+33 (0)4 93 29 11 29 siege@audemard.com

Aggregate and its uses

map1
EXTRACTION
1
The discovery

Vegetation, soil and sterile materials that cover the solid rock are removed and evacuated with earth-moving machinery. These materials are stored to be integrated into the final restoration of the site.

2
Excavation

This operation involves detaching and fragmenting materials of the rocky mass. It is carried out in three stages: The drilling involves making the holes that will receive the explosive. This is done using a drilling machine according to very precise parameters based on the quarry face, the volumes to be extracted and the size of the blocks to be obtained. The mining involves measuring and positioning the explosive charges in order to obtain the desired extraction. Today’s highly sophisticated techniques make it possible to optimize the use of explosives. The firing is carried out according to a precise plan with a defined methodical phasing to obtain the desired fragmentation. It is triggered by means of electric detonators placed at the bottom of the hole. It is designed to minimize the impact on the environment (shock, vibration, noise). These impacts are measured by recording seismographs.

LOADING
3
Removing quarry materials

Fragmented rock from blasting is picked up by loaders or hydraulic shovels and transported by dumpers to the primary crusher, which is the first step in the process of reducing the size of the materials. Before this step, blocks can be sorted for use as retaining materials.

AGGREGATE PRODUCTION
4

This process involves successive crushing, screening and washing phases which make it possible to manufacture the various classes of aggregates at rates of between 100 and 1,000 t / hr.

Crushing

Crushing reduces the size of the aggregates as they pass through the crushers. Several successive crushings (secondary, tertiary, even quaternary) are necessary to obtain the desired dimensions. Different types of crusher are used, jaw, impact and gyratory.

Screening

The screening involves separating the aggregates by granulometric class corresponding to the different uses. This sorting is done using screens.

Washing

Washing involves cleaning certain materials to remove the finest parts or impurities (clay) to meet industrial use requirements.

5
Sterile materials

Sterile materials resulting from the treatment are used for the restoration of the quarry.

6
Command post

Most of the facility is controlled by automation that manages the operation of all the elements (crushers, sieves, conveyors). The automation is controlled by specific software located in the facility’s control room. The facility manager supervises the production operation.

STORAGE
7

Storage is done by size in silos, hoppers or piles fed by conveyors.

COMMERCIALIZATION
8

Aggregates are loaded into trucks under silos or hoppers by means of loaders or by automated loading stations.

9

Weighing is done on a weighbridge. Trucks are weighed empty when they enter the quarry and re-weighed when they leave. These weights are linked to an automatic invoicing system.

10

The laboratory performs various tests on the aggregates manufactured to ensure continuous quality control. These tests are performed throughout the production process.

Where aggregate is used

map2
PUBLIC WORKS
PROJECTS
1
ROADS / EXPRESSWAYS
(30,000 T / km expressways)

– Crushed gravel for the foundation layer
– Untreated gravel for the base layer
– Fine gravel, filler sand for the surfacing layer

2
RAILWAYS
(10,000 T / km high speed line)

Gravel for sub-base and ballast

3
DIKES, SILLS, DAMS

– Blocks of 1 to 6 tons, or more depending on the current or the swell.

CIVIL ENGINEERING PROJECTS AND STRUCTURES
4
BRIDGES, TUNNELS

– Gravel and sand for concrete (2 T per 1 m3 of concrete)

BUILDING
PROJECTS
5
STRUCTURES CAST ON SITE

– Fine gravel and sand for ready to use concrete

6
PREFABRICATED STRUCTURES

– Fine gravel and sand for prefabricated concrete

7
FACINGS

– Fine gravel and sand for prefabricated concrete
– Stone for coatings
– Sand for facade plaster

8
DECORATION

– Building stone
– Facing stone

DEVELOPMENT OF ROADS AND SYSTEMS
9
Trenching

– All types of fill
– Gravel

10
Footpath coating

– Colored fine gravel
– Fine gravel for exposed aggregate concrete
– Paving stone

Our philosophy

FOUR GENERATIONS OF MEN AND WOMEN HAVE SUCCEEDED EACH OTHER AT AUDEMARD, ALWAYS WITH THE SAME ENTREPRENEURIAL PASSION.