Light weight concrete
Light weight concrete – or foamed concrete – is a versatile material which consists primarily of a cement based mortar mixed with at least 20% of volume air. The material is now being used in an ever increasing number of applications, ranging from one step house casting to low density void fills.
Foamed concrete has a surprisingly long history and was first patented in 1923, mainly for use as an insulation material. Although there is evidence that the Romans used air entrainers to decrease density, this was not really a true foamed concrete. Significant improvements over the past 20 years in production equipment and better quality surfactants (foaming agents) has enabled the use of foamed concrete on a larger scale.
Lightweight and free flowing, it is a material suitable for a wide range of purposes such as, but not limited to, panels and block production, floor and roof screeds, wall casting, complete house casting, sound barrier walls, floating homes, void infills, slope protection, outdoor furniture and many more applications.
Not everyone knows that density and compressive strength can be controlled. In the light weight concrete this is done by introducing air through the proprietary foam process which enables one to control density and strength precisely.
Normal concrete has a density of 2,400 kg/m3 while densities range from 1,800, 1,700, 1,600 down to 300 kg/m3. Compressive strengths range from up to 40 Mpa down to almost zero for the really low densities. Generally it has more than excellent thermal and sound insulating properties, a good fire rating, is non combustible and features cost savings through construction speed and ease of handling. It is used in over 40 countries worldwide today and has not reached the end of its possible uses.
Strength is a relative term. Concrete mixes should be designed based on end use. High compressive strength is useful where deadload or abrasion are factors, but are unnecessary for roofs and non-structural partitions. All concrete is deficient in tensile and shear strengths, however these are supplemented through structural reinforcement. Compressive strength can be made up to 40 Mpa, exceeding most structural requirements
The bubbles in lightweight concrete with well engineered liquid foam concentrates do not lose their volume. The pre-formed foam lightweight concrete products made from top quality liquid foam concentrates do not collapse. Air cell stability is the mark of a superior foam concentrate and foam generator combination. The proposed pre-formed foam for an application should be tested for stability or certified for stability before actual project placement.
Densities and Strengths
One of the most useful features of a lightweight concrete system is the system’s ability to be manufactured in a wide range of low densities and strengths. Application requirements for lightweight concrete range from very light density low strength fill dirt replacement to higher strength structural lightweight concrete. To accommodate this wide range of performance properties lightweight concrete has developed a mix design chart, which will illustrate the basics of making this wide range of materials from just one lightweight concrete concentrate. With a lightweight concrete foam generator and a single liquid foam concentrate the contractor now has available to them a wide variety of cost effective, high performance, lighter lightweight concrete products.
The different densities and strengths available:
Lightweight concrete exhibits a much lighter density than typical aggregate concrete. Typical plain concrete has a density of 2400 kg/m3, lightweight concrete densities range from 300 kg/m3 to 1800 kg / m3. Lightweight concrete is an insulator and can be used in a variety of applications which require an insulating material that can also exhibit some integrity and strength.
Cost effective lightweight concrete varies in price by application requirements such as density and strength requirement. A typical concrete structure project will be much less expensive cubic meter to cubic meter when compared to plain concrete due to labour savings, less cost of forming works, less steelworks, eliminate brickworks and the price savings is very substantial when compare to conventional methods
Implementation of Lightweight Composite design and construction utilizes existing technology. Its uniqueness, however, is the novel combination drawing from several fields at once: architecture, mix design chemistry, structural engineering, and concrete placement
- Spa Resorts
- Residential Developments
- Industrial Developments
- Commercial Developments
- Public Developments
- Extensions and Renovations
Advantages of Light Weight Concrete over Conventional Concrete
|LIGHT WEIGHT CONCRETE||CONVENTIONAL CONCRETE|
|LOW LABOUR COST||HIGHER LABOUR COST|
|LIGHT WEIGHT||HEAVY LOAD|
|THERMAL PROOF||HIGH THERMAL CONDUCTIVITY|
|SOUNDPROOF||HIGH SOUND CONDUCTIVITY|
|FIREPROOF||AFFECTED BY FIRE|
|NON TOXIC||NON TOXIC|
|NEEDS NO CURING||NEEDS CURING|
- FLOOR SCREED
- THERMAL& SOUND INSULATING MATERIAL