CONDAT is ISO 9001 approved.

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2 With more than 20 years of experience in tunnelling and underground works, has played an active part in developing special products for the underground industry. A complete range of products has been developed to suit the requirements of different types of ground, machines, environmental and security regulations. has been designed to improve the underground soil properties in order to facilitate further construction works or to repair existing construction. The Tunnel, Mines and Subsoil Improvement (TMSI) department is available for any additional details or further technical information. A team at your service:, T.M.S.I Dept Tel : +33 (0) Fax : +33 (0) tmsi@condat.fr is ISO 9001 approved. CONTENTS Principle and purpose of ground treatment Page 5 Principle of the silicate/ reaction Page 6 Using the grout Page 8 Laboratory expertise Page 9 Technical assistance Page

3 SITUATIONS REQUIRE WATER PROOFING Principle and purpose of ground treatment Water proofing of an area before excavation WATER WATER Principle of the silicate/ reaction Water proofing and sealing ground structures WATER Using the grout Repairing damaged existing underground works WATER Laboratory expertise Tunnel-boring machines under extreme conditions WATER Technical assistance and references

4 OR GROUND CONSOLIDATION Consolidation/sealing of access shafts, for the launching of tunnel boring machines WATER Consolidating embankments Temporary repairing ground works and consolidating foundations Consolidating foundations before excavation works 4 5

5 PRINCIPLE AND PURPOSE OF GROUND TREATMENT Principle and purpose of ground treatment offers hardeners for silicate based grout suitable for permeation grouting. Their high penetration capability results in maximum filling of voids and fractures in the ground and hence maximum water proofing by extrusion of the water. Pressure injection of the grout into the permeable ground results in: Improved mechanical strength Reduced permeability hardeners have been specially developed for silicate grouts. Their low viscosity means that the grouts have very high penetration rates into the ground. Depending on the formulation chosen, the operator can control the grout setting time, the injection rate and the compressive strength required. Principle of the silicate/ reaction R E M E M B E R Silicate/ grouts are suitable for most types of ground. The ground parameters will be as follows: Permeability from 10-2 m/s to 10-7 m/s Particle size from 2 mm to 0.02 mm Silt Sand Gravel Permeation grout (cement) Using the grout Particle size (mm) Permeability coefficient K (m/s) Ground treated with Silicate/ grouts should achieve impermeability more than 10 9 m/s and a compression strength up to 10 MPa. The gel grout can be produced for a wide range of specifications with setting times from 9 minutes to 4 hours depending on specifications. The grout formulation is chosen according to: The required final ground characteristics (permeability and/or compressive strength) The type of ground (chemical composition, pollution) Water content and type of water into the soil Climate conditions. Laboratory expertise Technical assistance and references

6 PRINCIPLE OF THE SILICATE / STAB REACTION 1 Type of grout Composition of the grouts The injection grout is made up of 3 compounds: Sodium silicate Water Silicate for injection grouts can help select the right silicate for the job. Silicates are defined according to several parameters: Weight ratio 3 < W R < 4 for water proofing/consolidation W R = % weight SiO 2 % weight Na 2 O Dry residue The dry residue between 30 and 40% will affect the viscosity of the grout and its final properties. Density expressed in g/cm 3. Viscosity expressed in mpa.s. This varies with: weight ratio the solids content the temperature ph For silicates with a W R between 3 and 4 the ph is around 10.5 to : hardeners for silicates offers several types of hardeners for silicate that all differ by their chemical composition, by the desired setting time with the silicate, and by the ground injection type: consolidation or water proofing. See technical data sheets enclosed. They have the following qualities: Low melting point: 0 to -30 C High boiling point: 200 à 235 C High flash point: > 93 C Low viscosity: < 5 mpa.s à 20 C Environment: WGK 1 (Wassergefährdungsklasse Self classification). Silicate/ reaction is first hydrolysed, then reacts with the alkaline silicate to form SILICA GEL 6 7

7 Principle of the silicate/ reaction Technical assistance Principle and purpose of of ground treatment 2 Properties Influence of the silicate concentration in the grout The silicate content has an impact on: Mechanical strength Grout viscosity (penetrability) Water proofing Setting time Importance of the neutralisation rate The neutralisation rate measures to what extent the and the silicate have reacted together. A rate of 100 % corresponds to full neutralisation of the Na 2 O entity by the. The neutralisation rate will have an impact on the properties of the gel: chemical stability mechanical properties (compression strength, creep) Influence of the type of For ground consolidation (construction works) several are available in order to provide the suitable setting time. The setting time may be modified depending on the type of used. Influence of temperature The setting time is also dependent on the temperature. An increase in temperature tends to reduce the setting time. Using the grout The approximate setting times are shown in the following table, which takes a setting time "t" at 20 C as a reference. Temperature ( C) Time Laboratory expertise 2t t t/2 Syneresis Syneresis is the progressive expulsion of water by the gel. Syneresis phenomena are controlled by a correct proportioning of the compounds. Released substances are more than 95% biodegradable after 21 days.

