90mm Cellcore HX S Under Slab EPS

90mm Cellcore HX S is a product specially designed to provide foundation protection from ground heave effects when installed under reinforced concrete floor slabs. It is consisted of specially moulded hexagonal cellular expended polystyrene, available in a number of different depths and grades. Ground movement is caused by the rehydration of clay or expansive shale soils, overburden recovery resulting from deep excavations or, in certain parts of the world, permafrost heave. 

Cellcore HX S panels are used for reinforced concrete slabs protection from the effects of ground heave.

• Available in a number of grades, suitable for different applications;
• Moulded for consistent performance and durability;
• Reduced depth and therefore less excavation;
• Less upward force is transmitted to the structure;
• Suitable for most lightweight slabs;
• Cost effective and reduced carbon footprint;
• BBA certified and in accordance with the NHBC’s Technical Standards.

Depending on the chosen grade, the boards are designed to support specified safe-load during a 16 hours period, with compression of less than 5. On the other hand, depending on the chosen depth of the product, it will collapse by a specified amount, under the product’s specified fail-load.

the safe-load is determined as the level of support of thickness of concrete each grade of the product can offer, plus a live load allowance of 1.5 kN/m2 with negligible creep compression during the given curing period of 16 hours. The fail-load is determined as the load under which the panels and polystyrene legs will collapse under the influence of the upward ground movement.

Given the most important structural aspects, the first thing that must be taken into account and pre-determined is the product depth which is chosen in accordance with its compression under the fail-load which should be equal or greater than the maximum ground movement. Thus, as shown in the Table 1, the 90mm Cellcore HX S should be used for voids of 50mm, in low shrinkage category and 10-20 plasticity index.

The other value that must be taken into account with every project refers to the product grade, as shown in the Table 2. The boards are available in five grades (7/10; 9/13; 13/18; 18/24; 24/32) whereas the grade is determined depending on the wet concrete maximum thickness that will be supported by the panel. Thus, it is important that beam, slab or pile cap is designed to accept the difference between its weight and the specified fail-load. The beams and slabs must be properly designed, otherwise, the slabs could be lifted off the foundation and beams lifted off the top of the piles, while these could also bend or shear due to the uplift. In case any assistance in choosing the right type of the beam or slab is required, please contact us via e-mail or given contact information.

The Cellcore HX S can be installed in a quite straightforward procedure, with standard precautions and safety procedures followed, as specified for EPS boards. For more specific instruction, please refer to this Data Sheet.

• certified under BBA, certificate number 11/4862;
• in accordance with the Building Regulations 2010 (England and Wales), the Building (Scotland) Regulation 2004 (as amended) and the Building Regulations (Northern Ireland) 2000 (as amended);
• in accordance with the NHBC’s Technical Standards.