粉煤灰珊瑚骨料混凝土内掺氯离子扩散和吸水性能  

Inner Chloride Ion Diffusion and Capillary Water Absorption Properties of Fly Ash Coral Aggregate Concrete

作　　者：苏丽 牛荻涛[1,2] 罗扬[1] 黄大观 罗大明[1,2] SU Li;NIU Ditao;LUO Yang;HUANG Daguan;LUO Daming(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,陕西西安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,陕西西安710055

出　　处：《建筑材料学报》2021年第1期77-86,92,共11页Journal of Building Materials

基　　金：国家自然科学基金重大项目支课题(51590914);国家自然科学基金资助项目(51808438)。

摘　　要：研究了粉煤灰掺量对珊瑚骨料混凝土(CAC)内掺氯离子含量、氯离子结合能力及毛细吸水性能的影响,并采用X射线衍射(XRD)和热重(TG-DTG)分析了水化产物、理论孔体积及结合水含量.结果表明:随着养护龄期的延长,CAC中总氯离子浓度增大,粉煤灰降低了早龄期总氯离子含量,增大了后期总氯离子含量,而自由氯离子含量随养护龄期的变化规律正好相反,粉煤灰提高了CAC的氯离子结合能力;粉煤灰对28d时CAC的抗毛细吸水性能提升较小,显著降低了60d时CAC的毛细吸水量和吸水率,掺加20%的粉煤灰使28、60d时CAC的二次吸水率分别减少了6.1%、15.4%;粉煤灰对水化产物种类没有影响,但降低了CAC中Ca(OH)2的含量,结合珊瑚骨料携带的氯离子,生成了Friedel's盐.The effects of different fly ash contents on chloride ion content,chloride ion binding capacity and capillary water absorption properties of coral aggregate concrete(CAC)was investigated.In addition,the hydration products,theoretical total pore volume and bound water content in CAC were analyzed by X-ray diffraction(XRD)and thermogravimetry(TG-DTG).The results indicate that the total chloride ion content increases with curing age.At early ages,the total chloride ion content in CAC containing fly ash is lower than that without fly ash;however,it increases at later ages.The change in the free chloride ion content with curing age is just opposite.The addition of fly ash improves the chloride binding capacity of CAC.Fly ash has little effect on the capillary water absorption of CAC for 28d;however,it can significantly reduce the absorbed water and sorptivity at 60days.Adding 20%fly ash decreased the secondary sorptivity of CAC for 28d and 60d by 6.1%and 15.4%.Fly ash has little influence on the types of hydration products formed,but it can reduce the content of Ca(OH)2 in CAC and lead to Friedel's salt.

关 键 词：珊瑚骨料混凝土 粉煤灰 内掺氯离子含量 毛细吸水性能 微观结构 

分 类 号：TU528.01[建筑科学—建筑技术科学]