France - Granules, gravel, fine sand, pebbles, gravel, crushed stone and crushed stone, mixtures of stone, gravel and other aggregates

Description

Aggregates are used to fill voids between radioactive waste packages in "Gravel Works (GC)" type storage facilities. This filling is done in one go when the structure is entirely filled with packages; the aggregate is brought to the top of the structure, via a grasshopper then distributed by gravity in the structure in the gaps between packages. The desired property of the aggregate is its propensity to flow well so as to penetrate as well as possible into the gaps between packages. In addition, the gravel must guarantee the stability of the structure to withstand earthquakes and must comply with NFP 18-545. the granular class is "4/8 mm". The granularity is as continuous as possible. The conditions to be met by the aggregate are as follows: - passing under the 12.5 mm = 100 mesh screen, - passing under the 8 mm mesh screen, ≥ 85%, - passing under the 4 mm mesh screen, ≤ 15%, - passing under the 2 mm mesh screen, ≤ 3%.The bulk density must be less than or equal to 15 kN/m3, the flattening coefficient must be less than or equal to 30% and in terms of cleanliness, the standard NF EN 933-1 must be respected. The aggregate must not contain any wood particles, coal or other residues. The fine content for the 0.063 mm pass is less than or equal to 1.5%. The shell element content is less than or equal to 3% and in terms of water content, the standard NF EN 1097-5 must be respected. The water content of the delivered material is less than or equal to 2% and in terms of physico-chemical measurements the standard NF EN 1744-1 must be respected. The sulphur trioxide (SO3) content is less than or equal to 0.4%. The chloride content is less than or equal to 0.01%. during the material qualification phase, the following criteria must be met:- internal friction angle ≥ 35o according to the direct straight shear test at the Casagrande box (NFP 94-071-1),- equivalent dynamic Young's modulus ≥ 40 MPa according to the non-drained consolidated triaxial test (NFP 94-074). Parameter influencing the seismic strength of the structure,- shear modulus ≥ 16 MPa following the resonant column test (for information the previous test was performed according to ASTM D4015-07),- damping coefficient ≥ 10% of the critical damping following the resonant column test (for information the previous test was performed according to ASTM D4015-07).NB: 2 triaxial tests are required to qualify the material (for the internal friction angle and Young's modulus) ANDRA draws the attention of economic operators to the fact that in the event of failure to demonstrate that the aggregate meets the requirements set out above, it reserves the right to terminate the contract without the holder being able to make any claim.

Opportunity closing date

10 July 2019

Value of contract

to be confirmed