644Soil Nail Retaining Walls

644.01.01 General. This work consists of constructing soil nail retaining walls. Perform soil nail construction

concurrently with pneumatically placed concrete mortar as specified in Section 660.

644.01.02 Qualif ications . Prepare a project reference list verifying the successful construction completion of

at least 4 permanent soil nail retaining wall projects during the past 2 years totaling at least 1,000 m2 (1,200 yd2) of wall face area and at least 500 permanent soil nails. Include a brief description of each project with the Owner's name and current phone number. Provide a Nevada Registered Professional Engineer, employed by the soil nailing Contractor and having experience in the construction of permanent soil nail retaining walls on at least 4 completed projects over the past 2 years, to supervise the work. Consultants or manufacturer's representatives will not be allowed to satisfy the aforementioned requirement. Use an on- site supervisor and drill rig operators having experience installing permanent soil nails on at least 4 projects over the past 2 years. Prepare a personnel qualifications list containing a summary of each individual’s experience and the respective projects.

644.01.03 Submit tals. Submit 5 copies of the following information for review and approval at least 30 days

prior to beginning wall construction:

644.02.01 General. Materials shall conform to the following Sections and Subsections:

Water ................................ ................................ ....................................................................................................................... Section 722 Grout and Mortar Aggregate .................................................................................................................................... Subse ction 706.03.04 Portland Cement ...................................................................................................................................................................... Section 701 Concrete Curing Materials a nd Admixtures ................................ .............................................................................................. Section 702 Soil nail bars shall be s olid bars and shall conform to ASTM A 706 or ASTM A615, Grade 420 (60) or 520 (75), or ASTM A722 Grade 1035 (150). Furnish deformed bars that are continuous without splices or welds. Bars shall be encapsulated when shown on the plans. Thread bars a minimum of 150 mm (6 in.) on the wall anchorage end to allow proper attachment of bearing plate and nut. Threading may be continuous spiral deformed ribbing provided by the bar deformations or may be cut into a reinforcing bar. If threads are cut into a reinforcing bar, provide the next larger bar number designation from that shown. Encapsulation shall be a minimum 1 mm (0.04 in.) thick corrugated HDPE tu be conforming to AASHTO M252 or corrugated PVC tube conforming to ASTM D1784, Class 13464- B. Encapsulation shall provide at least 5 mm (0.20 in.) of grout cover over the nail bar and be resistant to ultra violet light degradation, normal handling stresses, and grouting pressures. Centralizers shall be manufactured from Schedule 40 PVC pipe or tube, steel, or other material not detrimental to the nail steel. Wood centralizers will not be allowed. Securely attach centralizers to the nail bar. Size centraliz ers to position the nail bar within 25 mm (1 in.) of the center of the drillhole, allow tremie pipe insertion to the bottom of the drillhole, and allow grout to freely flow up the drillhole. Grout shall be neat cement or aggregate/cement mixture with a mi nimum 3 day compressive strength of 10.5 MPa (1,500 psi) and a minimum 28 day compressive strength of 21 MPa (3,000 psi) . Perform compressive strength testing according to AASHTO T106/ASTM C109. Admixtures which control bleed, improve flowability, reduce water content, and retard set may be used in the grout subject to review and approval. Accelerators will not be permitted. Expansive admixtures may only be used in grout used for filling sealed encapsulations. Use admixtures which are compatible with the grout. Mix according to the manufacturer’s recommendations. CONSTRUCTION

644.03.01 General. Build soil nail walls from the top down in existing ground. Soil nailing includes excavating

in accordance with the staged lifts shown in the plans or approved submittals , drilling soil nail drillholes to the specified minimum length and orientation, placing and grouting the encapsulated nail bar tendons into the drillholes , attaching bearing plates and nuts, and performing nail testing. The placing of drainage el ements , shotcrete reinforcement , and shotcrete facing as provided for in Section 660 shall be performed concurrently with the work specified herein. A mandatory pre- construction meeting will be scheduled and held prior to the start of wall construction. The Contractor, Engineer, and all personnel responsible for supervising work related to surveying, excavation, installing soil nails, grouting, testing, and shotcreting shall attend the meeting. The pre- construction meeting will be conducted to clarify the construction requirements for the work, to coordinate the construction schedule and activities, and to identify contractual relationships and delineation of responsibilities amongst the Contractor and the various Subcontractors, particularly those pertaini ng to wall excavation, nail installation and testing, excavation and wall alignment survey contr ol, and shotcrete construction. SOIL NAIL RETAINING WALLS 644

