摘要
海洋浪溅区的混凝土结构,由于长期受到氯盐的侵蚀和海浪冲刷作用,导致混凝土结构发生钢筋锈蚀、保护层胀裂剥落等耐久性破坏,无法满足长期服役要求。本工作选取3种不同矿渣掺量的高性能矿渣混凝土进行实验室自然扩散和海洋浪溅区现场暴露试验,基于可靠度理论和修正氯离子扩散理论的ChaDuraLife V1. 0寿命分析软件,对海洋浪溅区的高性能矿渣混凝土结构进行寿命分析与研究。结果表明:随着服役时间的延长,海洋环境下高性能矿渣混凝土结构的失效概率逐渐增大,可靠度指标逐渐降低。随着矿渣掺量和保护层厚度的增大,高性能矿渣混凝土结构的服役寿命呈增长趋势。海洋浪溅区环境下,矿渣含量为35%、粉煤灰含量为15%、强度等级为C50的高性能矿渣混凝土在保护层厚度取7 cm、8 cm和9 cm的情况下,其服役寿命分别可以满足50 a、100 a和120 a的使用寿命要求。同时,建议将GBT50476-2008《混凝土结构耐久性设计规范》中规定的浪溅区混凝土最小保护层厚度和28 d氯离子侵入指标DRCM最大值进行修正,以满足其规定的设计使用年限要求。
The long-term erosion and scouring effect of sea waves usually causes corrosion to steel bar as well as swelling and cracking of protective la-yer,which eventually affect durability and service life of concrete structures constructed in marine condition.Based on the reliability theory,modified chloride diffusion theory and the ChaDuraLife V1.0 life analysis software,herein we selected 3 kinds of high performance concrete differing in slag content and conducted the service life calculation and analysis upon long-term exposure to laboratory and marine wave condition.The results indicated that:the failure probability of high performance slag concrete structure in marine environment gradually increases and the reliabi-lity index gradually decreases as time goes on during service.Either a higher slag content or a larger thickness of protective layer is beneficial to the service life of high-performance slag concrete structure.Under the circumstance of ocean wave splash zone,the C50 high-performance slag concretes in which slag content and fly ash content are 35%and 15%,respectively,could meet the service life requirements of 50 a,100 a and 120 a in the cases of protective layer thicknesses of 7 cm,8 cm and 9 cm.In addition,we suggest that the minimum protective layer thickness of concrete in splashed zone and the maximum DRCM(28 d age chloride diffusion coefficient)in the"Code for Design of Durability of Concrete Structures"are revised to attain the stipulated designed service life requirements.
作者
吴彰钰
余红发
麻海燕
冯滔滔
达波
WU Zhangyu;YU Hongfa;MA Haiyan;FENG Taotao;DA Bo(Department of Civil Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016;Department of Materials Science and Engineering,Southeast University,Nanjing 210096)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2019年第2期264-270,共7页
Materials Reports
基金
国家重点基础研究发展计划(973计划)(2015CB6551002)
高性能土木工程材料国家重点实验室重点基金项目(2015CEM001)
江苏省普通高校研究生科研创新计划项目(KYLX15-0230)
南京航空航天大学研究生创新基地(实验室)开放基金(kfjj20170109)~~
关键词
海洋环境
矿渣混凝土
氯离子扩散
可靠度
寿命设计
marine condition
slag concrete
chloride diffusion
reliability
service life design
