722 - SIGN STRUCTURES AND BRIDGE MOUNTED SIGN ATTACHMENTS 700-100 b. Fabrication.
1.Shop Welding. Perform welding and repairs in accordance with SECTION 744 .
2.Test Loading. Test loading of fabricated tr usses is required only when inspection indicates the fabrication to be of doubtful or unacce ptable quality requiring repairs before acceptance. Test load the structure to demonstrate the adequacy of the repair. The C ontractor will bear the cost of test loading.
c.Electrical Equipment and Materials. Provide the electrical equipm ent and materials shown in the Contract Documents. Submit to the Engineer for approval a schedule of electrical equipment and materials proposed for installation before beginning construction. Include catalog cuts, diagrams, drawings and other descriptive data required by the Engineer. 722.3 CONSTRUCTION REQUIREMENTS
a.General. Do not damage the existing cables and conduits . If necessary, relocate the existing cables and conduits to clear the footing locations. Repair or replace existing cable s and conduits damaged during construction of the footings. If temporary signs interfere with th e erection of the permanent signs, relocate the temporary signs to the locations determined by the Engineer. When "Contractor Construction Staking" is not shown as a bid item, the Engineer will stake the locations of sign structure footings. For each foot ing location, the Engineer will provid e the Contractor with the vertical measurement from the crown grade of the pa vement to the top of the footing. Erect the bridge mounted sign attachments and sign structures according the Contract Documents. If removing, modifying or resetting sign structures, do not damage the existing sign structures. Repair or replace, as directed by the Engineer , sign structures damaged through the negligence of the Contractor.
b.Concrete Footings. Construct the concrete footings accord ing to the Contract Documents. When placing the concrete, consolidate the concrete in the footings by rodding and vibrating. Allow the concrete footings to cure a minimum of 4 days before attaching the sign structures.
c.Sign Structures.
1.Bolted Joint Connections. Before assembling the si gn structures, use a soft wire brush to clean the contact surfaces of the bolted connections. Remove all corrosion and coatings, except galvanizing. Wipe the cleaned contact surfaces with rags soak ed with acetone, syol or toluol. Re move excess solvent from the contact surfaces using clean, dry rags. Assemble the sign structures accord ing to the Contract Documents. S eal all bolted join ts immediately, using a sealant intended for this purpose, and applied according to the sealant manufacturer’s recommendations.
2.Attachment to Anchor Bolts. Pl ace the sign structure with anchor pl ate on the anchor bolts. After all signs are mounted on the structure, and the sign pole (or bridge support) is plumb, proceed with anchor bolt tightening procedures. Fill the gap between the top of the footing and the bottom of the anchor plate with concrete grout according to the details in the Contract Documents.
3.All Sign Structures. Do not use a pipe wrench to tighten nuts on Sign Structures; Use only a box end or socket wrench to snug tighten nuts; Maintain a minimum dimension of 6 inches from the top of foundation to finished grade; With approval of the Engineer, repair any marring of the galvanizing caused while lifting the structure into place; Submit specifications for the hydraulic wrench to the Construction Engineer (who will contact the Signing and Lighting Engineer) for approval; and If the four refusal maximum is exceed ed on any DTI, discontinue tighten ing and contact the State Bridge Office; Grade the surrounding area to drain away from the structure. 722 - SIGN STRUCTURES AND BRIDGE MOUNTED SIGN ATTACHMENTS 700-101 (4) Existing Sign Structures. Verify the existing anchors will extend a minimum of one thread above the top tightened nut in the final condition. Do not damage the ex isting anchors during the removal of the existing hardware. Clean the threads of all rust and lubricate with an approved wax, prior to placing the new hardware. Install DTIs on each anchor. Insta ll a hardened washer on each anchor, if required. Use new hardware galvanized according to SECTION 1616 . Verify the assembly (leveling nut, ha rdened washer(s), tower base plate, DTI, top nut) is in a snug tight condition before final tighten ing begins. Using the approved hydraulic wrench, tighten each nut to achieve a minimum of three refusals of the 0. 005 gauge. Do not exceed four refusals of the 0.005 gauge. After tightening, score the remaining threads.
