Insulation Effects of a Roof System Developed from Waste-Incorporated Geopolymer Concrete

Energy consumption of buildings has become a major issue contributing to greenhouse gas emissions. Thus, utmost care must be taken to manage building energy consumption through various technological advancements. Considering the current issues in tackling the insulation needs of the building, the focus should be on the structural component as well such as the roof. The present research focus is on developing a sustainable insulated roof layer system by utilizing locally available crumb rubber waste. The binder material used to develop the roof slab was taken as geopolymer considering its benefits over conventional cement concrete. Crumb rubber and palm oil fly ash-incorporated geopolymer concrete was developed and tested against various physical, thermal and mechanical performance measures. Thermal analysis was performed using conjugate heat transfer, and the temperature propagation through insulation layers are plotted for all cases. A flow solver including conjugate effect was developed, and numerical analysis was performed to observe the insulation strength of various layers. Based on the results, it was found that the performance of the developed material is on par with M20 grade concrete with the incorporation of 30% added crumb rubber and 10% palm oil fly ash. Further, the reduction in thermal conductivity with 30% added crumb rubber geopolymer concrete was found to be 22.72% as compared to the control mix. However, using the developed crumb rubber-incorporated geopolymer, the energy reduction was not so substantial; thus further addition of the insulation layer was required. The combination of expanded polystyrene, rock wool and crumb rubber-based geopolymer roof system reduced the energy dependence up to 9.55% as compared to the conventional cement concrete roof system. The thermal resistance of various layers is compared with various parameters including the average Nusselt number over the insulation layers, average temperature in the room, and centreline temperature profile, and is discussed in detail.