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A STATE OF THE ART: WORLDWIDE SPECIFICATIONS FOR MEMBRANES AND JOINTS
Stefan Lemke
Sika Services AG
INTRODUCTION
Modern traffic tunnels and shafts are generally protected against mountain waterand water penetrating through rock fissures by a sealing system. The waterproofingsealing systems must be reliably fulfilling their function during the whole service lifeof the tunnel structure of regularly 100 years. Watertightness is directly related tothe durability and serviceability of the concrete lining.
OWNER’S PROJECT REQUIREMENT
e.g. acc. to BS 8102 (UK), Ril 853 (GER), SIA 197 (CH),
STUVA Report (GER)
OWNER’S PROJECT REQUIREMENT
2a Predictable influences 2b Life time prognosis
During construction During service
log𝑎𝑇 =𝑐1𝑅
1
𝑇−
1
𝑇𝑟𝑒𝑓
Life time
OWNER’S PROJECT REQUIREMENT
2a Predictable influences 2b Life time prognosis
During construction During service
log𝑎𝑇 =𝑐1𝑅
1
𝑇−
1
𝑇𝑟𝑒𝑓
Life time
EXAMPLE SPECIFICATION CLAUSE
EXAMPLE MANUFACTURE'S RESPOND
Lifetime of tunnel membranes
Dear Sir or Madam,
Herewith we declare that the expected durability of our product is morethan 120 years under normal conditions when installed from ourauthorised installation company.
Our products are manufactures under extremely strict quality controland assurance management system.
LIFE TIME PROGNOSIS
During service the waterproofing is subjected to chemical, biological and physical influences from the environment, which affects its mechanical properties - and it ages.
The long-term resistance of the waterproofing defines its ability to maintain the required characteristics under exposure to the predictable environmental influences during its service life.
GOAL/CHALLENGE
The challenge for the industry, owners and designers is finally the development of qualification testing and requirements (acceptance criteria) for products to ensure the design life time performance.
Long-term aging behavior is not given per se and has to be explored extensively by suitable tests, which simulate - under accelerated processes -real exposures, loads and degradation mechanisms.
Hereby the understanding of the individual aging processes are crucial beside the long-term experience (references) with these materials to ensure the transfer of the laboratory results and performance to site practice (test calibration) and vice versa.
PREDICTABLE INFLUENCES
Predictable influences include the potential specific material performance reduction factors such as:
o hydrolysis (water attack) and humidity
o temperature effects
o oxidation (break-up of molecular chains due to acid, oxygen or ozone)
o solvation, i.e. change in physical properties due to absorption of liquids
o chemical and microbiological attack
o mechanical stresses/loads (e.g. pressures, tension, fatigue)
o high-energy radiation (e.g. UV light radiation)
These factors obviously also act in synergy.
Specific material groups are affected by these various degradation mechanisms in different ways, which means that the aging processes differ from each other, e.g. concrete vs plastics or PVC vs TPO → different lab-tests for each specific materials groups are necessary.
ARRHENIUS EQUATION
Accelerated aging is testing that uses aggravated conditions of heat, oxygen, sunlight, vibration, etc. to speed up the normal aging processes of items. It is used to help determine the long-term effects of expected levels of stress within a shorter time, usually in a laboratory by controlled standard test methods.
Chemical intuition suggests that the higher the temperature, the faster a given chemical reaction will proceed. Quantitatively this relationship between the rate a reaction precedes and its temperature is determined by the Arrhenius Equation.
ARRHENIUS EQUATION
A historically useful generalization supported by Arrhenius' equation is that, for many common chemical reactions at room temperature, the reaction rate doubles for every 10 degree Celsius increase in temperature.
Polymers are often kept at elevated temperatures, in order to accelerate chemical reaction or breakdown, measured indirectly by changes of material properties.
This indicates that a test temperature of 70˚C will accelerate with a factor of 4-5 the aging behavior in water at 45˚C and with a factor of 40 at 10-15˚C.
