LECA® LWA Replaces Polystyrene Fill

LECA® LWA was selected as an alternative to polystyrene by the designer with the design specification for the iconic start of the HS2 project.






As well as expanding the travel offer in the London, the large investment at the two sites will help create almost 80,000 jobs and 29,000 homes, thus attracting businesses and housing developers to the well-connected areas.

Over 232.7m3 of LECA® LWA was used to develop a piling rig platform for a new sub-station. LECA® LWA was used as the structural fill and an ideal alternative to Type 1 granular material for a pile rig base.   

The construction process involved installing 50 x piles within a perimeter of 25m x 15m and the deep ground beams were cast on top of the LECA® LWA. For this project, LECA® LWA replaced 1.5m Made Ground on the back of an existing wall to reduce the surcharge loading with 38kPA. Steel plates were not used due to the impractical ability to move around the rig and the ability for LECA® LWA to compact ensured that this would not pose a problem.

The rail engineers selected LECA® LWA for many different technical reasons and this included properties such as providing a quicker compaction solution saving on time and expense. LECA® LWA offered an environmentally friendly and sustainable solution – providing a needed test approved ability to be used in water affected areas. Through the nature of the project – LECA® LWA had to provide the engineers the ability to drill through the material with ease – offering a greater solution than type 1 granular material.

For the HV Earth Analysis – it was also required for there to be no issue installing LECA® LWA as a base or surround for cable ducts and draw pits of lighting pads. It was also essential for the completion of this project for LECA® LWA to not pose a problem with movement or displacement of pipes which would be installed below or within the LECA® LWA.

The LECA® LWA was delivered in bags on 8 –Wheel Tippers and was installed quickly over 7 deliveries (232.7m3). The lightweight nature of LECA® LWA meant that more material could be installed over a shorter time with the ability of the wagons to carry more material. One of the leading engineers on the project commented that major benefits of using LECA® LWA included “The larger delivery vehicles, the reduced weight, the ease of installation, thick layers and small whacker plate for compaction.”