Emploi des calcaires en limite de specification

Building a motorway involves to deal with enormous quantities of materials which, if not available near the site, will have an incidence on the transportation cost. This may considerably modify the economic balance of a project. A double mission was committed to the “Laboratoire Régional de Nancy” in the building of Lorraine-Bourgogne motorway:

-to detect all available resources near the project;

-to adapt, if necessary, production and building practise to the distinctive features of the encountered limestones.

This led to the opening of Harmonville quarry and the valorization of Bajocian oolitic limestones which had not yet been used in road construction. This quarry produces:

-materials for high quality embankments,

-up to one million tons of subgrade materials,

-materials for gravel-slag mixture for foundation layer and sand for gravel-bitumen mixture and bituminous mixes, in spite of geotechnical characteristics which were at first considered to be too weak.

Unusual or “risky” materials are not adapted to conventional production or building techniques, hence the research of new technologies leading to an increase of the price of the materials, which is widely compensated by the savings on transportation. It is also an economy in the field of traditional resources, because the production of this quarry is equivalent to 10 years of work for a medium size gravel-pit exploitation. Harmonville quarry exploitation can be considered as a regional first experience, because it represents on a large scale the importance of “near specification limits limestones” in road construction.     

Synthese des etudes de ressources en materiaux pour usages routiers

At the C.C.I.R. request (Comité Conseil à l'Innovation Routière) the C.E.T.E. (Centres d'Etudes Techniques de l'Equipement) carried out in 1981 and 1982 a synthesis on the aggregates resources for road-uses. The objects were:

-analysis of the various constraints lying on the supply in traditional materials (synthesis including the studies already realized, a balance-sheet for each department and area of the present market, and future prospects),

-working out of a list of the materials eventually utilizable, taking into account their natures, qualities and quantities, especially for “new materials”,

-to point out the main centers of interest and to propose future orientations and actions.

The investigation of the different reports allows to define:

-some particularly sensitive areas in which aggregates supplies are already difficult or are going to be short in the near future leading to promote the utilization of “new materials”. Examples: Aquitaine, Midi Pyrénées, Champagne-Ardennes, Centre, Charentes, Région Parisienne.

-some regions or districts where difficulties of supply exist in limited areas or some other districts where difficulties will only come out at several years date. Examples: Provence, Alpes, Côte d'Azur, Corse, Auvergne, Bourgogne, Franche-Comté, Rhône Alpes, Haute Normandie, Nord, Picardie, Lorraine,

-some regions where there are no problems of supply in the foreseeable future. Examples: Limousin, Bretagne, Pays de Loire, Basse Normandie, Languedoc, Poitou, Alsace.

     

Remise en etat des carrieres

The application of the law on Environment, states in article n^o 24 that a quarry's site must be restored when the extraction is over. This oblitation belongs to the quarry or gravel pit's society, but the use of the site itself belongs to the owner of the ground. The two notions are often the subject of quarrels between quarries' societies and groups taking the protection of Nature into account, because they are not always correctly separated. The “Ponts et Chaussées” Laboratories have included this problem in their action of technical support to the stone industry. Three notes have been written pointing out the main topics that must be included in a restoration study after extraction, to allow the owner to make afterwards, the best use of the site at the lowest cost possible. These notes concern 3 cases:

-The use of ancient quarries' sites for sport or open air activities.

-The restitution of the site to its natural context.

-The use of the site for agriculture.

     

Etudes prealables a l'etablissement de zones d'exploitation et de reamenagement coordonnes en Alsace,France.

Problems related to gravel-pits, their exploitation (26 Mt/year) and the disorderly spreading of the sites in the Rhine alluvial plain are a matter of regional concern. The establishment of a regional master plan for the gravel pits (referring to article 109–1 of the Mining Code) has become compelling. This operation started in its working stage with the setting up of a “gravel-pits technical group” within the D.R.I.R., which secured the backing of several regional technical departments, among those the SGAL which has been instructed to supply the required data for:

- defining 16 workable areas as planed for the 30 coming years,

- working out analytical summaries, specifying for each area, the main features of the gravel beds, the technical aspects of their working, and the impact on ground-water,

- drafting the specifications governing the working of gravels in these areas,

- specific research on technical problems tied to the deepening of some gravel-pits coming up against day or conglomerate layers.

This work is part of a broad action concerning 7 Z.E.R.C. (Zones where Exploitation and Recovering of aggregates sites are Coordinated) which cover the whole valley of Alsace, in order to follow the goals defined at a regional level:

- to ensure a good management of the resource corresponding to the regional common good,

- to locate the future working sites, in order to respect at best the economical, geological, agricultural and environmental limitations.

