硅灰对冻融环境下混凝土断裂损伤的影响  

Effect of Silica Fume on Fracture Damage of Concrete Subjected to Freeze-thaw Cycle

作　　者：宁作君[1] 巴恒静[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150006

出　　处：《武汉理工大学学报》2009年第5期46-50,共5页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(50078019)

摘　　要：依据GBJ82—85混凝土快速冻融循环试验方法,采用四点弯曲试验法分析了不同冻融循环条件下引气剂对普通混凝土及硅灰混凝土断裂韧度、断裂能及抗压强度的影响;对混凝土断裂面进行了形貌分析,利用扫描电镜进行混凝土内部微观结构分析。结果表明,随冻融循环次数的增加,未掺引气剂的混凝土的断裂韧度、断裂能及相对动弹模损失率呈明显下降趋势;混凝土随冻融循环次数增加损伤程度增大。相同条件下,普通混凝土较之硅灰混凝土的抗冻性差;引气剂能够大幅度降低由于冻融循环造成的混凝土内部结构的损伤,提高混凝土的抗冻性。According to GBJ82--85 test method for frost resistance of concrete, four-point bending tests were used to exam- ine the effects of air-entraining agent on fracture toughness, fracture energy and dynamic elastic modulus of concrete subjected to different freeze-thaw cycles. The microstructure of the concrete was also analyzed by using SEM. The results show that with the increase of the times of freeze-thaw cycles, the fracture toughness, and the fracture energy and the dynamic modulus of con- crete are downward trend obviously, which is not mix the air-entraining agent. And the degree of damage of concrete is up with the times of cycles increasing. In the same condition, the frost resistance of common concrete is poor than concrete with silica fume. By mixing the air-entraining agent, the damage of microstructure concrete may be reduced evidently due to freeze-thaw cycle, and the frost resistance of concrete may be enhanced.

关 键 词：硅灰 断裂韧度 引气剂 动弹性模量 断裂能 

分 类 号：TU528[建筑科学—建筑技术科学]