New screed rail system provides simple solution

Acra screed has been extensively tried and tested on site and was launched at the 2006 World of Concrete exhibition in Las Vegas, USA where it was awarded the prestigious MIP (Most Innovative Product) attendees' choice award in the placing and finishing category.

Innovative system

The

system is an adjustable 'screed-rail' to control the top surface profile of slabs. The rail at the surface consists of 50 x 8mm steel flats, supported vertically by adjustable stirrups, which in turn are supported by concrete blocks. The top rail section is removed and is reusable, thus nothing is left at the surface. The top of the rail can be set up to tight tolerances thereby allowing the system to be used to construct floors to tight flatness tolerances, e.g. Superflat or Category 1 defined movement flatness, conforming to The Concrete Society Technical Report (TR) 34(1).

The base block, which sits underneath the reinforcement, can be turned at 90? intervals to achieve four different cover heights: 40,50,75 and 100mm. Push-fit connectors then stem from and insert into the block to the height required. The minimum height is 100mm and the system has been successfully tested to a depth of 1.2m. Final adjustments can then be made using the speed adjuster, a device that fits into a cordless drill at one end and slots over the rail supports at the other, making set-up time extremely fast with the capability of achieving tolerances as accurate as ? ?mm. Finally, a flat steel rail is inserted into the rail support which is eventually removed after screeding is complete. Tough enough to accept power screeds, the Acra Screed is stable, durable and extremely versatile. It also offers numerous accessories, one of which is a reinforcement support that allows steel to be set at extremely accurate levels, particularly advantageous as a ring beam support.

The system has been well received by various companies who have worked with the George Owen civils division. Many have commented favourably on its speed, accuracy, versatility and tolerance capabilities.

Concluding remarks

The George Owen building and civil engineering division has used and developed this system over a number of years and it has totally revolutionised the scope of contracts undertaken by the company. It is cost-effective, labour saving and above all else, extremely accurate. When the system is accurately set to a level of ??mm it consistently produces high-tolerance flooring regardless of the slab width.