Full-scale testing of high-strength RACFST columns subjected to axial compression

Abstract

The axial compression performance of concrete filled steel tubular (CFST) columns using high-strength recycled aggregate concrete (RAC) instead of normal concrete (NC) was studied in an attempt to use demolition debris for effective recycling in construction works. Five specimens (three RAC-filled steel tubular (RACFST) columns and two reference CFST columns) were tested to investigate the influence of tube shape (circular or square), concrete type (NC or RAC) and internal structure (installation of a steel reinforcement cage or not). The test results indicate that damage development and failure mode of RACFST columns are similar to those of CFST columns. For the same cross-sectional area, steel ratio and material strength, circular section specimens were found to have a higher load-bearing capacity and better deformability than square section specimens. The replacement of NC with RAC has relatively less influence on the axial compressive behaviour of square section specimens than on circular specimens. A steel reinforcement cage inside the square section specimen was found to strengthen confinement to the core concrete, which significantly improved the bearing capacity and deformability. The results obtained are compared with the ultimate strengths of RACFST columns predicted using existing design codes. Considering the size effect, a formula for calculation of the bearing capacity of square CFST columns is suggested; comparisons of the predicted results show good agreement with the experimental data.

Seismic Performance of Recycled Concrete Filled Circular Steel Tube Columns

“…Shi et al (2015) tested two section sizes of square hollow sections filled with geopolymeric RC (GRC) and RC, respectively. Niu and Cao (2015) reported the damage development and failure mode in RCFST columns. Dong et al (2016) experimentally and theoretically investigated the influence of different parameters on RCFST and CFST columns.…”

Strength of eccentrically loaded slender columns made with high-strength concrete

“…In addition, the stress-strain models for unconfined concrete adopted by the available methods influence modeling errors (Zhou and Hong, 2001). Ignoring confinement effect has been reported to result in an overly conservative post-peak response of the columns (Niu and Cao, 2015;Elchalakani, Aslani and Duan, 2017). Soliman (2011) studied the Behaviour of long confined slender concrete columns confined by proper plastic tube (FRP).…”

“…In contrast, Canbay, Ozcebe and Ersoy (2006) reported that increasing stirrup sizes was also found effective in enhancing HSC column capacity as the columns failed at higher loads. Niu and Cao (2015) reported that the incorporation of reinforcement cage made of longitudinal reinforcement and transverse stirrups resulted in an increase in the ultimate strength of steel tubular columns. Column enhancement effectiveness was also found to be greatly influenced by the geometric factors of a column and reduced with increasing aspect ratio by Li et al (2017).…”

Time-dependent behaviour of steel tubular columns filled with recycled coarse aggregate concrete

“…Extensive studies have been devoted to achieve a better understanding of the mechanical behaviour of the RACFST members under ultimate condition (e.g. [15][16][17][18][19][20][21][22][23]). It is commonly accepted that due to the contribution of steel tubes, the capacities of RACFST members to resist compressive, flexural, and cyclic loading are similar to (the order of 10% decrease in maximum) that of the companion normal CFST members, which have provided a promising future for the extensive application of the recycled aggregate concrete filled steel tubular (RACFST) columns in multi-level buildings.…”