| There are endless uses of concrete- from the biggest of dams
to the smallest of back yards or concrete block walls. Some common
forms are:
Readymixed
For large projects, concrete is delivered to the construction site
already mixed. Materials are prepared and batched and mixed at the
concrete plant and transported by truck-mixers. The concrete may
also be mixed in the truck itself.
Precast
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Dublin Port Tunnel,
Precast Lining Segments |
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Concrete can be delivered to site as precast units that have been
made in a factory. This facilitates greater quality control in producing
the end product, and a more consistent material. Precast units can
range from beams and slabs to entire housing units.
Concrete Masonry
Many millions of concrete blocks are produced in Ireland every
year for use in the construction industry. Also, though not strictly
concrete, mortars and renders made from sand, cement and water are
used to bond blocks or provide protection to block walls.
Coloured Concrete
Concrete does not have to be grey. Colour can be introduced in several ways- by adding a pigment to the mix, by shaking pigment into the fresh concrete surface, using white cement or painting the surface.
Small Concrete Jobs
There are many jobs around the house and garden for which concrete
can be used in small quantities and hand mixed on site.
Concrete Innovations
Over the years, technologies have improved greatly. Other new developments
include self-compacting concrete- eliminating the need for costly
and time-consuming compaction, lightweight concrete- made with special
lightweight aggregate and even the use of bamboo as reinforcement
in developing countries. The future of concrete focuses on sustainability,
the reuse of materials alongside very high strengths.
Some powders have been found to have cementitious properties when added with cement. These include ggbs- ground-granulated blastfurnace slag and pfa- pulverised fuel ash- by-products of the iron and coal industries respectively. They have been found to enhance concrete properties by reducing the temperature rise of the concrete and can lower permeability, hence increasing durability."
Believe it or not, the concrete spring shown here has a strength
of over 200 N/mm2. David Bennett, a consultant on architectural
concrete, predicts concrete will overtake plastics and ceramics,
with applications such as thin staircases and even telephones.
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