基于工业CT试验的轻骨料混凝土细观裂纹扩展规律研究  

Study on the Meso-crack Propagation Law of the Lightweight Aggregate Concrete Based on Industrial CT

作　　者：高英力[1] 陈家宝[1] 邹超[1] 程领[1] 

机构地区：[1]长沙理工大学交通运输工程学院,长沙410114

出　　处：《硅酸盐通报》2014年第4期947-952,共6页Bulletin of the Chinese Ceramic Society

基　　金：高等学校博士学科点专项科研基金资助课题(20104316120001);湖南省自然科学基金项目(13JJ3070);湖南省教育厅重点科研基金项目(11A005)

摘　　要：采用圆球型和碎石型骨料分别制备了轻骨料混凝土,并采用工业CT(ICT)研究了其在受荷和非受荷条件下的细观裂纹扩展规律。结果表明:连续加载受压过程中,利用自建的单位荷载作用下裂纹面积增长量μ值能客观表征轻骨料混凝土受荷条件下的裂纹扩展速率,其中碎石型轻骨料混凝土和圆球型轻骨料混凝土μ值分别达到了8.5 mm2/MPa和6.9 mm2/MPa,表明裂纹在碎石型轻骨料混凝土中扩展更快;而在非受荷硫酸盐腐蚀条件下,轻骨料混凝土裂纹扩展速率与界面区状态密切相关,碎石型轻骨料混凝土中,骨料粗糙多孔,且呈多棱角状,其浆骨界面区较圆球型轻骨料混凝土密实度高,因而抗蚀及抗裂能力更优,实测发现裂纹数量与深度有一定程度的降低。Two kinds of lightweight aggregate concrete （LWAC） were prepared by spherical aggregate and crushed aggregate respectively, then industrial computed tomography scanner System （ICT） was adopted to study the meso-crack propagation law of them under the conditions of loaded and non-loaded. The results showed that during the continuous loading compression process, the crack growth rate of LWAC under loading condition was characterized well by μ value which means the increment of crack area via self-constructed unit load. The μ value of LWAC made with spherical aggregate （LWAC-SA） and LWAC made with crushed aggregate （LWAC-CA） were 6, 9 mm^2/MPa and 8.5 mm^2/MPa respectively, that is to say, crack in the LWAC2CA expanded faster than that in the LWAC-SA. Under the condition of nonload sulfate attack, the crack growth rate of LWAC was closely related with the state of interfacial transition zone. Moreover, aggregate is rough, porous and angular in the LWAC-CA. The interface transition zone in the LWAC-CA was denser than that of the LWAC-SA, so LWAC-CA has stronger sulfate resistance and crack resistance, and its crack numbers and depths decrease in a certain extent.

关 键 词：轻骨料混凝土 工业CT 裂纹 荷载 硫酸盐腐蚀 

分 类 号：TU414[建筑科学—岩土工程]