BASICS FOR LIFE TIME PROGNOSIS
As with many methodologies, there is also some criticism:
Arrhenius' equation is mostly applicable to elementary thermo-oxidation related processes
Struggle with more complex and superimposed processes as found, for example, for PVC-P based products, where polymer degradation, water incorporation and diffusion processes running parallel
In contradiction to the thermo-oxidation related processes, such diffusion processes are more related to the contact with various media showing the fastest decrease of properties in the first years of application. This initial decrease is followed by an exponential slowdown
Fig.: Change of mechanical properties of aPVC-P roofing membrane over time
BASICS FOR LIFE TIME PROGNOSIS
Ecritical material characteristic
(e.g. tensile strength)
Elimit
lg t(years)
T2 > T1 Life time extrapolationaccording to Arrhenius
Problems/ Discussions:
T2: Higher test temperatures → significant accelerated reaction within a shorter test period
T1: Lower test temperatures → realistic transfer from laboratory test to site-practice within a longer test duration
Consequence → different degradation processes at different temperatures
T1 (temperature)
BASICS FOR LIFE TIME PROGNOSIS
Regarding the long-term effects of water, two processes are combined:
o Some water absorption occurs
o Constituents can leach out (e.g. plasticizers from PVC-P, or stabilisers from polyolefin).
The most important parameter for the aging behaviour in accelerated aging tests in short-term investigations are:
o for PVC-P is the leaching of plasticizer constituents at elevated temperatures. This depends on the specific material compound, the type of plasticisers (e.g. molecular weight and linearity) and its stabilisation system.
o for polyolefin materials is their oxidation resistance. This depends on the specific material compound and its stabilisation system (HALS, HAS, antioxidants, thermo-stabilisation).
BASICS FOR LIFE TIME PROGNOSIS
The Use of Autoclaves to Assess the Oxidation Resistance of Plastics made from Polyolefin according to EN ISO 13438 or ROXI (Neat, Alptransit)
A combination of specific temperature, an increase oxygen pressure and the presence of an aqueous medium allows an acceleration of the auto-oxidation with simultaneous extraction of additives.
ISO 13 438 Method C, 28d80˚C; 50 bar; O2; ph 10; tensile testing
ROXI, 2 years 70˚C; 3 bar O2 ; ph 10; tensile testing
BASICS FOR LIFE TIME PROGNOSIS
change of material characteristics during the aging process
Induction period Degradation
slow oxygen up-takesmall increase in ROOH
← fast oxygen up-take← rapid increase in ROOH (hydroperoxide)← carbonyl built-up← deterioration of physical properties← changes in molecular weight and MW distribution← mechanical failure
time
abrupt change
The process of polymer degradation,especially in view to TPO/FPO/EVA
BASICS FOR LIFE TIME PROGNOSIS
A B C
100
50
A = depletion time of antioxidants
B = induction time to onset of polymerdegradation
C = time to reach 50%degradation of a particular property
aging time (log scale)
property retained (%)
In stage A → prevention of the oxidative polymer (polyolefin) degradation by use of antioxidants (additives, stabilisers, HAS, HALS), along with their own depletion
BASICS FOR LIFE TIME PROGNOSIS
change of material characteristics during the aging process
time
The process of plasticizer migration,especially in view to PVC-P
Degradation
← complex and superimposed processes ← diffusion processes running parallel← polymer degradation is negligible,
based on strong/resistant polymers← leaching/migrating of plasticizer← water incorporation (saponification)← reduction of the flexibility← embrittlement effects← shrinkage effects (change of dimension)
time
BASICS FOR LIFE TIME PROGNOSIS
Finally, all these methods cannot predict an exact lifespan for the tested materials, but they can be used to rank products in their specific application fields.
Correlations with the results obtain during an accelerated test are not precise, but the material whose properties proven to be very poor in the long term showed very poor properties during the accelerated test.
A typical example for such evidence is shown by testing recycled materials in contradiction to virgin (new) materials. This highlights the interest of such a test type → e.g. drainage pipe investigation for the Gotthard Base Tunnel (AlpTransit).
TEST PROGRAMS
Concerning the aging mechanisms of PVC-P and FPO based materials, some information is already available from various evaluation programs.
o NEAT (new railway tunnels through the Swiss Alps) has investigated in a 2, 5 and 10 years research program for the waterproofing systems in view to a permanent temperatures up to 45-50˚C .
