September 2019. Issue No.32

In this issue: Case History Interesting Projects Interesting Projects We have seen projects with very typical usage of and related products, New Product / Application some in unique applications. Here are several products that catch our attention and • TriAx Geogrid might be of interest to you. • Deckdrain with Woven CV/2013/08 - at Liantang / Heung • Mini Roll Geotextile for Landscaping Yuen Wai Boundary Crossing, BOSTD Technical Note geocell is designed to retain 150 mm European Union – Falling Rock thick of planting on steep Protection Kit Certification Opinion Column slope for vegetation establishment. Sheet Membrane Seaming [email protected]. For Your Information • A Word from General Manager At SENT Landfill – • 35th Anniversary Recap Bonar 185 l/m2/s Reader’s Response high permeability woven geotextile is used as French drain drainage filter separation. The HF series allows up to a 400 l/m2/s water flow rate. ivan@g- and-e.com. CV/2012/05 - at Lung Mei Bathing Beach, Maccaferri is used to construct a 4 m high wing wall DC/2009/24 - at leading to an open drainage Harbour Area Treatment channel extended from the box Scheme (HATS) culvert to the outfall. natural@g- Cyberport Port landing, and-e.com. ACE high strength woven geotextile is prefabricated into a 150 mm φ x 4 m tube in HY/2014/06, at Hiram Highway expansion, which grout is infilled to Maccaferri Macmat is used for slope form a concrete joining erosion protection, the polyamide mat pin to interlock vertical offers distinct fire-retardant characteristic. seawall blocks. ivan@g- [email protected]. and-e.com. NE201501, at Lam Tin – TKO In a Tsuen Wan Private – Bonar woven geotextile Development – Daehan Hori- is sent to Korea to fabricate into drain, a 200 mm width x 9 mm a hybrid curtain incorporating thick prefabricated drainage a widely accepted Bontec composite is designed to dissipate SG110/110 geotextile to an water pressure in the basement engineered design silt curtain. structure. [email protected]. [email protected]. September 2019. Issue No.32 G and E Times HKT submarine fiber optic cable between TKO and Siu Sai Wan – Maccaferri prefabricated articulating concrete block mats are fabricated in Malaysia and shipped to Hong Kong. It finds excellent application in ballasting and protection of valuable cable laid on seabed. ivan@g- and-e.com.

New Product / Application TriAx Geogrid Tensar introduces the concept of soft ground stabilization by confining and interlock granular to initiate lateral restraint using radial stiffness of triaxial geogrid, as opposed to tension membrane where high strength geosynthetics are sought to carry the loading by anchorage and . Extensive performance research has shown that hexagonal aperture confines aggregate better to support and spread heavy load, limiting rutting and differential settlement, prolonging serviceability. With proper engineered design, thickness of aggregate can be reduced to a minimum, site activity becomes more cost effective and efficient. TriAx interlock granular material

TriAx geogrid is developed under this principle. It is ideal for formation of temporary access, haul and working platform. The geogrid can be laid on area with CBR as low as 2. A layer of granular can be spread onto the geogrid to form an immediate stiff formation for construction traffic and load bearing . For more, talk to Steven Lee at [email protected].

TriAx distribute heavy loading instantly Subgrade stabilization and reduction of differential Deckdrain with Woven Geotextile Filter settlement at Cape Town Stadium, South Africa ABG developed Deckdrain in UK 20 years ago. The drainage composite has worldwide recognition since. It has a single cuspated HDPE core and a non-woven geotextile filter bonded to one side, an equivalent of Miradrain, ideal for drainage behind . Deckdrain now comes with a woven geotextile filter which can be used as an engineered drainage layer beneath concrete slabs and in subsurface structure. For info, prices and availability, contact Ivan at [email protected]. Deckdrain Mini Roll Geotextile for Landscaping Geotextile is commonly used as soil and aggregate separation in planter boxes. Bonar used to supply jumbo roll that suits most . Mini rolls Bontec NW 6 UV are now available. This has all the standard filter and drainage characteristics but comes in 2 m width x 25 - 50 m length, weighs 5 – 10 kg. It is ideal for small projects with limited space where manual operation is essential. Some sample rolls are available for trial. Contact Ivan at [email protected]. 2. Mini roll geotextile NW6 September 2019. Issue No.32 G and E Times Technical Note European Union – Falling Rock Protection Kit Certification European Organisation for Technical Approvals (EOTA) published ETAG 027 a guideline for technical approval of falling rockfall protection kits in 2008. The aim was to approve and certify steel barriers according to a common European Union (EU) standard and practice. In July 2018, EOTA issued the European Assessment Document: EAD 340059, a new guideline in assessing falling rock protection kit, replacing ETAG 027.

Under ETAG 027, the certificate issued was European Technical Approval (ETA(Approval)) whereas under the EAD 340059, the certificate refers to European Technical Assessment (ETA(Assessment)). Both documents provide the same testing method and assessment procedure, under which full-scale tests would European Technical Approval have to be done by a qualified conducting body and inspected and certified by a Guideline (ETAG 027) Technical Approval/Assessment Body (TAB) designated by EOTA. The TAB (as listed in EOTA website https://www.eota.eu/en-GB/content/how-to-find-a-tab/55/) are authorized and entrusted to issue the ETAG and EAD certificate.

