Giving a lift to sinking floors
27 April 2016
A common problem in industrial and manufacturing plants, according to Uretek, is that many of their floors are sinking into the ground, causing headaches throughout the supply chain. Here Aleister Willis, marketing manager at Uretek explains more about the problem and outlines a solution
Factory or warehouse floors can drop for a variety of reasons. In many cases the loads – whether they be machines or racking – put extreme pressure on the slab beneath, meaning it can sag and drop into the ground; or the pressure on the structural piles is so great that the entire floor will sink.
The consequences of a facility floor dropping are the impact on safety and the disruption to operations. With heavy loads, the floor may sag or drop causing step hazards and comprising a structure's integrity. This also has a serious affect on the ability of machines to operate, as the levels of vibration are exaggerated by floor movement. In traditional warehouse facilities the racking will begin to lean which may mean it will fall outside safe operating limits and fork lifts may not be able to navigate the racking correctly.
The Uretek process for solving these problems is to inject specialist geopolymer resins beneath the concrete slab. The resin expands, filling voids and permeating into the the ground. The expansive resin follows the path of least resistance: Once it reaches maximum depth (or 'the point where it can go no further') it will force the slab to lift back up. Laser monitoring is used to measure the changes in level and the process can be accurate to within 3mm.
Depending on the initial ground surveys a specific type of resin will be selected in accordance with the ground composition and load bearing requirements of the site. The resins used will hardened to withstand massive loads and lift an incredible weight – anything up to 40t/m2 (400kPa).
One of the clear benefits of Uretek is its flexibility. The technical teams drill 12mm holes and inject resin using mobile pumping units. This means they can isolate small areas of facilities, allowing the majority of business operations to continue. The process requires no excavation and areas are returned to operational use within hours.
A recent example of a Uretek application is at one of Europe’s largest bottling facilities. The facility is more than 80,000m2 and the problems began after the tenant moved in and commenced operations. As the facility was loaded it began to experience significant slab settlement making the entire facility unstable. The maximum settlement experienced on site was 36mm.
Uretek designed a solution which would re-level the slabs based on the level survey drawings, bringing them back to within 4mm from the original spec.
In another instance Uretek used its resins to stabilise a soft drinks production facility. The facility used high volumes of water to wash down production equipment. These liquids seeped into the soils through cavities and the floors began to sink. This created significant machine vibration and led to serious delays to operations. Uretek injected its geopolymer resins which, through their expansion, forced the groundwater out and filled voids to provide a solid foundation for the plant. This treatment took less than two weeks.
Uretek continues to work on facilities that include major manufacturing sites, warehouses and distribution centres and the Uretek technology has now been used on 200,000 sites around the world.