Ali Al-Rifaie

In the present research, ten simply supported reinforced concrete beams having a rectangular cross-section were cast and tested up to failure under the action of two-point loads. Eight of these beams were designed to contain horizontal construction joints (HCJs) of different number and location in the beam while the other two beams had no construction joint which were referred to as reference beams for the sake of comparison of results. All the tested beams had been designed to fail in flexure and had the same amount and type of longitudinal and transverse reinforcement as well as similar concrete properties. The results of this series of tests have indicated that the presence of HCJs in reinforced concrete beams leads to a decrease in its ultimate loads and increase in its ultimate deflection. The values of the recorded ultimate loads ranged between 83% to 98% times that of the reference beam while the ultimate deflection ranged between 102% to 133% times that of the reference beam.

Non-destructive tests (NDTs) represented one of the solutions that aid the engineers to evaluate the strength of materials. However, the results obtained using such tests still questionable as they may be affected by different factors. One of these factors is the presence of steel reinforcement in concrete. An experimental investigation is presented in the current study to investigate the effect of the distribution of steel reinforcement on the one of the most common NDTs named Ultrasonic Pulse Velocity (UPV). However, two small-scale concrete slabs were tested and the results were successfully obtained. Two different spacing between the longitudinal reinforcement were considered. Also, the effect of measuring the UPV in the top and bottom surface of the RC slab was studied. The effect of direct path length was also investigated. The results showed that the presence of reinforcement considerably affects the UPV values. Besides, no judgement was made to decide the effect of path length as fluctuated results were obtained.