Working Group 2

WG 2: Develop new options for tailor-made building materials to incorporate NORM residues.

Sub-task 2.1: Studying the developed options for building materials to incorporate residues investigated for possible use in the near future for (a) the cement, (b) the concrete and (c) the ceramic industry. Information in the database will be updated in close collaboration with WG 1. Deliverables: Updating the database with relevant information regarding new developed options.

Sub-task 2.2: Analyse the effect of higher substitution rates of virgin raw materials in terms of radiological content, for NORM residues currently used and possibly used in the future in the synthesis of building materials.

Considering a number of EU policy documents (as listed in the State-of-the-Art) promoting higher substitution rates of virgin raw materials, models need to be developed where the effect of this trend in terms of radiological content, per building materials, is analysed. This work is approached by a breakdown analysis per material, listing all material streams used in its synthesis. For example, in the case of cement clinker, higher alternative fuels will lead to an increased level of residual ash incorporated in the clinker. Similarly, use of non-ferrous slags may become more widespread in the future but this might have an adverse effect on the radiological content. To this extend, a holistic analysis is envisaged.

Deliverables: Analytical model per type/family of building materials where the % of virgin raw materials substituted is related to the radiological content.

Sub-task 2.3: Analyse the radiological content of emerging building materials, in particular geopolymers/inorganic polymers. Detect which materials are used and which can be used. Give

recommendations on the raw materials used.

Geopolymers/inorganic polymers are very promising as they can be synthesized primarily by secondary resources. This fact, corroborated by life-cycle assessments (LCA analyses), has provided convincing data that these materials are more sustainable and “green”. Still, no information is available on how the selection of raw materials affects the radiological content and performance in a real-life scenario. This sub-task aims to address this and deliver insight also in these aspects.

Deliverables: List of possible raw materials to be used in the synthesis of geopolymers/inorganic polymers and recommendations on the raw materials used with respect their radiological content.

Sub-task 2.4: Develop and recommend methodologies and materials to reduce the radiological impact of building materials. In particular, techniques related to: (i) the pretreatment of the raw materials (for the separation of the radiologically enhanced fraction), (ii) the development and application of the building material, (iii) the effect of its inherent and engineered properties by application of coatings, laminates or other treatment (density, X-ray shielding, radon barriers etc). It is often the case that a pre-treatment of a raw material may result to its beneficiation in terms of a specific chemistry or mineralogy. For example, particle size separation by sieving or other means may result to a fine fraction with particular characteristics, possibly lower/higher radiological content. These opportunities will be analysed in the first part of this sub-task. In the second part, the development of the materials as a research question is addressed. Existing models make assumptions based on data derived from concrete. However, surface materials (e.g. tiles) should be considered as such and their radiological effect should be quantified in a more realistic manner. Finally, in the last part, the inherent properties as well as the engineering properties, each building material bears, are taken into consideration. For example, many building materials are quite sophisticated and surface coatings could reduce gas (radon) permeability. Similarly, materials with controlled porosity (low density) are expected to become more widespread in the future in view of their enhanced heat (and sound) insulation capacity. In both cases, the effect of these properties needs to be understood and, in a reverse engineering approach, to be used to the benefit of producing safe building materials with NORM residues.

Deliverables: report on the effects of techniques related (i) to the pretreatment of the raw materials, (ii) the development and application of the building material, and (iii) the effect of the inherent and engineered properties of the building material, to the radiological content of building materials itself and the exposure a dweller experiences in a building.