Bond Strength-Splice Length in Concrete Beams Confined by Transverse Reinforcement

Abstract

This work aim to study the effect of transverse reinforcement , area of splicebar, concrete cover thickness , rib area and the increasing in concrete strength (highstrengthconcrete) on bond strength between concrete and reinforcing spliced bars .Therefore, a new simple equation is derived for beams with spliced bars andconfined by transverse reinforcement to calculate bond strength and reflects theeffects of these factors .Where many of existing codes and provisions used tocalculate the spliced strength do not include or reflect the influencing of these factorsin bond strength estimation . Based on experimental results from previous works ,(116) confined beams with spliced bars are investigated in this study , whereconcrete compressive strength ( c f ¢) ranging from 25 MPa to 113.793 MPa ,amountof transverse reinforcement vary in a wide range and , conventional and highrelative rib area of deformed bars are present in these beams . The proposed methodexceed the limitation of ( f MPa c ¢ £ 69 ) that given by ACI code .Where theproposed method is examined and applicable for concrete compressive strength upto 113 MPa . Also, in this work the second root of c f ¢is examined , as concretestrength increased with high-strength concrete , to reach a suitable value for bothnormal and high- strength concrete and to be more appropriate with the heavypresent of transverse reinforcement . Power of (0.35) is adopted and used in thiswork instead of the second root of c f ¢

Keywords

• beams
• concrete
• bond strength
• splice length
• transverse reinforcement
• confinement
• rib area
• high
• strength concrete
• deformed bar