FRACTURE FREQUENCY EFFECT ON ULTRASONIC WAVE VELOCITY AND UNIAXIAL COMPRESSIVE STRENGTH IN CONCRETE SAMPLE

• Main Author: Limarco, Dion
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67758
• Institution: Institut Teknologi Bandung

The existence of fractures is a common condition in rocks, in this study discussed the effect of fracture frequency on ultrasonic wave velocity (Vp) and uniaxial compressive strength. In addition, it is also discussed whether a short sample can represent a longer sample with the same fracture-to-length ratio. The sample to be tested is a concrete sample with a mixture composition of 1:1 (cement: sand). Each sample was artificially fractured and cut into pieces as needed. The sample made is approximately 5.5 cm x 12 cm according to the test standard. The artificial fractures made are varied in frequency. These fractures were made horizontally/laterally with frequency variations of 0, 1, 2, 3, 4, and 5. In addition to the six samples, three samples with a length of 10 cm, 20 cm, and 30 cm respectively were made with fracture frequencies of 1, 2, and 3 respectively. The tools used for testing are the Hung Ta brand UCS machine to measure the uniaxial compressive strength of the sample and Ultracon 170 to measure the P wave velocity (Vp) of the sample. UCS testing was carried out on the six samples after the Vp was tested. The remaining three samples were also measured for their Vp to know whether the short sample could represent a longer sample with the same fracture-to-length ratio. From the results of this study, it can be concluded that the addition of fracture will reduce the ultrasonic wave velocity and the uniaxial compressive strength of the material. The second conclusion is that short samples cannot represent the ultrasonic wave velocity of long samples with the same fracture-to-length ratio. However, short samples can help predict the ultrasonic wave velocity of longer samples with the same fracture-to-length ratio.