Structural element and methods of use thereof

Abstract

A pre-formed structural concrete element for use in the formation of a composite concrete floor of a building or the like, the element comprising: a generally planar base portion having opposing faces; a series of generally parallel spaced apart formations extending from one said faces of the base portion each defining along with an adjacent formation a void space therebetween and wherein the formations terminate in a plateau and have at least a narrow portion and a wide portion between the plateau and the one said faces of the base portion.

Description

BACKGROUND[0001]The present invention relates to structural engineering and more specifically to a structural member capable of use in the construction of structures such as concrete slabs and elements. The invention further relates to methods of use of the structural member including its application in preparatory formwork and as an element in a composite structure including in layered concrete. The invention also relates to structures which employ the structural member. The invention further relates to lightweight structural members used in a variety of concrete structures.PRIOR ART[0002]Slab beam concrete constructions is widely used in civil and structural engineering. The typical structure will comprise columns of a size dictated by applied such as dead loads and self weight and live loads and of a spacing dictated by loadings and slab spans. Reinforced and pre stressed concrete floors for buildings are generally made in one of two methods. The floors are either cast in situ us...

AI Technical Summary

Benefits of technology

[0040]According to one embodiment, the overlay layer spans between the plateaus of each said formations closing said recess thereby forming voids in said slab. The system is preferably used in the construction of a composite suspended beam and floor slab assembly. The voids improve the structural performance of the element both during construction carrying wet concrete and in the permanent composite structure. They also provide through passages for services. Preferably, the structural elements are formed in a mould which includes a steel base which imparts a smooth high quality surface finish to the element soffit. The voids reduce the weight of the element. The structural geometry of the formations allow more efficient use of concrete in that the so formed composite has a large compression flange at the top of the formations imparting to the composite a high strength to weight ratio for a given span. The elements may therefore be much thinner for a given span than a prior art conventional slab. In one embodiment the side walls of the formations are generally planar and are inclined at an angle less than 90 degrees and around 40° to 70° to the upper surface of the element. The structural element has a versatility allowing the voids to be filled with polystyrene, cement or concrete Alternatively the voids may be retained with empty spaces.

Problems solved by technology

Cast in situ reinforced concrete floors, require extensive formwork, are relatively time consuming and labour intensive particularly with respect to the assembly and dismantling of formwork and the time required for the in situ concrete to achieve the required strength.

Existing construction systems using pre-cast elements have significant cost and other disadvantages including poor underside surface finish, ribbed profiles on the underside necessitating separate ceilings in many applications, difficulty of running services through and lack of flexibility of the type of structures which can be built.

These disadvantages render in situ casting construction the preferred method of slab and floor construction.

This construction system can span relatively long distances, but has the disadvantage that it typically has a very poor surface finish on the underside necessitating in many applications a false ceiling or cladding over the concrete finish.

The structural planks are typically produced in quite narrow strips requiring many joints and it is difficult to put services through the floor, as it is very difficult to access the voids.

Also the planks are relatively thick and the services typically have to be either hung on the underside, also necessitating false ceilings in some applications or the services may be hidden in thick topping concrete.

A further disadvantage of Ultrafloor is that it has a limited span both during concrete pouring and as a finished floor.

Ultrafloor is limited in the types of floor structure which can be made from the basic panel and from the panel used in conjunction with the shell beam.

This system has the disadvantage that it is limited to relatively short spans of about 7 m or so.

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