不同骨料混凝土的界面结构特征及极限拉伸性能  

Interfacial Microstructure Characteristics and Ultimate Tensile Properties of Concretes with Different Kinds of Aggregates

作　　者：欧阳幼玲[1,2] 陈迅捷[1,2] 蔡跃波[1,2] 

机构地区：[1]南京水利科学研究院材料结构所,江苏南京210029 [2]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,江苏南京210029

出　　处：《建筑材料学报》2011年第6期834-838,共5页Journal of Building Materials

基　　金：国家自然科学基金委员会;二滩水电开发有限责任公司雅砻江水电开发联合研究基金重点项目(50539040)

摘　　要：采用扫描电镜和能量散射能谱分析仪分析了混凝土中砂岩、大理岩、正长岩和玄武岩4种骨料与水泥浆体界面结构特征,并对这4种骨料混凝土的极限拉伸性能进行了研究.结果表明:不同骨料饱和面干吸水率不同,影响了骨料-水泥浆体界面过渡区水化产物的化学组成,进而影响了界面结构特征.砂岩、大理岩骨料与水泥浆体界面过渡区存在氢氧化钙的富集;正长岩、玄武岩骨料与水泥浆体界面过渡区则较少见到氢氧化钙的富集.4种骨料与水泥浆体界面过渡区宽度大小顺序为:大理岩>砂岩>正长岩>玄武岩.不同骨料混凝土的轴心抗拉应力应变行为受骨料-水泥浆体界面结构特征的影响.Interfacial microstructure characteristics of four different aggregate-cement paste were investigated by scanning electron microscope(SEM) and energy dispersive spectrometer(EDS).The four aggregate were sourced from sandstone,marble,syenite and basalt,respectively.The ultimate tensile properties of concrete with those four different aggregates were discussed.Test results show that the water absorption at saturated surface-dry basis varies among the four aggregates and affects the chemical composition of hydration products in interfacial transition zone of aggregate-cement paste,and then affects the interfacial microstructure characteristics.Calcium hydroxide crystal is identified more clearly to be concentrated along the aggregate-cement paste interfacial transition zone of sandstone and marble than those of syenite and basalt. The width of interfacial transition zone varies among four aggregates,i.e.in descending order;marble, sandstone,syenite and basalt.It is also implicated that the interfacial microstructure characteristics play a role in affecting the axial tensile stress-strain behaviors of concretes.

关 键 词：水工混凝土 骨料 吸水 界面 结构特征 极限拉伸性能 

分 类 号：TU528.0[建筑科学—建筑技术科学]