Page 76 - Build 165

The future is now
outer layer of synthetic bre and inorganic bre that is then impregnated with ther- moplastic resin.
● Spray-on strengthening – consists of a ductile cementitious composite that is applied in a 10 mm thick coating to walls or existing structures. The material comprises polymer-based bres, y ash that replaces 70% of the cement and other industrial additives.
Variations on traditional concrete and bricks:
● Cement-less concretes – these use organic
renewable materials like rice hull ash, bones, shells and sea sponges to bind the aggregate rather than cement.
● Concrete alternative that use recycled materials including waste steel dust to create a concrete-like building material said to be stronger than concrete.
● Green-mix concrete – an economical and eco-friendly substitute for traditional concrete using conventional ingredients mixed with suitable waste and recycled materials such as y ash, recycled concrete aggregates and aluminium can bres.
● Smart bricks – moulded from concrete that t together like Lego but they have an adhesive applied to contacting surfaces. Holes formed in the bricks allow for the installation of reinforcing and services.
Some di erent energy sources for lighting, heating and cooling:
● Beer power – this occurred when waste
biogas from a brewery was used as an
alternative energy source for a hospital.
● Hydroceramics – a manufactured tile component combining the thermal mass and humidity control properties of clay and fabric with the liquid absorption and
evaporation properties of hydrogel bubbles or spheres. They can absorb liquid, and on hot days, the contents evaporate and cool the space. Hydroceramic wall finishes could replace conventional air conditioning.
● Solar concentrators – use mirrors or lenses with tracking systems to focus a large area of sunlight onto a small area. The concen- trated light is then used as heat or as a heat source for a conventional power plant in a process called solar thermoelectricity.
● Mechanoluminescence – occurs when a speci c material is put under stress and lights up as a result. In South Korea, it has been moulded into plastic tubes infused with coloured phosphors made from copper-doped zinc sulphide. When subject to wind, the tubes de ect and illuminate with a white light.
Further innovations
Other innovations include:
● silicon living glass with embedded wires
that provide an electrical stimulus allowing material cells to open and close in response to CO2 levels in the air, thereby regulating air quality
● applying the way organisms can maintain equilibrium for everything from sugar content levels to temperature to mimic in buildings what we do naturally – self- regulate based on environment
● bricks made from plastic residues
● pollution-absorbing bricks
● cement that can generate light and also
absorb and irradiate light energy
● optically transparent wood
● break-sensing conductive paint – a break
in the paint lm indicates a crack
● boards made from compressed chicken feathers bound in cement
● bioplastics, cellulose and other materials created by combining certain materials with speci c varieties of bacteria — the resulting metabolic process produces solid, surprisingly durable byproducts
● bioplastics made from discarded shrimp shells utilising the tough yet flexible natural chitin or insect cuticle
● fungal mycelium from mushrooms for use as insulation
● synthetic spider silk. Ready for use
Already available, although not necessarily in New Zealand, are:
● translucent concrete with optical bres in a
ne concrete matrix that is supplied as tiles ● hempcrete, a biocomposite, thermal wall
material made of hemp, lime and water ● bendable self-healing concrete with up to
5% tensile strain
● carbon-absorbing magnesium silicate
cement substitutes
● food waste used to manufacture construc-
tion products, including:
panel products made from compressed wheat, corn cobs, a blend of seeds, stalks, leaves and sun ower crop waste fabrics and textiles from banana plants, pineapples and citrus peel bres
cork substitute from potato peelings
● wood made from newspapers, nappy roo ng, blood bricks and asphalt that uses recycled plastic instead of sand as a ller.
These are innovations in the early stages of development that could result in products to aid building and construction in the future.
74 — April/May 2018 — Build 165
FEATURE SECTION