Included in Nationwide’s concrete flooring services is the installation of the final layer of sub base utilising our laser guided sub base leveller. This equipment uses the very latest in laser technology in order to achieve extremely tight tolerances and achieve vast daily outputs.
The word ‘subgrade’ refers to the soil below the sub base. The sub base is the finely graded compactable material between the subgrade and the concrete. Geotechnical engineers typically are contracted by owners to evaluate soil conditions on a construction site and sometimes they specify the sub base fill materials to be used and how they should be placed. But structural engineers hired by owners to design floors and pavements also get involved in the specifications for sub base materials as part of the concrete system. Jon Wilcox, Director, says its standard for our firm to review all base materials for a project and make recommendations based on our experience. But we are careful to point out that we work together with the geotechnical company to solve the problems related to a particular site. It may be discovered, for instance, that soil conditions are inadequate to support a floor slab or parking area and that designing a compactable-fill sub base will solve a problem by spreading the load over a wider area. Sometimes water tables may be high, causing problems and affecting the choice of sub base material.
The sub base is a critical part of the construction process as this provides a working platform for construction activity and is used to transmit the load from the floor slab to the subgrade.
Our experienced workforce can achieve tolerances of at least plus or minus 5mm from the overall datum using this laser controlled machinery. This not only minimises any potential waste of ready mixed concrete but also provided an excellent working platform during the concrete process. A level sub base enhances the long term performance of the concrete floor slab as the concrete can shrink more evenly without restraint. This reduces the chance of shrinkage cracking occurring over the life span of the concrete floor slab.
The settlement and differential settlement of concrete slabs is a serious problem, and although they reflect on concrete, they aren’t caused by the concrete. They stem from failures of the subgrade or the sub base. Installing sub base properly is just as important as placing and finishing concrete and using the right mix design.
To enquire further about our laser controlled sub base preparation service please call 01430 436596 or complete our enquiry form here