Experimental Research on Fatigue Behavior of Reinforced Concrete Beams Strengthened with HPFL under Overloading Conditions

Abstract

In order to study the fatigue behavior of RC beams strengthened with High Performance Ferrocement Laminates (HPFL) under overloading conditions, static and fatigue experiments were conducted on two control beams and nine strengthened beams. The failure mode, fatigue life, deflection and material strain under overloading conditions were analyzed. The result shows that (1) fatigue failure of the beams subjected to overload starts with steel rupture at the bottom and the fatigue life is only between 327,000 and 668,000 while fatigue life of strengthened beams is greater than two million times in case of not overloading; (2) compared with the control specimen, the fatigue life of strengthened beams is obviously extended and increased with the increase of steel mesh consumption; (3) after the same number of cycles, the deflections, the strains of concrete and steels of four strengthened beams are lower than those of the control specimen. Debonding at the interface of HPFL and concrete is not observed because of shear pins planted at the end of the beams.