Municipal waste facilities experience very rapid deterioration of the concrete slabs which are exposed to low pH leachate from waste and also subject to regular abrasion from loaders managing material from the slab. The life expectancy of municipal waste floors is often only two to three years.
Waste Management companies have been asking for a slab solution where we can do away with surface coatings and treatments as these just wear off of are chipped off over time, exposing the reinforcement and the concrete beneath.
Research and field performance have shown that high percentage silica fume concrete can be used to effectively reduce chemical attack depending on specific exposure conditions. In general high percentage silica fume concrete was found to increase resistance to aggressive chemical by a factor of two to five times compared to ordinary Portland cement concrete.
Dr James Aldred, Technical Director with AECOM, worked with Lipman, its consultant, Costin Roe, and the premix suppliers to develop a high volume silica fume steel fibre reinforced concrete for a new municipal waste facility in Banksmeadow. The intention of this concrete mix was to significantly reduce chemical and mechanical deterioration compared to normal concrete. It was not expected to prevent surface deterioration over time.
The floor was inspected after 6 months service and found the general condition of the concrete surface appeared to be good with limited wear even in the area where there is consistent activity of loaders feeding the compactors.