EFFECT OF CONSTRUCTION JOINT ON STRUCTURAL PERFORMANCE OF REINFORCED SELF-COMPACTING CONCRETE BEAMS

This paper presents the effect of construction joints on the performance of reinforced self-compacting concrete slender beams. The experimental program included casting and testing four beams with dimensions of 125×150×1000 mm. The first beam is without construction joint as a reference specimen, the second beam is of horizontal construction joint at mid-depth of the beam, the third beam is of vertical construction joint at mid-span (maximum bending moment point) and the fourth beam is of vertical construction joint on fourth-span (maximum shear region). The test results showed that the effect of construction joint on the ultimate load was more significant than that on the first crack load, also, the results showed that the beam of horizontal construction joint gave better structural performance as compared with the other cases of the construction joint, in which the first crack load decreased 6.7% and the ultimate load decreased 26.7%as compared with the reference beam. Also the results showed that the beam with vertical construction joint on the fourth-span represented the less efficiency case, in which the first crack load decreased 16.7% and ultimate load decreased 56.2% as compared with the reference beam. Furthermore the load-deflection becomes less stiff with presence construction joint especially beyond the first crack load.