EFFECT OF FRACTURE ORIENTATION ON ULTRASONIC WAVE VELOCITY ??ON CONCRETE SAMPLES.

• Main Author: Purnando, Hengki
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67788
• Institution: Institut Teknologi Bandung

The presence of fractures is often found in many rocks in nature, this can affect the strength of the rock. Research to determine rock strength can be done by ultrasonic wave test on a rock. This study was conducted to analyze the effect of fracture orientation on ultrasonic wave velocity by applying the non destructive test (NDT) method. This method can be used to detect the condition of the material without damaging the material. Samples were made with a size of 5.4 x 12 cm according to the ISRM test standard (1981). The composition of the material for making concrete samples using sand, cement, and water in a ratio of 1: 1: 0.67. Artificial fractures in the samples were made with orientations of 0°, 30°, 45°, 60°, and 90°. The tool used for ultrasonic wave testing is Ultracon-170. This tool measures the velocity of the P wave (Vp) in samples with different fracture orientations. From the results of the study, it was found that the graph of the P wave (Vp) on the sample with different orientations was in the form of a curve. The lowest Vp value is found in the sample with an angle of 45°. The graph has the same shape as the UCS test graph on rocks that have certain fractures, where the weakest rock strength is at 45° - 55° fractures. It can be concluded that the presence of fractures in the rock will affect the speed of ultrasonic waves and ultrasonic wave testing is related to UCS testing. Therefore, the greater the value of Vp, the greater the strength of the rock.