644.03.02 Construction Site Survey . Field locate and verify the location of all utilities prior to starting the

work. Maintain uninterrupted service for those utilities designated to remain in service throughout the work. Give notification of any utility locations different from that shown that may require nail relocations or wall design modification. Prior to start of any wall co nstruction activity, inspect the site to observe and document the pre- construction condition of the site, existing structures, and facilities. During construction, observe the conditions above the soil nail wall on a daily basis for signs of ground movement in the vicinity of the wall. Immediately give notification if signs of movements such as new cracks in structures, increased size of old cracks, or separation of joints in structures, foundations, streets, or paved and unpaved surfaces are observed.

644.03.03 Control of Water. Provide positive control and discharge of all surface water that will affect

construction of the soil nail retaining wall. Maintain all pipes or conduits used to control surface water and repair damage caused by surface water during construction. Upon substantial completion of the wall, remove surface water control pipes or conduits from the site. If approved, pipes or conduits may be left in place, provided they are fully grouted and abandoned or left in a way that protects the structure and all adjacent facilities from migration of fines through the pipe or conduit and potential ground loss. Localized areas of perched water or seepage may be encountered during excavation. See the geotechnical report for regional groundwater table. Immediately give notification if unanticipated existing subsurface drainage structures are discovered during excavation. Suspend work in these areas until remedial measures, as approved, are implemented. Capture surface water runoff flows independentl y of the wall drainage network and convey them as directed.

644.03.04 Excavation. Coordinate the work and the excavation so the wall is safely constructed. Perform the

wall construction and excavation sequence as shown and according to the approved submittals. Do not excavate above or below the soil nail wall steeper than specified herein or shown on the plans without written approval. Provide survey reference and control points at or offset along the top of wall alignment at approximate 10 m (30 ft ) intervals prior to starting wall excavation. Be responsible for providing the necessary survey and alignment control during excavation of each lift, locating and drilling each drillhole within the allowable tolerances, and for performing the wall excavat ion and nail installation in a manner which will allow for constructing the shotcrete construction facing to the specified minimum thickness and such that the finish cast -in-place structural facing can be constructed to the specified minimum thickness and to the line and grade as indicated. Where the completed location of the front face of the shotcrete exceeds the allowable tolerance from the wall control line as shown, submit procedure to provide proper attachment of nail head bearing plate connections and satisfactory placement of the final facing for review and approval. Complete excavation and grading above and behind the wall before commencing wall excavation. Do not over-excavate the original ground behind the wall or at the ends of the wall, beyond the limits shown. Do not perform excavation that will affect the soil nail wall until wall construction starts. Coordinate roadway excavation with the soil nailing work. Perform excavation from the top down in a horizontal staged excavation lift sequence with the ground level for each lift excavated no more than mid- height between adjacent nail rows or the short -term stand- up height of the ground, whichever is less. Do not excavate the full wall height to the final wall alignment. Maintain a working bench of native material to serve as a platform for the drilling equipment. Construct the bench wide enough to provide a safe working area for the drill equipment and workers. Excavate to the final wall face using procedures that: prevent over excavation; preve nt ground loss, swelling, air slaking, or loosening; prevent loss of support for completed portions of the wall; prevent loss of soil moisture at the face; and prevent ground freezing. Complete excavation to the final wall excavation line and apply shotcrete in the same work shift, unless otherwise approved. Application of the shotcrete may be delayed up to 24 hours if the delays will not adversely affect the excavation face stability. During each excavation lift, nails may be drilled and installed through a temporary stabilizing berm. Do not excavate the stabilizing berm until the nail grout has aged for at least 24 hours. Excavate the temporary stabilizing berm to the final wall face excavation line and clean the final excavation face of all loose materials, mud, rebound, and other foreign matter which could prevent or reduce shotcrete bond. Ensure that installed nails and corrosion protection are not damaged during excavation of the stabilizing berm. Repair or replace nails or corrosion protection damaged or disturbed during excavation of the stabilizing berm, as approved. 644 SOIL NAIL RETAINING WALLS Remove hardened nail grout protruding more than 50 mm (2 in.) from the final wall excavation line in a manner that prevents fracturing the grout at the nail head. Sledge hammer removal of the grout will not be allowed. The use of hand held rock chippers will be acceptable provided their use does not damage or disturb the remaining grout at the nail head, the nail bar, or corrosion protection. Submit alternative excavation and soil nail installation methods that meet these objectives for review and approval. Do not excavate the next lift until nail installation, shotcrete placement, attachment of bearing plates and nuts, and nail testing has been completed and accepted in the current lift. Cure nail grout and shotcrete for at least 72 hours or until they have attained at least their specified 3 day compressive strength before excavating the following underlying lift. Excavation of the following lift in less than 72 hours will only be allowed if submitted compressive strength test results, for tests performed by a qualified independent testing lab, verify that the nail grout and shotcrete mixes being used will provide the specified 3 day compressive strengths in the lesser time. Give notific ation immediately if raveling or local instability of the final wall face excavation occurs. Temporarily stabilize unstable areas by means of buttressing the exposed face with an earth berm or other methods. Suspend work in unstable areas until remedial measures are developed. If sections of the wall are to be constructed at different times, prevent sloughing or failure of the temporary slopes a t the end of each wall section. Remove all or portions of cobbles, boulders, rubble, or other subsurface obstruc tions encountered at the wall final excavation face which protrude into the shotcrete facing. Determine the method of removal of face protrusions, including method to safely secure remnant pieces left behind the excavation face and for promptly backfilling voids resulting from removal of protrusions extending behind the excavation face. Backfill voids, overbreak, or over -excavation beyond the plan wall excavation line resulting from the removal of face protru sions or excavation operations.

