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Waterproofing Membranes for Concrete Bridge Decks (2012)

Chapter: APPENDIX A Survey Questionnaire

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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
×
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Suggested Citation:"APPENDIX A Survey Questionnaire ." National Academies of Sciences, Engineering, and Medicine. 2012. Waterproofing Membranes for Concrete Bridge Decks. Washington, DC: The National Academies Press. doi: 10.17226/14654.
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Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

23 a 6% discount rate, hot rubberized asphalt membrane was the cost of retrofit epoxy-coated reinforcement, Iowa system the sixth-lowest-cost strategy. The analysis was based on a overlays, Kansas system overlays, and membrane overlays. service life of 75 years and assumed that the top 40 mm (1.6 She concluded that the membrane overlays, with an average in.) of the asphalt overlay was replaced at 20 and 60 years cost of $0.12/ft2/year of service life based on 1979 dollars, and the membrane and asphalt overlay replaced at 40 years. were the most cost-effective rehabilitation technique. Hearn and Xi (22) evaluated the relative costs of the follow- Liang et al. (23) reported that preformed sheet membranes ing four types of protection of reinforcement in bridge decks: with asphalt overlays have been used in Colorado. Hot rub- berized asphalt membranes and spray-applied liquid mem- · Uncoated reinforcing bars with rigid overlay, branes are less expensive than preformed sheet membranes. · Epoxy-coated reinforcing bars and a concrete surface sealer, In the survey for this synthesis, agencies were asked · Uncoated reinforcing bars protected with a waterproof- to provide unit costs for labor, equipment, and materials ing membrane and bituminous overlay, and for waterproofing membranes systems used on new and · Epoxy-coated reinforcing bars protected with a water- existing bridge decks. The reported data showed a wide proofing membrane and bituminous overlay. variation of costs within each state and between states. In the United States, reported bid prices ranged for $0.56 to The history of 82 bridge decks built between 1969 and $42.80/ft2. In Canada, reported costs ranged from C$1.69 1991 was used to estimate the service life and to generate to C$8.55/ft2. population models of service life. Costs were computed as present value, discounted annualized cost, and annual- ized cost without discount factors. Discount factors rang- REPAIRS ing from 2% to 10% were used. By all present value and annualized cost measures, decks with waterproofing mem- In the survey for this synthesis, agencies were asked if they branes were the least expensive. This conclusion was not had requirements or specifications for repair of membrane sensitive to the value of the discount factor but was influ- systems. Most respondents who answered this question indi- enced in part by the longer service life predicted for bridge cated that they do not repair damaged membranes but would decks with membranes. replace a part or all of the system depending on the sever- ity of the damage. Any damage caused before the asphalt Distlehorst (20 ) provided estimates of relative annual overlay was placed would be repaired per the manufacturer's costs of bridge deck overlays used in Kansas. She compared recommendations.

