Research

SPB Brick

‘silica plastic block’ is a sustainable brick made from recycled sand + plastic waste.

india-based company, rhino machines has launched the ‘silica plastic block’ – a sustainable building brick made from recycling foundry dust/ sand waste (80%) and mixed plastic waste (20%). the ‘silica-plastic block’ or SPB attempts to confront the massive dust waste and overall pollution production in india which has created a severe environmental hazard. the project was completed in collaboration with r+d labs; the research wing of the architectural firm r+d studio.

the ‘silica-plastic block’ project started with a clear mandate of producing zero waste from the sand reclamation plant in rhino machines foundry plant. in the initial stages, experiments were conducted by using foundry dust in cement-bonded fly ash bricks (7-10% waste recycled) and clay bricks (15% waste recycled). this experimentation also required the use of natural supplies such as cement, fertile soil and water. the amount of natural resources consumed in the process was not justified by the waste it was able to recycle. these trials led to more research by the inhouse r&d team, resulting in a possibility of bonding the sand/foundry dust with plastic. by using plastic as a bonding agent, the need for water during mixing and thereafter curing is completely eliminated. the blocks can be directly used after cooling down from molding process.

3d printing and concrete

Materials play a key role in 3D printing construction. The material used must blend design with adequate consistency and workability. For structural applications, this predominantly means a concrete base, consisting of cement, sand, and other additives. However, there are a few variants that stray off this path.

Apis Cor: Residential Home in Russia

They have developed their own material mix, which is an extrudable concrete consisting of cement, sand, geopolymers, and fibers. They prepare the final material mix by mixing the raw materials in a large hopper. This mix is then fed by a pump system to the extruder, which deposits the material.

Their 3D printer has an independent robotic arm which prints the structural components on-site. They intentionally left a small gap between the interior and exterior of walls, where they placed fiberglass reinforcements and sprayed a polyurethane-based mixture for insulation. Once the walls were printed, they removed the printer with the help of a crane to install windows, appliances, and the roof. The entire structure took just 24 hours to complete.

Material Mix: Concrete mix made out of cement, sand and other additives

The Building On Demand in Copenhagen (COBOD)

COBOD collaborated with FORCE Technology to develop a strong and sustainable concrete mix using recycled materials. The material delivery system consists of a mixing pump which automatically fills dry material mix from the mixer. Water is then added to the mix to keep the pump filled. In addition to 3D printing, they also use the printer as an on-site “crane” to place certain elements into the building.

Material Mix: Concrete mix made out of cement, sand and other additives

WASP: GAIA, the First Architectural Building Printed

WASP is an Italian start-up with aims to provide 3D printed sustainable shelters at minimum costs using naturally available local materials. This led them to 3D print a new eco-sustainable house, the Gaia.

This was the first step towards 3D printing load-bearing earthen structures. The specially designed 3D printable material mix consisted of soil, rice fibers provided by RiceHouse, and lime. They mixed this material thoroughly in a wet pan mill to make it homogeneous and workable. The mix was then extruded with the Crane WASP 3D printer.

To get the final structure, they printed a monolithic wall and finished with a shaving clay lamina and smoothed and oiled with linseed oils. The machine is a frame based gantry setup that prints the structural components in shorter lead times.

Material Mix: Earth-based material mix consisting of 25% soil (30% clay/40% silt/30% sand), 40% straw chopped rice, 25% rice husk and 10% hydraulic lime

Paper tube

The foundation consists of donated beer crates loaded with sandbags. The walls are made from 106mm diameter, 4mm thick paper tubes, with tenting material for the roof. The 1.8m space between houses was used as a common area. For insulation, a waterproof sponge tape backed with adhesive is sandwiched between the paper tubes of the walls. The cost of materials for one 52 square meter unit is below $2000. The unit are easy to dismantle, and the materials easily disposed or recycled.