Fig.: Gotthard tunnel, Sikaplan PVC Fig.: Gotthard tunnel, Sikaplan/Sarnafil FPO
Section Bodio
Section Erstfeld
TEST PROGRAMS
Concerning the aging mechanisms of PVC-P and FPO based materials, some information is already available from various evaluation programs.
o NEAT (new railway tunnels through the Swiss Alps) has investigated in a 2, 5 and 10 years research program for the waterproofing systems in view to a permanent temperatures up to 45-50˚C .
Fig.: NEAT, Installation Test in an Experimental Gallery
TEST PROGRAMS
Concerning the aging mechanisms of PVC-P and FPO based materials, some information is already available from various evaluation programs.
o NEAT (new railway tunnels through the Swiss Alps) has investigated in a 2, 5 and 10 years research program for the waterproofing systems in view to a permanent temperatures up to 45-50˚C .
Fig. Aged PP and PE products during NEAT test evaluation, insufficient stabilized
TEST PROGRAMS
Concerning the aging mechanisms of PVC-P and FPO based materials, some information is already available from various evaluation programs.
o NEAT (new railway tunnels through the Swiss Alps) has investigated in a 2, 5 and 10 years research program for the waterproofing systems in view to a permanent temperatures up to 45-50˚C .
o BASt (German Federal Highway Research Institute) has investigated in life time prediction of polyolefin, in-situ aged materials (PVC, FPO, ECB) and in new test method for assessing the durability of PVC-P based products .
o Polymer Competence Centre Leoben/Austria (PCCL) GmbH has investigated in life time prediction of polyolefin.
o Muenster University of Applied Sciences (IKFM-Institute of Construction and Functional Material/Germany) has investigated in life time prediction of materials under the consideration of tunnel relevant exposure conditions.
IN-SITU AGED MATERIAL
Tunnel Reussport/ Lucerne/ Switzerland
built 1970, mined construction 600 meters long twin tubes, each with three lanes PVC-P membrane installed 1971 still watertight, 41 years of service life
Tunnel Allmend/ Thun/ Switzerland
part of the A8, bypass of city of Thun built in 1968, cut and cover construction 960 meters long twin tubes, each with two lanes PVC-P membrane installed 1968 still watertight, 44 years service life time
1970, Reussport
IN-SITU AGED MATERIAL
The 41 year old membrane, excavated in 2012 by heavy construction equipment, which caused scratches and holes
membrane was very flexible
single ply membrane made of PVC-P, monomeric plasticizers
contains a glass fleece inlay, roofing membrane (state of the art 1971 for tunnel application)
original thickness 1.5 mm
semi-transparent with a beige colour
IN-SITU AGED MATERIAL
The 44 year old membrane, excavated in 2012
membrane was very flexible
single ply membrane made of PVC-P, monomeric plasticizers
contains a polyester fabric inlay, roofing membrane (state of the art 1968 for tunnel application)
original thickness 1.2 mm
black colour
IN-SITU AGED MATERIAL
Samples were tested at - Institute of Materials Application at the University of Applied Sciences, Cologne, Germany - manufacturer’s R&D centre
Requirements according to the current standards of ZTV-ING/ German road authority, 2007 and SIA 272, 2009
Test program:o Thickness acc. EN 1849-2o Tensile Strength and elongation at break acc. EN ISO 527-3o Impact Resistance acc. EN 12691, Method Ao Folding at Low Temperature acc. EN 495-5o Water Tightness acc. EN 1928o Plasticiser Content acc. Manufacturer's Testo Seam testing acc. ZTV-ING/2007
IN-SITU AGED MATERIAL
Conclusion:
PVC-P waterproofing membranes with 41 and 44 years of real exposure in road tunnels still possess material properties that exceed the requirements for new membranes.
After this long exposure period the aged membranes can securely be joined with new membranes by means of hot air welding.
The above fact and the excellent material properties after 41/44 years of real service life suggest that these membrane properties will fulfil their waterproofing function for many more decades.
This evaluation assumes that these membranes can reach the expected 100 years of service life.
