混杂纤维大体积混凝土配合比试验OA

To mitigate hydration-induced cracking in mass concrete,the optimal mix proportion of hybrid fiber-reinforced concrete was investigated.First,polypropylene(PP)fibers and polyvinyl alcohol(PVA)fibers were mixed at different ratios to study their effects on the slump,compressive strength(3,7,and 28 days),and splitting tensile strength of concrete,thereby determining the optimal hybrid fiber ratio.Second,the effects of different fiber contents on the slump,compressive strength(3,7,28,and 60 days),splitting tensile strength,and thermal conductivity of C35,C40 and C45 concrete were examined to identify the optimal fiber content for each strength grade.The results show that,considering workability,thermal conductivity,and mechanical properties,the optimal PP-to-PVA fiber ratio is 1:1.Under this ratio,the optimal fiber contents for C35,C40,and C45 concrete are 1.5 kg/m3,1.2 kg/m3 and 1.2 kg/m3,respectively.