7-108 Section 710. Waterproofing and Protective Covers
710.01 Description
This work consists of providing and placing membrane waterproofing and protective covers.
710.02 Materials
Provide materials in accordance with the following sections : Water ..................................................................................................... 911 Joint and Waterproofing Materials ......................................................... 914 Mortar and Grout ................................................................................. 1005 Select premixed s hotcrete containing latex modified Portland cement and fine aggregates, as recommended by the manufacturer for use as a pneumatically applied concrete. Secure the Engineer ’s approval before use on the project . Do not use slag aggregate.
710.03 Construction
A.Joint Waterproofing . Use preformed waterproofing for the full length of joint locations shown on the plans or as directed by the Engineer. Provide preformed joint waterproofing at least 18 inches wide. Apply the preformed waterproofing membrane system in accordance with the manufacturer ’s recommendations . Do not install membrane system sooner than 4 hours after removing the forms. Prepare and prime the concrete surface for at least 12 inches on each side of the joint in accordance with the manufacturer ’s recommendations . Complete preparatory work if the air and c oncrete temperatures are above 40°F and the surfaces are dry . Clean the surface designated for coverage using a solvent and scraping to remove deleterious materials . Deleterious materials include, but are not limited to, oil, grease, old waterproofing material, and asphalt residue. Remove protrusions that could puncture the membrane or cause a void with a diameter greater than ¾ inch before applying the primer . Remove dust from the concrete surface with compressed, oil -free air . Fill surface imperfections, potholes , and spalls with a Department -approved epoxy mortar, mortar, or concrete. Cure cement -based patching mixtures at least 24 hours before installing the membrane. Apply the primer with a roller or brush, in accordance with the manufacturer ’s recommen dations, over the concrete surface required for membrane coverage. Provide an additional application of primer if the MDOT Standard Specifications for Construction Section 710 7-109 membrane is not placed within the time specified by the membrane system manufacturer. Apply the membrane in accordance with the manufactur er’s recommendations . Remove the release paper from the back surface of the membrane immediately before placing. Center the membrane over the concrete joint, straight and wrinkle-free . Immediately after applying each sheet, hand roll with a roller using enough pressure to remove air voids and ensure complete adhesion. Overlap seams at least 6 inches. Demonstrate to the Engineer that the entire membrane has fully adhered to the underlying concrete surface before backfilling. Waterproofing membrane systems th at exhibit a loss of adhesion to the concrete surface is not acceptable. Repair punctures, tears, wrinkles, or other imperfections in the installed membrane. Make repairs by applying a patch of membrane over the damaged material, or remove and replace the membrane. Size patches to extend 6 inches beyond the perimeter of the repair area.
B.Expansion Joint Waterproofing . Apply a two-layer, preformed joint waterproofing membrane system for the full length of joint locations shown on the plans or as directed by the Engineer . Apply expansion joint waterproofing in accordance with subsection 710.03.A except as modified by this subsection (710.03.B ). Provide a preformed waterproofing membrane that is at least 18 inches wide. Do not apply primer to the tw o beveled surfaces next to the expansion joint at the interface of the abutment wall and backwall. Apply a bond breaker tape, or equivalent material, to the face of each beveled surface next to the expansion joint at the interface of the abutment wall and backwall in order to prevent the membrane fold from adhering to these concrete surfaces. Center the membrane over the concrete joint, making it straight and wrinkle -free, and insert it full depth into the beveled cavity of the expansion joint to provide sl ack in the membrane for bridge movement. Apply a second layer of membrane over the first layer . Do not apply bond breaker tape on top of the first layer . Coat the entire exposed surface of the first layer of membrane, including the fold, with primer before applying the second layer of membrane. Center the second layer of membrane over the concrete joint, making it straight and wrinkle-free. The second layer must conform, and fully adhere, to the first layer of membrane. MDOT Standard Specifications for Construction Section 710 7-110 C. Deck Waterproofing – Preformed
1.Constr uction Procedure . Clean the surface using a solvent and by scraping to remove deleterious material, including oil or grease. Remove sharp protrusions by grinding. Remove old membrane material or asphalt residue using methods approved by the Engineer . Fill potholes and spalls with a diameter greater than ¾ inch with a Department -approved epoxy mortar, cement mortar, or concrete and cure as required. Correct elevation differences in the tops of box beams, such as those resulting from camber variation, by wedg ing with cement mortar or concrete. Sweep and clean surfaces with brooms and compressed air, as required. Allow concrete, including grout and repair areas, to cure according to manufacturer ’s recommendation but no less than 7 days before applying the primer . Prime and place the membrane when the air and concrete temperatures are above 40°F and the surfaces are dry. Apply the primer after cleaning the deck . Use a