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Based on our experience and the in-house expertise at Fondasol, as well as our routine tests, we are also able to carry our and/or develop and/or custom tests for your project.

20210610 111734

Rocks & concrete: velocity of sonic waves

The measurement of the propagation of Vp and Vs sonic waves in rocks is governed by standards NF P 94-411 - NF P 18-417 - NF EN 12504-4.

This non-destructive test must be done ahead of and as a complement to compressive strength tests on rocks.

The aim is to determine the E and G moduli as well as Poisson's ratio.

  • The test consists of emitting a pulse at the surface of a rock specimen and measuring the time it takes for the wave to propagate between the emitter and the receiver at a known distance.
Labo Resistivite Elec WEB

Soils & rock: electrical resistivity

Measuring electrical resistivity by the WENNER PROBE method is governed by British standard BS 1377-3.

This test aims to determine electrical resistivity (Ohm.m), which indicates the relative capability of the soil to carry electric currents and the ability of the material to withstand the displacement of free electrical charges (electrons, ions) under the effect of a magnetic field.

  • The test consists of inserting 4 probes in the specimen in the Wenner configuration. A current is created between the outer electrodes and the resistance between the inner electrodes is determined by balancing the bridge circuit. The soil resistivity is then calculated based on that resistance.
  • This test can be done on an intact or a reconstituted specimen.
DSC04561 BDWEB

Soils & rocks: thermal conductivity

The measurement of the thermal conductivity of soils and rocks by the thermal needle probe procedure is governed by ASTM 5334 and IEEE guide Std 442-1981: IEEE Guide for Soil Thermal Resistivity Measurements.

The thermal conductivity value  l (in W/m.K) is defined as quantity of heat transferred per unit time per unit area at a temperature gradient of one Kelvin per metre.

  • The tests consists of placing in a sample of soil a probe consisting of a heating element and a temperature measurement device. The probe is heated with a certain quantity of heat Q for a time t and the change in the temperature T° of the sample is monitored.
  • This test can be done on an intact or a reconstituted specimen of soil or soft rock.

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Fondasol Group in 2023

100 M€

revenues

850

fondasolers

75%

of the capital held by employees

35

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