Non-Destructive Testing of Reinforced Clayey Sand Stabilized with Seashell Ash Using Ultrasonic Pulse Velocity Test

This research uses seashell ash (SAA) and polyethylene terephthalate (PET) fibers to improve clayey sand soil. For this purpose, CBR and ultrasonic pulse velocity (UPV) tests are conducted on sandy soil samples with different clay contents and stabilized with different contents of SSA and PET fibers. Results indicated that the SSA and PET fiber inclusion caused an increase in CBR values, and it was found that the optimal mix design of the treated clayey sand is 30% clay, 7% SSA, and 1% PET fiber, and the optimum curing time was 28 days. The exponential relationship between UPV values (P-wave velocity or VP) and CBR test results showed that CBR could be predicted by UPV with acceptable accuracy.