SBIR Phase II: Using Geopolymerisation of Natural Aluminosilicate Minerals to Develop Sustainable Masonry Materials

This Small Business Innovation Research (SBIR) Phase II project will develop a full-scale working prototype of manufacturing equipment to produce a novel environmentally sustainable masonry unit. Conventional concrete masonry unit (CMU) manufacture relies on ordinary Portland cement (OPC) for strength and durability. OPC is energy-intensive and is the most expensive ingredient in conventional masonry. In contrast, this project proposes a manufacturing process that transforms naturally occurring soil elements called aluminosilicates into strong and durable masonry products through a chemical process called geopolymerization. The broader impacts of the proposed activity include societal benefits in the form of human health, enhanced scientific and technological understanding, and commercial considerations. The adoption of geopolymer masonry blocks by the construction industry will have the following benefits: i) a dramatic reduction of the 14 million metric tons of CO2 emitted annually by domestic CMU manufacturers ii) a decrease in the energy required to process aggregates as a result of a fine particle constituent to be used in the formulation, and iii) the elimination of the requirement of aggregate washing, which will enable widespread use of recycled aggregates. The proposed activity will increase domestic construction material manufacturing capabilities, and create skilled jobs for the US economy. The results of Phase I demonstrated the scientific feasibility of using a proprietary manufacturing process to create geopolymer-based masonry specimens with performance comparable to OPC-based specimens. During Phase II, this knowledge will be applied to develop equipment capable of producing cost-effective geopolymer masonry block to meet the steadily increasing demand for sustainable masonry materials in domestic and global markets. Geopolymer masonry is a disruptive product that has the potential to dramatically improve the environmental profile of one of the most common construction materials on the planet. The Phase II work will include the design and construction of a full-scale working prototype for the production of geopolymer masonry at a cost comparable to conventional OPC-based masonry products, evaluations of mechanical properties of the resulting geopolymer masonry blocks to verify their performance against laboratory specimens and ASTM standards governing masonry materials, and research to address outstanding issues related to performance by incorporating water-repelling admixtures and hydrophobic additives into geopolymer mix designs.