Mycelium-infused geopolymer bricks for non-load-bearing walls: experimental investigation and life cycle assessment

The growing importance of energy conservation has placed it at the forefront of global attention in recent years. To meet ambitious environmental requirements, the construction industry must engage in research on innovative materials. An emerging solution, mushroom-induced construction, offers a novel and sustainable approach that resolves ecological challenges and generates economic benefits. With the increasing prevalence of vegan diets among individuals, the demand for mushroom products has surged due to their high amount of fiber, protein, vitamins, and minerals. This work is looking at the possibility of using mycelium blocks for non-load-bearing walls by conducting a comprehensive experimental study on mechanical, functional, and durability factors. Several methodologies were considered to reduce the water permeability of pure mycelium, including mycelium as a partial replacement for fly ash in geopolymer, geopolymer layer on mycelium epoxy mix, mycelium in cement mortar etc. In this year-long duration project, mechanical tests, such as compression and flexural test, durability tests including water absorption tests, sorptivity test, acid attack test, fire resistance test, sulfate test, drying shrinkage test and ultrasonic pulse velocity test, and functional tests such as thermal conductivity and sound absorption tests were carried out. Comparative analysis revealed that mycelium as a replacement material in geopolymer bricks (10% of fly ash) exhibited superior properties compared to other methods. Various treatments were applied to raw mycelium (heating, ash formation, and treatment with NaOH), to reduce the surface salt formation produced during the curing of mycelium-induced block. Energy-dispersive X-ray spectroscopy (EDS) method was utilized to analyze the salt formation and the elements present in mycelium ash. With the assistance of COMSOL Multiphysics, a 3D model was constructed to evaluate the thermal insulation properties of the materials. The material properties such as heat flux, thermal conductivity, and density are given as the input parameters. The result shows a good thermal comfort with the usage of NaOH-treated mycelium-infused blocks in the building. From the result analysis, it is clear that mycelium-infused products are good in providing thermal comfort and acoustic comfort to occupants than pure geopolymer products. The effects of mycelium on the environment are assessed using a comparative life cycle evaluation with SimaPro 9.5.0.1. ReCiPe 2016 technique observation clearly indicates that the addition of mycelium in geopolymer has meagre impact on the environment when compared to pure geopolymer.