水利学报2018，Vol.49Issue(4)：419-427,9.DOI:10.13243/j.cnki.slxb.20171243
干湿循环下改性混凝土硫酸盐腐蚀的断裂性能试验研究
Experiment study on fracture properties of modified concrete attacked by sulfate corrosion under dry-wet circulation
摘要
Abstract
The ordinary concrete was modified by adding fly ash,slag powder,silica fume and polyester fiber,respectively.Corroded by 5％ Na2SO4 solution coupling with dry-wet circulation,the concrete beams with notch were performed by means of the three-point bending fracture test to study the cracking resistance behavior of sulfate corrosion concrete.The variation tendencies of P-CMOD (load-crack mouth opening displacement) curves,fracture toughness and fracture energy of modified concrete were analyzed.The anti-corrosion toughening coefficient was defined to research the toughening effects of modified concrete contrast to the ordinary concrete under the condition of sulfate attack.The deterioration mechanism of modified concrete was probed at different corrosion periods.The results indicate that the P-CMOD curves of modified concrete undergo four stages including damage initial flexure section,elastic proportional section,stable extension stage and softening phase after sulfate corrosion.The anti-corrosion toughening coefficients of modified concrete increase firstly and decrease later varied with the dry-wet circulations.The addition of 25％ fly ash improves the fracture toughness of concrete in the early corrosion stage significantly,while polyester fiber and slag have the better effects on enhancing the unstable toughness in the late corrosion period as well as increasing fracture energy.Incorporation of silica fume takes little effects on improving the comprehensive fracture properties.关键词
改性混凝土/硫酸盐/干湿循环/腐蚀/断裂韧度/断裂能/抗腐蚀增韧系数Key words
modified concrete/sulfate/dry-wet circulation/corrosion/fracture toughness/fracture energy/anti-corrosion toughening coefficient分类
建筑与水利引用本文复制引用
郭进军,杨梦,陈红莉,韩菊红..干湿循环下改性混凝土硫酸盐腐蚀的断裂性能试验研究[J].水利学报,2018,49(4):419-427,9.基金项目
国家自然科学基金项目(51679221) （51679221）
