| Title |
An Experimental Study on the Shear Behavior for Reinforced Concrete Beams with Strengthening by Epoxy Mortar Panel Including Steel Fiber |
| Authors |
Lee Sang-Ho ; Kim Tae-Hyun |
| Keywords |
Reinforced Concrete Members ; E.M.S.F Panel ; Steel Fiber ; Shear Strengthening ; High Toughness |
| Abstract |
The purpose of this study is to develop new strengthening material, increasing shear strength and deformation capacity of reinforced concrete beam members. To develop strengthening material that has high strength-toughness characteristics, the new composite material, name of E.M.S.F(Epoxy Mortar including Steel Fiber), is made by combining steel fiber into epoxy mortar. In this study, the testing programs are divided into two groups. The first group is aimed to assess the influence of the volume ratio, the length of steel fiber on the tensile strength and toughness capacity of the composite material(E.M.S.F). There are 3 series of tensile tests, each with the different fiber length and volume ratio: 35mm, 50mm, and the hybrid of two fibers. In each case, the following volume ratios of steel fiber are from 0.5% to 4.0% at interval of 0.5%. The second group is aimed to assess the influence of the kind and thickness of E.M.S.F panel on the shear capacity, and shear failure mode of strengthened RC beam. There are 3 series of test in this group, one shear strengthened with E.M panel including no steel fiber, another with E.M.S.F panel including 35mm steel fiber with volume ratio of 3.0% and the other E.M.S.F panel including both 35mm steel fiber with volume ratio of 3.0% and 50mm with volume ratio of 0.5%. In each case, the thicknesses of panel are 7.5mm and 12.5mm. The results of the two groups in the testing program are as follows : 1) From the result of tensile test, E.M.S.F panel including 35mm steel fiber shows high tensile strength and E.M.S.F panel including 35mm and 50mm steel fiber show good toughness capacity. 2) The bond strength between steel fiber and E.M matrix is very high. 3) RC beam strengthened by E.M.S.F panel including short fiber(35mm) has the highest shear strength. 4) RC beam strengthened by E.M.S.F panel including both short fiber(35mm) and long fiber(50mm) has the improved deformation capacity. 5) The shear strength equation is derived from the equilibrium of cracked RC beam and agrees well with the test results. |