Analysing the Confinement Effect in Hollow Core Steel-Concrete Composite Columns under Axial Compression.

Antanas Šapalas,Andrej Mudrov

doi:10.3390/ma14206046

Abstract

Spun concrete technology allows manufacturing the reinforced concrete poles, piles, and columns with a circular hollow core. This concreting method ensures higher concrete density and strength than the traditional vibration technique and self-compacting concrete. This technology defines an attractive alternative for producing steel-concrete composite elements, allowing efficient utilisation of the materials due to the confinement effect. This study experimentally investigates the material behaviour of the composite columns subjected to axial compression. The experimental results support the above inference—the test outcomes demonstrate the 1.2–2.1 times increase of the compressive strength of the centrifugal concrete regarding the vibrated counterpart; the experimental resistance of the composite columns 1.25 times exceeds the theoretical load-bearing capacity. The proposed mechanical-geometrical parameter can help to quantify the composite efficiency. The parametric analysis employs the finite element model verified using the test results. It demonstrates a negligible bond model effect on the deformation prediction outcomes, indirectly indicating the steel shell confinement effect and confirming the literature results.

Highlights

This study experimentally investigates the material behaviour and structural performance of the hollow core steel-concrete composite columns
This study focuses on the composite behaviour of the hollow core steel-concrete elements subjected to axial compression
Spun or centrifugal casting technology allows the development of efficient composite elements using high W/C ratio concrete

Summary

Introduction

Steel and reinforced concrete are typical materials for compressive structural members. Such a decision comes with additional costs because of certain advantages and drawbacks of these materials. Steel structures are lightweight, but their thin-walled cross-sections are susceptible to local buckling. The high thermal conductivity of steel and insufficient fire resistance make such structural systems unacceptable in many cases without additional fireproofing. Concrete structures are resistant to buckling and fire, but they are heavy and massive, taking up much usable space. The concrete-filled steel columns exemplify the structurally efficient solution [2,3,4,5] in which the steel shell confines concrete, while the concrete restrains local buckling of the steel cover [6]. The confinement effect increases the compressive strength and deformation capacity of the concrete core [3,7]

Methods

Discussion

Conclusion