results of the study can provide a reference for the selection of regrouting materials for regrouting and repairing the steel sleeve grouting connection.