MECHANISM OF SPALLING OCCURRENCE OF HIGH STRTENGTH CONCRETE REFLECTING WATERWAY PASSAGE BY BLEEDING AND SPALLING PREVENTION DUE TO FIBER COCKTAIL
This study proposes a spalling mechanism of high strength concrete consideringwaterway passage by bleeding (WPB),based on the results of a fire test in response to thefactors affecting spalling occurrence and provides the experimental results of fire resistance ofhigh strength concrete containing fiber cocktail including polypropylene (PP),polyvinylalcohol (PVA),cellulose (CL) and nylon fiber (NY) subjected to fire. Firstly,fourteenspecimens were set up to monitor the effect of WPB on the spalling occurrence of highstrength concrete (HSC) experimentally,according to the influential factors of spalling,suchas water to binder ratio (W/B),mineral admixture,air content,moisture content,aggregateexistence and casting method Based on the experimental results,the hypothesis of vapormovement with time progressive at elevated temperature is suggested. In this hypothesis,itclosely defined the WPB,which can currently explain how the vapor moves and whichchannel the vapor uses in fire circumstance in the inside of concrete. Hence,new concept ofspalling mechanism is proposed,based on the hypothesis related to WPB. For the spalling andfire resistance after the fire test,specimens containing only 0.05 vol.％ of NY+PP fibers hadno spalling,while specimens containing PVA+PP fibers needed more than 0.15 vol.％ of fiberto prevent spalling. The residual compressive strength ratio of all specimens after fire testranged around 0％-60％ compared with compressive strength before the fire test. Especially,residual compressive strength ratios of the specimen with more than 0.05 vol.％ of PP+NYfiber combination exhibited to be more than 50％.
spalling mechanism high strength concrete waterway passage by bleeding (WPB) fiber cocktail residual compressive strength
Cheon-Goo Han Min-Cheol Han Chang Chun Pei Dong-Gyu Lee
CheongJu University,Cheongju,Republic of Korea
国际会议
The International Conference on Durability of Concrete Structures(2008年混凝土结构耐久性国际学术会议)
杭州
英文
356-366
2008-11-01（万方平台首次上网日期，不代表论文的发表时间）