Requirement for CE marking of aggregates
for protective works

A construction product is subject to being CE marked for that specific use in a construction when there is a harmonized EU standard in the scope of which the type of product and its use is clearly identified. When this happens, the manufacturer is obliged to CE mark its product so that it can provide a statement that it complies with European safety, health and environmental protection regulations.

The European standard EN 13383-1:2002 “Armourstone - Specification,” implemented in Italy as UNI EN 13383-1:2003 “Aggregates for protective works (armourstone) - Specifications,” lists and classifies the properties of aggregates obtained by processing natural, artificial or recycled materials and mixtures of said aggregates for use as aggregates for protective works. Such works mainly consist of the construction of reefs for water erosion defense of harbors and coastal areas, riverbank protection, and supporting infrastructure works.

The characteristics and properties of stone material

The protective works that can be carried out are many, and consequently the aggregates used may also differ depending on their intended use.

The smallest lumps are determined by sieving and can measure up to 250mm, while the coarsest aggregates are identified by a weight distribution: the lightest are included up to 300kg, while the heaviest can reach 15,000kg. Other geometric characteristics that contribute to the stability to the structure are the length-to-thickness ratio of each individual granule, which should be contained as much as possible within the value 3, and the percentage of crushed or broken surfaces chich should be as high as possible since rounded pieces of aggregate could cause the work to become unstable.

The physical properties of the material greatly influence its potential uses. The density is one of the main characteristics as works are mainly made gravity, so aggregates with higher mass are preferred. The resistance to compression defines the total load that the structure can bear and in fact are desirable materials with strengths above 80MPa. Finally, wear resistance due to sediment determines its use in environments that are moderately, highly or extremely abrasive.

Another very important aspect to consider is the environmental conditions under which the work will be carried out because these affect its durability over time. The durability to freeze-thaw cycles is critical in Atlantic and continental climates when the structure is subject to conditions of total or partial saturation with fresh water and areas concerned present a climate susceptible to frost. The corrosion resistance of the stone aggregate due to salt crystallization is a source of criticality when the work can occur in situations of total or partial saturation with salt water, a regardless of weather conditions. In such cases, it is preferable to use a Category A aggregate. Geologic alterations identifiable by a 'survey petrography that lead to a rock type classification can often provide A clear indication of whether or not it is resistant to deterioration. In the case of the use of basaltic material it is necessary to investigate the presence of“Sonnenbrand” which can lead the disintegration of the aggregate showing such traces.

The fill material for gabions with structural purposes

The material for filling metal gabions for structural use falls within the scope of use of the harmonized standard UNI EN 13383-1 and is therefore subjectto CE marking. The 90/180mm grain size is a grain size specifically covered in the standard and is designed precisely for special applications such as the gabions. The grain size limits identified are important because they must ensure an adequate degree of compaction without leading to material spillage from the holes or point stresses in the metal cage. The Ministerial Decree 11/04/2007 (Official Gazette 19/04/2007 No. 91) concerning the identification of products and related methods for checking the conformity of aggregates marketed in Italy, issued in consultation with the Ministry of Infrastructure, by the Ministry of Economic Development and the Ministry of the Interior, shows in Annex No. 2 the level of attestation required (level only for non-structural use, otherwise level 2+) and in Annex No. 3 the characteristics that must be included in the declaration of performance and CE marking label accompanying the material.

CE marking for aggregates from gabions: obligations and requirements according to UNI EN 13383-1

Eng. Stefano Zendri

Stefano Zendri is a chemical engineer and director of the CET Servizi laboratory. An expert in building materials, sustainability and road infrastructure, he has coordinated research projects, technical publications and training activities at the national level. He actively collaborates with agencies and associations for innovation in the construction sector.