Perbandingan Karakteristik Pengujian Non Destructive Test (NDT) dalam Beton Fly Ash sebagai Bahan Substitusi Parsial Semen terhadap Suhu 1000OC

Abstract

This research investigates the mechanical performance of concrete incorporating fly ash as a partial cement replacement subjected to high temperature exposure. Fly ash sourced from the Pangkalan Susu power plant was utilized in replacement proportions of 0%, 10%, 20%, 30%, 40%, and 50%. Concrete specimens aged 28 days were evaluated using non destructive testing methods, namely Ultrasonic Pulse Velocity (UPV) and Rebound Hammer, as well as a destructive testing method, the Compression Test. All specimens were exposed to a temperature of 1000OC for 3 hours followed by cooling through water immersion. Post fire UPV testing demonstrated an optimum compressive strength of 13 MPa in the 0% fly ash mix. Conversely, the Rebound Hammer Test yielded a maximum compressive strength of 2,05 MPa for the 10% fly ash variation. It is noteworthy that Rebound Hammer measurements were only perfomed on specimens containing 0% and 10% fly ash, as those incorporating higher replacement levels (20%-50%) exhibited extensive cracking that rendered them unsuitable for testing. The Compression Test conducted on post heated specimens recorded an optimum compressive strength estimations most closely aligned with those obtained from destructive testing, underscoring its potential utility for assessing residual strength in fire exposed concrete.