24 CHAPTER THREE TESTING AND RESEARCH LABORATORY TESTING then exposed to a saturated sodium chloride solution for 28 days. A sample of the concrete directly below the membrane At the request of the New England Transportation Consor- is then obtained from each block and chloride ion concentra- tium, the U.S. Army Cold Regions Research and Engineer- tion determined. The measured chloride ion concentration is ing Laboratory conducted laboratory studies to develop then compared with the background chloride ion concentra- standardized procedures for the evaluation of bridge deck tion of the reference concrete block. membranes (24 ). They reported that although there are ASTM tests to evaluate various engineering properties of tape, rubber, roofing, plastics, and geomembranes, there EVALUATING FIELD INSTALLATIONS is no group of standards or ways to interpret them that all manufacturers follow when reporting performance data Manning (5) described various methods to evaluate water- for their products. The intent of the work was to recom- proofing systems in the field, including visual inspection, mend tests to compare membranes. Six sheet products electrical methods, embedded devices, physical sampling, were tested to measure adhesion, tensile strength and elon- ultrasonic methods, and air permeability methods. These same gation, puncture resistance, and water vapor permeability. techniques still exist today, though many have been improved Liquid membranes were not included in the scope of the through the use of electronics and automation to make them study. Conclusions based on testing and analyses included more practical to use on large areas of bridge decks. the following: One of the challenges of detecting defects is that the defect · A membrane does not have to be perfectly adhered to has to be large enough to be detected using the selected the deck to avoid blistering. method. If the defect is small, it is like looking for a needle · High bond strength matters less than continuity of in a haystack. If the defect is large, it may be detected by bond. visual observation of surface defects such as delaminations · The smallest void size that can originate a blister is or water leakage through the deck. about the size of a quarter. · Elongation rather than strength is a more appropriate Seven agencies responding to the survey reported that property to judge a membrane's ability to span a crack. they had used the following nondestructive test methods to · Puncture resistance is an important property of a good assess the condition of the in-place waterproofing systems: sheet membrane. · ASTM E96 Procedure B (Water Method) is an accept- · Visual inspection, able method to measure water vapor permeability. · Electrical conductivity or electrical resistance, · Ground-penetrating radar (GPR), The authors stated that even though laboratory tests can · Chain drag or hammer sounding, and help rank membranes according to individual properties, · Leak testing. exposure to the complex combination of natural forces is essential for proving a material's durability. Visual Inspection The European Organisation for Technical Approvals has Visual inspection requires observation of the top and bottom a report that describes a method for determining the resis- surfaces of the bridge deck from a relatively close position, tance of liquid-applied bridge deck waterproofing member such as walking on the deck surface. With this method, the to chloride ion penetration following the indentation of the condition of the membrane cannot be directly observed. The membrane by simulated hot asphalt (25). In this method, most direct method would be observation of the deck under- three heated concrete blocks with the membrane applied side after a period of rain to check for wet spots or efflores- are indented at four locations using a heated 8-mm (0.3-in.) cence. Rust stains or spalled concrete may also be evident, diameter truncated cone applied at a specified rate until a but by the time these are visible, active corrosion has been maximum force is applied. The surface of the membrane is ongoing for some time.