644.03.05 Drilli ng. Determine the final drillhole diameters required to develop the specified pullout resistance

and to also provide a minimum 25 mm (1 in.) grout cover over bare bars or minimum 13 mm (1/2 in.) grout cover over the encapsulation of encapsulated nails. A minimum drillhole diameter will be shown on the plans. Do not begin drilling or installation of production nails in any soil/rock unit until successful pre- production verification testing of nails is completed in that unit. Install the production soil nails before the application of the reinforced shotcrete facing. The shotcrete facing may be placed before drilling and installing the nails subject to written approval. Provide a blockout through the shotcrete facing at drillho le locations using PVC pipe or other suitable material to prevent damage to the facing during drilling. As part of the required construction submittals, provide structural design calculations demonstrating that the facing structural capacity will not be reduced and that the bearing plates are adequate to span the nail drillhole blockout. If required, furnish larger size bearing plates and/or additional reinforcement beyond that detailed. Select drilling equipment and methods suitable for the ground conditi ons. If encountered, engineered fill may be non- cohesive and require casing during drilling operations. Cobbles and/or boulders may be encountered in the engineered fill. Use of drilling muds such as bentonite slurry to assist in drill cutting removal will not be allowed. Air may be used to assist in drill cutting removal. If caving ground is encountered, use cased drilling methods to support the sides of the drillholes. Remove casings prior to, or during, the grouting operation. When drilling through rock, cobbles, boulders, or obstructions, use percussion or other suitable drilling equipment capable of drilling and maintaining stable drillholes through such materials. Clean holes to remove material resulting from the drilling operations and any other material that would impair the strength of the soil nails or test soil nails. The use of water for cleaning holes will not be permitted. Do not install nails in the drilled holes until the holes have been inspected and approval is given. Remove foreign material dislodged or drawn into the holes during construction of the assemblies. Immediately suspend drilling operations if ground subsidence is observed, the soil nail wall is adversely affected, or adjacent struc tures are damaged from the drilling operation. Immediately stabilize the adverse conditions, make necessary repairs, and modify drilling operations prior to resuming drilling.

