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With thirty years of experience as a specialist in concrete construction, we are rapidly becoming one of the leading contractors in the country, making a positive impact on the UK’s construction market.
Hampsey undertakes the design and installation of post tension structures for use in a wide range of applications. Post tensioned construction is a method of construction used throughout the world that allows for a more efficient use of resources in the construction of buildings and structures. Post tension structures are particularly suited to residential, car park, retail and hospital uses.
Post tensioned concrete structures offer many advantages over traditionally-reinforced structures.
The design of post tensioned structures allows the normal steel reinforcing bar, normally present in a structure to be replaced with post tensioned strand. The shape of the strand laid within the slab allows compressive stress to be introduced into areas where tensile stresses develop under load. This results in a reduction of the amount of reinforcement required and also reduces the amount of cracking occurring in the concrete.
Reduction In Programme Time
Post tensioning is generally a quicker form of construction giving reduced turnaround times for the cycles and hence giving an overall reduced construction programme for the frame. This has advantages in giving earlier access for follow on trades, water tightness of the building will therefore be achieved more quickly.
The overall main contract programme may be reduced allowing earlier access for the Client. Requirements for phased or sectional completion of parts of the building may be achieved more readily due to this increased speed of construction.
Reduction In Amount Of Raw Materials Utilised
The nature of post tensioned construction makes it more economical in terms of time and materials and labour.
Generally, post tensioning uses only one third of the reinforcement used in traditional reinforced slabs
Greater Spans & Reduction Of Beams
The use of post tensioning allows the use of flat slab construction, generally without the need for beams. This has many advantages such as ease of construction, reduction of waste, simplified service installation etc.
Greater spans can be achieved more economically using post tensioned techniques which gives greater flexibility for designers and the possibility of reducing the amount of white space locked into a traditionally restrained design.
Flexibility
Generally, post tensioning can allow greater flexibility with post drilled holes. The amount of services required within a hospital, together with late service design information mean that there is usually a requirement for post drilled holes in the slabs. Due to the reduction in reinforcement and strand density of post tensioned slabs, greater flexibility is afforded for the late changes that may occur in the construction process.
Reduced Storey Height
The use of thinner slabs results in an overall saving in storey and building height. This results in savings being made in other packages such as cladding, services etc. and may in certain instances, result in a lessening of the environmental impact of the new structure.
Reduction In Slab Deflection
In steel and traditional concrete frame construction, pre-cambering is often used to try and minimise the impact of deflection of the structure once the temporary works are removed. Post tensioning reduces the need for this pre-cambering as it inherently deflects very little in its final state. The tension imposed on the strand results in the slab deflecting a minimal amount in the final state.
Future Flexibility
Once a building has been designed and built, the greatest asset it may have is that of being able to change for future development or changes in use. Post tensioning allows changes to be made to it for future changes.
Reduction In Loads
Due to thinner slab thickness, the total load of the building may be reduced to give savings in foundation design. This may be to the order of 10% to 15% and may give the option not only of reducing a cost in the chosen solution, but may offer an option for using a much cheaper foundation design. In addition, it may be possible to reduce the size of the columns to increase the space available to the project, giving much greater flexibility.
Reduction In Floor Thickness
The thickness of the slab can be much reduced over a conventional slab that will lead to a reduction in cost in terms of deliveries to site and environmental impact. Up to 30% of concrete and 66% of the reinforcement can be saved over a traditional reinforced slab. In certain areas such as theatres, the slab thickness may not be reduced as much due to the need for controls of vibration.
