As the quantity of residues is increasing in Europe, providing a feasible alternative for handling wastes is required to acquire an effective practise of resources, as the EU will demand for a low carbon economy. Therefore, it... [ view full abstract ]
As the quantity of residues is increasing in Europe, providing a feasible alternative for handling wastes is required to acquire an effective practise of resources, as the EU will demand for a low carbon economy. Therefore, it is essential to go one step forward regarding sustainable alternatives in materials to incorporate different kind of waste, and different percentages in their formulations. In this sense, Municipal Waste Incineration (MWI) is increasing in Europe, and its accessibility in landfill is restricted. MWI generates two different kinds of wastes: Bottom ash (BA) which is the main by-product (85 - 95% wt.) after combustion classified as non-hazardous, and Air Pollution Control (APC) which is considered as hazardous. BA is rich in calcium and iron and sodium silicates, and it is revalorized as secondary material in construction or civil engineering fields previous weathering stabilization during 2-3 months (WBA, Weathered Bottom Ash). When WBA is mixed with residual agricultural biomass as renewable resource, a new Lightweight Aggregate (LWA) material for several applications can be achieved. This statement is in agreement with waste management European policies. Considering the above mentioned residual biomass, rice husk is a by-product of the rice industry which contains high content of silica and has been extensively used in buildings as natural thermal insulation material. The low cost, abundance, and eco-friendly nature of the raw materials make the new LWA very attractive. The WBA used in this study is from Tarragona, Spain. The particle size of the WBA used for the developed LWA is lower than 30 mm. The WBA fraction was first milled under 100 mm, and then mixed with 2.0-5.0 mm rice husk. Afterwards, different small ball-shaped pellets of around 1.0 cm have been sintered in a furnace at temperatures above 1200 ºC in a time range between 1-2 minutes, removing the organic matter content generating high porosity. The LWA samples obtained were characterized and tested considering their physico-chemical nature, mechanical behaviour, and environmental performances by means XRF, XRD, TGA, FT-IR, density, ICP-MS, compression, among other techniques. The obtained results provide a suitable formulation by using WBA as unique silica source as well as crop by-products.
Interaction and chemical compatibility with other materials and structures , New products, applications and machinery
