肋形永久梁模板结合面抗剪强度研究

Study on the shear strength of interfaces on the rib permanent beam formwork

为了研究肋形永久性梁模板与梁身混凝土抗剪性能,分别制作了60组不同肋数、掺加不同纤维混凝土试件,进行新老混凝土结合面抗剪试验。试验结果表明,老混凝土掺纤维可提高新老混凝土结合面的抗剪强度;新老混凝土结合面抗剪强度与横向肋数呈二次函数增长关系;掺加聚乙烯醇纤维或短钢纤维试件肋面积占总面积42%时,结合面抗剪强度超过同配合比混凝土抗剪强度,无纤维试件肋面积占总面积42%时,掺加聚乙烯醇纤维试件肋面积占总面积28%时,结合面抗剪强度接近同配合比混凝土抗剪强度。

In order to research on shear performance of rib permanent beam formwork and concrete in the beam, 60 groups of specimens are made to test shears of new-old concrete, which uses different number of transverse ribs and different kinds of fibers.The results show that it can improve the shear strength of new-old concrete interfaces that adding fibers to old concrete;The shear strength of new-old con- crete interfaces increases with the number of ribs as quadratic function;When area of ribs adding PVA fibers or SS fibers accounts for 42 percent of the total area, its shear strength is higher than shear strength of same mix proportion concrete, When area of ribs without fibers accounts for 42 percent of the total or ribs adding PVA fibers accounts for 28 percent of the total area, its shear strength is higher than shear strength of same mix proportion concrete.