8 USING THE GROUT Sequence of on-site operations SILICATE/ grouts are suitable for providing water proofing and/or consolidation. The main sequences on a typical jobsite are as follows: Drilling the area to be injected Fitting the injection tubes Injecting the sleeve grout around the tubes* Rough plugging depending on the particle size of the ground by a cement/bentonite mix for example Sealing/consolidation using SILICATE/ grouts How the grout is injected Depending on the site set up, the grout can be injected in batches or from a line. A B C A - Storage tank for silicate B - Storage tank for water C - Storage tank for D-E-F - Constant level holding tanks G - Chamber dosing pumps H - Product mixing tank I - Pump grouting unit D E F H G I Injection parameters are monitored to control: pressure flow rate volume In order to maintain the mixture of /silicate/water stable it is recommended to keep it stirring until injection. Principle of the Tube - a - Manchette injection system (TAM system) The grout can be injected using Manchette Tubes. The area to be worked on is isolated by means of a double packer system. The grout must first pass through a cement sheath of low resistance, before penetrating the ground. The TAM system allow to inject the same area several times. Grouting pipe Treatment is stopped when the Packer predetermined pressure or volume is reached. Rubber sleeve Grouting orifice * Option valid for Tube - a - Manchette system. Packer Sleeve grout Rubber sleeve 8 9

9 LABORATORY EXPERTISE The results obtained for water proofing and/or consolidation, with the same formula, differ from one type of ground to another. The type of ground will have an impact on setting time, stability, mechanical properties, the volume injected (void filling), etc. Principle and purpose of ground treatment has a dedicated technical centre and laboratory, which will analyse the ground to be treated and will recommend the optimum formulation for the job. Characterising the leak-proofing has set up tests to measure the effect of the injection treatment on ground permeability. Principle The permeability coefficient "K" of the treated and untreated ground is determined using the Darcy law. Δh L A Ground Level kept constant Q The test involves applying water at a pressure of 3 bar and then determining the permeability of the treated ground. Several parameters influence permeability: type of silicate content of silicate neutralisation rate 1 A = K Δh L K : Ground permeability coefficient (m/s) Q : Fluid flow rate (m3/s) L : Thickness of ground (m) Δh : Hydraulic load applied to the ground (m) A : Straight section of the ground (m 2 ) Principle of the silicate/ reaction Using the grout has studied each of these parameters and has a database available so as to be able to draw up the most efficient formulation and the best suited to your needs. Technical assistance and references Laboratory expertise

10 Characterising consolidation is equipped with a press to carry out compressive strength (Rc) and determine the rupture force. Effect of the silicat e on the grout behaviour. (Laboratory conditions) 9 Neutralisation rate = 100% - V= 20 mm/mn Fontainebleau sand 8 7 Rc (MPa) % 40% 60% Silicate content For the same parameters, increasing the silicate content in the composition of the grout by using gives better compressive strength. Effect of the neutralisation rate. (Laboratory conditions) 16 Silicate content 70% - V= 20 mm/mn Fontainebleau sand Rc (MPa) % 75% 100% Neutralisation rate For a given silicate content, increasing the Neutralisation rate and thereby the content, improves the compressive strength of the treated ground

11 TECHNICAL ASSISTANCE The technical assistance service performs special studies in laboratories to help choose the right product for the job and to estimate consumption levels. Our service can help you: To select the appropriate sodium silicate. To optimize your formulation depending on: the the type of ground the setting time the permeability of the ground to be treated the desired mechanical resistance to compression the climate conditions. To follow your jobsite and provide on site advice based on our experience.

12 Subsidiaries Agents and distributors Production units RCS Vienne 71 B 73 - Photos : Condat - Document non contractuel - P.P. - Rev.1-10/ Avenue Frédéric Mistral - B.P Chasse-sur-Rhône FRANCE Tél. : +33 (0) Fax : +33 (0) tmsi@condat.fr - ndat.fr