roller, brush, squeegee, or mechanical means to apply primer to the surface of the deck and 2 to 3 inches up the vertical face of the curb. Prime only those surfaces that can be covered by membrane the same day . Allow the primer to dry to a non-tacky co ndition before applying the membrane. Drying time may vary from ½ hour to 1½ hours, depending on the air temperature. Small bubbles on the primer are normal and do not affect the bond. Apply a Department -approved liquid fillet material to all inside corner s after the primer has cured or dried. Apply a Department -approved mastic to locations where membrane edges will fall, including the curb face, raised expansion dams, and drain castings . Apply an 8-inch-wide strip of the sheet membrane to the vertical surf ace of the curb so it comes to a height equal to the planned depth of HMA . Place an 8-inch-wide strip of sheet membrane, centered over transverse joints or cracks wider than 3/16 inch. Do not place the strip at raised steel expansion dams . Firmly press the membrane into the primer and mastic. Start at the low or down-slope side of the deck . Place the membrane by hand or using equipment designed for this purpose. Shingle-lap successive strips of membrane . Place the membrane straight and wrinkle free, with no bubbles or air spaces under it. Overlap the edges and ends of the membrane in accordance with the manufacturer ’s recommendations . Overlaps must be a minimum of 6 inches . At the deck drains, cut the membrane and turn it down into the downspouts or bleeder pipes . Apply a continuous bead of MDOT Standard Specifications for Construction Section 710 7-111 Department -approved mastic along the base of raised expansion dams, butt the sheet membrane up to the dam , and press into the mastic. Hand roll each sheet of membrane immediately after installation with a roller th at weighs enough to ensure total contact with the deck . Patch torn or cut areas or narrow overlaps by placing sections of the membrane over the areas so the patch extends at least 6 inches beyond the defect in all directions . Roll the patch or press firmly in place and apply a Department -approved mastic to the edges. Remove the separation sheet of plastic or paper as specified by the manufacturer during the installation of the membrane and before the application of the HMA . Remove stones or other foreign matter found under the membrane after application and patch the area as described in this subsection (710.03.C.1 ). Do not allow vehicles, except HMA hauling units and the approved rubber -tired paver , on the completed waterproofing membrane.
2.Placing HMA over Waterproofing Membrane . Place the HMA mixture at a temperature from 250 to 350°F according to section 501 after placing the membrane. Pave only on a clean and dry membrane surface . Use rubber -tired equipment . Inspect equipment and remove burrs on tires, st ones, or sharp projections that could damage the membrane. If the rubber -tired machine skids during warm weather, broadcast fine sand or cement in the tire paths . Avoid excessive use of cement or sand that would prevent adhesion of the HMA. Preheat paver s creeds, but turn burners off during paving to avoid damaging the membrane. Deliver the HMA directly from the hauling unit to the paver . Do not stop the paver with a full hopper . Prevent build-up of material in the auger . Keep the level of the HMA in the auger just below the level of the auger shaft . Do not damage the membrane when restarting paving operations . Avoid sudden stops or sharp turns with the compaction rollers. Apply a fillet or cove seal using the asphalt -mineral, fiber -solvent caulking materi al supplied with the membrane after rolling the surface. Apply the seal at the curb line to form a ¾ - by ¾ -inch triangular seal along the edge of the new surface for the full length of the curb.
D.Shotcrete . Pneumatically eject the shotcrete mixture from a m ixer or gun through a hose and discharge nozzle under regulated pressure. Add the liquid latex component at the mixer or gun or at the nozzle, depending on equipment type and material manufacturer ’s recommendations. MDOT Standard Specifications for Construction Section 710 7-112 1. Test Panels. Demonstrate to the Engineer that nozzle operators are capable of apply ing shotcrete correctly . Use test panels simulating job conditions for each gun shooting position (down, horizontal, and overhead) required on the project . Use the same shotcrete material on the test panels as proposed for use on the project . Use a panel 2 by 2 feet square and at least 3 inches thick or the same thickness required on the project, whichever is greater . At least half of the panel area must have the same reinforcing steel pattern that is required on the project. Keep test panels continuously moist and above 40°F for 5 days after shotcrete application. Remove at least five cores from the test panels and test for compressive strength in accordance with ASTM C39/C39M . Cut cores with a diameter of at least 3 inches meeting a length-to -diameter ratio (L/D) of at least 1.0. Adjust core strengths in accordance with ASTM C42/C42M if the L/D is less than 2.0. The average compressive strength of the cores must be at least 85% of the required compressive stre ngth with no individual core having a compressive strength below 75% of the required compressive strength. Take additional cores through the reinforcing steel so the Engineer can evaluate the soundness of the shotcrete behind the steel . The Engineer will e xamine the cored surfaces and require additional cores or sawcuts if necessary to evaluate soundness and uniformity of deposited material . The Engineer will evaluate the test panels and cores to verify that shotcrete surfaces are dense and free from lamina tions, voids, and sand pockets.
