Retrofitting of Simply Supported RC Rectangular Beam by Near Surface Mounted Technique

Abstract

In this experimental investigation we had retrofitted RC beam by Near Surface Mounted ( NSM) technique. To find out percentage increase in flexural strength of beam. We had use two-point load test on it. We casted and retrofitted RC beam of size 700*150*150 mm. To increase flexural strength, we retrofit with the help of FE500 bars of diameter 6mm externally by Near Surface Mounted (NSM) Method. The FE500 bars are applied in different length like 12d, 24d and full length. For fixing the bar we had use epoxy MYK ANCHOR HF 66. we retrofit the bar in different groove sizes like 1.5d and 2d (d is diameter of FE500 bar)

In this experimental study we compare results in flexural load as well as in deformation format. The test result shows that flexural strength of beam was increased when groove size and diameter of bar is increases. A parametric study was conducted to examine the effect of type, number, diameter of FE500 bars and bond length on flexural response. Also study was conducted changes in ultimate load carrying capacity of the retrofitted beams due to effect of groove size and bonded length of bar. Some studied parameters affected the flexural strength and deflection of beam models. Retrofitting by FE500 bar increase flexural strength of beam by 33.10% than regular RC beam, where deflection is ranges between 3.6 mm to 4.6 mm the first crack is developed on retrofitted beam. The first crack is seen at the load ranges between 37.12 to 40.00 kN. which take average load 38.60 kN safely. Retrofitting by NSM technique increases the strength of damaged member and increasing the lifespan of structure. this technique has more future scope because saving the cost of maintenance.