5.New Sign Structures. Construct the elements of th e structure according to th e Contract Documents. Threads of the anchors shall be plumb and free of any construction debris. Install DTIs on each anchor. Install a hardened washer on each anchor, if required. Use hardware galvanized according to SECTION 1616 . Verify the assembly (leveling nut, hardened washer(s), tower base plate, DTI, top nut) is in a snug tight condition be fore final tightening begins. Using the approved hydrau lic wrench tighten each nut to achieve a minimum of three refusals of the 0.005 gauge. Do not exceed four refusals of the 0.005 gauge. After tightening, score the remaining threads.
6.Overhead Truss. In erection of the truss, allow the dead load de flection to take place before fully tightening all the connectors. Fully tighten the vertical portion which clamps the column in all corners, but tighten only the top of 1 end of the horizontal portion of the truss-to-end-support connector while the truss is fully suspended from the crane. The rest of the truss-to-end supports shall be fully tightened after the dead load of the truss is being supported by the connectors, but still attached to the crane with a slack line. Erect the signs within 24 hours of erecting the truss. (7) Dissimilar Materials. Whenever dissimilar mate rials are to be in permanent contact, provide an insulating barrier of alkali resistant asphalt paint or equivalent.
d.Electrical Work. Comply with all Local, State and Federal ordinances.
1.Conduit. Install conduit entrances through the concrete footing as indicated in the Contract Documents. Place temporary screwed caps on the conduit ends. (2) Grounding. Ground all structures and sign bridges as detailed in the Contract Documents. Measure the resistance of the installed grounding system; the Engineer will observe the testing. The grounding system must have less than 25 Ω resistance to ground. 722.4 MEASUREMENT AND PAYMENT The Engineer will measure each sign structure, bridge mounted sign attachment, removal and resetting of a sign structure and modification of a sign structure. Payment for each "Bridge Mounted Sign Attachment", "Butterfly Overhe ad Sign Structure", "Cantilever Sign Structure", "Overhead Sign Structure", "Overhead Sign Structure (Mast Arm Type)", "Overhead Sign Structure (Single Tapered Tube)", "Remove and Reset Sign Structure", "Reset Sign Structure" and "Sign Structure Modification" at the contract unit prices is full compensation for the specified work. 723 - SUBSTRUCTURE WATERPROOFING MEMBRANE 700-102 SECTION 723 SUBSTRUCTURE WATERPROOFING MEMBRANE 723.1 DESCRIPTION Apply an epoxy primer or an epoxy system to areas of the substructu re as specified in the Contract Documents. BID ITEM UNITS Substructure Waterproofing Membrane Square Yard 723.2 MATERIALS Provide materials that comply with DIVISION 1700 . 723.3 CONSTRUCTION REQUIREMENT Clean all surfaces that are to be waterproofed. Apply the waterproofing membrane according to the manufacturer’s recommendations. Apply the membrane to a minimum 40 mils dry film thickness on the bridge seat as shown in the Contract Documents. Apply waterproofing membrane to promote draina ge of the bridge seats, an d to fill any low areas that may retain moisture. The average coverage should be approximately 3 ¾ gallons per 100 square feet. 723.4 MEASUREMENT AND PAYMENT The Engineer will measure the substructure waterproofing membrane by the square yard to the limits shown in the Contract Documents. Payment for the "Substructure Waterproofing Membrane" at the contract unit price will be full compensation for th e specified work. 724 - BRIDGE BACKWALL PROTECTION SYSTEM 700-103 SECTION 724 BRIDGE BACKWALL PR OTECTION SYSTEM 724.1 DESCRIPTION Prepare the concrete surface and apply a bridge back wall protection system to the face of the concrete abutment and or the top surface of box culverts as specified in the Contract Documents. BID ITEM UNITS Bridge Backwall Protection System Square Yard 724.2 MATERIALS Provide materials for bridge backwall protection systems that comply with DIVISION 1700 . 724.3 CONSTRUCTION REQUIREMENTS Provide the Engineer with a copy of the manufacture r’s recommendations for application. If approved by the Engineer, apply the bridge backwall protection system as recommended by the manufacturer. 724.4 MEASUREMENT AND PAYMENT The Engineer will measure the bridge backwall protecti on system by the square yard to the limits shown in the Contract Documents. Payment for the "Bridge Backwall Protection System" at the contract unit price will be full compensation for the specified work. 725 - ABUTMENT DRAINAGE SYSTEMS 700-104 SECTION 725 ABUTMENT DRAINAGE SYSTEMS 725.1 DESCRIPTION Install the abutment drainage system specified in the Contract Documents. For an abutment strip drain, install a geocomposite dr ainage system consisting of a prefabricated abutment strip drain, and perforated and non-pe rforated underdrain pipes, as designated in the Contract Documents. For an abutment aggregate drain, install a geocomposite drainage system consisting of geotextile enclosed aggregate materials layered with base coarse reinforcemen t and perforated and non-perforated underdrain pipes, as designated in the Contract Documents. B I D I T E M S U N I T S Abutment Strip Drain Square Yard Abutment Aggregate Drain Cubic Yard 725.2 MATERIALS Provide materials that comply w ith the applicable requirements. Abutment Strip Drain ............................................................................................ DIVISION 1700 Geotextile Fabric…………………………………………………………………… DIVISION 1700 Perforated Pipe for Underdrains ............................................................................ DIVISION 1900 Non-Perforated Pipe for Underdrains .................................................................... DIVISION 1900 Geosynthetics (Class 2 S ubsurface Drainage) ....................................................... DIVISION 1700 Geosynthetics (Base Cour se Reinforcement) ........................................................ DIVISION 1700 Geofoam ............................................................................................................... DIVISION 1700 Aggregate for Structures and Pipe Backfill* .......................................................... DIVISION 1100 *Specified in the Contract Documents 725.3 CONSTRUCTION
a.General. Construct abutment drainage system s according to the Contract Documents.
b.Abutment Strip Drain. Clean the surfaces against which the geoc omposite drains will be placed. Remove all soil, debris and irregularities that will preven t intimate contact between the surface and the drain. Install the geocomposite drains either vertically or hor izontally, according to the C ontract Documents. Secure the geocomposite drains using metal stick clips or adhesive s. When a waterproofing membrane is included in the Contract Documents, do not use nails to attach the geocom posite drain, unless the waterproofing membrane is self- healing. Form all joints and splices according to the manufacturer’s recommendations. Cover all exposed edges of the geocomposite drainage core with geotextile filter fabric. Tuck and secure a minimum of 4 inches of fabric behind the core. This may be done by utilizing the excess fabric at the ends, or using a 12-inch strip of fabric in the same manner, taping it to the exposed fabric 8 inches in from the edge with a continuous strip of 3-inch, waterproof plastic tape and folding the remaining 4 inches over and tucking behind the core edge. If the fabric is torn, perforated or ripped, patch it w ith a second layer of fabric having a 4-inch overlap, and secure the edges with 3-inch waterproof plas tic tape. Replace damaged core sections. Place the underdrain pipes as shown on the Contract Documents. Separate the fabric from the core. Wrap it around the circumference of the perforated unde rdrain pipe and tuck it behind the core.
c.Abutment Aggregate Drain. If the abutment area was over-excavated, replace the ove r-excavated area with a ggregate for structures and pipe backfill to the limits of the excavation shown in the Contract Documents. Compact aggregate to Type B compaction, SECTION 205 . This work will be performed at no additional cost to KDOT. 725 - ABUTMENT DRAINAGE SYSTEMS 700-105 After installing the Bridge Backwall Protection System (constructed and paid for according to SECTION 724), grade, shape and compact the cohesive soils to the dimensions shown in the plans. Shape and secure the geofoam to the previously placed Bridge Backwall Protection System without damaging the geofoam. Protect the geofoam from dama ge due to hydrocarbons (gas, diesel, solvents, etc.) and sunlight. Place the Class 2 Subsurface Drainage geosynthetic between the geofoam and the limits of the excavation with enough material to fully enclose and overlap at the top 3.0 feet and to fold and enclose the ends. Secure folds, any seams or splices and overlap s by sewing or manufacture’s approved methods. Place the perforated 4-inch pipe as shown in the plan s. Verify that any couplers are secured, that the slope is correct and in the intended direction. Place the first lift of aggregate so that there is 8 inches of aggregate above the pipe, level the aggregate and compact to Type B compaction, SECTION 205 , using a hand operated plate compactor or other means approved by the Engineer. If the granular material cannot be shaped and compacted, as shown in the plans, then wrap 3.0 feet of the ends of each lift with Class 2 Subsurf ace Drainage Geosynthetic. Place the Base Coarse Reinforcement geosynthetic on compacted aggregate without gaps or sags and to the limits shown in the plans. Using the same me thods above, successively pl ace aggregate and Base Coarse Reinforcement geosynthetic in 12 inch lifts to the dimensions shown on the plans. Overlap the Class 2 Subsurface Drainage Geosynthetic a minimum of 3 feet on the top of the completed fill. Fold ends of the Class 2 Subsurface Drainage ge osynthetic to enclose the fill and cut an opening, at the correct elevation, allowing the 4- inch pipe to exit the contained fill, but not the retained aggregate. Secure the lap, folds or any splices by sewing or by other methods approved by the manufacturer. Place Class 2 Subsurface Drainage geosynthetic over geofoam and encl osed aggregate as shown in the plans. Place and compact to soil cap material to the limits shown in the Contract Documents. Use material with a Unified Soil Classification of ML or CL. Compact to Type A compaction, MR-90, SECTION 205 . When shown on the plans, taper the contained aggregat e, Base Course Reinforcement geosynthetic, and Class 2 Subsurface Drainage geosynthetic at the edge of the road way. Fold, wrap and secure to create shape shown on the plans. Terminate the geofoam at limits shown in the plan s. Perform work outside these limits shown on the plans according to the Contract Documents.
