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PRODUCT TECHNICAL STATEMENT

4131BB - BENTECH BENTONITE® HEAVY DUTY TANKING MEMBRANE

Company Name Contact Details

Bentech Pacific Limited Al Stephen Technical Director 021 565 696 al@bentechbentonite.co.nz www.bentechbentonite.co.nz

Name of Building System Bentech Bentonite® Heavy Duty Self-Sealing GCL Tanking Waterproofing System

MasterSpec Reference 4131BB BENTECH BENTONITE®

Product Description 1) BENTECH BENTONITE® HEAVY DUTY TANKING MEMBRANE – Manufactured from high performance natural Sodium Bentonite Clay, Heavy Duty membrane contains at least 5.5kg/m² natural Sodium Bentonite. Bentech Bentonite® can be installed on compacted sub base, sheet piles, sacrificial shutters and on concrete substrates and precast panels. Can be installed on damp substrates or in inclement weather provided de-watering, backfilling and compaction happens on the day. 2) BENTECH BENTONITE® HEAVY DUTY HDPE TANKING MEMBRANE – High density polyethylene-backed, Heavy Duty Bentech Bentonite® membrane is manufactured from high performance natural Sodium Bentonite Clay and recommended for high risk or contaminated groundwater situations. Heavy Duty membrane contains at least 5.5kg/m² natural Sodium Bentonite. Bentech Bentonite® HDPE can be installed on compacted sub base, sheet piles, sacrificial shutters and on concrete substrates and precast panels. 3) BENTECH BENTONITE® COMPOSITE WATER STOPS – Bentech Bentonite® 20/10 Water-stop is manufactured from high performance Sodium Bentonite clay. Bentech Bentonite® 20/10 Water-stop is suitable for sealing all cold pour joints, columns and floor to wall transitions. 4) BENTECH BENTONITE® GRANULES / MIXED PASTE – Bentech Bentonite® Granules available in 20kg bags. Used to seal laps and around complex detailing and protrusions. 5) BENTECH BENTONITE® CEMENTITIOUS COATING – Bentech Bentonite® Cementitious Coating (BCC), an acrylic two component material (mixed 50/50, one part BCC liquid/ one part high grade cement) forming a flexible, UV stable, water resistant and low shrinkage, impervious membrane compatible with most concrete, stone and metal building surfaces.

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6) BENTECH BENTONITE® ACCESSORIES –

a) Termination Bar – Galvanized 50mm Galvanized Flat Bar (Primarily Use When In

Contact With Concrete). b) Nails & Washers - Mechanically Fixed Drive Pins & Flat Washers. c) Non Rigid Protection Sheet 3.3mm Plastic Coreflute® Protection Board

Geotechnical Information Sodium Bentonite is a 100% naturally occurring volcanic clay mineral. When hydrated, it must swell — up to 800%. When installed as GCL membrane to below grade wet conditions and 'confined' between a solid concrete structure and suitable backfill; hydration and subsequent swelling creates a pressure zone between the wall and the backfill. Any leaks cause a loss of pressure resulting in the viscous clay migrating to the hole(s), and plugging them with an impervious clay plug able to withstand up to 70m of head pressure.

Scope of Use Bentech Bentonite® is recommended for all below ground basement, lift-pit, foundation, sump, wall, tunnel, reservoir, landfill, pond and canal waterproofing, confining and tanking applications when basement waterproofing is critical such as large and complex construction projects. Bentech Bentonite® is suitable for deep excavations where a full tanking system is required and where basement waterproofing is critical, such as below the water table or in large/complex constructions or excavations where detecting membrane damage make the risks of using traditional waterproofing systems high.

NZBC Compliance Bentech Bentonite® meets the requirements of the CodeMark certificate SAIG-CM20070 when used within the conditions of its Certificate of Conformity. Achieves compliance with NZBC B2.3.1 & E2.3.3 Bentech Bentonite® is accredited to AS/NZS ISO 9001:2008.

Preparation Work to be carried out and materials used to be in accordance with the Bentech Bentonite® GCL Membrane Installation Manual with special attention given to surface preparation, compaction and backfilling.

Installation Install GCL / HDPE rolls with white geotextile surface side to concrete surface to be waterproofed. Ensure Bentech Bentonite® Granules/Paste is applied to all side and end laps. Stagger rolls to prevent build up, ensuring laps remain intact while placing confining concrete over the top (prepared sub-base surface). Ensure the concrete is poured ‘with’ the direction of the overlap and not against it, making sure the membrane is not lifted by the pressure of the wet concrete flowing over it.

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Confine horizontal membrane with reinforced concrete or backfill immediately after the membrane installation is complete (to prevent premature edge paste hydration or overnight rain causing premature activation). Vibrate concrete ensuring no voids taking care to vibrate right into the corners, compressing the Bentech membrane firmly against the substrate. Bentech Bentonite® works through a mechanism of swelling (when in contact with water) under confinement. It is important that in both horizontal and vertical applications that the membrane is adequately confined. Note that when installing in hydrostatic situations, the engineer should specifically design the floor slab thickness/reinforcement to accommodate the anticipated hydrostatic pressure. BACK FILL Ensure the quality of the back fill (Gap 20/40) is such that the Bentech Bentonite® membrane is not damaged and it allows uniform compaction and confinement of the membrane. Use a suitable whacker or plate compactor to compact the backfill ensuring loose stones do not get behind the membrane during installation. Place backfill in layers and compact to greater than 85% Proctor every 400mm. Do not use sand, scoria or soil for backfill. COMPACTION During installation compact and confine Bentech Bentonite® between concrete, shotcrete, masonry, rock (GAP20/40), brick, polystyrene/concrete masonry or compacted clay substrates. Compact to >85% Modified Proctor Ensure Bentech membrane is not damaged during backfill.

QUALITY ASSURANCE

Contractor to ensure preparation of surface is in accordance with Bentech Bentonite® Installation Manual. Installer to maintain application quality necessary to warrant the installation is performed in accordance with the specification and the qualifying requirements of Bentech Pacific Ltd., who shall have such access to site as may be required to guarantee this process. Installer to be an approved applicator of Bentech Pacific Ltd. Please contact Bentech for a current list of installers.

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CLEAN UP as the work proceeds. REMOVE debris, unused materials and elements from the site. LEAVE the work in a sound condition, free of any defect.

Warranty Information 25 Year Product Warranty.

BENTECH BENTONITE® Documentation

Product Brochure Installation Manual Standard detailed drawings Safety Data Sheets 25 year Warranty 50 year Geotechnical Durability Statement AS/NZS ISO 9001:2008 CodeMark Certificate SAIG-CM20070

Product Support

24/7 availability – Al Stephen – 021 565 696

©2016 Bentech Pacific Ltd. All rights reserved