Flexural performance of high strength engineered cementitious composite-steel beam coupling with shrinkage load

Abstract

With increase of traffic volume, orthotropic steel deck stiffened with a cementitious composite overlay becomes a popular deck type in long-span bridge. In this paper, flexural performance of high strength engineered cementitious composite (HSECC)-steel composite beam, especially the effect of internal curing of HSECC on cracking load, ultimate load, deflection and crack opening under load, is studied by experiments. In the test program, five mixtures of HSECC, including four mixtures internally cured (IC) with pre-wetted calcined particles and one mixture with ordinary curing (OC), are used. The test results show that cracking and ultimate bending load of internally cured HSECC-steel composite beam is greater than that of ordinarily cured composite beam. Deflection at cracking and peak load of internally cured composite beam is larger than that of the beam with ordinarily cured HSECC. Internal curing can also improve the ability of crack opening control after cracking. Reduction on shrinkage stress resulting from shrinkage of the cement composite layer in the structure should be responsible for the positive effect on bending performance of HSECC-steel composite beam.