改性珊瑚骨料混凝土的电阻率模型  

Resistivity Model of Modified Coral Aggregate Concrete

作　　者：张路 牛荻涛[1,2] 文波[1,2] 张永利[1] 陈昊[1] ZHANG Lu;NIU Ditao;WEN Bo;ZHANG Yongli;CHEN Hao(School of Civil Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;State Key Laboratory of Green Building in Western China,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,西安710055 [2]西安建筑科技大学省部共建西部绿色建筑国家重点实验室,西安710055

出　　处：《材料导报》2022年第1期74-79,共6页Materials Reports

基　　金：国家自然科学基金(51590914,52078413,52078415)。

摘　　要：海洋环境中的混凝土结构长期遭受氯盐侵蚀,导致结构损伤严重,因此材料抗氯离子侵蚀能力对珊瑚混凝土结构的耐久性有重要影响。为了表征混凝土的抗氯离子渗透能力,采用改进交流电测试方法对珊瑚骨料混凝土与普通混凝土的电阻率进行测量,同时测试不同矿物掺合料珊瑚骨料混凝土的孔隙率,得出掺合料珊瑚骨料混凝土抗氯盐侵蚀的机理。研究表明:粉煤灰、硅灰和矿渣的掺加影响了珊瑚骨料混凝土的电阻率,提高了珊瑚骨料混凝土的抗氯离子渗透能力。当珊瑚骨料混凝土中掺合料的掺量为10%(占胶凝材料)时,硅灰珊瑚混凝土的电阻率是粉煤灰珊瑚混凝土的3.71倍,是矿渣珊瑚混凝土的2.02倍。在相同的掺量下,硅灰对混凝土电阻率的影响最大,矿渣次之,粉煤灰最小。在相同强度下,珊瑚骨料混凝土的电阻率小于普通混凝土的电阻率,约为普通混凝土的0.6倍;珊瑚骨料混凝土的孔隙率是普通混凝土的2.0~3.1倍。根据珊瑚骨料混凝土在365 d的电阻率,考虑温度、湿度、水胶比及掺合料等因素,最终建立了改性珊瑚骨料混凝土的电阻率模型。Reinforced concrete structures in marine environment suffer from chloride erosion for a long time,which leads to the decline of durability on structures.Therefore,the resistance ability of materials to chloride ion erosion plays an important role in the durability of concrete structures.As a nondestructive testing technology,the resistivity can be used to characterize the chloride penetration resistance of concrete.In this study,the resistivity of coral aggregate concrete(CAC)and ordinary concrete(OC)were measured by improved alternating current test method,and the porosity of CAC with different mineral admixtures was measured,so as to obtain the mechanism that mineral admixtures could improve the chloride penetration resistance of CAC.The results show that fly ash,silica fume and slag affect the resistivity of CAC and improve the anti-chloride ion permeability of CAC.When the content of admixture in CAC is 10%,the resistivity of CAC with silica fume is 3.71 times and 2.02 times that of fly ash and slag.At the same content of admixture,silica fume has the greatest influence on the CAC resistivity,followed by slag and fly ash.Under the same strength,the CAC resistivity is less than that of OC,about 0.6 times that of OC.The porosity of CAC is 2.0—3.1 times that of OC.According to the CAC resistivity in 365 days,temperature,humidity,water-binder ratio and admixtures were considered,and the resistivity model of modified CAC was finally established.

关 键 词：珊瑚骨料混凝土 电阻率 交流电测试 抗氯离子侵蚀 

分 类 号：TU502.5[建筑科学—建筑技术科学]