CORDEK BENTONITE WM A UNIQUE WATERPROOFING SYSTEM For all below ground waterproofing applications BENTONITE WM MEMBRANES BENTOSTRIP CONSTRUCTION JOINTS
The Optimum Waterproofing Solution Cordek BENTONITE WM exploits the special property of naturally occurring sodium bentonite, which forms an impervious gel when in contact with groundwater and can swell up to 18 times its dry volume. These properties make it ideal for waterproofing reinforced concrete structures, and they have been harnessed by containing sodium bentonite between two layers of geotextile. The Product Cordek Bentonite WM is manufactured using Naue Fasertechnik s patented needle punched process, which creates a labyrinth of fibres that hold the bentonite in position. Powdered sodium bentonite ensures intimate contact with the concrete Upper geotextile layer - non-woven Core layer of sodium bentonite incorporating needle punched synthetic fibres Lower geotextile layer - woven Patented under No. EP O 278 419, Cordek Bentonite WM is unique in that: 800 gms/m 2 of natural sodium bentonite are impregnated onto the upper surface (the non-woven geotextile). This results in impermeable lap joints, and ensures that small cracks and fissures are sealed. Fibres are heat sealed to the woven geotextile. This process substantially increases shear strength and minimises displacement of the bentonite. These unique properties are vital when the membrane is used in conjunction with Cellcore which is designed to protect against ground movement. Note: Please see page 9 for the detailed Product Specification and Test Data
Cordek BENTONITE WM is the solution for below ground waterproofing applications. Advantages Ideal for use on Cellcore Quick and simple to install in almost all weather conditions Robust and damage resistant Impermeable lap joints Resistant to methane, radon and CO2 when hydrated Has a high level of adhesion to concrete Available in three roll sizes Supported by full product warranty Backed by a high quality installation service Successfully used across Europe for more than 15 years Cordek BENTONITE WM is available as follows: Roll Size Dia. Weight Application (mtrs) (mtrs) (kg) 1.20 x 2.42 0.20 18 Ideal for small areas and vertical application 2.42 x 15.00 0.50 210 For small to medium horizontal areas 4.85 x 30.00 0.65 1000 For large horizontal areas with lifting equipment 1
Installation Guide On timber formwork The membrane can be secured using nails or staples, and then the concrete cast against it. The bentonite impregnated non woven geotextile should face the concrete. On vertical concrete surfaces Fix the membrane to the previously poured concrete wall by nailing with soft washer fixings. Ensure that the inner liner concrete wall is cast against the bentonite impregnated geotextile. Horizontally under concrete Lay the material with the non woven layer upwards. Ensure that the material is not damaged or punctured during placement of the reinforcement. Care should be taken when compacting the concrete. Timber Formwork Vertical Surfaces Horizontally under concrete Cordek Bentonite WM being attached directly to a vertical face 2
Backfilling The fill materials must be free of angular stones or hardcore that could puncture or rupture the membrane. In certain circumstances it may be appropriate to use Correx protection board. Corners Double layering should be used at all corners, and at the end of a day s work all exposed edges should be protected so they remain clean. Joints Joints between panels, or repair patches, should be overlapped by at least 150mm. Care should be taken to avoid creases, wrinkles or contamination. Correx protection applied to a vertical face Backfilling Sealing around pile cap Corners and joints. 3
Installation Guide Other vertical surfaces The use of Cordek s Pile Infills ensures a level surface when laying the membrane against sheet piling. Sheet Piling Pile Infills Secant Piled wall Cordek Bentonite WM 150mm minimum overlap Details showing Cordek Pile Inserts Bentonite WM placed directly against sheet piles 4
Repairs Damaged areas should be swept clean and overlaid with a patch that provides at least 150mm overlap in all directions. Bentonite powder, which can be mixed with water to form a paste, is available in 30kg bags for sealing awkward details and small repairs. Drainage If a drainage layer is required around the structure, avoid sharp materials and ensure that the particle size is less than 18mm and that the membrane is undamaged. Please Note: For advice on sealing penetrations around pipes, holes, etc., please contact our Technical Department on 01403 799601. Sealing around a pipe At no time should any plant/equipment run on the unprotected surface of the membrane. Material should not be laid on standing water. If required Cordek can provide a post installation remedial service. Sealing around drainage pipes Cordek Bentonite WM used under a deep raft foundation. 5