Notwithstanding this, all flexible barriers tested and certified under ETAG 027 remain valid and comply to EAD 340059 based on the equivalence of full- scale test procedures, method of assessment and verification and of constancy of performance between ETAG 027 and EAD 340059. Current ETAG certificate with a 5 years validity has been converted to EAD certificate which has an unlimited validity. The certificate verifies and ensures the flexible barrier meets the specific performance, based on which, many flexible barriers are specified and approved. The approval procedure is adopted not only within the EU, but worldwide European Assessment including Hong Kong. For more details, call Steven [email protected]. Document (EAD 340059) Opinion Column Sheet Membrane Seaming Proper field seaming is fundamental to the integrity of water tightness when working with sheet membrane. There are several methods.

Method Procedure Conditon Remarks Extrusion welding of HDPE membrane Overlapping No bonding Press by pressure Not relaible into one integral sheet Thermal Melting two opposing surfaces, Surface cleaning & temp Unreliable seam, bonding apply pressure to bond dependent very low strength Chemical Liquid solvent softens surface, Controlled amount of solvent, Uncertain and bonding roll pressure to bond curing, setting ; environment inconsistent seam condition & cleaniless dependent strength Adhesive Dissolved bonding agent, proper Need compatible glue, curing, Durability of bonding tackiness, continuous pressure setting ; environment condition & adhesion, low seam Wedge welding of HDPE membrane to bond cleaniless dependent strenth with double seam Extrusion A ribbon of molten polyolefin is Surface grinding, equipment Form one integral welding extruded over the overlap, melt welding rod needed sheet, seam strength and bond & integrity is ensured Thermal Double track hot wedge melts Equipment limited to straight Reliable with double fusion the surfaces, roll pressure to seam weld, seam quality is welding press the heated surface fully controlled Wedge welding into one integral sheet 3. with air test channel September 2019. Issue No.32 G and E Times Opinion Column (Con’t) While there are merit and drawback with each seaming method, the key is to attend to details, to ensure all overlaps are seamed properly and continuously. Seam quality can be verified by testing during and post installation. Seam integrity can be affected when the seam is subject to consistent straining, movement, environment in contact and deterioration of seam components. Welding to form an integral sheet seems to be the most effective. For Your Information A Word from General Manager G and E has established representation with more than 50 globally renowned manufacturers covering a fully diversified range of geosynthetics. From the early 1990’s, our scope extended from being a distributor / supplier to engineering application, designer and installation contractor. In the last issue, I began our history of introducing geosynthetics into the market here, from 1987 to 2003, our journey continues….

2003 – wetland, MTR West Rail Line, 2000 – 5,000 kJ rockfall barrier, Discovery Bay Kam Tin 2009 – GCL Bentoliner, Route 8 Tsing Yi 2004 – Concrete mat, Shing Mun River 2010 – 1,000 gsm non-woven, Central Wanchai Bypass 2005 – Geogrid reinforced fill slope, NENT Landfill 2011 – Geotextile container, Express Railway Line 2005 – Woven geotextile for silt curtain, debut 2011 – PVC T-keyed lining, Stonecutter Sewage Treatment 2006 – Lining system with vegetation, Kau Sai Chau Plant Golf Course 2011 – Grass Paver, TKO landfill restoration 2007 – Waterproofing lining system, design, supply 2012 – Geogrid reinforced surcharge, Wo Shang Wai and installation, the Venetian, Macau 2012 – Tunnel invert drainage geocomposite, MTR West 2008 – Light weight geotextile slope cover, Anderson Island Line Road Development 2013 – Pre-fabricated band drain, HK-Zhuhai-Macau Bridge 35th Anniversary Recap We stepped into our 36th year in business last June, with enthusiasm, passion and some anxiety. The kick-off dinner was shared with our principals, associates, partners and, of course, our entire devoted company backbone, and some of our earlier staff as . Over sumptuous gourmet and wine, everyone cracked jokes, reminded each others’ past glories, touched off embarrassments and greeted with best wishes. I drew a recap on the pain and joy we have come to this stage from 1984. It is this moment that we hope we will be able to foster a more competent team to look after our clients with commitment and dedication.

Some of our principals from ACE, CeTeau, A happy G and E team A moment of joy and sharing Bonar, Maccaferri, Q. One, Solmax, Tensar Reader’s Response Let us hear from you. Write to us at [email protected]. For back issue, please write to [email protected] or visit our website at www.g-and-e.com. Tell a Colleague - Want your colleague to receive G and E Times also, click here. G and E Company Limited 14th Floor, Kiu Yin Commercial Building, 361-363 Lockhart Road, Wanchai, Hong Kong Tel: 2570 0103 Fax: 2570 0089 e-mail: [email protected] http://www.g-and-e.com

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