Structural behvaior of reinforced concrete beams cast using blended cement

An experimental study has been carried out in the present work to study the structural behavior of reinforced concrete beams cast using blended cement concrete. The eight tested beams were 160 cm long × 20 cm deep × 12 cm wide. The test beams were reinforced with two different steel reinforcement ratios of 0.70% and 1.0%. Two beams were control beams cast using Portland cement and the other six beams were cast using blended cement incorporating 5%, 10% and 15% dolomite powder as cement replacement. To achieve the aim of the research; all beams were tested under 4-point loading until failure and the following measurements have been recorded during testing the beams for each load increment; the compressive and tensile strains in concrete and steel, and mid-span deflection. The propagation of cracks was marked on the side and soffit of the beam. The results of monitoring the tensile and compressive strains, mid-span deflection and cracking pattern are presented. The results demonstrated that the 5 percent replacement ratio did not influence the structural behavior, while the ultimate loads and stiffness were reduced as the 10 and 15 percent replacement ratios. On the other hand, the cracking characteristics and failure mode were not influenced by the cement replacement.