At MAKE we have covered a type of paper brick before, but it was used simply as a fire starter. Professors Rahul Ralegaonkar and Sachin Mandavgane of the Visvesvaraya National Institute of Technology in India (VNIT) have come up with a process to make paper bricks designed for creation instead of destruction.
It started when they visited a paper recycling plant in 2009. They learned that 15% of the material that went through the plant was piled up into an unsightly sludge and sent to a landfill. For those not familiar, this is a prime example of one of the perils in recycling as opposed to upcycling. Recycling results in materials being turned into products of a lower quality than their predecessors, while upcycling preserves the quality of the product through many generations. For more about this subject, I recommend the book Cradle to Cradle.
Raleganokar and Mandavgane decided to take some of that sludge back to their lab and play around with it along with students over the summer. What resulted was a brick made of 90% recycled paper mill waste (RPMW) and 10% cement. The slurry is mechanically mixed, pressed into molds, and left in the sun to dry.
The bricks have seen practical use so far in false ceilings and partition walls. They are also experimenting with a waterproofing coat for use in exterior walls. The materials used in their process are not just limited to RPMW. They have also successfully used cigarette butts, fly ash, textile effluent treatment plant (ETP) sludge, polystyrene foam, plastic fiber, straw, polystyrene fabric, cotton waste, dried sludge collected from an industrial wastewater treatment plant, rice husk ash, and granulated blast furnace slag. The bricks are half the cost of conventional ones, much lighter, and could be a boon to the Indian construction economy, which currently has a 30% deficit in brick supply.