Waste Blended Building Envelop Construction For Cooling Demand Reduction

Building sector is responsible for 35–40% energy consumption and related CO₂ emission, resulting climate change and global heating phenomena. On the other hand, huge accumulation of flyash in thermal power plants and rapid decline in sand availability causing environmental issues. The objective of this study is to find the effect of flyash usage as replacement of sand in building envelop construction and compare the energy saving results in a building with two different walling types. By modifying the concrete with flyash and mortar mixes with flyash-lime combination in lieu of sand, the physical and thermal properties were evaluated. Separate masonry wall panels of identical volume were constructed with conventional mortar and plaster and with modified ones with flyash-lime mix, the U-values of which were evaluated with the help of guarded hot box method. Reduction in U-value for test wall panel with modified mortar was observed. A simulation program was run with DesignBuilder (version 6.1) for a model building located under Warm-Humid zone with built-up area of around 94 sq.mtr. Altogether five combinations of material mix each for AAC block wall and Red clay brick wall construction separately were adopted with roof concrete layers of modified mix with flyash for the building in the simulation study. Substituting sand with flyash results reduction in cooling energy demand for entire building, and additional application of SRI paint on top roof surface reduces the demand further, as observed through the simulation study.