2.Surface Preparation . If applying shotcrete to protect waterproofing, perform the work immediately after the completion of waterproofing. If using shotcrete to repair concrete members, remove unsound concrete and concrete contaminated by chemicals or oils . Saw cut and repair the edges of the area required for repair, and patch to a depth of at least ½ inch. Provide tools that will not damage sound concrete surrounding and beneath the area being removed. Use galvanized or epoxy -coated welded wire reinforc ement on repairs greater than 2 inches deep. Place the reinforc ement at mid- depth of the repair and at least 1 inch below the surface. Attach the reinforc ement to sound concrete with stainless steel anchoring devices spaced in a grid no greater than 18 by 18 inches . Use anchors that can support three times the weight of shotcrete allocated to each anchor. MDOT Standard Specifications for Construction Section 710 7-113 Blast -clean the prepared area and remove traces of dirt, oil, and loose material . Follow with an oil-free air blast to remove abrasive material and dust.
3.Shotcrete Placement . Pre-wet the surface with the liquid latex component immediately before placement of shotcrete. Balance air and material to ensure a steady flow and to prevent slugging of material, plugging, and excess rebound . Apply the shotcrete using pneumatic equipment that sprays the mix onto the prepared surface at a high enough velocity to produce a compacted dense homogeneous mass with no sagging or sloughing. Place each layer of shotcrete in several passes over a section of the work area . Divide large expanses into smaller areas and apply shotcrete to its full thickness before moving to the next area . Avoid laminations during placement. Keep the nozzle 2 to 6 feet from the work . Hold the nozzle as close to perpendi cular to the surface as possible and never less than a 45-degree angle to the surface. Remove rebound and overspray that does not fall clear . Do not salvage or recycle rebound and overspray. Do not apply shotcrete under the following conditions :
a.High wind preventing proper application;
b.Surface temperature below 45°F; or
c.Rain causing washouts or sloughing of the fresh shotcrete.
4.Curing . Cure shotcrete and provide temperature protection in accordance with subsection 706.03.N.3.
5.Testing . The Engineer may require cutting cores from the completed work for compression testing. If the Engineer orders tests, obtain and test at least three cores in accordance with subsection 710.03.D.1.
710.04 Measurement and Payment
Pay Item Pay Unit Joint Waterproofing ........................................................................ Square Foot Shotcrete ................................................................... Square Foot, Cubic Foot Membrane, Preformed Waterproofing ............................................ Square Foot Joint Waterproofing, Expansion ..................................................... Square Foot
A.Joint Waterproofing . The Engineer will measure Jo int Waterproofing by area based on a width of 18 inches and the p lan length of joints MDOT Standard Specifications for Construction Section 710 7-114 requiring treatment . The unit price for Joint Waterproofing includes the cost of preparing the concr ete surfaces and installing the joint waterproofing system.
B.Joint Waterproofing, Expansion . The Engineer will measure Joint Waterproofing, Expansion by area based on an 18- inch width and the plan length of joints requiring treatment . The Engineer will not measure the area of folds or overlapped material for payment . The unit price for Joint Waterproofing, Expansion includes the cost of preparing the concrete surfaces and installing the two-layer preformed expansion joint waterproofing membrane system.
C.Membrane, Preformed Waterproofing . The Engineer will measure Membrane, Perf ormed Waterproofing by the area covered with no allowance for laps, patches, the 8-inch strips over transverse joints or cracks, or the 8 -inch strip applied to the vertical surface of the curb. The Engineer will not deduct the areas of expansion dams or dr ain spouts. The unit price for Membrane, Performed Waterproofing includes the cost of cleaning the deck; applying the primer, liquid fillet material, and mastic; applying, rolling, and repairing the membrane; and applying the final cove seal mastic along t he curb line.
D.Shotcrete . The unit price for Shotcrete includes the cost of surface preparation; providing, mixing, and applying shotcrete material; test panels, and coring.
E.Removing HMA Surface. If required, the Engineer will measure, and the Department will pay for , removing HMA surface separately as HMA Surface, Rem in accordance with subsection 501.04. The Engineer will measure, and the Department will pay for , scarifying, hand chipping, and patching, if required, separately in accordance with subsection 712.04. If the Engineer cannot determine the amount of scarifying, hand chipping, and patching required before removal of the HMA surface, the Department will pay for this as extra work.
F.Wedging Along Joints . The Engineer will measure, and the Department will pay for , required wedging along joints between prestressed concrete box beams as Patching Mortar or Conc in accordance with subsection
712.04 The wedging must meet the approval of the Engineer.
G.The Engineer will measure, and the Department will pay for , the HMA mixture separately in accordance with su bsection 501.04.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 472–478 of 1,146.