盐冻环境下钢筋混凝土构件性能研究  

Study on the Performance of Reinforced Concrete Members Under Salt Freezing Environment

作　　者：屈锋[1] 牛荻涛[2] 杨宇曦[2] 

机构地区：[1]湖南科技大学土木工程学院,湘潭411201 [2]西安建筑科技大学土木工程学院,西安710055

出　　处：《材料导报》2015年第24期87-91,共5页Materials Reports

基　　金：教育部"创新团队发展计划"项目(IRT13089);湖南教育厅科研项目(15C0554);湖南科技大学校级自科基金项目(E54009)

摘　　要：为掌握保护层厚度、钢筋直径及其位置对混凝土盐冻损伤的影响,以质量分数为3.5%的NaCl溶液为冻融介质进行了快速冻融试验,测试了各构件盐冻后的混凝土质量损失率及相对动弹性模量变化规律。分析表明,基于混凝土和钢材不同的比热容与热膨胀系数,配筋混凝土构件在盐冻过程中损伤程度不同。研究结果表明,在盐冻循环作用早期阶段,配筋混凝土试件相对动弹性模量下降幅度和质量损失率变化较快,随即劣化速度降低。光圆钢筋比带肋钢筋的混凝土盐冻损伤小,混凝土保护层厚度与钢筋直径比值存在合理值,使配筋混凝土试件的相对动弹性模量降低和质量损失率最小。To evaluate the effect of the design parameters including thickness of concrete cover,diameter and station of steel bar on the salt frost damage law of reinforced concrete,the rapid freeze-thaw experiments were carried out with 3.5% NaCl solution by mass.At a given freeze-thaw cycles,the salt-frost damage degree of the reinforced concrete specimens were observed,including the mass loss,and the relative dynamic elastic modulus by ultrasonic method.Based on the different heat capacity and thermal expansion of concrete and different steel rebar,the accumulative frost-damage of the reinforced concrete with different design parameters is also different generated by temperature elevating cyclic.The salt frost damage of reinforced concrete developed faster in early stage than later stage under salt frost action.Especially,all the decrease of relative dynamic elasticity modulus and mass loss rate are larger,then the degradation rate reduce.The frost damage degree of reinforced concrete specimens are smaller by the use of plain round bars than ribbed bar.Further,there lies in a reasonable value of the ratio between the cover thickness and reinforcement diameter to assure the salt-frost durability of reinforced concrete members that have minimum relative dynamic elastic modulus decrease and mass loss.

关 键 词：混凝土 冻融循环 耐久性 相对动弹性模量 质量损失率 

分 类 号：TU528[建筑科学—建筑技术科学]