Highlights. Grace Around the World

Transcription

1 A New Approach to Waterproofing Below Ground Order of Engineers & Architects, Beirut 4 March W. R. Grace & Co

2 Table of Contents Grace Around The World Reference Material Developing a Waterproofing Strategy Grace philosophy & technology New vs old Case Studies Questions W.R. Grace & Co.

3 Grace Around the World Global Headquarters Columbia, MD, USA ME Headquarters Dubai 2 2 Highlights Operations in Over 40 Countries Leading specialty chemical and materials company Founded in 1854 Approximately 6,000 employees with $3bn turnover Global headquarters Key offices Regional headquarters 93 manufacturing sites 44 R&D/Tech Service sites W. R. Grace & Co

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10 Substructure DSC0435 Elevated Decks, Green Roofs Engineered Facade Sloped Roof Structural Concrete Structural Steel Fire Protection W. R. Grace & Co

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12 STRUCTURAL WATERPROOFING Reference Material BS8102: 2009 Code of Practice for Protection of Below Ground Structures against Water from the Ground Provides guidance on methods of dealing with and preventing the entry of water into a structure below ground level. Institution of Civil Engineers (ICE): Reducing the Risk of Leaking Substructure a Clients Guide: 2011 Substructure waterproofing issues and the risks associated with waterproofing for clients Concrete Society (UK) Guide to design of concrete structures in the Arabian Peninsula Specific recommendations for durable design of structures in the most aggressive environment for concrete in the world W. R. Grace & Co.

13 STRUCTURAL WATERPROOFING The Waterproofing Strategy Waterproofing Strategy Design Flow Chart Design Team Clients Requirements Desk Study Risk Assessment Consequences of Failure W. R. Grace & Co.

14 STRUCTURAL WATERPROOFING Consequences of Failure Consequences of Failure Structural deterioration Disputes costs, legal fees Private or public property damage liability Endangerment of building operative or public from damage to electrical equipment Damage to archives, stored goods or plant Loss of rent Reduction in value of property Damage to reputation of landlord/developer Facility, business disruption Lack of access/utility of basement areas Costs of remedial work and operational delays Ref: ICE Clients Guide W. R. Grace & Co.

15 STRUCTURAL WATERPROOFING Design Flow Chart Assess the risks from external environment, then adopt a waterproofing strategy capable of achieving client s requirements Early inclusion of waterproofing specialist Clear understanding of clients requirements and expectations Selection of waterproofing system as part of robust design Initial Information Design Philosophy Design Team Site Evaluation Desk Study Risk Assessment Water table Classification Review of Structure Type (e.g.. New or Existing?) Intended use Foundation form and design Construction Methodology Structural Design Considerations Selection of type A, B or C Waterproofing Protection Is combined Protection Necessary? Has Buildability been considered? Has repairability been addressed? Yes No Solution W. R. Grace & Co.

16 STRUCTURAL WATERPROOFING Design Team A waterproofing specialist should be included as part of the design team so that an integrated waterproofing solution is created. The waterproofing specialist should: Be suitably experienced; Be capable of devising solutions that accommodate various projects constraints and needs; Note: The waterproofing specialist could be the manufacturer or material supplier, provided that the manufacturer/supplier has the relevant expertise BS8102:2009 clause 4.2 Provide the design team with information and guidance that assists with and influences the design, installation and future maintenance of the waterproofed structure W. R. Grace & Co.

17 Why waterproofing is so critical in the Middle East region? Europe and N America Waterproofing = enhance internal space Standards written for temperate conditions Basement waterproofing needs generally dictated by internal environment Internal and integral waterproofing options Worst case scenario = leaking basement, wet feet 17 Middle East Waterproofing = structure performance and durability Most severe ground conditions, temperature extremes Basement waterproofing generally dictated by external environment External positive side waterproofing only option Worst case scenario = structural deterioration, rebar corrosion, reduced service life

18 Root causes of structural deterioration in Middle East conditions Groundwater contains inexhaustible sources of aggressive contamination Climate Increases risks of concrete cracking accelerate ingress Mechanisms of deterioration Bonded high performance waterproofing system Sulfate attack of hardened concrete Chloride induced rebar corrosion Water is the common factor Eliminate water to eliminate the problem

19 Chloride induced rebar corrosion: Methods of contamination ingress Water is wicked into and upward in concrete structures. Dry cool airconditioned interiors and wet exteriors. Airborne salts Exposed concrete: Chemical corrosion inhibitor Ground level Source: Saltwatch.org. Chlorides Sulfates Buried concrete: Positive side High performance membranes - eliminate diffusion and wick action Chloride builds up on concrete surfaces and penetrates by diffusion. Each +10 o C = x2 rate of diffusion. Rebar corrosion is initiated when ~ 1kg/m3 is accumulated at the rebar. 19

20 Concrete Society (UK) Design Guide Clause Durability provisions reinforcement corrosion All structures with design life >30 yrs or all in Extreme exposure classed as Special Additional enhancement techniques will be necessary, e.g. bonded membranes Clause 5.16 Waterproofing/tanking Quotes The membrane should restrict the passage of water between the membrane and the structural concrete. It must be durable under the conditions prevailing and should not permit passage of chlorides and sulfates to the concrete.

