The construction industry has been the leading and most demanding industry in today's times, but its effect on the environment has always been a concern. The industry has accounted for about 39% net carbon dioxide emission. Constructors use concrete as it is cheap and quick and is applied for several layers, which cannot be recyclable, requires a lot of energy to mix and transport accounting for about 7% of emissions. This has led scientists to find some alternatives to lessen the carbon footprint, by using 3D printers to build structures layer by layer, but have not overcome the problem of sustainability.
Trying to find solutions to these construction material limitations, The researchers at Texas A&M University, have developed print structures using the type of soil that can be found in any garden. Soil is like a mimic of concrete with different layers of materials, 1st layer being the top organic layer where plants get its nutrition for growth and the organic layer being clay as 2nd layer which gives the soil its stability and moldability, and ending with a 3rd layer of hard bed of rocks.
Using this these researchers have collected the soil samples from backyards and added some environmental friendly additives that help in binding and can be applied easily to the 3D printer. They want to build a “chemistry toolkit” that can transform any soil into 3D printable material. Researcher Bajpayee checked this model, how efficiently it worked when stacked up by building small-scale test structures, cubes measuring two inches on each side. Next step was to confirm how much the mixture could withstand the weight of construction materials like rebar and insulation, for load bearing these researchers, sealed or “zippered” the microscopic layers to prevent from absorbing water or expanding, showing that this material could hold twice as much weight as unmodified clay mixture.
The Ayush Banerjee lab researchers who aim to make this a replacement for concrete by improving the soil load bearing capabilities, and also further checking the statistics of carbon footprinting and recycling potential of these 3D printed structures. After the research of all the functionalities and feasibility of constructing local soil, Banerjee and Bajpayee are planning the additive manufacturing with soil that could one day be used beyond Earth, to create settlements on the moon or even Mars.