644.03.06 Nail Placement. Provide nail bars in accordance with the schedules shown. Position centralizers

as shown so their maximum center -to-center spacing does not exceed 3 m (10 ft). Locate centralizers within 0.6 m (2 ft) from the t op and bottom of the drillhole. SOIL NAIL RETAINING WALLS 644 Inspect each nail bar before installation and repair or replace dam aged bars or corrosion protection. Check uncased drillholes for cleanliness prior to insertion of the soil nail bar. Insert nail bars with centralizers into the drill hole to the required length without difficulty and in a way that prevents damage to the drillhole, bar, or corrosion protection. Do not drive or force partially inserted soil nails into the hole. Remove nails which cannot be fully inserted to the design depth and clean the drill hole to allow unobstructed installation. Do not extend nails bey ond the right -of-way or easement limits shown. Install soil nails to plan location within the following tolerances: Nail Head Location, deviation in any direction ................................ ...................................................................................... 150 mm (6 in.) Nail Inclination ................................ ................................ ......................................................................................................... ± 3 degrees Nail Location, deviation from center of dril lhole ...................................................................................................................... 25 mm (1 in.) Location tolerances are applicable to only one nail and not accumulative over large wall areas. Replace soil nails which do not satisfy the specified tolerances. Backfill abandoned nail drill holes with tremied grout.

644.03.07 Gro uting. Use grout equipment which produces a uniformly mixed grout, free of lumps and

undispersed cement, and capable of continuously agitating the mix. Use a positive displacement grout pump equipped with a pressure gauge which can measure at least twice b ut no more than three times the intended grout pressure. Size the grouting equipment to enable the entire nail to be grout ed in one continuous operation. Place the grout within 60 minutes after mixing or within the time recommended by the admixture manufacturer, if admixtures are used. Grout not placed in the allowed time limit will be rejected. Place nails and grout within 2 hours of completion of drilling, unless otherwise approved. Inject the grout at the lowest point of each drillhole through a grout tube, casing, hollow -stem auger, or drill rods. Keep the outlet end of the conduit delivering the grout below the surface of the grout as the conduit is withdrawn to prevent the creation of voids. Completely fill the drillhole in one continuous operation. Cold joints in the grout column will not be allowed except at the t op of the test bond length of proof tested production nails. The grout tube may remain in the hole provided it is filled with grout. Grouting before insertion of the nail will be allowed provided the nail bar is immediately inserted through the grout to the specified length without difficulty. During casing removal for drillholes advanced by either cased or hollow -stem auger methods, maintain sufficient grout level within the casing to offset the external groundwater/soil pressure and prevent hole caving. Maintain grout head or grout pressures sufficient to ensure that the drillhole will be completely filled with grout and to prevent unstable soil or groundwater from contaminating or diluting the grout. Record the grout pressures for soil nails installed us ing pressure grouting techniques. Control grout pressures to prevent excessive ground heave or fracturing. Remove the grout and nail if grouting is suspended for more than 30 minutes or does not satisfy the requirements specified herein. Submit corrective procedures for review and approval.