25 In Denmark, where more than 85% of the bridge deck (27 ). That synthesis reported that GPR is a noninvasive and area has a bitumen overlay and waterproofing membrane, nondestructive tool that has been used successfully in trans- invasive inspections are sometimes performed on bridge portation structures for applications such as profiling asphalt decks. An area of wearing course and membrane approxi- thickness, detecting air-filled voids, and determining rein- mately 0.8 x 0.8 m (30 x 30 in.) is removed so the condi- forcement spacing and depths in concrete. However, no pub- tion of the structural concrete deck can be inspected (15). A lished papers about the use of GPR to evaluate waterproofing similar procedure is followed in Sweden when deterioration membranes were identified for this synthesis. is observed at the deck surface. Kansas reported on the use of GPR on a bridge with a Visual inspection of the asphalt surface may offer some waterproofing membrane. Based on the results, Kansas indications of the condition of the membrane. Wide cracks, decided to rehabilitate the bridge deck. The deterioration radial crack patterns, wet spots, and gaps at curbs or barriers levels found in the concrete during the rehabilitation work may be signs of potential problems. were much higher than expected, and near full-depth patch- ing was needed throughout most of the deck. The final reha- Electrical Methods bilitation cost was almost as high as the estimated cost for complete deck replacement. Virginia's standard specifications require that the water- proofing effectiveness of the membrane system be deter- Chain Drag and Hammer Soundings mined in accordance with Virginia Test Method T 39. In this test method, the electrical resistance between the top surface Chain drag and hammer soundings are simple techniques of the asphalt and the top mat of reinforcement is determined to detect delaminations in bridge decks. In both methods, using an ohmmeter. The specification requires a minimum the change in sound from dragging chains across a deck or resistance of 500,000 ohms. Areas having a lower resistance striking a local area with a hammer is used to identify areas are to be repaired if determined by the engineer to be detri- of delaminations. The method is labor-intensive and is not mental to the effectiveness of the system. If more than 30% foolproof. of the deck area is determined to be detrimental to the effec- tiveness of the system, the membrane is to be replaced. Leak Testing Washington State has a similar procedure, Test Method Leak testing involves ponding the deck top surface with T 413. The scope of the method indicates that it may be used water and checking underneath for leaks. This method may for either membrane alone or membrane-pavement combina- not be feasible on some bridge decks owing to longitudinal tion. The use of the method has been discontinued because of or transverse slopes. Oregon requires leak testing as soon difficulty in training staff to use it and because membranes as the deck is ready for traffic. No water leakage is allowed. rarely failed the test. Interestingly, McKeel (26 ) commented on Virginia's T 39 method that a great deal of judgment is Missouri reported that it has recently started to do leak necessary to perform the test and it is advisable to use the testing on newly constructed adjacent box beam bridges. In same crew as much as possible. Manning (5) also points out some instances, it has flooded the deck before waterproof- that low resistivity readings are not necessarily associated ing to establish which joints leak or after the membrane and with defects in the membrane but may be the result of mois- asphalt overlay have been placed and prior to bridge open- ture in the surface layers. ing. Missouri reported that the best way to perform the test is during a rainstorm. This approach does not delay the project ASTM D3633, Standard Test Method for Electrical Resis- or impact traffic but is dependent on the weather. tivity of Membrane-Pavement Systems, is similar to Virgin- ia's T 39 method and Washington State's T 413 method and Bond Testing may be used to measure the electrical resistance between the saturated top surface of the system and the reinforcing steel The New Hampshire special provisions for liquid-spray bar- embedded in the concrete. rier membranes requires that the prepared substrate and the completed membrane be tested for adequate tensile bond Ground-Penetrating Radar strength in accordance with ASTM D4541, Standard Test Method for Pull-Off Strength of Coatings Using Portable GPR consists of transmitting pulses of radio frequency Adhesion Testers. At least one test is specified for every 55 energy into the deck and recording the reflected signal. yd2 of deck area, with a minimum of three tests per structure Reflections occur from each interface where there is a or deck construction phase. When the bond strength of the change in the dielectric constant, such as at voids, cracks, substrate is less than 100 psi, the engineer may request addi- or steel reinforcement. The use of GPR for evaluating sub- tional surface preparation. Illinois has a similar specifica- surface conditions was the subject of NCHRP Synthesis 255 tion and specifies a minimum tensile adhesion value of 100