Construction Joints Cordek BENTOSTRIP should be used on all vertical and horizontal construction joints. A minimum of 75mm concrete cover on all sides is required, and the BENTOSTRIP must be adequately secured with steel nails to prevent displacement during concreting. In certain circumstances BENTOSTRIP can be secured using adhesive. This is available from Cordek. BENTOSTRIP waterstop consists of 75% natural sodium bentonite and 25% butyl rubber. On contact with water it expands over 4 times. 9 6
A number of Cordek products can be accessed on RIBA's NBS Plus specification database. For Bentonite WM the suggested specification clause is: The waterproofing membrane is to be a needle punched geotextile sandwich layer containing 4200 gms/m2 natural sodium bentonite powder and an additional 800 gms/m2 natural sodium bentonite powder into the top layer of non-woven polypropylene geotextile, to provide a self sealing lap. BBA BRITISH BOARD OF AGRÉMENT STANDARD DETAILS Another feature of Cordek's back-up support for specifiers is this Standard Details brochure. It provides typical details for a number of frequently used waterproofing applications. The example on the next page is for a LIFT PIT. For further information, on-site design, standard details or technical support, please contact Cordek on 01403 799601. for Cordek Bentonite WM A RANGE OF WATERPROOFING APPLICATIONS 7 10
8 Standard Detail
Specification and Test Data Cordek Bentonite WM Property Value Unit Test Method (based on) Mass per unit area, total 5,500 g/m2 DIN EN 965 Mass per unit area, cover non woven 300 g/m2 DIN EN 965 (PP white, filled with 800 g/m2 bentonite) Mass per unit area, bentonite layer 5,000 g/m2 DIN EN 965 (natural sodium bentonite powder)** Mass per unit area, carrier woven 200 g/m2 DIN EN 965 (PP-slit film woven, black or beige) Thickness, total 7 mm DIN EN 964-1 Max. tensile strength, md/cmd* 20 / 11 kn/m DIN EN ISO 10319/ASTM-D-4595 500 / 270 Peel strength 360 N/m ASTM - D-6496 Permeability 2 x 10-11 m/s DIN EN 18130 / ASTM-D-5887 + 5084 *md: machine direction, cmd: cross machine direction ** Including bentonite in the face membrane. Natural Sodium Bentonite Property Value Unit Test Method (based on) Monmorillonite content approx.. 90 % XRD Methylene blue consumption 300 mg/g Methylene blue test, VDG P69 Water content 15 % DIN 18121 (5hrs, 105ºC) Water absorption 600 % DIN 18132 (24hrs) Swell index 25 ml/2g ASTM-D-5890 Fluid loss <18 ml ASTM-D-5891 Note: Where DIN or EN test methods are quoted, they are used for QC testing Quality Assurance The manufacturer is certified to ISO 9001:2000. In-house and independent test data available on request. Independent quality assured to DIN 18200. RIBA accredited CPD provider 9
For our detailed literature on these other Cordek Solutions, please call our technical sales on: +44 (0) 1403 799601 Architectural Formwork For spiral staircases and complex formwork Gas Protection For venting hazardous gases from under buildings Trough Moulds For forming ribbed concrete floors Waffle Moulds For forming two-way ribbed concrete floors Cellcore For protecting foundations against ground movement Claymaster Low density polystyrene for accommodating lateral ground movement Cellform Like Groundform but with built-in protection against ground movement Groundform A formwork system for in-situ ground beams and pile caps Correx & Seekure For temporary protection Tipform A system for constructing steep sided landfill sites Piling Accessories A range of product solutions and systems If the contents of this brochure do not point to a solution for a waterproofing application, we urge contractors and specifiers to call our Technical Sales line on 01403 799601. Our reputation is built on innovation and we have a wealth of problem solving experience for you to call on. Cordek Limited Spring Copse Business Park Slinfold West Sussex RH13 0SZ England Telephone +44 (0) 1403 799600 Facsimile +44 (0) 1403 791718 e-mail sales@cordek.com The contents of this brochure are the copyright of Cordek Limited and may not be reproduced without permission. November 2005 www.cordek.com