Nanayakkara Ominda, Najm Hadee Mohammed, Sabri Mohanad Muayad Sabri
Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou 215000, China.
Department of Civil engineering, Zakir Husain Engineering College, Aligarh Muslim University, Aligarh 202002, India.
Materials (Basel). 2022 Jun 29;15(13):4565. doi: 10.3390/ma15134565.
Non-destructive tests (NDTs) represent one of the solutions that aid engineers in evaluating the strength of materials. However, the results obtained using such tests are 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 this study to investigate the effect of the single reinforcement steel bar on ultrasonic pulse velocity (UPV). Seven concrete beams, one containing no steel and the other six beams containing varying bar diameter and cover thicknesses, were tested. UPV measurements were obtained using the indirect method and then modified to eliminate the effect of the steel bar. To provide the scientific evidence to give a reliable and reasonable solution, a statistical analysis was also conducted. The results show that a large bar diameter and a small cover thickness significantly influence the measured UPV. Measured UPV with a spacing between transducers up to 500 mm can effectively be used to predict the compressive strength of concrete after the modification of the initial UPV.
无损检测（NDTs）是帮助工程师评估材料强度的解决方案之一。然而，使用此类检测获得的结果仍存在疑问，因为它们可能受到不同因素的影响。其中一个因素是混凝土中钢筋的存在。本研究进行了一项实验调查，以研究单根钢筋对超声脉冲速度（UPV）的影响。测试了七根混凝土梁，一根不含钢筋，另外六根梁的钢筋直径和保护层厚度各不相同。使用间接方法获得UPV测量值，然后进行修正以消除钢筋的影响。为了提供科学依据以给出可靠合理的解决方案，还进行了统计分析。结果表明，较大的钢筋直径和较小的保护层厚度对测量的UPV有显著影响。在对初始UPV进行修正后，换能器间距达500mm时测得的UPV可有效用于预测混凝土的抗压强度。
