Bond strength-splice length in concrete beams confined by transverse reinforcement

الملخص EN

This work aim to study the effect of transverse reinforcement, area of splice bar, concrete cover thickness, rib area and the increasing in concrete strength (high-strength concrete) on bond strength between concrete and reinforcing spliced bars.

Therefore, a new simple equation is derived for beams with spliced bars and confined by transverse reinforcement to calculate bond strength and reflects the effects of these factors .Where many of existing codes and provisions used to calculate the spliced strength do not include or reflect the influencing of these factors in bond strength estimation.

Based on experimental results from previous works, (116) confined beams with spliced bars are investigated in this study, where concrete compressive strength f c ranging from 25 MPa to 113.793 MPa, amount of transverse reinforcement vary in a wide range and, conventional and high relative rib area of deformed bars are present in these beams .

The proposed method exceed the limitation of ( fc ≤ MPa 69MPa) that given by ACI code .Where the proposed method is examined and applicable for concrete compressive strength up to 113 MPa .

Also, in this work the second root of f c is examined , as concrete strength increased with high-strength concrete , to reach a suitable value for both normal and high- strength concrete and to be more appropriate with the heavy present of transverse reinforcement .

Power of (0.35) is adopted and used in this work instead of the second root of f c.