d.Backfill. Do not damage the abutment drainage system when backfilling the structure. Use backfill soils with a liquid limit of less than 50. 725.4 MEASUREMENT AND PAYMENT The Engineer will measure abutment strip drains by the square yard to the limits shown in the Contract Documents. The Engineer will measure abutment aggregate drains by the cubic yard to the limits shown in the Contract Documents. Payment for "Abutment Strip Drain" and "Abutment Aggregate Drain" at the contract unit price is full compensation for the specified work. All other associated work is subsidiary. 726 - CONCRETE MASONRY COATING 700-106 SECTION 726 CONCRETE MASONRY COATING 726.1 DESCRIPTION Prepare the concrete surfaces and apply a concrete mas onry coating to the concrete surfaces designated in the Contract Documents. BID ITEM UNITS Concrete Masonry Coating Square Yard 726.2 MATERIALS Provide concrete masonry coatings that comply with DIVISION 1700 . 726.3 CONSTRUCTION REQUIREMENTS Provide the Engineer with a copy of the coati ng manufacturer’s recommendations for application. Submit a sample panel exhibiting the color specified and the uniformity of the finish for approval by the Engineer. Clean the concrete surfaces that will receive the coat ings, before applying the c oncrete masonry coatings. Remove all projections and loose mortar particles from the concrete surfaces. Store, mix, apply and cure the concrete masonry coating as recommended by the manufacturer. 726.4 MEASUREMENT AND PAYMENT When shown is a bid item in the contract, the Engineer will measure concrete masonry coating by the square yard to the limits shown in the Contract Documents. Payment for "Concrete Masonry Coating" at the contract unit price will be full compensation for the specified work. 727 - REPAIR (STRUCTURES) 700-107 SECTION 727 REPAIR (STRUCTURES) 727.1 DESCRIPTION Perform the necessary procedures to repair the designated portion of the structure. B I D I T E M S U N I T S B r i d g e R e p a i r L u m p S u m Jacking of Existing Structure Lump Sum Raise Expansion Device Each Remove and Reset Expansion Device Each Reset Existing Bearing Each 727.2 MATERIALS Provide the materials indicated in the Contract Documents. Provide th e specified materials that comply with the materials’ divisions ( DIVISIONS 1000 – 2500 ). 727.3 CONSTRUCTION REQUIREMENTS
a.General. Repair the structure according to the Contract Documents and DIVISION 700 . If the Contract Documents require the superstructure be raised and supported on falsework while the repairs are made, allow the repaired areas to cure before resetting the structure. Remove the old concrete to the limits shown in the Contract Documents. Dispose of the old concrete removed from the structure. Do not damage the existing concrete that is to remain in place. Repair any damage to the existing structure caused by the Contractor. Before any new concrete is placed, clean all reinfo rcing steel exposed during concrete removal. When specified, place new reinforcing steel as detailed in the Contract Documents. When specified, apply an epoxy resi n base bonding system to the adjace nt concrete surfaces before placing the new concrete.
b.Jacking of Existing Structures. Use jacks, supported on falsework or by other methods, to raise the designated spans as units. When specified, move th e spans as indicated in the Contract Documents.
