Behaviour of Steel Strapping Tensioning Technique (SSTT) confined high-strength concrete with different lateral pre-tensioning stresses

Abstract

This paper presents the results of an experimental and analytical study on the application of Steel Strapping Tensioning Technique (SSTT) confinement on twelve high-strength concrete cylinder specimens with dimension of 100 mm and 200 mm in diameter and height respectively. The specimens were confinement volumetric-identically wrapped with two different confining materials of different mechanical properties and lateral pre-tensioning stresses, namely SSTT(HC) and SSTT(SS). The performance of SSTT-type confined specimens were studied through their stress-strain relationship upon the longitudinal and transverse deformation, mode of failure, level of lateral pre-tensioning stress, etc. The results show that SSTT-type confinement would significantly controlled the brittleness problem of high-strength concrete and at the same time, enhancing both ultimate compressive strength and ductility up to 65% and 344%, 36% and 269% for both SSTT(HC) and SSTT(SS), respectively. In addition, the result of an analytical comparison between SSTT-type confinement and existing confinement models show a linear relationship between the compressive strength enhancement and confinement ratio. The experimental results also been validated by comparing the observed stress-strain relationship to those calculated based on Mander's confinement.