Effect of Spalling Depth on the Fire Behaviour Simulation of High-Volume Fly Ash Nano-Silica Reinforced Concrete Slab at Various Fire Curves

Roszilah Hamid (Department of Civil and Structural Engineering, Universiti Kebangsaan Malaysia)
Noor Azim Mohd. Radzi (Department of Civil and Structural Engineering, Universiti Kebangsaan Malaysia)
Azrul A Mutalib (Department of Civil and Structural Engineering, Universiti Kebangsaan Malaysia)

Bulletin of Civil Engineering
Vol 3, No 2 (2023): Agustus

Pengelupasan beton ditandai dengan pemisahan elemen beton yang berulang-ulang yang terpapar suhu tinggi. Karena struktur mikronya yang padat, beton mutu tinggi cenderung menyerpih dan kehilangan kekuatannya. Makalah ini menyajikan simulasi perilaku termal pelat beton bertulang (RC) abu terbang isipadu tinggi isipadu tinggi abu terbang (HSHVFANS) beton bertulang (RC) kekuatan tinggi yang terpapar berbagai kurva api (HC, RABT-ZTV, dan RWS) menggunakan analisis elemen hingga (FE). Dua model FE, yaitu No Spalling (NS) dan Maximum Spalling (MS) divalidasi dengan uji api pelat HSHVFANS RC yang terpapar kurva api ISO 834 selama 120 menit. Model FE yang divalidasi digunakan untuk memprediksi efek kedalaman spalling pada kurva api yang berbeda. Hasil profil suhu menunjukkan bahwa model NS FE tetap berada di dalam hasil percobaan, sedangkan model MS FE menunjukkan peningkatan suhu berkisar antara 680 °C hingga 840 °C. Suhu penguatan untuk model NS FE tetap di bawah 300 °C hingga 120 menit, sedangkan model MS FE lebih tinggi dari 300 °C pada 72 menit (ISO 834), 55 menit (HC), 48 menit (RABT-ZTV), dan 46 menit (RWS). Telah ditemukan bahwa periode tahan api dari pelat RC HSHVFANS secara signifikan dipengaruhi pada kedalaman serpihan maksimum.Concrete spalling is characterised by a repetitive breakaway of concrete elements exposed to elevated temperatures. Due to its dense microstructure, high-strength concrete tends to spall and lose its strength. This paper presents the thermal behaviour simulation of a high-strength high-volume fly ash nano-silica (HSHVFANS) reinforced concrete (RC) slab exposed to various fire curves (HC, RABT-ZTV and RWS) using finite element (FE) analysis. Two FE models, namely No Spalling (NS) and Maximum Spalling (MS) were validated with the fire test of the HSHVFANS RC slab exposed to ISO 834 fire curve for 120 min. The validated FE models were used to predict the effect of spalling depth at different fire curves. The temperature profile result shows that the NS FE model remains inside the experimental results, while the MS FE model showed an increase in the temperature ranging from 680 °C up to 840 °C. The reinforcement temperature for the NS FE model remained below 300 °C until 120 min, while the MS FE model was higher than 300 °C at 72 min (ISO 834), 55 min (HC), 48 min (RABT-ZTV), and 46 min (RWS). It has been found that the fire-resistant period of the HSHVFANS RC slab was significantly affected at maximum spalling depth