NUMERICAL INVESTIGATION OF AXIALLY LOADED RC COLUMNS STRENGTHENED WITH STEEL ANGLES AND BATTEN

Abstract

The need of strengthening reinforced concrete columns, due to loss of strength and/or stiffness is an essential requirement due to variation of loads and environmental conditions. The present research proposes innovative retrofitting mechanism using steel angles and discrete steel battens. This research numerically investigates performance gains of steel angles and battens strengthened reinforced concrete column. Experimental results reported in literature is used for validation analysis using ANSYS nonlinear finite element analysis software program. Further, parametric studies are performed on influential variables such as Concrete strength; steel angles and battens yield strength, thickness and size, jacketing height, length of jacketing RC column, the same area of steel angle and batten spacing to get insight into performance of steel angles and battens strengthened reinforced concrete column. Finite element results indicated as compared to control, strengthening of RC column using steel angles and discrete battens and varying concrete strength is mostly affected by 34% of load increment by changing the Concrete strength from 34 to 50MPa.The yield strength of structural steel specimen S-460 increase by 5% compared to the strengthened RC column with S-360. Load increment is recorded by changing 50*50*5 to 75*75*5 the angle size 2% compared to the reference with strengthening specimen. Angle thickness with 10mm and 15mm have a +3% and +8% compared to the specimen with different size steel angles 5mm. Batten thickness, two RC strengthened columns with 6mm and 4mm are developed and gave have a +2% and +1% compared to the specimen with different thickness compared to batten 2mm. Height of partial strengthened part the load-carrying capacity is dramatically increased by 28.2%, 28% and 26% of the region middle half, middle third and a half of jacketed with steel angle and batten respectively, compared with unstrengthen RC column. The number and configuration of horizontal batten did not have a noticeable effect on the ultimate capacity of the columns. Due to closely spacing column, the confinement did not affect the entire column, and failure occurred in the space between the horizontal batten. From the result, it was observed thatload carrying capacity highly affected by the compressive strength of concrete, yield strength of steel angle and batten, angle thickness and angle of steel width.