06/01/2025
•H**p blocks were tested for fire behaviour and resistance.
•Fire resistance, heat release rates, calorific value, and smouldering were studied.
•Discolouration and charring were observed and quantified.
•H**p blocks have a low propensity to contribute to fire severity and spread.
•2-h fire resistance rating achieved.
H**p blocks, also known as h**pcrete, are eco-friendly and sustainable construction materials composed of h**p, lime, and water. In this study, the fire behaviour and structural performance of h**p-based materials were experimentally investigated. Fire exposure scenarios using raw h**p shives, h**p blocks, and non-load-bearing h**p block walls were examined. Tests conducted include cone calorimeter, bomb calorimeter, standard furnace, heat-transfer rating inducing system (H-TRIS), and small-scale elevated temperature material tests. H**p shives exhibit ignition with sustained flaming, a relatively high heat release rate (HRR), and a relatively low critical heat flux (CHF). However, the h**p blocks exhibited no flaming ignition, only smouldering combustion, and an HRR an order of magnitude lower. H**p blocks and h**p shives produced minimal smoke. H**p blocks charred, and associated discoloration zones have been documented. Tests indicate that limited structural capacity is lost up until 200 °C, whereas at 300 °C, the residual material strength is almost negligible. The h**p block walls maintained their structural stability and integrity for 2 h of standard fire testing. The ambient-temperature compressive strength of the h**p blocks was determined to be 1.0 MPa. This work is the first comprehensive study on the fire behaviour of h**p blocks and highlights their good performance, whereby they are likely to have a limited impact on fire risk in buildings. Plastered walls will have a fire performance exceeding those reported here.
https://www.sciencedirect.com/science/article/pii/S2352710223023276