c.Raise Expansion Device. Raise the expansion device as shown in the Contract Documents.
d.Remove and Reset Existing Expansion Devices. Relocate the existing expa nsion devices according to the Contract Documents and DIVISION 700 .
e.Resetting Existing Bearing. Use jacks to raise and support the existing superstructure. Raise the existing superstructure no more than necessary to remove the load from the existing bearings. Reset the existing bearing to the position shown in the Contract Documents. Any welding required for the resetting of the existing bearing must comply with DIVISION 700 . Repaint areas damaged during the resetting of existing bearing according to the Contract Documents. 727.4 MEASUREMENT AND PAYMENT The Engineer will measure jacking of existing struct ure by the lump sum. The Engineer will measure each raised or reset expansion device and reset bearing. The En gineer will measure the various types of structure repairs by the units shown in the Contract Documents. Payment for "Bridge Repair", "Jacking of Existing Structure", "Raise Expansion Device", "Remove and Reset Expansion Device" and "Reset Existing Bearing" at the contract unit prices is full compensation for the specified work. 728 - BRIDGE CURB REPAIR 700-108 SECTION 728 BRIDGE CURB REPAIR 728.1 DESCRIPTION Repair the bridge curb according to the Contract Documents. Use e ither the conventional method or the concrete surface repair-shotcrete method for placing the concrete. B I D I T E M U N I T S Bridge Curb Repair Linear Foot 728.2 MATERIALS Provide materials that comply w ith the applicable requirements. Concrete (Conven tional Meth od) .......................................................................... SECTIONS 401 & 402 Concrete Surface Repair-Shotcrete ........................................................................ SECTION 826 Aggregate for Concrete Not On Grade .................................................................. SECTION 1102 Concrete Curing Materi als .................................................................................... DIVISION 1400 Expansion Joint Material s ..................................................................................... DIVISION 1500 Reinforcement Material s ....................................................................................... DIVISION 1600 Epoxy Resin Base Bo nding Systems ..................................................................... DIVISION 1700 728.3 CONSTRUCTION REQUIREMENTS Remove and dispose of the unsound concrete to the limits shown in the Contract Documents. Do not damage sound concrete that is to remain in-place. Repair any damage to the existing structure caused during removal. Prior to placing any new concrete, clean all reinforcing steel exposed during the removal of the unsound concrete. Apply an epoxy resin base bonding system to th e adjacent concrete surfaces before placing any new concrete. If epoxy resin dries, reapply another coating. If the new concrete is placed using conventional met hods, construct and cure the bridge curb according to
Division 700
If the new concrete is placed by the concrete surface repair-shotcrete method, apply the concrete according to SECTION 826 . 728.4 MEASUREMENT AND PAYMENT The Engineer will measure repaired bridge curb al ong the base of the curb by the linear foot. Payment for "Bridge Curb Repair" at the contract un it price is full compensation for the specified work. 729 - MULTI-LAYER POLYMER CONCRETE OVERLAY 700-109 SECTION 729 MULTI-LAYER POLYMER CONCRETE OVERLAY 729.1 DESCRIPTION Prepare the surface of the reinforced concrete bridge deck and constr uct a multi-layer polymer concrete overlay (overlay) as shown on the Contract Documents. Provide an overall combination of labor and equipmen t with the capability of proportioning and mixing the polymer resin components and placing the primer and ag gregate, in accordance with this specification and the manufacturer/supplier’s recommendations. B I D I T E M U N I T S Multi-Layer Polymer Concrete Overlay Square Yard 729.2 MATERIALS
a.General.
1.Proportion all polymer materials according to the manufacturer/supplier’s recommendations.
2.Provide the Engineer with a copy of the pol ymer materials manufacturer/supplier’s mixing and application recommendations.
3.If concrete bridge deck patching is specified, polymer concrete materials may be used for patching of the concrete bridge deck. See SECTION 731 .
b.Epoxy. Provide a Type III epoxy resin as defined in DIVISION 1700 .
c.Polyester. Provide a polyester resin as defined in DIVISION 1700 .
d.Aggregate.