21 Waterproofing options Loose laid sheets: PVC, EPDM Requires compartments, no structural bond complex, labour intensive For those serious about waterproofing Installed cost Torch-on Inflexible, partial bonding, embrittles with age Flame hazards, Adhesively bonded sheets High resistance to water migration Cold applied, self sealed laps Mesh bonded sheets No resistance to water migration Difficult to work Increasing Benefits/Performance Grace philosophy: Flexible, Safe, durable systems adhesively bonded to all structural surfaces provides maximum protection. Simple and Fast to Apply.

22 Grace Philosophy Flexible, Safe, durable... Flexible Safe: Durable Essential for crack bridging and ease of installation Composite elastomeric sheets sealed to the structure by self- adhering compounds that will not embrittle with age All Grace products are cold applied to reduce fire risk No hot works, flame hazards or gas bottles All membranes are based on HDPE, the most durable material available...bonded to all structural surfaces... Fully sealed to positive side of slab and walls Prevents water ingress and migration using micro-compartmentalisation...simple, Fast to apply Self sealing laps, no specialist equipment, no compartments,, Single layer, no protection screed below slabs Minimises application risk W. R. Grace & Co

23 Pre-applied Waterproofing Preprufe Membrane System External waterproofing applied prior to installing structural walls or slabs Highly critical because it is inaccessible once structure is complete Traditionally, waterproofing options for these applications were limited to adapting post-applied technologies (e.g. self adhesive, torch on, PVC & EPDM) vulnerable to water migration W. R. Grace & Co

24 W. R. Grace & Co Preprufe video

25 Dealing with water migration Preprufe compared with conventional approach W.R. Grace & Co.

26 Addressing water migration: Conventional wisdom for loose laid - Compartmentalisation Loose laid (PVC, EPDM) sheet systems Adapted for basements from tunnelling (double layer) & roofs PVC now being replaced by TPO Environmental & aging concerns No bond to concrete To limit water migration Compartments are formed (50-200m 2 ) Welded PVC waterstop sections Complex installation, high risk Supplemented with injection hose systems Water ingress can still track over large areas even where effective Exposes large areas of concrete to chlorides and sulfates Relies on 100% workmanship at waterstop joints and edges High risk of transfer across compartments Sourcing leaks difficult

27 Preprufe vs. Conventional waterproofing Preprufe System: Slab detail Typical loose laid compartmented membrane system: Slab detail Source: Sika.com Preprufe system requires no special equipment or protection and avoids multiple layers 27

28 Preprufe vs. Conventional waterproofing Preprufe System: Wall/slab detail Typical loose laid compartmented membrane system: Wall/Slab Detail Source: Sika.com Preprufe system requires no special equipment or protection and avoids multiple layers 28

29 Preprufe vs. Conventional waterproofing Preprufe System: Shoring Wall detail Typical loose laid membrane system with injection: Wall detail Source: Sika.com Preprufe system requires no special equipment or protection and avoids multiple layers 29

30 Typical Preprufe day sequence 1. Wet patch does not delay application No primer 2. Loose laid membrane application - 2 man team -36m2 rolls, typically 500m2 day 3. Self adhesive laps -- no heat, power or equipment 4. No protection layers membrane immediately trafficable Fast, Simple, Secure 6. Bottom rebar quickly provides working platform 5. Rebar follows SAME DAY

31 Membrane Installation Typical Timelines Typical System Installation Sequence: below slab Loose laid PVC system Install 1st Geotextile Lay PVC membrane Weld laps Test laps Install and weld compartmental waterstops Install and weld injection flange per compartment Install 2nd Geotextile Lay concrete concrete layer Cure concrete layer Place rebar Install Injection hoses and access boxes in slab/columns Place concrete slab PVC System: Typically m2/day Grace Preprufe Lay Preprufe Membrane, self seal laps Seal end laps with Tape Place rebar Place concrete slab Preprufe System: Typically 500m2/day Key Waterproofing applicator Concrete Contractor Preprufe installation is quicker, less complex and avoids sequencing conflicts with other trades 31

32 Post Applied Waterproofing for walls Bituthene 8000 Post-applied Membrane Applied after concrete cast Bonded to concrete Just like Preprufe Solar Reflective Significantly reduced heat absorption reduces wrinkles Damage easily visible System Compatibility Laps directly over Preprufe Ancillary Products Bituthene Primer Bituthene Protection Board