     

Les matieres en suspension dans les estuaires

This paper, devoted to the behaviour of suspended matters in estuaries, deals successively with:

- the nature and origin of sediments suspended in some estuaries

- the behaviour of suspended materials: flocculation, falling rate of flakes, shrinkage, rheology, picking up by currents, slides inside the deposits

- the sedimentary movements of floating materials in the estuaries: transport under the influence of the tides, sedimentary materials available in the estuary, influence of the river discharge and of the salinity, ejection of suspended matters out of the estuary,

- volume of the deposits in some estuaries.

     

Protection et amenagement des sites d'interet geologique

Quarry workfaces sometimes constitute precious sources of scientific—mainly geological—data. Some quarries have contributed to the definition of the international stratigraphic scale (stratotypes), others can be of pedagogical interest or natural curiosity (palaeontology, pedology, archaeology, zoology, botany, ...). Recent studies have shown that some French sites of international geological interest have been irremediably destroyed and others considerably endangered. It has been possible to carry out some studies and work on certain quarry sites in order to preserve and make use of endangered scientific zones, in particular with financial aid from the “Taxe Parafiscale sur les Granulats”. Amongst these operations—presently in progress or already finished—, particular mention may be made of the following:

- the Saucats-La Brède sites (Gironde): Aquitanian and Burdigalian stratotypes;

- the Pontlevoy (Loir-et-Cher) and Channay S/Lathan (Indre-et-Loire) falun quarries, which present characteristic facies of the Helvetian of the Bassin Parisien;

- the Hettange-Grande site (Moselle), Hettangien stratotype;

- the Cuise-La-Motte sand-pits (Oise), Cuisan stratotype, and those of Mailly-Champagne (Marne), characteristic of the Ludian.

Work of this nature is usually undertaken to restore and secure old quarry faces, to protect them against the effects of weather and the public, and to make them accessible to visits. In certain cases, some sites have even been classified as natural reserves.     

Comportement à l’eau des roches argilo-marneuses, suivi du gonflement, importance de la minéralogie et des textures

In the presence of water, clayey-calcareous rocks display behaviours which are often significantly different. Through the study of four materials which are representative of the marly formations commonly met on the occasion of road construction, the authors show how this behaviour depend on the mineralogical and textural characteristics of rocks. After reminding the main mechanisms of swelling phenomena the authors characterize the selected materials on the one hand through the measured physical and physico-chemical parameters and on the second hand through the mineralogical and textural characteristics obtained from X-ray diffractometry and scanning electron microscopy. The materials are then studied firstly in “free swelling” conditions submitted to cycles and secondly in “stress swelling” conditions. These studies lead to the determination of their swelling capacity and of resulting swelling pressures. Afterwards, the materials are examined from the textural point of view. The study with the help of the S.E.M. allowed to point out:

—the evolution of textures and their role in the initiation of the changes which affected the materials.

—the role of minor minerals such as pyrite, which contribute after oxidation to the degradation of clayey minerals and consequently to the evolution of textures which finally lead to a decay of mechanical characteristics.

     

Etudes Françaises de materiaux de substitution

The authors examine the substitution materials studies realized in France during the last 10 years with the “Tax on Aggregates” financial support. The different types of substitution are first looked into:

-substitution of crushed hard rocks to fluviatile sands and gravels, whose reserves are becoming exhausted or sterilized by environmental constraints;

-materials not respecting standard specifications of aggregates: 1) soft rocks; 2) soils (fine sands, clayey sands, moraines, superficial deposits); 3) quarries, mines and industrial wastes.

Technical possibilities of uses for these “out of standards” materials are examined for natural or treated materials.     

Influence of capillary water on compressive strength of marls

Tests of compressive strength carried out on calcareous marl samples showed very different results in the four following cases:

1. the test was made in air on a dry sample,
2. in air on a sample saturated with water by capillary rise,
3. in air on a fully water-saturated sample,
4. in water on a fully water-saturated sample.

These results are interesting on a theretical point of view, and also on a practical point of view for works to be carried out under the ground-water table.     

Sous-produits industriels comme granulats routiers

Relation between the characteristics of the aggregates and the properties of some materials—Experimental research works (laboratory or site). Industrial by-products used are as follows:

- as an aggregate:

? stone and gravel pit refuse

? crushed blast furnace slag

? incenerator waste slag

- as a binder:

? hydraulic and non-hydraulic fly ash

? granulated blast furnace slag

? hydrated and carbide lime refuse.

Pavement layers applied are as follows:

- unbound base courses: mechanical stabilisation using stone pit refuse, crushed blast furnace slag, waste incinerator slag

- with hydraulic binder: (cement, fly-ash, granulated slag):

? lean concrete with crushed blast furnace slag and stone pit refuse

? hydraulically bound crushed blast furnace slag, waste incinerator slag, and sand obtained as refuse at sieving

- with hydrocarbon binder:

? bituminous stone pit refuse, bituminous crushed blast furnace slag, and bituminous mixture of gravel and sand and waste incinerator slag

? rolled asphalt with crushed blast furnace slag.

