Recycling plants
Recycling and reduction in waste going to landfill has become a major issue of social responsibility and, as such, the construction of waste recycling and energy from waste facilities has become a growth industry. Concrete is commonly used within these facilities as construction material but can be subject to deterioration because of the harsh environment inherent to waste.
Concrete as a material has high strength in compression but is weak in tension. Due to this, welded steel mesh has traditionally been placed within the matrix to reinforce it and to prevent failure. If a concrete slab is ground bearing, then the design calculation may allow for the elimination of any welded steel mesh in the bottom half of the slab. This means that “reinforcement” would only be needed in the top half to prevent shrinkage cracking.
The presence of liquids and leachates within waste facilities, for instance from orange juice, milk and wine, can lower the alkalinity of the concrete and therefore will lead to corrosion and subsequent spalling and failure. The use of Adfil Durus Macro fibres and Adfil Micro fibres can eliminate some of the potential problems associated with the use of concrete within this application, as well as improving the properties of both the wet and hardened concrete.
The introduction of Adfil Durus Macro fibres as the reinforcement material may eliminate the requirement for welded steel mesh and, as such, eliminates any issue that may arise from the presence of acids. Adfil Durus Macro fibres are manufactured from 100% polypropylene and are therefore unresponsive to acids, liquids and leachates.
Adfil Micro fibres are added at a rate of 0.91 kg/m3 to the concrete mix to improve the properties of the wet concrete. In the hardened concrete, the fibres will improve the abrasion and impact resistance and the resistance to freeze-thaw.
Leachates from domestic waste can penetrate concrete and accelerate the corrosion of any steel reinforcement. With the expansion caused by the corrosion of the steel the concrete service will eventually crack and spall, a process which can be exacerbated when the blades of the waste handling equipment snag on any fractured concrete or exposed rebar.
The use of Micro fibres enhances the hardened properties of the concrete and this creates a more durable surface. Macro fibres are used to reduce or eliminate the need for traditional steel mesh reinforcement which could erode and create spalling.
Functions:
- Eliminating welded steel mesh reinforcement
- Reducing plastic shrinkage
- Enhancing residual flexural strength
- Improving freeze-thaw resistance
- Increasing impact and abrasion resistance
Relevant products:
