摘要
采用SEM和BET试验,研究分析了聚丙烯纤维混凝土和纤维素纤维混凝土的微观结构特征。开展了混凝土冻融循环试验,研究分析了两种纤维混凝土的抗冻耐久性能退化规律,并探讨了纤维改善混凝土抗冻性能的机理。研究表明,纤维与水泥石的界面区是硬化混凝土微观结构中的薄弱环节。随着混凝土龄期的增长,纤维与水泥石的界面区逐渐致密,硬化水泥浆体的孔隙不断减少,龄期84 d时,两种纤维混凝土的总孔体积均小于普通混凝土。纤维减小了混凝土内部的静水压和渗透压,抑制了混凝土的冻融损伤,减小了混凝土冻融循环后的质量损失以及动弹模量损失。
The microstructure characteristic of polypropylene fiber concrete and cellulose fiber concrete were studied by SEM and BET tests.Launched a freezing and thawing test, the frost resistance performance of fiber reinforced concrete was analyzed and the reinforcement mechanism of the fiber under the action of freeze and thaw was also discussed.The research results show that the interface region of fiber and cement paste is a weak link in the microstructure of hardened concrete.As the growth of the concrete age,the interface region become compact,and the porosity of hardened cement paste decrease continuously.At the age of 84 d,total pore volume of two kinds of fiber concrete is less than that of plain concrete.It is also shown that the fiber reduces the hydrostatic pressure and osmotic pressure inside the concrete,inhibited the freeze-thaw damage of concrete,and decreases the mass loss and the dynamic modulus loss of concrete after the freeze-thaw cycles.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2015年第10期2919-2924,共6页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金项目(51408553)
河南省水利科技攻关项目(GG201408)
河南省教育厅科学技术研究重点项目(14A560009)
河南省博士后科研资助项目(2012010)
关键词
聚丙烯纤维
纤维素纤维
混凝土
微观结构
冻融循环
polypropylene fiber
cellulose fiber
concrete
microstructure
freezing and thawing