NEW STANDARDS
Austrian ÖBV-Guideline "Tunnel Waterproofing"
The "Principles of tunnel waterproofing execution and inspection" incorporating the knowledge base of the 1980s, were encapsulated in the 1988 road research volume 365, which was issued by the then Federal Ministry of Economic Affairs. The requirements it contained for the substrates and waterproofing materials, together with the relevant inspections, were for many years the basis for the design and execution of tunnel waterproofing, including far beyond Austria’s borders.New knowledge and further technical developments, including those developed with the latest European Standards, provided the impetus in 2007 for the ÖBV Concrete in Tunnelling working group to revisit the subject of tunnel waterproofing.
Now available in English language
NEW STANDARDS
ÖBV-Guideline "Tunnel Waterproofing" covers waterproofing systems for :
Closed (NATM and TBM) and cut-and-cover construction methods for tunnels, with and without water pressure, drained/undrained
Including the requirements for the various components (e.g. substrate, installation (e.g. fixation, welding, flexibility), geotextile, drainage design, quality control, inspection and joint design
Repairs (e.g. grouting, material compatibility) and some specialized construction methods are also described in brief (e.g. spray-applied)
Material specification for a design life time of > 100 years, related on different permanent groundwater temperatures
Environmental and health aspects: REACH (Regulation on Registration, Evaluation, Authorization and Restriction of Chemicals)
SPECIALITIES
→ Spray applied waterproofing→ Cross-passage waterproofing
Spray-/liquid appliedmembrane
Loose-laid plastic sheetmembrane, PVC
Loose-laid plastic sheetmembrane, LLDPE/VLDPE
SPRAY-APPLIED MEMBRANES
APPLICATION FIELDS OF SPRAY-APPLIED MEMBRANES
01. Feb. 2015
1 Soil/rockShotcrete, primary liningGeotextile/Drainage Sheet waterproofing, loose-laidCast-in-place concrete, permanent lining
2
3
4
5
6 Spray-applied waterproofingwith double side adhesionShotcrete (or cast-in-place),permanent lining
7
Conventional
double-shell lining
2
3
4
5
1
1
2
6
7
Composite shell lining with
spray-applied membrane
DESIGN ASPECTS/ SPRAY-APPLIED
Sliding surface, prevention of the
transfer of shear stresses
Minimize potential shrinkage cracks in
the inner concrete shell
Improvement of the impermeability of
the inner shell by providing redundancy
Full surface bond → transfer of shear
stresses
Potential shrinkage cracks in the
inner concrete shell
Delamination → water pathes on both
sides of the waterproofing layer
DESIGN ASPECTS/ SPRAY-APPLIED
Conventional
double-shell lining
2
3
4
5
1
1
2
6
7
Composite shell lining with
spray-applied membrane
DESIGN ASPECTS/ SPRAY-APPLIED
1 Soil/rockShotcrete, primary liningGeotextile/ Drainage Sheet waterproofing, loose-laidCast-in-place concrete, permanent lining
2
3
4
5
6 Spray-applied waterproofingShotcrete (or cast-in-place),permanent lining
7
Advantage in comparison to the conventional double shell lining with sheet waterproofing:
Direct application of sprayed concrete onto waterproofing units
Elimination of costly formwork operations
If a fibre-reinforced sprayed concrete is used, additional savings on reinforcement works
Application fields: Short tunnel lengthsComplex geometries
Double-shell lining withspray-applied membranes
1 Soil/rockShotcrete, primary liningGeotextile/ Drainage Sheet waterproofing, loose-laidCast-in-place concrete, permanent lining
2
3
4
5
6 Spray-applied waterproofingShotcrete (or cast-in-place),permanent lining
7
Double-shell lining withspray-applied membranes
Disadvantage in comparison to the conventional double shell lining with sheet waterproofing:
The whole system has to be designed to withstand water pressure → increase of the design thickness, reinforcement and need of rounded geometry
By definition unsuitable for drained tunnels
Additional drainage methods , e.g. dimple sheets, will effect the bonding and finally the monolithic behaviour of the whole structure
DESIGN ASPECTS/ SPRAY-APPLIED
A waterproofing system has the key function of:
Protecting the tunnel construction against the unintentional entry of water, as well as the danger posed by aggressive water or soils and the effects of chemicals.
