DIFFERENT VARIABLE EFFECTS ON BOND STRENGTH OF NORMAL HIGH AND ULTRAHIGH STRENGTH CONCRETE.pdf

The bond characteristics of reinforcing steel bars embedded in structural concretemade with normal, high and ultra-high strength concrete, was investigated applyingpull-out tests on cubic molds of size (100*100*100mm) with the effect of somevariables parameters such as, type of concrete, strength of concrete, steel fiber withvolume fraction (0%, 1% and 2% with aspect ratio of l/d=65) and size of steelreinforcing. The preliminary study was presented to measure the average cubicspecimens of size (100*100*100mm) according to ASTM for determining thecompressive strength which performed at age of 28 days. The experimental workconcluded that the joining of steel fibers to mixture strengthens the bond between thereinforcing bar and the concrete and an improvement in the bond strength is achievedwhen the strength of concrete increase but it noticed that a decrease in bond strengthis achieved when the bar diameter was increased. Comparisons of measured bondstrength with codes and others researcher’s equations were presented here. Threedimensionnonlinear finite component design using ANSYS program was applied toinvestigate the performance of bond measurements within the concrete andreinforcing bar. The efficiency of this representation is examined by analyzing thefinite element analytical performance with that predicted from laboratory results ofthree pullout concrete types. High-grade compromises within the finite elementsolution and laboratory outcomes were achieved.