26 psi with failure in the concrete. Testing is performed using stick barrier membranes was discontinued and replaced samples of the membrane before installation of the com- with welded-by-torch and spray-applied liquid membrane plete membrane. Testing of the installed membrane is not systems because of the latter's higher adhesion strengths. specified. Illinois requires and New Hampshire may require According to the survey for this synthesis, NHDOT has holiday testing of the liquid membrane in accordance with used heat-applied barrier membranes on essentially every ASTM D4787, Standard Practice for Continuity Verification bridge deck since 2000. Although spray-applied barrier of Liquid or Sheet Linings Applied to Concrete Substrates. membranes are still permitted, contractors provide the heat-applied systems because of their lower initial cost. The New York State DOT special specification for spray- Various installation methods were also studied, with the applied waterproofing membranes also requires testing of the following conclusions: substrate after the primer has been applied and after the mem- brane has been installed. A minimum adhesion of 1 MPa (145 · Air blast versus abrasive blast surface preparation psi) is specified for portland cement concrete decks. showed no effect on bond. · Rolling versus brooming of preformed membranes New Jersey requires testing of the adhesion between the showed no substantial benefit of either method. primer and the substrate in accordance with ASTM D4541, Standard Test Method for Pull-Off Strength of Coatings Alaska DOT performed field evaluations of selected Using Portable Adhesion Testers, at a frequency of at least bridges to determine whether the waterproofing membrane three tests for areas less than 5,000 ft2 and one test for every was bonded to the concrete bridge deck and the asphalt over- 3,000 ft2 for areas more than 5,000 ft2 and at locations where lay (32). The project was initiated because some of the pre- deficient adhesion is suspected. formed membranes, generally on high-traffic volume roads, had failed to bond adequately to either the asphalt overlay Infrared Thermography or the concrete bridge deck. Five proprietary products were included in the evaluation. Infrared thermography senses the emission of thermal radia- tion and produces a visual image from the thermal signal. It Concrete cores were taken from three bridge decks to has the potential to identify defects in waterproofing mem- inspect for bonding. Bonding between the membrane and branes because it permits large areas to be surveyed in a short the concrete or the asphalt overlay was observed in all but time. Its disadvantage is the requirement for the appropriate one core, although no measurements of bond strength were environmental conditions to achieve the heat flow conditions reported. Separate pull-out tests using similar procedures to to detect the presence of anomalies. Thermography has the ASTM C900, Standard Test Method for Pullout Strength of ability to detect blisters in waterproofing membranes (28), Hardened Concrete, were used to determine the tensile bond delaminations in bridge decks (29), and defects after the strength between the asphalt overlay and the membrane. installation of waterproofing membranes (30 ). Based on the reported loads, the bond stresses ranged from 22 to 112 psi, with higher asphalt temperatures giving higher bond strengths. RECENT RESEARCH One recommendation from the research was to require In 1996 and 1997, the New Hampshire Department of Trans- a 4-in. thickness of pavement over the membrane to allow portation (NHDOT) evaluated various membrane materials, for future pavement surface rehabilitation without damaging primers, and application methods to determine the effects the existing membrane (33). of materials and methods on the adhesion strength of com- mercially available membranes (31). Concrete pads simulat- Research about tack coats for use with asphalt is being ing dry and wet substrates as typically encountered on New performed under NCHRP Project 09-40, "Optimization Hampshire bridge decks were constructed at two locations. of Tack Coat for HMA Placement." The objectives of this The test program included 11 preformed membranes, 5 liquid study are to determine optimum application methods, equip- membranes, and 14 primers in various combinations. The pri- ment type and calibration procedures, application rates, and mary method of evaluating the systems was adhesion testing. asphalt binder materials for the various uses of tack coats and to recommend revisions to relevant AASHTO methods The study findings resulted in a change in NHDOT spec- and practices related to tack coats. Bond tests are expected ifications in 1998. The use of standard preformed peel-and- to be recommended.

