Physical properties of cementitious composite material with Iraqi bentonite as partial cement replacement under elevated temperatures

The impact of higher temperatures on the qualities of normal-strength mortar containing Iraqi bentonite powder (BP) as a partial substation of cement was examined in the present research. The bentonite concrete was made by replacing cement with bentonite in weight ratio of 5 and 10%. A strength test (compressive strength) was performed, and the durability performance (mass loss) and absorption were performed and discussed. The results showed that samples containing bentonite outperformed the control mix regarding heat endurance. The flowability of the mixture decreased by 15% and 25% for 5% and 10%BP, respectively. Bentonite-containing concrete had a lower compressive strength than the control mix at ambient temperature and at 300 o C by 22.8% and 38.9, respectively for 5%BP and 10.5% and 24.8%, respectively for 10%BP. But at 600 o C, the compressive strength of mixes containing BP is higher than that of the control mix by 33% and 49.5% for 5% and 10%BP, and it had good resistance to water absorption at all temperature levels. A somewhat significant color change was noted for mortar compositions with higher BP ratios. A color change was observed from gray to pink for samples containing BP.