Both functions for a service life time of over 100 years.
The real Achilles heel of composite shell linings remains the position of the waterproofing layer, which is more or less in the center of the lining.
The permanent bond of the spray-applied membrane to the substrate is system-relevant. Hereby the substrate itself is relevant and has to be dry.
Permanent
protected
Permanent contact
with fluids and soil
H2O
Cl-
SO42
Mg2+
Exposure
classes acc.
to EN 206
DESIGN ASPECTS/ SPRAY-APPLIED
DESIGN FLOW CHART/ SPRAY-APPLIED
STANDARDS
1-shell 1-shell 1-shell 2-shell
Emergency escape tunnel (X) X X ̶
Air ventilation channel (X) X X ̶
Cross passages ̶ ̶ (X) X
Enlargements (above
intermediate-ceiling level)̶ ̶ ̶ X
Cavern (above inter-
mediate-ceiling level)̶ ̶ ̶ X
Portals ̶ ̶ ̶ ̶
Main tunnel/tube ̶ ̶ ̶ ̶
2. layer
shotcrete,
reinforced
2. layer
shotcrete,
fiber rein-
forced
2. layer cast-in-
place concrete,
fiber reinforced
2. layer
shotcrete,
bar-/steel fiber
reinforced
waterproofing
X recommended (X) restrictive recommended ̶ not recommended
Recommended application fields for permanent shotcrete (BAST/ GER, 2004)
Application field
SIA 272 (Swiss)/ 2009
•Open pits
•Cut&cover
•Galeries
Mined
tunnel
Pit&
Ponds
Water
canals
Swimming
-pools
Water
reservoires
Sewage
plants
Upcom-
ming
humidity
according standard
SIA 270, table 3
B1.1
B1.2
B2 B3 B4 B5 B6 B7 E
Watertightness class of
the whole structure
1 or 2 1 or 2 2 or 3 2 or 3 1 or 2 2 2 1
rigid
3.1 watetight concrete
3.2 watertight mortar
3.3 fluid asphalt
x
x
x
x
x
x
x
x
x
x
x
x
x
x
flexible
3.4 polymer-bitumen
3.5 plastic sheet membrane
3.6 bentonite layer
3.7 liquid applied membrane
3.8 polymer- mod. bituminouse
coatings
x
x
x
x
x
x1
x
x1
x
x
x
x
x
x
x
x x
x
x
1 lower-ranked (subordinated) application fields (e.g. emergency escape tunnel) X recommended
STANDARDS
STANDARDS
Ril 853/ 2011 – GER, watertightness class 1 (absolutely dry) only via sheet waterproofing system incl. redundancy
STANDARDS
Primary layer/ shotcrete
Preliminary waterproofing and a polymer modified, accelerated waterproofing gunite
Inner liner/ shotcrete or
polymer modified shotcrete
For example: emergency access tunnel acc. ZTV-ING part 5 (2)/ GER,
reduced (lower) watertightness class, now class 3, single shell, polymyer
modified shotcrete with steel fibers (Friebel et al. 2013)
Friebel et al. 2013
BONDING STRENGTH/ SPRAY-APPLIED
Comparison of long term bond test – all available spray-applied products, Crossrail
Typical manufacturer’s bond test data: 1.2+/- 0.2MPa
1.5MPa “Greater than the cohesive strength of the concrete”
Long term behaviour in contact with water ?
