Improvements In Sprayed Concrete Technology Have Occurred Rapidly Over The Past
Decade, Allowing It To Be Considered As A 'Permanent' Structural Support For Urban
Tunnels And Resulting In Greater Use Worldwide. Developments Have Focused On
Attaining High-quality, Homogeneous, Environmentally Safe Sprayed Concrete. This
Has Been Achieved By The Use Of The Wet-mix Process, Involving Modern Robotic
Spraying Techniques, Advances In Sprayed Concrete Mix Proportions, And The
Availability Of Liquid Accelerators.
A Tunnel Lining Should Be Designed In Such A Way That It Remains Safe And
Serviceable Throughout Its Designed Lifespan With Minimal Maintenance. To Achieve
This, The Designer
Glass concrete is not a new concept. The idea of using recycled glass as an aggregate for concrete
has been around for at least 30 years. Until now, however, the concept could not be realized because
of chemical reactions between the glass and cement that can cause cracks and damage
unacceptable for a building material. In the Carleton Lab, Meyer and his team have created a
successful recipe for a durable, strong form of glass concrete . The first "green" office building in
Manhattan is the recently complete
Depending on the customer's wishes, the glass concrete can be produced with glass particles of
different sizes and color, matched with a suitably colored matrix as background -- architects and
designers are finding that glass concrete is not only environmentally sound but can be aesthetically
pleasing as well. Yet, such high-end or value-added products can absorb only so much of the millions
of tons of waste glass collected by municipalities nationwide.
Also, the glass needs to be cleaned and crushed to specifications and possibly color sorted as well,
which would increase costs.
A major problem with traditional concrete is that once you
lay it down and color it, you can't change it (without a
demolition act), and people have to just get used to it.
But, thanks to the students from the Royal Colle