The purpose of crane outrigger mats is to spread the outrigger load over the entire mat area. To achieve this, the mat material must be suitably stiff to distribute the outrigger load applied to the ground – reducing the applied pressure. This will be dependent on the supporting ground and must be considered/specified within the Temporary Works design.
ALIMATS® is a unique patented handleable interlocking outrigger mat system which is manufactured from recycled certified Aluminium. It’s been specifically developed to spread outrigger loadings and is fully certified and load tested.
It’s mostly crane companies, plant hire specialists, main contractors, house builders, streel frame contractors, concrete frame contractors, scaffold contractors and other temporary works specialists. They’re used under cranes, concrete pumps and other plant that have outriggers. Brilliant Ideas also provide temporary platforms for MEWP’s in both the tracking and operating load conditions.
ALIMATS® are trusted by some of the biggest names in construction, including Balfour Beatty, Grahams Construction, Kier, BAM, FP McCann, Willmott Dixon and Bison Precast – on all sorts of high-profile projects: HS2, Lower Thames Crossing, RAF Alconbury, Gatwick Airport, Tideway, Heathrow Airport, London Guildhall, Google HQ Kings Cross, Olympic Park, Tottenham Hotspur and London Bridge.
There are two types of available systems, handleable and non-handleable. They come in steel, aluminium, composite, plastic (UHMW and HDPE) and timber (European/Tropical hardwoods).
ALIMATS®, is handleable and made from interlocking recycled certified extruded aluminium modules. Other handleable systems are manufactured in High-Density Polyethylene (HDPE) or timber. The problem with HDPE is that it doesn’t have sufficient stiffness to work as intended – and used timber doesn’t have any certification at the time of use.
We’ve carried out multiple independent finite element analysis (FEA) simulations on our system. One simulated aluminium, timber and plastic as simply supported beams. Results concluded that timber (D40 Oak) bends five times more than aluminium, and plastic (UHMW) bends 50 times more than aluminium – which proves that ALIMATS® are strong and safe.
Another was a compression test to the point of failure on a single 60mm thick module, when applying a 500mm-by-500mm square outrigger load – internal rib failure occurred at 463.94t.
One disadvantage of non-handleable systems is that they have to be craned into position. This defeats the object of using crane mats. Cranes should only operate when the mats are insitu.
Our system is extremely strong, so as long as they’re handled in line with our Risk Assessment/Site Placement Guidelines, then damage is extremely rare. When mats are returned on our hire scheme, they’re cleaned and inspected before going back into our hire stock, ready for the next project.
The size of mat is determined within the temporary works design. This will weigh up multiple factors including the type of ground, allowable ground bearing pressure and outrigger load. From this, a size of mat will be specified. The most important aspect is that the selected crane mat is capable of distributing the outrigger load to the ground.
The suitability of the crane mat is determined by:
No – crane pads are generally adopted up to 1.0m² and come as a single round or square pad. Due to inferior material properties of High-Density Polyethylene (HDPE) we only recommend Nylacast Big Foot crane pads, which are manufactured from certified Nylanite. Crane mats are generally intended to deal with larger outrigger loads in sizes greater than 1.0m² – though we do specify a Nylacast crane pad in conjunction with our mat configurations.