Concrete isn't just Concrete.
Concrete can come in a variety of different strengths, aggregate sizes and colours. Premixed concrete can come in strengths from 15mpa up to 100mpa with a slump ( How wet the concrete is ) from 20 up to 180 slump.
Blockfill / Cavity fill is used for filling up block work or double skin brickwork with concrete for either retaining walls or for when the engineer has designed that the wall needs extra strength. These mixes can vary in strength from 20mpa to 40mpa which use a 7mm aggregate and can be ordered from 120 to 360 slump. The Concrete has a higher slump ( Wetter then normal ) which is required to fill the voids and leave no air pockets or sections with concrete which will weaken the wall. These mixes are generally pumped in via a concrete pump using a 2" delivery line to make the filing of the walls as easy and mess free as possible.
Spray Mixes are used for shotcreting where concrete is pumped using a concrete pump where a compressed airline is connected to the delivery hose and actually throws the concrete from hose. These mixes are generally used for swimming pools, retaining walls and embankments. Spray mixes are generally 20 mpa to 50mpa and have a design slump of 60, Silica fume is used to help the concrete stand up vertically.
Slabs on the ground is the most common and has two variants: conventional slabs with deep excavated beams dug into the ground and waffle pod slabs, which sit near ground level and have a grid of expanded polystyrene foam pods as void formers creating a maze of beams in between. The concrete strength will vary depending on soil test results and what the engineer has specified, 20Mpa and 25Mpa are the most commonly used concrete strength.
Foundations and footings as they are also know by are typically made of 20Mpa or 25Mpa concrete with rebar reinforcement that has been poured into an excavated trench. The depth and width of the trench will be determined by an engineer. Foundations are commonly used on sloping blocks where bricks are layed directly onto the concrete and the house will generally have stumps to support the flooring.
Coloured Premixed concrete is a effective way of bringing the concrete to life. Colour can be added to any strength of concrete in many different colours ranging from the traditional charcoal to colours that glow in the dark. The possibilities are endless..... Colour guides are available online from both Boral and Hanson.
Stabilised sand is used on applications where a compacted or hardened fill is required. Most common practice is backfilling trenches over the top of pipes but is also used for backfilling around fibreglass swimming pools. Stabilised sand comes in 3% to 30% cement content.
No fines concrete is commonly used when strength is required and water must be able to penetrate the surface. Common use of no fines concrete is behind retaining walls, around trees and on driveways where too much of the site is covered not allowing for water to soak into the ground. Achieve's excellent water drainage.