Behaviour of Steel Tubular Stub and Slender Columns in-filled with Recycled Aggregate Concrete

Abstract

In this paper, an attempt was made with steel tubular columns in-filled with recycled aggregate concrete instead of normal conventional concrete so as to utilize the construction and demolition debris for effective recycling in construction works. The behaviour of circular and square concrete-filled steel tubular sections (CFSTs) with partial replacement of coarse aggregate by recycled aggregates under axial load is presented. The effects of steel tube dimensions, shapes and the confinement of concrete are examined. Measured column strengths are compared with the values predicted by Eurocode 4, Australian Standards and American Codes. 12 specimens were tested with strength of concrete as 20 MPa and D/t ratio 18.5, 25.3 & 36.0. The columns were 76 & 89 mm in diameter and 72 & 91 mm in square are 350 & 900 mm in length. All three codes predicted lower values than that of measured during the experiments. Eurocode 4 gives the best estimation for both conventional and recycled aggregate concrete. From the results it was noted that square columns saving 30 % of steel when compare to circular columns. Also it was observed that the load carrying capacity of steel tubular columns in-filled with recycled aggregate concrete is higher than that of conventional concrete and it saves 10 % cost of concrete. Hence this research would give a solution for effective solid waste management as well as cost effective.