27 CHAPTER FOUR CONCLUSIONS AND RESEARCH NEEDS CONCLUSIONS Information obtained from the survey and additional contact with several agencies that have used multiple sys- A waterproofing membrane is defined as a thin imperme- tems revealed little unbiased literature and data about the able membrane that is used in conjunction with a hot-mix performance of different systems. Although there were asphalt wearing surface to protect the deck concrete from reports about products failing to work properly on individ- the penetration of moisture and deicing salts. Most Canadian ual bridges, there does not appear to be a general consensus provinces and many European countries require the use of across North America about the best materials to use. The waterproofing membrane on new bridge decks. In contrast, Canadian provinces, however, appear to have a preference about 60% of the U.S. state agencies use them, with greater for using rubberized asphalt membranes. usage on existing bridge decks than new bridges. Waterproofing systems consisting of either constructed- The number of states and provinces using waterproof- in-place membrane systems or preformed membrane systems ing membranes on concrete bridge decks has not changed are addressed in the AASHTO LRFD Bridge Construc- significantly since NCHRP Synthesis 220 was published in tion Specifications. The individual materials used in both 1995. Most of the states and provinces that did not use them systems are required to conform to various ASTM speci- in 1994 are still not using them today. Reasons these agen- fications. State specifications are similar to the AASHTO cies do not use them include the nonuse of deicing salts, poor specifications, with some states providing more details and performance of membranes in the past, the use of alternative others providing fewer. Three major differences were noted deck protection strategies, and the preference for having an between the U.S. state and Canadian province specifications: exposed concrete deck to observe any deterioration. 1. Canadian specifications generally require the use The survey identified 23 different proprietary products of hot-applied rubberized asphalt, whereas the U.S. that have been used in the past 16 years. Most are still specifications permit other types of membranes. available today. The systems can be classified as preformed sheet systems or liquid systems. Preformed sheet systems 2. Some Canadian specifications required rubber mem- are often rolled into place and bonded to the concrete deck branes or reinforcing fabric over cracks or joints using a pressure-sensitive adhesive on the sheet or through before applying the membrane. the use of heat. Liquid systems are applied either hot or cold using spray equipment or by hand using rollers and 3. Most Canadian specifications require the use of pro- squeegees. Liquid systems may include a layer of reinforc- tection board, whereas U.S. specifications do not. ing fabric. Both systems use a tack coat between the mem- brane and the asphalt overlay to enhance the bond between The survey conducted for this synthesis identified the fol- the materials. lowing findings: Waterproofing membranes are not expected to last longer · Agencies have a broad range of criteria for using mem- than the asphalt wearing surface, including one resurfac- branes, ranging from standard practice to temporary fixes. ing of the asphalt overlay. To achieve this, the initial asphalt · The three primary reasons for selecting a particular thickness has to be sufficient to allow the top surface to be membrane are track record of previous installations, milled without damaging the membrane. The expected ser- cost, and desired service life. vice life of waterproofing membranes is generally 16 to 20 · Approximately 50% of the agencies that use water- years when installed on new bridge decks and anywhere proofing membranes do not have standard details relat- between 6 and 20 years when installed on existing bridge ing to their installation. In many cases, the installation decks. From the information provided in the survey, it could has to conform to the manufacturer's procedures. not be determined whether preformed sheet systems or liq- · Approximately 60% of the agencies that use water- uid systems have a longer service life. proofing membranes on new bridge decks have specifi-

28 cations for the surface preparation. The corresponding · Use a primer to enhance the bond between the con- number for existing bridge decks is 80%. crete deck and the membrane, where required by · The two major products used in conjunction with the specifications or the manufacturer. waterproofing membranes are primers applied to the · Install reinforcing membrane over cold joints and concrete deck and tack coats applied to the membrane cracks. before placing the protective surface layer of asphalt. · Make a complete seal with the curb up to the depth · Although several types of defects have been observed of the asphaltic concrete overlay. with waterproofing systems, the three predominant · Begin placement of preformed membranes on the ones are lack of adhesion between the waterproofing low point of the deck and provide adequate lap membrane and the concrete deck, lack of adhesion between adjacent strips. between the waterproofing membrane and the asphalt · Stagger membrane overlaps in the transverse direction. surface, and moisture penetration through the mem- · Repair any blisters that appear in the membrane brane. All types of defects were more prominent with before the overlay is placed. membranes applied to existing bridge decks than with · Prohibit or minimize traffic on the membrane and membranes applied to new bridge decks. allow only rubber-tired vehicles until the overlay · Unit costs showed a wide range of values for mem- is placed. branes installed on either new or existing bridge decks. · Specify a minimum and maximum time between membrane application and the first layer of overlay The literature review found that only a few articles about placement. research and use of waterproofing membranes have been · Use a tack coat to enhance the bond between the published since NCHRP Synthesis 220 in 1995. In addi- membrane and the overlay. tion, the methods reported in 1994 to evaluate waterproof- ing membrane systems in the field still exist today, but no 4. Quality Control method has emerged as being universally acceptable. · Conduct adhesion bond testing for spray-applied The review of state and provincial specifications identi- membranes. fied the following installation practices for waterproofing · Perform leak testing after the overlay is placed. membranes: No standard tests exist to evaluate the overall perfor- 1. Pre-installation mance of waterproofing membrane systems, no reliable methods exist to assess the quality of the installed systems, · Require a manufacturer's representative to be pres- and no proven techniques exist to determine any deteriora- ent when work is performed. tion of the membrane system during its service life. Conse- · Require that all work be performed by the manu- quently, it is not surprising that agencies with no experience facturer's certified personnel. in installing membranes are reluctant to start using them. On the other hand, agencies with experience believe they 2. Surface Preparation provide a reliable bridge deck protection strategy. · Ensure that the concrete surface is free of protru- Most Canadian provinces and many European and Asian sions and rough edges. countries that utilize waterproofing membranes believe that · Use abrasive blasting to remove all contamination they are essential for the protection of bridge decks. from the deck, including all material from any pre- vious membrane. · Do not use water to clean the deck. FUTURE RESEARCH · Clean surface with brooms, vacuum, or compressed air to remove all loose material before applying the The information collected for this synthesis suggests a need membrane system. to conduct a more in-depth investigation of systems used · Reinforce or repair cracks before placing the in the United States and Canada. This investigation would membrane. include site visits and meetings with owners who have installed membranes successfully and believe in their use as 3. Installation of Waterproofing System a deck protection strategy. It could be conducted as a state pooled fund research project by those states interested in · Specify a minimum deck and/or air temperature enhancing their use of waterproofing membranes. before applying the membrane. · Specify a dry deck and application only in dry Standard test methods should also be developed to evalu- weather. ate the overall performance of proprietary waterproofing