Source: M. King/Hagerbach-Sargans 2015
MATERIALS/ SPRAY-APPLIED
The material characteristics vary considerably according to their specific material composition (e.g. water: powder ratio) and layer thickness
Environmental conditions have a significant influence on the product curing behavior and finally on the material characteristics and durability
The layer thickness itself has an influence on the curing performance
Plastics or plastic hybrids generally “creep” under permanent load
Water absorption has a significant influence on the material characteristics, e.g. bonding strength (reduces ≈ 70%), cohesion or tensile strength
The properties based on laboratory testing/sampling (e.g. hand mixed and molded into sheet samples) will vary when applied on a construction site where conditions are not similar
SUBSTRATE/ SPRAY-APPLIED
The success of sprayed waterproofing systems is closely linked with the condition of the substrate
Surface roughness can result in excess material consumption, application time and cost
Pre-sealing, drainage measures, water management methods, regulating layer or water-stopping mortars and remedial grouting may be required
If the substrate is presumed to be ‘water saturated’ in the long term → the waterproofing is fully exposed to hydrolytic attack
If the substrate is not permanent, the bond is not either
SUBSTRATE/ SPRAY-APPLIED
The regulating/smoothening/levelling layer is used, a typical thickness of 3 cm
Maximum aggregate size of 4 mm, surface texture must be closed
Application technique: dry-spray or towel applied
The bond has to be of the same quality and characteristic as needed for the spray-applied membrane
The regulating layer is one of the cost-driver
Surface pollution has a negative impact
Finally, the substrate for spray-applied water-proofing has to be in a much better condition/ quality than for sheet waterproofing
REFERENCE/ SPRAY-APPLIED
total 400mm as primary, no steel bar reinforcement
Project: Crossrail C510, Liverpool Street, Whitechapel
Partly in London clay (dry ground conditions)
Sealing layer SFRC: 75mm
Primary lining 1 SFRC: 225mm
Primary lining 2 SFRC: 100mm
Regulating layer: nominal approx. 35mm (would be more in practice to cover the fibres)
Spray-applied waterproofing in 2-3 layers , each min 2mm (= total 4-6mm).
Secondary lining SFRC in 2 layers 250mm + 150mm
Designed as a double shell lining
Fire proofing layer (in addition to the steel fibers, PP fibres ): 50mm
Finally → wet primary lining, the invert was sealed via sheet waterproofing
REFERENCE/ SPRAY-APPLIED
Fig.: Spray-applied water-proofing, above axis, UK 2014
Fig.: Loose-laid waterproofing, below axis, UK 2014
CONCLUSION/ SPRAY-APPLIED
The use of site-produced spray-applied waterproofing system, with all of their necessary components, is much more complex to handle than promoted
It is also impossible to establish a realistic cost and time saving when compared with a loose-laid sheet membrane system, and especially when considered as a whole, with identical waterproofing requirements, quality aspects and risk assessments
Composite systems with an integrated spray-applied water-proofing system generally remain an idealistic approach, as there are still far too many unknowns, risks and unanswered questions, especially in view of a structural element
From practical experience and references - it is recommended for a max water head of 5 m and for a lower-ranked watertightness class
CHALLENGES/ CROSS-PASSAGES
Finnetunnel/ Germany
Uneven surfaces (e.g. shotcrete)
Damp/ wet surfaces
Ground freezing treatment
Expansion/ dilatation joints between segmental lining and cross-passages
Finnetunnel/ Germany
CHALLENGES/ CROSS-PASSAGES
Cut of a segment jointwith EPDM gasket
Ground settlements
Offsets between segments of approx. < 1.5 cm (tolerance)
Location of the gaskets/ grooves
3-dimensional water paths
Grease/dirt inside the joints
POSSIBLE SOLUTION FOR TERMINATION
B → Adhesive Strip/Tape
Acc. to SIA 272/2009 (Swiss Standard)
Acc. to ÖBV tunnel waterproofing/2012 (Austrian Guideline)
Acc. to Tunnelling Manual 2014 (DGGT/Germany))
A → Mechanical Clamping
Acc. to DIN 18195-part 9
(German Standard)
Acc. to Tunnelling Manual 2014 (DGGT/Germany)
There must be a minimum of unevenness in the mortar bed
Any offsets in the segment joints may require a mortar bed thickness of up to 3cm
The mortar bed is complex to construct and has to be drilled into for the anchors
The mortar levelling layer must be load bearing, sound, watertight and free from cracks, voids, defects and burrs and unevenness
Mortar levelling layer
Offset and mechanical clamping ?
