Inventory of armourstone

Natural armourstone is widely used for hydraulic works, both in the coastal domain and in border of rivers and torrents, especially to protect against flood and the effects of waves and currents. To meet the expectations associated with this resource, an inventory of armourstone quarries was realized on a national scale in France. This inventory informs not only about the localization of quarries but also about the quality and the availability of materials. To fully optimize this inventory in a dynamic format, the association of all actors of the sector was preferred to archival research. This partnership approach led to project deliverables that can constitute durably a shared reference. The database can indeed be updated regularly thanks to the contacts established with the professionals of quarries. The access to this database is offered to a wide public: maritime and fluvial ports, local authorities in charge of planning and managing structures that protect against flood and other hydraulic hazards. This new database was organized considering its importance on the operational plan. This led to a hierarchical organization at two levels for each quarry face: first level, a synthesis sheet brings the essential information to realize choices upstream to the operational phases. Second level, a detailed specification sheet presents the technical characteristics observed in the past on the considered face. The atlas has two information broadcasting formats: a pdf file with browsing functions and a geographical information system that allows remote request of the database. These two media have their own updating rhythms, annual for the first and continue for the second.


Introduction
In recent years, a number of situations exist where the knowledge of armourstone resource was insufficient.It is not uncommon that these materials with a rough appearance, which seems to be easily accessible in many landscapes, appear finally, when projects are launched, to be the main source of difficulty for the conduct of operations.Either to localise quarries that may produce armourstone or to know more precisely characteristics of materials, knowledges of project owners and project managers are often very patchy and lead in design to technical and economic choices that are not optimized.In addition contexts in which armourstone are used also require to appreciate fairly accurately their availability: the conduct of operations in crisis following a major flood and the implementation of development projects cannot tolerate such uncertainties on the condition under which materials can be delivered.
One common reason for this lack of information is that armourstones are often a by-product for quarries, the main products being either aggregates or ornamental stones.Ordinarily, quarries operating mode is therefore turned to research specific characteristics for armourstone on well-defined periods, in response to specific requests.When answering to a tender request, two options are possible for quarries, sometimes in combination: operating an armourstone stock built up over time by blocks that did not fit in the manufacturing process of the main product, operating walls of a quarry with suitable extraction methods, in order to generate blocks that meet the criteria of desired size and integrity for the tender.
In the first case, armourstones are available relatively quickly, with the sorting and control operations.In the second case, the drilling and blasting will lengthen significantly the time required.
It was very crucial for us when we designed the database and the front-end Atlas to make sure we were taking in account the knowledge of this types of operational constraints at the scale of the quarry to manage in a better way the expectations of people in To produce a useful, shared and lasting Atlas in a dynamic format, the association of all the actors of the sector was preferred to an archival research.This desire to create a shared and sustainable reference founded the partnership approach adopted by Cerema and CNR (Rhône river National Company with quarries professional and the associations that represent them: UNPG (National Union of Aggregates Manufacturers) and CIGO (union of Independents Quarries from Great West) in particular.

Principles
Although the State decentralized services and the Cerema already had information about most of the quarries, these data had a good "degree update" only if they dealt with the petrographic nature of rocks or their intrinsic characteristics, that vary slowly.Conversely the information on the grading and integrity of armourstone and on the availability of blocks and the production capacity was insufficient, because more dependent on the progress in working faces.To update the information more regularly, the principle adopted was to get the information directly from quarries.

Study protocol
The objectives, methodology and funding plan of the study have been defined by Cerema in collaboration with the Ministry of Environment, Energy and Sea.
Cerema (laboratory of Angers) was in charge of undertaking the data collection, defining and creating the database structure and producing deliverables.
Workers quarries unions accompanied the project with their advices on the conditions of the partnership with quarries and established contacts.In the case of independent quarries not affiliated with a union, the laboratory of Angers exchanged directly.In all cases, to obtain reliable data, the laboratory of Angers offered to quarries technical assistance by phone.Following the treatment of transmitted information and before their final integration in the database, a validation phase was organized, so that each quarry could verify and approve the publication of its own data.
Over the period 2010-2014, Cerema and its partners engaged the professionals of quarry sector in a series of seven roundtables about armourstone to give the opportunity to learn about standards and, more generally, to discuss the state of the art.These roundtables have been used to gather information from quarry operators.
The organization of these roundtables was provided by the Cerema in partnership with: x  x resistance to breakage, x UHsistance to attrition (for armourstone used as top layer that will be subject to abrasion due to sediment),