29 membrane systems, assess the quality of installed systems, The waterproofing membrane is only one component of and identify deterioration of the membrane system during its waterproofing systems that may include primers, adhesives, service life. Waterproofing membrane systems could then be protection board, tack coat, and bituminous concrete layers. included in the AASHTO National Transportation Product The performance of the system is determined by the com- Evaluation Program. plex interaction of material factors, design details, and quality of construction. Research is required to define performance A TRB Maintenance Research Master Planning Work- requirements for waterproofing systems, to be followed by shop was held in January 2000 to develop a 3-, 5-, and development of a suite of quantitative prequalification tests 10-year phased master plan of maintenance research needs and quality assurance procedures, the findings to be embod- (Transportation Research Circular E-C022 2000). Before ied in a performance specification. The specification should the meeting, the TRB Highway Maintenance Committees cover the material requirements for the membrane, adhesives, prepared 60 research needs problem statements. The end and protection board (if used), together with requirements for result of the workshop was a series of recommended research installation. The performance specification could also include projects and synthesis topics. TRB Committee A3C15-- provisions for life-cycle costing so that systems that offer Corrosion developed and submitted the following research superior performance can compete on an equitable basis with problem statement to the workshop: systems that have low initial cost but a short service life. Performance Specification for Bridge Deck Water- Objectives: Develop a performance specification for proofing Membrane Systems Problem: Waterproofing bridge deck waterproofing membrane systems based on a membranes can be an effective method of protecting both quantitative definition of performance requirements, objec- the concrete and embedded reinforcement in new and exist- tive prequalification tests, and a life-cycle cost analysis. The ing bridge decks. Except for a few states, membranes are objective is to encourage competition between a wide range used only sporadically in the United States, often to pro- of products and processes, all of which will perform satis- vide only a short extension of service life on existing decks. factorily in the field. NCHRP Synthesis Report 220, Waterproofing Membranes for Concrete Bridge Decks, noted that North American prac- Cost: $350,000. tice has changed little in the past 20 years. The vast majority of membranes installed in the United States are preformed Duration: 36 months. products, and the market is dominated by three products introduced in the 1970s. A 1995 FHWA scanning tour of The statement was not selected by the workshop partici- bridge technology in Europe observed the broad range of pants for the master plan. However, based on the information materials and widespread use of waterproofing systems in provided in this synthesis, the need for a performance specifi- protecting bridge decks in aggressive environments. cation for bridge deck waterproofing systems still exists today.

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 425: Waterproofing Membranes for Concrete Bridge Decks documents information on materials, specification requirements, design details, application methods, system performance, and costs of waterproofing membranes used on new and existing bridge decks since 1995.

The synthesis focuses on North American practices with some information provided about systems used in Europe and Asia.

NCHRP Synthesis 425 is an update to NCHRP Synthesis 220: Waterproofing Membranes for Concrete Bridge Decks that was published in 1995.

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