A → MECHANICAL CLAMPING/ DETAILS
(1) Watertight concrete structure (e.g. segments)
(2) Mortar/Grout as levelling layer
(3) Substrate (e.g. shotcrete)
(4) Mortar chamfer/groove
(5) Protection geotexile
10
10
11
(6) EPDM/neopren gasket/ rubber seal
(7) Plastic waterproofing sheet membrane
(8) Loose-flange/external mechanical clamping
(9) Anchor/bolt
(10) Hydrophilic waterstop
(11) Injection hose
8
Schlüchterner Tunnel/ Germany
A → MECHANICAL CLAMPING/ DETAILS
Adhesive Tape/Strip
Concrete structure
Epoxy resin
B → ADHESIVE STRIP/TAPE
Finnetunnel/ Germany
In-situ applied bonded (adhesive) strip/tape
External termination, flexible solution
Epoxy resin levels all offsets and unevenness
Thermal-welding of waterproofing membrane with the adhesive tape/strip
Limitation: Concrete tensile strength, requirement of resin application
B → BONDED STRIP TERMINATION
Segments
Gasket profile
Water path injected with
PU-injection resinReinforced (e.g. glass fiber fabric)
inside the epoxy resin
Epoxy resin
Waterproofing membrane
Epoxy resin as
adhesive for the strip/tape
Adhesive tape/strip
Gap between segments <
1.5 cm (tolerance)
A-A
DESIGN ASPECTS FOR A & B
Table: Comparison between clamped and bonded connection systems according to Tunnelling Manual 2014/ DGGT (Germany).
Criteria Clamped type Bonded type
Effect on the excavation geometry High workspace requirement Low workspace requirement
Substrate requirements 1) No difference No difference
Surface characteristics requirements
High Low
Required assembly steps Medium Low
Time required for installation High Low2)
Inspection demands High Low
Susceptibility to defects High Medium
Effectiveness Medium High
Cost High Low
1) e.g. evenness criteria 2) carried out crosswise parallel to the waterproofing works
BONDED STRIP VS MECHANICAL CLAMPING
MATERIAL CHARACTERISTICS
A close fit to the shotcrete substrate and small radiuses require a multi-axial elongation of the waterproofing material, a high flexibility and an excellent workability.
Joints and cracks are always bi-axial
Bi-(multi) axial behaviour/ burst strength (EN 14151, Ø 1m: > 50%)
E1-2 modulus (material flexibility) acc. ISO 527 < 65 N/mm2 (ÖBV/ 2012 AT)
Workability/welding behaviour/testing acc. DVS 2225-part 5 (tunnelling)
Waterproofing incl. thermal-welded seam during
bi-axial-behaviour
Thermal welded seam
REFERENCESADHESIVE STRIP
Project: Finnetunnel/ Germany(Part of NBS Erfurt – Halle/Leipzig)
Client: Deutsche Bundesbahn (DB Netz AG)
Contractor: JV Wyss & Freytag, Max Bögl, Porr
Tunnel Lining Installer: I.A.T Gmbh
Construction period: 2010-2011
Construction:Rail tunnel, twin tubes of each 6.8 km, TBM driven, with pre-cast-concrete-elements, water pressure of 6.5 bar, environ-mental sensitive area, watertightness class two. Cross-passages: NATM, shotcrete, loose-laid FPO-membrane acc.RIL 853, cast-in-place concrete, watertightness class one“completely dry”. Connection detail between segment andcross-passage waterproofing via bonded termination, epoxyresin and hot-air welding.
3 mm, FPO waterproofing sheet membrane
FPO Waterbar AF-600/34
FPO Protection Sheet, 4 mm
FPO Adhesive Tape, 200 mm width, 2 mm thickness
Epoxy resin (SD 31)Source: Bonded strip termination, RETC 2015
…as a water barrier systembetween shotcrete and
sheet membrane
…as a water barriersystem for cut & coverstructures (roof area)
…as a connection detail, e.g. for pre-cast-concrete
elements
Weinbergtunnel/ Switzerland Bypass Bazenheid / Switzerland Gotthard/ Switzerland
ADDITIONAL APPLICATION FIELDS
WATERPROOFING OF TBM DRIVEN TUNNELS
Project: Islisbergtunnel / Switzerland(Part of West-bypass Zurich)
Client: Baudirektion Kanton Zürich
Designer: Pöyry Infra AG
Contractor: Marti AG
Tunnel Lining Installer: Renesco AG
Construction period: 2005-2007
Construction:Road tunnel, twin tubes of each 4.7 km, TBM driven, double shell method with pre-cast-concrete-elements (tubbing), loose-laid plastic sheet membrane, umbrella seal, 15 cm cast-in-place concrete lining. Horizontal Ventilation Shaft: In-situ-concrete with SCC technology.
