- July 16, 2018
- Posted by: admin
- Category: Concrete Slab Design
Davron engineering, based in Wollongong, Illawarra are experienced structural engineers making sure structures and buildings are properly constructed including the concrete slab design.
David at Davron Engineering says, “A slab design as part of a home or building is structural and is actually the most important part of a building, as it is the one part of the building that bears the weight of everything”.
What is concrete?
Concrete is made up of three ingredients
- Various aggregates such as sand, pebbles, gravel, stones and
Concrete is strong and inexpensive as a direct result it is everywhere. Roads, sidewalks, houses, bridges, skyscrapers, pipes, dams, slabs, walls, beams, foundations and more. In fact, it is the most frequently used material in construction.
What is Reinforced concrete?
Concrete has the ability to withstand heavy weight or forces on it and actually gains strength as it ages. Some very thick concrete structures, like dams, will continue to gain strength for months or years. However while concrete is strong in compression it has almost no tensile strength, the ability to withstand expansion, contraction or stretching. Sufficient tensile stresses cause the concrete to crack.
Concrete, however, can be strengthened with steel to make reinforced concrete. The steel reinforcement (Rebar)—rods, bars, or mesh—absorbs the tensile stresses.
In concrete slabs, the concrete provides the slab with compressive (squeezing) strength and the steel tensile (stretching) strength.
The thickness and rebar installation on structural concrete slabs are carefully determined by a structural engineer.
Slabs are classified into two main groups depending on whether they are supported on the ground or suspended in a building.
- Raft or Ground Slab: is usually used as the foundation for new houses and extensions, raft slabs in Australia are designed to comply with Australian standard AS2870. They are poured directly into excavated trenches in the ground. They rely entirely on the existing ground for support. The ground, known in the industry as the foundation, must be strong enough to support the concrete slab. Another term is a waffle slab which is like an egg box arrangement i.e. it is not one solid slab.
- Suspended Slabs: A suspended slab is raised off the ground and has an accessible sub-floor area. In a residential situation, the slab is supported by external sub-floor walls of brick or concrete block etc. The slab is also supported by free-standing brick or concrete piers.
A structural engineer will design a concrete slab according to the specifications for the individual project.
Cracks in concrete can never be entirely eliminated. While not all cracks are structurally significant, a qualified engineer should be consulted when there is any doubt.
Davron Engineering provide a comprehensive range of structural engineering services and consultancy for all structural engineering works including buildings, landscaping, retaining walls, swimming pools, slabs and structural and dilapidation reports.