Concrete – some types and treatments

aerated concrete A lightweight concrete with no coarse

aggregates, made of cement, lime, sand and chemical admixtures

which cause bubbles to make a cellular consistency. It

has low strength but good insulation properties. It is easily cut

and nailable. There are many grades, some unsuitable below

ground. Water absorption will impair its thermal performance.

bush hammering Tooling concrete or stone with a compressed

air hammer to remove 1 to 6 mm of the outer skin to

reveal a surface texture that improves its appearance.

granolithic finish A thin topping of cement, granite chippings

and sand laid over a concrete slab, preferably as a

monolithic screed to provide a good wearing surface. Can be

made non-slip by sprinkling carborundum powder over the

surface before final trowelling.

glass-reinforced concrete (GRC) Precast concrete, reinforced

with glass fibre to make thin panels with improved

strength and impact resistance.

polymer-impregnated concrete Concrete made with a

polymer to improve the strength by filling all the voids normally

left in conventional concrete. Water absorption is thus

reduced and the concrete has greater dimensional stability.

refractory concrete Concrete made with high alumina

cement and refractory aggregate, such as broken firebrick, to

withstand very high temperatures.