Effect of elevated temperature on the calcined clay-limestone and marble stone blended cement concrete

ABSTRACT The impact of high temperatures on calcined clay-limestone cement concrete (LC3) and calcined clay-marble stone cement concrete (MC3) is studied in this paper. In the present study, M25 and M35 grades of concrete was prepared using LC3 and MC3 cement and ordinary Portland cement (OPC). After 28 days of moist curing, prepared cubes of size 100 × 100 × 100 mm3, which were subjected to 100°C, 200°C, 400°C, 600°C and 800°C temperatures. Scanning electron microscopy (SEM), mass loss, surface texture and compressive strength (CS) were studied before and after specified temperatures. The X-ray diffraction (XRD) patterns, thermogravimetric analysis (TGA) and Fourier transformed infrared (FTIR) spectroscopy have been studied over M25-OPC, M25-LC3 and M25-MC3 concrete. The result shows that when the temperature exceeds 400°C, the mass loss in OPC was more than LC3 and MC3 concrete. CS was more in LC3 and MC3 concrete than OPC concrete at all high temperatures. The SEM results reveal that M25-LC3 and M25-MC3 concrete specimens have a sound structured C–S–H gel at high temperatures as compared to M25-OPC concrete specimens.