Crack arrester techniques in concrete structures

External steel plating has been applied to flexural elements such asbeams and slabs to increase both their strength and stiffness. Therefore,The bonded steel plate has recently become an attractive solution inrehabilitating existing infrastructure. Unfortunately, in addition to theconventional modes of failure observed in RC beams, some prematuremodes of failure can be observed in beams strengthened by means ofexternally bonded plates or sheets such as concrete cover delamination orpeeling failure. This kind of failure is caused by shear transfer mechanismsand local regions of tension at the interface between the concrete andbonded plate.In the present work, different crack arrester techniques, plate endanchorage, concrete cover replacement, and side plates addition, aresuggested to prevent or delay the peeling failure of the plated beams. Threegroups of different reinforced concrete beams, have the same dimensionsand different reinforcements, were cast and tested under four point bendingafter the application of strengthening technique. Furthermore, a theoreticalmodel was proposed for predicting the load-deflection behavior of thestrengthened beams.The experimental results demonstrated that, the ultimate load ofcontrol beam is slightly decreased due to the presence of the stirrups inconstant moment region. The peeling load of plated beams is mainlydependent on the ratio of the plate length to the loaded span of the beamand also the ratio between the steel plate area and the area of tensilereinforcement.