Study on Structural Performance of Reinforced Concrete Columns with Waist-High Walls Strengthened by Carbon Fiber Reinforced Plastic Sheets

Abstract

This research aims on understanding the influence of the method using carbon fiber reinforced plastic (CFRP) sheets on the performance of 13 reinforced concrete columns with waist-high walls. Main parameters of the specimens include the thickness and height of the attached walls, axial load, and the amount of CFRP sheets. The strengthening method is done by wrapping the upper portion of the column with sheets in a closed form. Also, the waist-high walls are equipped with holes where the carbon fiber strands (CF-anchor) are inserted and anchored to the ends of the sheets attached only on the surface of the lower portion of the column. Test results show that there is a great improvement in the ductility of the shear-failure type specimens when strengthened with CFRP. Also with an increase in the amount of the sheets, the ductility is further enhanced. The specimens strengthened using CFRP with CF-anchor also show higher ductility than the specimen where only the upper column is strengthened. The bending and shear strengths of the columns with waist-high walls can be calculated by using effective column height h(e) considering the presence of the all portions.