644.03.08 Verification Testing. Perform pre- production verification testing prior to installation of production

nails to verify installation methods and nail pullout resistance. Verification test nails are sacrificial and are not incorporated as production nails. Bare bars may be used for the sacrificial verification test nails. Furnish necessary testing equipment including dial gauges, dial gauge support, jack and pressure gauge, electronic load cell, and a reaction f rame. The load cell is required only for creep test portion of verification test. Test nails shall have both bonded and temporary unbonded lengths. Prior to testing, grout only the bonded length of the test nail. The temporary unbonded length of the test nail shall be a minimum of 1 m (3 ft). Determine the maximum bonded length of test nail by the following equation: LBV = C f Y AS / 2 Q d Where: LBV = Maximum Verification Test Nail Bonded Length, m (ft) C = 0.9 for Grade 420 (60) and 520 (75) bars and 0.8 for Grade 1035 (150) bars fY = Bar Yield or Ultimate Stress, kN/m2 (ksi) AS = Bar Steel Area, m2 (in2) Qd = Allowable Pullout Resistance, kN/m (kips/ft) 644 SOIL NAIL RETAINING WALLS The actual bonded test length constructed for testing shall be greater than 3 m (10 ft) but less than the maximum bonded length, L BV, as calculated above. Determine the Design Verification Load by the following equation: DVL = L BA x Q d Where: DVL = Design Verification Load, kN (kips) LBA = Actual Test Nail Bonded Length, m (ft) Qd = Allowable Pullout Resistance, kN/m (kips/ft) Construct verification test nails using the same equipment, installation methods, nail inclination, and drillhole diameter as planned for the production nails. Changes in the drilling or installation method may require additional verification testing as determined. Verification test nails may be installed through either the existing slope face prior to start of wall excavation, drill platform work bench, stabilization berm or into slot cuts made for the particular lift i n which the verification test nails are located. Slot cuts shall only be large enough to safely accommodate the drill and test nail reaction setup. Subject to approval, verification test nails may also be installed at angle orientations other than perpendi cular to the wall face or at different locations than specified, as long as it can be demonstrated that the test nails will be bonded into ground which is representative of the ground at the designated verification test nail locations. Do not perform nail testing until the nail grout and shotcrete facing have cured for at least 72 hours and attained at least their specified 3 day compressive strength. If approved, testing in less than 72 hours may be allowed if submitted compressive strength test results v erify that the nail grout and shotcrete mixes being used obtain the specified 3 day compressive strengths in the lesser time. Design the testing reaction frame to be sufficiently rigid and of adequate dimensions such that excessive deformation of the test ing equipment does not occur. If the reaction frame bears directly on the shotcrete facing, design it to prevent cracking of the shotcrete. Independently support and center the jack over the nail bar so that the bar does not carry the weight of the testing equipment. Align the jack, bearing plates, and stressing anchorage with the bar such that unloading and repositioning of the equipment is not required during the test. Isolate the test nail bar from the shotcrete facing and/or the reaction frame used dur ing testing. Isolation of a test nail through the shotcrete facing shall not affect the location of the reinforcing steel under the bearing plate. Where temporary casing of the unbonded length of test nails is provided, install the casing in a way that prevents any reaction between the casing and the grouted bond length of the nail and/or the stressing apparatus. Apply and measure the test load with a hydraulic jack and pressure gauge. Graduate the pressure gauge in 0.7 M Pa (100 psi) increments or less. The jack and pressure gauge shall have a pressure range not exceeding twice the anticipated maximum test pressure. Jack ram travel shall be sufficient to allow the test to be done without resetting the equipment. Monitor the nail load during testing with bot h the pressure gauge and the load cell. Use the load cell to maintain constant load hold during the creep test load hold increment. Measure the nail head movement with a dial gauge capable of measuring to 0.025 mm (0.001 in.). Use a dial gauge with suffic ient travel to allow the test to be done without having to reset the gauge. Visually align the gauge to be parallel with the axis of the nail and support the gauge independently from the jack, wall, or reaction frame. Use two dial gauges when the test setup requires reaction against a soil cut face. Incrementally load verification test nails according to the schedule below. Record the soil nail movements at each load increment. Verification Test Loading Schedule Load Hold Time, Minutes Alignment .................................................................................... 1 0.25 DVL ................................................................................... 10 0.50 DVL ................................................................................... 10 0.75 DVL ................................................................................... 10 1.00 DVL ................................................................................... 10 1.25 DVL ................................................................................... 10 Creep Tes t ................................ .................................................. 60 1.75 DVL ................................................................................... 10 2.00 DVL ................................................................................... 10 SOIL NAIL RETAINING WALLS 644 The Alignment Load shall be the minimum load required to align the testing apparatus and shall not exceed 0.05 DVL. Set dial gauges to "zero" after the alignment load has been applied. Monitor the verification test nail for creep at the 1.50 DVL load increment. Measure and record nail movements during the creep portion of the test at 1, 2, 3, 5, 6, 10, 20, 30, 50, and 60 minutes. Maintain the load during the creep test within 2% of the intended load by use of the load cell. A test nail will be considered acceptable when:

644.03.09 Proof Testing. Perform proof testing on 5% of the production nails in each nail row with a

minimum of 1 per row. The nails t o be tested will be designated. Furnish necessary test ing equipment including dial gauges, dial gauge support, jack and pressure gauge, and a reaction frame. Provide production proof test nails having both bonded and temporary unbonded lengths. Prior to testing, grout only the bonded length of the test nail. The temporary unbonded length of the test nail shall be a minimum of 1 m (3 ft). Determine the maximum bonded length of test nail by the following equation: LBP = C f Y AS / 1.5 Q d Where: LBP = Maximum Proof Test Nail Bonded Length, m (ft) C = 0.9 for Grade 420 (60) and 520 (75) bars and 0.8 for Grade 1035 (150) bars fY = Bar Yield or Ultimate Stress, kN/m2 (ksi) AS = Bar Steel Area, m2 (ft2) Qd = Allowable Pullout Resistance, kN/m (kips/ft) The actual bonded test length constructed for testi ng shall be greater than 3 m (10 ft) but less than the maximum bonded length, L BP, as calculated above. Determine the Design Proof Load by the following equation: DPL = L BA x Q d Where: DPL = Design Proof Load, kN (kips) LBA = Actual Test Nail Bonded Length, m (ft) Qd = Allowable Pullout Resistance, kN/m (kips/ft) Do not perform testing until the nail grout and shotcrete facing have cured for at least 72 hours and attained at least their specified 3 day compressive strength. If approved, testing in less than 72 hours may be allowed if submitted compressive strength test results verify that the nail grout and shotcrete mixes being used obtain the specified 3 day compressive strengths in the lesser time. Design the testing reaction frame to be suffici ently rigid and of adequate dimensions such that excessive deformation of the testing equipment does not occur. If the reaction frame bears directly on the shotcrete facing, design it to prevent cracking of the shotcrete. Independently support and center t he jack over the nail bar so that the bar does not carry the weight of the testing equipment. Align the jack, bearing plates, and stressing anchorage with the bar such that unloading and repositioning of the equipment is not required during the test. 644 SOIL NAIL RETAINING WALLS Isolate the test nail bar from the shotcrete facing and/or the reaction frame used during testing. Isolation of a test nail through the shotcrete facing shall not affect the location of the reinforcing steel under the bearing plate. If necessary, provide casing for the unbonded length to allow grouting and completion of the nail subsequent to testing. Where temporary casing is provided, install the casing in a way that prevents any reaction between the casing and the grouted bond length of the nail and/or the s tressing apparatus. Apply and measure the test load with a hydraulic jack and pressure gauge. Graduate the pressure gauge in 0.7 M Pa (100 psi) increments or less. The jack and pressure gauge shall have a pressure range not exceeding twice the anticipated maximum test pressure. Jack ram travel shall be sufficient to allow the test to be done without resetting the equipment. Measure the nail head movement with a dial gauge capable of measuring to 0.025 mm (0.001 in.). The dial gauge shall have a travel suff icient to allow the test to be done without having to reset the gauge. Visually align the gauge to be parallel with the axis of the nail and support the gauge independently from the jack, wall, or reaction frame. Use two dial gauges when the test setup requires reaction against a soil cut face. Perform proof tests by incrementally loading the proof test nail to a maximum test load of 1.50 DPL. Measure and record the nail movement at each load in the same manner as for verification tests. Monitor the test l oad by a jack pressure gauge with a sensitivity and range meeting the requirements of pressure gauges used for verification test nails. At load increments other than the maximum test load, hold the load long enough to obtain a stable reading. Incrementally load proof test nails according to the schedule below. Proof Test Loading Schedule Load Hold Time Alignment ............................................................................ Until Stable 0.25 DPL ............................................................................ Until Stable 0.50 DPL ............................................................................ Until Stable 0.75 DPL ............................................................................ Until Stable 1.00 DPL ............................................................................ Until Stable 1.25 DPL ............................................................................ Until Stable Creep Test ................................ ........................................... See Below The Alignment Load shall be the minimum load required to align the testing apparatus and shall not exceed 0.05 DPL. Set dial gauges to "zero" after the alignment load has been applied. Maintain all load increments within 5% of the intended load. Depending on performance, perform either 10 minute or 60 minute creep tests at the maximum test load of 1.50 DPL. Start the creep period as soon as the maximum test load is applied and measure and record the nail movement at 1, 2, 3, 5, 6, and 10 minutes. Where the nail movement between 1 minute and 10 minutes exceeds 1 mm (0.04 in.) , maintain the maximum test load an additional 50 minutes and record the movements at 20, 30, 50, and 60 minutes. A test nail will be considered acceptable when:

