Post-peak Behaviour of Composite Column Using a Ductile Lightweight Aggregate Concrete

Mohammad Reza Hamidian,Payam Shafigh

doi:10.1186/s40069-020-00453-6

Abstract

Oil palm shell (OPS) concrete filled steel tube (CFT) columns are acknowledged to be a new type of sustainable composite column. In this type of column, the conventional coarse aggregate was partially replaced with OPS lightweight aggregate to provide a green composite column. This type of CFT column showed higher energy absorption and flexibility compared to CFT columns with normal weight concrete. This research studied the effect of the strength of OPS concrete on the axial compressive behaviour of CFT columns for two grades of OPS concretes. The behaviour was comparable to that of CFT columns with two grades of normal concrete. The results showed that the CFT columns with OPS concrete achieved a new post-peak behaviour. The experimental results of the axial compressive load were compared with the estimation of two international standards. EC4-1994 and ACI318-14 showed a reliable and conservative estimation of the axial load capacity of CFT columns, respectively.

Highlights

Concrete filled steel tube (CFT) columns have been widely used in the construction industry because of their superior structural behaviour, such as high strength and ductility (Abed et al 2013; Matsumoto et al 2012)
The behaviour of the CFT columns consists of two stages: first, elastic behaviour, and, second, from the last elastic point to the peak load
The behaviour of CFT columns in the second stage is more influenced by the properties of concrete (Hamidian et al 2016)

Summary

Introduction

Concrete filled steel tube (CFT) columns have been widely used in the construction industry because of their superior structural behaviour, such as high strength and ductility (Abed et al 2013; Matsumoto et al 2012). De Oliveira et al (2009) studied the effect of the compressive strength of concrete on the post-peak behaviour of CFT columns They investigated the behaviour of a series of CFT columns with the same steel tube and different grades of concrete under axial load. Many researches have been conducted on the effect of the material properties on the behaviour of CFT columns In these studies, different conditions for the steel tube and concrete core were considered. The effect of OPS concrete grade on the pre- and post-peak behaviours of CFT columns was studied, and the results were compared with normal concrete filled steel tube (NCFT) columns. Studies on the CFT column are usually in two groups of short and long columns To investigate parameters such as the maximum load capacity, load–displacement behaviour, pre- and post-peak behaviours, the failure mode of concrete and local buckling of steel tube, short columns are used. To study the effect of concrete properties on the post-peak behaviour of the CFT column, two types of concrete as normal and OPS concrete were used and the results have been discussed in detail

Axial Load Behaviour of CFT Column with Normal Weight Concrete

Axial Load Behaviour of CFT Columns with OPS Lightweight Concrete

Comparison of Experimental Test Results and Standards

Conclusion