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34 Performance testing of Preprufe against water migration Modification of ASTM D 5385 (designed originally to test overlaps) Simulates hole in membrane close to a remote break in the concrete Only barrier to leakage is resistance of adhesve layer to water pressure and the strength of the bond to concrete Control sample without adhesive leaked immediately. Exit Path for Water Hollow tubes Concrete cast in Concrete Hole in Preprufe Water (80m Head) Edges of patch teased to encourage water migration Independent testing conducted by the Istituto Centrale per L Industrializzazionne e la Technologia Edilizia (ICITE), Milan (2001) and supervised by Removed patch

35 Control sample is prepared without adhesive between holes in membrane and concrete Sample leaked immediately Hollow tubes

36 Testing apparatus filled with water Pressurised up to 8 bar Equivalent to 80 metre head of water for 24 hrs Zero leakage with the Preprufe sample Tests both: Bond of concrete to membrane + Membrane itself

37 Grace Systems proven in the field W.R. Grace & Co.

38 Shoring Walls: Diaphragm / Secant Pile All require Pre-applied membrane

39 Piles Termination Detail Bituthene LM (Two part polyurethane liquid membrane)

40 STRUCTURAL WATERPROOFING Detailing Grace Project Support CAD details and design service: membranes and joints Expert technical advice with over 30 years experience in the region Site assistance and training Specification clauses Network of Applicators W. R. Grace & Co.

41 Preprufe Application Manual 60 pages Do s & Don ts Health, Safety & Environmental Issues Installation & Detailing Trouble Shooting Installation Checklist

42 W.R. Grace & Co. Case Studies

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44 STRUCTURAL WATERPROOFING Case Study Haramain Rail Stations, Saudi 4 major stations along 460km High Speed Rail Link between Mecca, Jeddah & King Abdullah Economic City Project Team Foster + Partners, London Buro Happold, London, Bath Dar al Handasah, Beirut, Jeddah Saudi Oger, Jeddah Oger International, Paris Clients requirements & Risk Assessment Mix of Grade 3 and Grade 2 environments High Water table Highly aggressive groundwater containing chlorides, sulfates Waterproofing to be installed in extreme heat and desert conditions W. R. Grace & Co

45 STRUCTURAL WATERPROOFING Case Study Haramain Rail Stations, Saudi Waterproofing Strategy Extreme conditions and client s requirements demand a combined system of protection - All areas: Primary Protection Type A Barrier to provide waterproofing and concrete durability using PREPRUFE pre-applied and BITUTHENE post applied hdpe membranes, fully bonded and detailed to minimise risk and ensure continuity. Grade 3 (habitable) Areas: Additional protection provided by Type C (drained cavity) using HYDRODUCT membrane/cavity formers Key Learning Detailed method statements words and pictures Training of all operatives and supervisors International coordination from design to execution W. R. Grace & Co

46 STRUCTURAL WATERPROOFING Case Study Crossrail Canary Wharf, London One of largest Crossrail stations, 250m long x 30 m box constructed within waters of North Dock Project Team Canary Wharf Contractors Limited Architects: Foster + Partners, Tony Meadows Associates Engineers: Arup Contractor: Expanded Clients requirements & Risk Assessment Four level basement constructed behind cofferdam Primarily Grade 3 environment with very high water table - adjoining Thames and dock basin Intensive programme of works speed of installation essential W. R. Grace & Co

47 STRUCTURAL WATERPROOFING Case Study Crossrail Canary Wharf, London Waterproofing Strategy Risks from permanently high hydrostatic pressure required a combined system of Type A and Type B protection Primary Protection: Fully adhered barrier membrane to provide waterproofing using PREPRUFE pre-applied membrane below slab, fast installation in wet conditions without protective layers combined with Type B (integral protection) crack limited concrete design with SERVITITE pvc and ADCOR injection/active waterstops at joints Key Learning Joints between slab and piled wall injected as a precaution Substructure links with plaza deck waterproofing SILCOR seamless liquid system proposed W. R. Grace & Co

48 STRUCTURAL WATERPROOFING Teamwork Summary Waterproofing in the Middle East is critical for the durability of structures Fully bonded membranes are more effective at preventing water migration than conventional compartmentalistion Grace systems provide bonded, flexible HDPE membranes for fast, safe and secure waterproofing With more than 30 years experience of waterproofing in the Middle East, Grace systems and proven and relied on by industry leaders W. R. Grace & Co

49 STRUCTURAL WATERPROOFING Any Questions? Thank you for your attention & participation Questions W. R. Grace & Co.

50 Contact Information For additional information, please visit or contact Kevin O Gorman EMEAI Leader, Global Projects kevin.ogorman@grace,com W. R. Grace & Co