摘要
用铁尾矿沙替代河砂制备超高性能混凝土(UHPC),研究不同掺量的钢纤维(0%、0.5%、1%、1.5%、2%)对UHPC的硫酸盐冻融循环耐久性,基于灰色关联分析了铁尾矿砂UHPC盐结晶析出量、质量损失率和动弹性模量对28 d抗压强度的影响大小。结果表明,铁尾矿砂UHPC在经历冻融循环200次后,盐结晶析出量随钢纤维掺量增加而减小,A05、A10、A15组的盐结晶析出量较A0组分别提高了108%、75%、17%,A20组的盐结晶析出量较A0组减少了25%;A20、A15、A10、A05组的质量损失率对比A0组分别增加了23.5、16.3、7.8、1.3倍,A20组在冻融200次前的动弹性模量最高,A0组在冻融200次后的动弹性模量最高,钢纤维掺量越高,动弹性模量下降越快;对铁尾矿砂UHPC 28 d抗压强度的影响最大的为动弹性模量,影响最小的为质量损失率。
The ultra-high performance concrete(UHPC)was prepared with iron tailing sand instead of river sand,and the durability of UHPC on sulfate freeze-thaw cycles with different dosages of steel fibers(0%,0.5%,1%,1.5%,2%)was studied.Based on grey relational analysis,the influences of UHPC salt crystallization amount of iron tailings sand,mass loss rate and dynamic elastic modulus on 28 d compressive strength were analyzed.The results show that after 200 freeze-thaw cycles of iron tailings UHPC,the amount of salt crystallization decreases with the increase of steel fiber content.The amount of salt crystallization in the A05、A10、A15 groups is increased by 108%,75%and 17%,respectively,compared with the A0group,the amount of salt crystallization in the A20、A15、A10、A05 groups were reduced by 25%compared with the A0 group;the mass loss rates of the A20、A15、A10、A05 groups were 23.5,16.3,7.8 and 1.3 times higher than that of the A0 group,respectively.The A20 group was frozen and thawed 200 times before The dynamic elastic modulus of A0 group is the highest after 200 times of freezing and thawing.The higher the content of steel fiber,the faster the dynamic elastic modulus decreases;the impact on the 28 d compressive strength of iron tailing sand UHPC is the greatest.is the dynamic elastic modulus,and the least affected is the mass loss rate.
作者
史波
何旺
SHI Bo;HE Wang(Architectural Arts College,Jiangsu Urban and Rural Construction Vocational College,Changzhou 213147,China;School of Civil Engineering,Southeast University,Nanjing 210096,China)
出处
《金属矿山》
CAS
北大核心
2022年第12期65-69,共5页
Metal Mine
基金
国家自然科学基金项目(编号:51908119)。
关键词
铁尾矿砂
超高性能混凝土
质量损失率
动弹性模量
冻融循环
灰色理论
iron tailings sand
ultra-high performance concrete
mass loss rate
dynamic elastic modulus
freeze-thaw cycle
grey theory