644.04.01 Measurement. Soil nails will be measured by the linear meter (linear foot), measured from the nail

tip to the plane of cutoff. Soil nail verification tests will be measured by the each. BASIS OF PAYMENT

644.05.01 Payment. The accepted quantities, measured as provided abo ve, will be paid for at the contract

price per unit of measurement for the pay items listed below that are shown in the proposal. Payment will be full compensation for the work prescribed in this Section. Payment will be made under: Pay Item Pay Unit Soil Nail ................................ ............................................................................................................................. Linear Meter (Linear Foot) Verification Test ................................................................................................................................................................................. Each SECTION 646 DAMPPROOFING , WATERPROOFING , SEALING , AND MEMBRANES DESCRIPTION

646.01.01 General. This work consists of bridge deck preparation and furnishing and applying dampproofing,

waterproofing, sealant s, and membrane materials to concrete and masonry elements . MATERIALS

646.02.01 Dampproofing and Waterproofing. Primer shall conform to ASTM D41.

Asphalt shall conform to ASTM D449, Type I for below ground and Type III for above ground, except that the ductility for Type III shall be 5 minimum. Glass f abric for waterproofing shall conform to ASTM D1668.

646.02.02 Crack Sealant. Manufacturers of crack sealants are listed in the QPL.

646.02.03 Surface Sealant. Manufacturers of surface sealants are listed in the QPL.

646.02.04 Sheet Membrane. Manufacturers of sheet membrane s are listed in the QPL.

646.02.05 Liquid Membrane. Manufacturers of liquid membrane s are listed in the QPL.

CONSTRUCTION

646.03.01 Dampproofing. Make concrete surfaces smooth and free of depressions and projections which

might damage the dampproofing. The surface shall be dry and cleaned of dust and loose materials. Do not apply primer or asphalt in wet weather, nor when the surface temperature is either below 4 °C (40 °F) or below that recommended by the manufacturer. Apply a coating of primer and 2 moppings of asphalt. Begin dampproofing application at the low point of the surface being treated. Apply primer at an approximate rate of 0.41 L/m2 (0.09 gal/yd2) and allow to dry before the first coat of asphalt is applied. Apply asphalt at a temperature between 149 °C and 177 ° C (300 °F and 350 °F). Apply each mopping of asphalt at the rate of approximately 1.6 L/m2 (0.35 gal/yd2). The total thickness of the 2 coats shall be approximately 2 mm (0.08 in.). After the first mopping of asphalt has set sufficiently, mop on the second coating. Take special care to ensure that there are no skips in the coatings and that all surfaces are thoroughly covered.

646.03.02 Waterproofing. Make concrete surfaces smooth and free of depressions and projections which

might damage the waterproofing. The surface shall be dry and cleaned of dust and loose materials. Do not apply primer or asphalt in wet weather, nor when the surface temperature is either below 4 °C (40 °F) or below t hat recommended by the manufacturer. Do not apply waterproofing until prepared to follow its application with the placement of the backfill within a sufficiently short time so that the waterproofing will not be damaged as a result of exposure to weatherin g. Remove waterproofing which loses its bond with the concrete and replace with acceptable waterproofing. Apply a coating of primer and 2 layers of glass fabric within 3 moppings of asphalt. Apply primer at an approximate rate of 0.41 L/m 2 (0.09 gal/yd2) and allow to dry before the first coat of asphalt is applied.