Short term creep tests of low strength rectangular concrete members jacketed with carbon FRP sheets


Demir C., Aydogmus A., İlki A.

3rd Asia-Pacific Conference on FRP in Structures, APFIS 2012, Sapporo, Japan, 2 - 04 February 2012 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Sapporo
  • Country: Japan
  • Keywords: Carbon fiber, Confinement, Creep, Low strength concrete, Rectangular cross-section, Retrofit, Sustained loading
  • Istanbul Technical University Affiliated: Yes

Abstract

Usage of low strength concrete is common in many developing countries all around the World. For example, in Turkey, the approximate average concrete compressive strength of existing reinforced concrete buildings constructed before 1990s is around 10 MPa. Since the concrete strength is foreseen higher during structural design, the sustained axial stresses of columns of such existing buildings may be remarkably high (70~90% of axial capacity). These high axial stresses sometimes cause collapse of columns or overall structure due to effects of creep of concrete. The service life of such structures can be enhanced through external jacketing of columns with FRP sheets. The efficiency of such a rehabilitation is higher in case of low strength concrete. In this study, the short term creep behavior of carbon FRP sheet jacketed low strength (~7 MPa) rectangular concrete prisms is investigated under varying levels of sustained axial stresses. The safe lifetime of the specimens are extrapolated considering the variations in axial and transverse strains measured during short term creep tests (48~96 hours). In addition, the residual capacities of carbon FRP jacketed rectangular prism specimens are investigated after being subjected to short term creep tests.