Sealing system:Hot-Melt Technology, PVC-P membrane acc. SIA-V280 (Swiss standard) backed with a 500 g/sqm PP geotextile
2 mm, PVC-P waterproofing sheet membrane with 500g/sqm
PP geotextile laminated acc. SIA V 280 (fire behaviour class
V.2)
GeoComposite strips for drainage: Tundrain Typ A
SHAFT WATERPROOFING
Project: STEP Pumping station / Abu Dhabi
Client: Abu Dhabi Sewerage Services
Designer: Mott MacDonald/ Halcrow-CH2M Hill
Contractor: Odebrecht (Design and Build)
Tunnel Lining Installer: Tashareeq
Waterproofing Supervisor: Renesco AG
Construction period: 2014
Construction:Sewerage tunnel, shaft, water pressure of 100 m, double shell method with shotcrete, 1000 g/sqm geotextile and 3 mm PVC-P membrane incl. compartment system (redundancy) and water-bars acc. ÖBV (Austrian standard). Connection between shaft waterproofing and sewerage tunnel via adhesive tape/ strip.
3 mm, PVC-P waterproofing sheet membrane acc. ÖBV
Waterbars 400/30/6 inject
Protection geotextile 900 g/ sqm
Adhesive tape/ strip, SD 31 epoxy resin
Acrylate injection resin, injection hoses
TENT WATERPROOFING
Project: Norrströmtunnel/ Sweden(Stockholm City Line)
Client/Owner: Swedish Transport Administration
Designer: WSP
Contractor: NCC Sverige AB
Waterproofing applicator: Renesco a.s.
Construction period: 2012-2013
Construction:Stockholm City Line is a 6 km long commuter train tunnel runningbetween Tomteboda and Stockholm South, with two new stations atOdenplan and T-Centralen, wherein the Norrström’s contract extendbetween Riddarholmen and Gamla Brogatan. The requirements forwaterproofing and construction were according to BV Tunnel. Theconstruction (inner tunnel) consists of a membrane behind a meshreinforced shotcrete (90mm) suspended from the anchor bolts,building a tent inside the shotcrete supported rock-structure.
1.5 mm thick LLDPE incl. signal layer and roughed surface
Swelling profile, FPO Waterbars
Sigunit, S-MonoTop-910N
S-Quick 506 FG, Flexodrain system
WATERPROOFINGUNDER HIGH PRESSURE
Project: Hallandsås/ Sweden
Client: Trafikverke (Swedish Transport Administration)
Contractor: Skanska-Vinci
Tunnel lining applicator/installer: Renesco AG
Construction period : 1992-1997, 2004-2014
Construction:Rail tunnel, twin tubes a 8.7km, 19 cross sections, waterpressure of 15 bar. 1992-1997: pre-sealing by grouting, NATMincl. shotcrete, 1st concrete liner (cast-in-place), loose-laid FPOwaterproofing membrane, compartments via waterstops,injection system, 2nd liner of cast-in-place concrete. 2004-2014:TBM driven incl. pre-cast-concrete elements (approx.65% of thetotal tunnel). Cross-passages: NATM, shotcrete, loose-laidplastic sheet membrane, FPO acc. ZTV-ING/Ril853, cast-in-place concrete, adhesive tape to connect the segments with thewaterproofing membrane. Environmentally sensitive (water,chemicals and ecology).
3 mm, FPO waterproofing sheet membrane
FPO Waterbar AF-600/34
FPO Protection Sheet, 2.5 mm, embossed surface
FPO Adhesive Tape, 200 mm width, 2 mm thickness
Stefan Lemke
Sika Services AG
Tueffenwies 16, 8048 Zurich/Switzerland
Telephone: +41 58 436 78 80
Website: www.sika.com
THANKS