The Bond Strength of Structural Lightweight Pumice Aggregate Concrete with/without Silica Fume

Abstract

In this study, the bond strength between concrete and steel reinforcement of structuralconcrete produced by lightweight pumice aggregate (SLWAC) is investigated by comparingwith the normal-weight aggregate (NWAC) without additives. To achieve these objectives, 7different types of concrete mixtures were produced. In producing of the SLWAC mixtures, amineral additive, Silica Fume (SF), was used to replace the Portland cement in the ratios of 0%, 5 % and 10 % by weight. The remaining three types of mixtures were obtained by addingSuper Plasticizers (SP) to the above mixtures in the ratio of 2 % by weight.In conclusion; the use of SF and SP together, increased the bonding between theconcrete and the steel reinforcement in SLWAC. The bond strength of deformed bars inSLWAC was lower compared to those of NWAC. Normalized bond strength of L-5-2 and L-10-2 coded specimens were found to be 1.01 and 1.10 times (with respectively) highercompared to normal weight concrete without additives (R). Other all SLWAC specimens wereless than R (ranges between 0.92 and 0.96 times). Besides, it was also observed that the slip atpeak load for pullout failure of ribbed bar did not vary too much for both NWAC andSLWAC specimens (ranges between 1.0 and 2.3 mm).