     

Gestion des risques et des crises liés à l'instabilité des carrières souterraines abandonnées

Instability of underground excavations and karsts generally leads to violent events that affect zones which are difficult to locate precisely. For this reason, monitoring and alarm systems are not very efficient and risk management must therefore be essentially focused on prevention. In France, the aim of such prevention is to find a balance. Although the French legal and regulatory framework is rational, it is deficient in certain respects, and particularly faces difficulties concerning implementation as revealed by the development of the Plans of Exposure to Risks (PER) having taken too long. The comments made during the symposium held at Nainville-les-Roches have lead to the proposal of a number of improvements for the present system:

-promote a global approach which integrates risk management into land-use planning, ensuring coherence between national, regional, departmental and local plans,

-develop an operational approach for each “basin” at risk,

-speed up hazard mapping by its separation from regulatory procedures,

-develop plans for crisis management at a municipal level; bring experts, technical services and emergency services closer together and involve populations at risk in the preparation process,

-launch an operational information policy on the risks and develop a true culture of risk prevention,

-set up a local public service responsible for risk management of underground excavations within areas of greatest risk.

     

Relation entre les caracteristiques des granulats et les proprietes des materiaux qu'ils permettent d'elaborer. Recherches en laboratoire et sur chantier

The introduction of the report presents data concerning the evolution of the traffic in the Cracow District between 1965 and 1983, and the aggregates used for road construction during the same period. The most important characteristics aggregates made of crushed rocks in the district are dealt with. Mineral aggregates usually belong to II–III class, and require improvements to achieve better physico-mechanical properties and after improvement they are commonly used for roadbases, basecourses and wearing courses. This report also deals with the relations between the characteristics of aggregates and the properties of same stabilized materials:

1. Mechanical stabilization for sub-base,
2. Stabilization of aggregates with granulated slag and hydrated lime for roadbases,
3. Stabilization of aggregates with granulated slag and with cement for roadbases,
4. E. Fly-ash concrete and stabilization of sand with cement for roadbases,
5. Hot bituminous mixtures/with asphalt as a binder/for basecourses,
6. Hot bituminous mixtures/with coal tar pitch as a binder/for wearing courses.

For all stabilized materials, the main results of the laboratory tests achieved during the preparation of mixes are presented, as well as the tests realized on compacted mixtures inside the road, under the traffic. It proved that satisfactory road-bases, base-courses and wearing courses could be made of aggregate of a rather poor quality. The choice of the technique must derive from the quality of the aggregates. The permanent technical control of the laboratory is necessary at all stages: designing, realization and maintenance.     

Application de la teledetection a la recherche de sites d'exploitation de granulats et a l'etude de leur impact sur l'environnement

A statistic sampling of publications concerning “aggregates” prospecting and environment impact studies shows that remote sensing is not so often used, contrarily to what heppens generally in the geological field. Which can be the reasons of that under-use?

- pecularities and traditions in prospecting?

- redundency of the results of remote sensing studies with the result of other methods?

- inadequation or underperforming of remote sensing in the peculiar field of “aggregates” prospecting.

In a first part, that note defines what seems to be the most common wishes of the users concerning remote sensing. In a second part, the various tools of remote sensing are described and their performances evaluated. In a third part, a comparison between the tools and the needs of the users try to evaluate the adequation of remote sensing. After some considerations about environmental impact studies the conclusion shows that Remote Sensing, even if not able to solve all the problems, offers to the users a great variety of usefull tools which, combined with other methods, give valuable results in efficiency and cost-effectiveness.     

Une analyse de la deformation des couches de base non traitees

The checking of standardised properties does not allow a complete judgment to be made about the behaviour of the material on the road. This is mostly the case with unbound layers of the road. Before constructing the road, the following tests are carried out in the laboratory:

- Particle size distribution

- Shape of the aggregate

- Impact value

- Susceptibility to freezing.

On the basis of the test results, the suitability of the materials for road construction is judged, although no test results on strains in practice are available. For this reason a research has been carried out using full-scale test sections to establish the relation between the following parameters and deformation on the road as measured by the plate-bearing test:

- Particle size distribution

- Shape index

- Flake index by sieving with parallel slots

- Void content

- Water content

- Subgrade stiffness.

The stiffness of the frost-layer and the road-base-layer were calculated using a Boussinesq settlement analysis. The results showed that the stiffness of the different layers could be expressed as a transcendental function in three parameters of the settlement of the layer. Linear multi-regression analysis enabled the relation to be established between the three stiffness parameters for the first loading and the particle size distribution, shape of the aggregate voids and water-content. As a result of the work, it is now possible to establish the relationship between laboratory testing of aggregates and the contractual requirements for the finished layer.     

Sable-cendre volante: Influence de la nature du granulat

The evolution, at 20°C and 40°C, of unconfined compressive strength (R'_c) and of splitting tensile strength (S_t) has been studied for five “sand-lime-fly ash” mixtures. Those mixtures are very similar with respect to grading, volumic mix design (aggregate, binder, water) and state of compaction, but they differ in the nature of the 0/2 mm sand: natural or crushed silica, limestone, porphyry and LD-slag. According to the aggregate treated, strengths and cohesion at the same age vary in a ratio from one to about two, even at long term. This difference in behaviour has been assigned principally to three factors which are in decreasing weight:

- surface texture of particles: strengths increase with micro-roughness owing to better adhesion between sand and binder mixture (fly ash + lime),

- chemical nature of aggregate (“acid-base”, character): at 40°C and 20°C till about 50 days of age, its influence seems to be of minor importance in comparison with that of micro-roughness. Later on, at 20°C, its effects appear clearly by a much slower strength increase when the aggregate has a rather “acid” character (silica and porphyry),

- angularity of particle: the influence of crushing is rather of little weight.

The estimation of the angle of internal friction from the S_t/R'_c ratio must be regarded more as an evaluation of the particle-binder adhesion for bound granular material than as one of the angle itself.     

Influence des argiles illitiques sur les graves ciment

This paper deals with the properties of 0–14 mm gravels stabilized with cement, with the addition of different clay contents (illite: 0–2–4–8%). The clay influence has been emphasized by replacing the clayey particles by calcareous fines. The quantitative and qualitative influence has been appreciated by the means of:

- cleanliness tests (methylen blue, S.E.);

- quality tests (R_t, E_t, I.Q.E.).

This work has been carried out with a 0–14 mm alluvial gravel from the river “Garonne”. This study reveals that the cleanliness tests are only influenced by the nature of the fine particles when the quality tests depend both on the nature and on the percentage of those fine particles.     

Les granulats siliceux en Catalogne,Espagne

The object of this paper is to give an idea of the state of use of high quality aggregates for wearing and railway-ballast. An inventory of those rocks used as high duality aggregates is drawn up, explaining the geological and technical characteristics of each of them. The second part analyzes the use which is actually made of each of these geological units. In Catalunya, the following rocks are used to elaborate high quality siliceous aggregates:

- Granites and granodiorites of the coastal mountain range, and some from the Pyréneées.

- Basalts in the areas of influence of volcanic rocks. Ophites in the western area.

- Paleozoic quartzites and somtimes, some metamorphic rocks as well as porphyritic rocks.

Is some areas only aggregates derived from alluvial materials extracted in the river beds are used mainly in the Segre river, which is intensely exploited. The Barcelona area of influence is mainly supplied with granite, the Tarragona area with quartzites, the Gerona area with granites and basalts and the Lérida area with the river Segre rocks and now and then, with ophites.     

The reliability and availability of heating,ventilation and air conditioning systems

Reliability theory has been applied to building HVAC facilities. In order to do this, the type of probability distribution for “mean time to repair”, “mean time between failures” and “decision time” was first studied, and it has been shown that the log-normal type of distribution applies here. This was evaluated from a large amount of data collected from buildings belonging to seven large real estate operators. Based on those results and assumptions, a “model” using standard reliability theory equations was deducted. The model has been used in a study of the seven large real estate operators.

• •The study shows that the model can give a good picture of the reliability and availability of HVAC systems.

The study also gave interesting results about the status of the studied HVAC systems:

• •the operational availability is high, almost 100%;
• •the decision time of the maintenance staff is large compared to repair time;
• •the system reliability depends strongly on the technical solutions and the number of components; and
• •the functional availability of the systems was low, partly because of malfunction of the ventilation systems. (Note: this depends, naturally, on the function criteria.)

Values of functional availability depend strongly on the function criteria. In this study, criteria connected to the actual buildings were used and no evaluation of the criteria themselves was made. The measurements were taken from different buildings both connected and not connected to the seven studied organisation.     

Bedeutung des Speichersystems Lohsa II für die wasserhaushaltliche Sanierung im Spreegebiet

Within the framework of the mining remidiation the residual holes of the former brown coal opencast mines “Lohsa”, “Dreiweibern” and “Burghammer” will be connected with each other in order to form the retaining system “Lohsa II”. Including the neighbouring residual hole “Bärwalde” they will provide a storage capacity of more than 90 millions m ³ (118.421 millions cu yards). Considering the water economy the project is expected to be completely ready for operation in the year 2005. Up to 13 m ³ /s (16.9 cu yards per second) of water are to be supplied during dry spells. This will sustain the draining function of the river Spree which has been damaged by lignite mining. At the same time the ecological requirements of the biosphere reserve “Spreewald” and the demands of the conurbation Berlin – concerning its water supply and water storage – will be fulfilled