1.Provide FA-C aggregate meeting TABLE 1102-5 and TABLE 1102-6 , or
2.As provided by the polymer concrete overlay supplier in a prequalified system, DIVISION 1700 . 729.3 CONSTRUCTION REQUIREMENTS
a.General. Wet cure concrete on new bridge decks for 14 da ys and allow the deck to dry for 21 days before applying the overlay. Portland cement concrete patches require a minimum cure period of 28 days before application of the overlay. At the preconstruction conference, discuss the patching material and the corresponding curing period. Submit changes, including a written statement from the polymer manufacturer/supplier recommending changes, to the Engineer for approval.
b.Equipment. Equipment is subject to approval of the Engineer and must comply with these requirements: (1) Surface Preparation Equipment.
a.Shot blasting equipment capable of produci ng a surface relief equal to the International Concrete Repair Institute (ICRI) Surface Prepar ation Level 6 to 7 or ASTM E 965 Pavement Macrotexture Depth of 0.04 to 0.08 inch. Fi nal acceptance is based on testing procedures as outlined in KT-70, Part V.
b.Shot/Sand blast equipment capable of pro ducing the required surface relief on the deck adjacent to bridge rails and barriers and ar eas not accessible with shot blast equipment.
c.Empty shot blasters and dispose of waste material a minimum of 50 feet from the prepared bridge deck. On long structures empty shot blas ters on the unprepared surface a minimum of 50 feet from prepared surface to prev ent contamination of the deck by return of dust to the prepared surface. (d) The Engineer must approve the use of scarifiers, scrablers or milling machines. 729 - MULTI-LAYER POLYMER CONCRETE OVERLAY 700-110 (e) Wet sand blasting is prohibited.
2.Mechanical Application Equipment.
a.Polymer mixing and distributio n system capable of accurate and complete mixing of the polymer resin and hardening agent, verificati on of the mix ratio and uniform and accurate distribution of the polymer materials at the specified rate on 100% of the work area.
b.A self-propelled aggregate spreader (if requir ed) capable of uniform and accurate application of the dry aggregate over 100 % of the work area.
c.An air compressor capable of producing a sufficient amount of oil free and moisture free compressed air to remove all dust and loose material.
d.Adequate additional hand tools to facilitate the placement of the polymer concrete overlay in accordance with this specifica tion and the manufacturer/s upplier’s recommendations.
3.Hand Application Equipment.
a.Calibrated containers for accurate m easurement of the po lymer components.
b.Paddle type mixer or other mixing device cap able of accurate and complete mixing of the polymer resin and hardening agent. (c) Notched squeegees and brooms capable of spre ading the polymer material in accordance with this specification and the manufact urer/supplier’s recommendations.
d.Aggregate spreader capable of uniform and accurate appli cation of the dry aggregate.
e.Adequate additional hand tools to facilitate th e placement of the polymer concrete overlay in accordance with this specifica tion and the manufacturer/s upplier’s recommendations.
c.Preparation of Surface.
1.When specified, perform any required repairs under SECTION 731 and cure repairs, before preparation of the surface, unless placed with the overlay.
2.Protect metal deck drains and areas of the curb or railing above the proposed surface from the shot blast.
3.Close deck drains so the overlay materials will not pass through the drains. (4) Remove any remaining contamination of the prepared deck surface or surface of subsequent courses. Sand blast or bush hammer contaminat ed areas to produce an acceptable surface for placement of the overlay.
5.As the final preparation for the placement of the overlay, make a complete cleanup by shot blasting and/or other approved means, followed by an air blast with dry, oil free air or vacuum. Brooming is not acceptable. Remove all pavement marking, loose disintegrated concrete , dirt, paint, oil, asphalt, laitance carbonation and curing materials from patches and other foreign material from the surface of the deck.
6.Produce a surface relief equal to the International Concrete Repair Institute (ICRI) Surface Preparation Level 6 to 7 or ASTM E 965 Pavement Macrotexture Depth of 0.04 to 0.08 inch.
7.Place the first coat of the overlay within 24 hours of preparing th e deck surface. Prepared surfaces exposed for more than 24 hours must be lightly sand blasted prior to application of the overlay.
d.Placing the Multi-Coat Polymer Concrete Overlay. Place the overlay to the grades, thickness and cross-sections as shown in the Contract Documents. Provide a technical repr esentative of the polymer manufacturer/supplier on the job site du ring the placement of the overlay at no ad ditional cost. The representative is to provide technical expertis e to the Contractor and the Engineer regard ing safe handling, placement and curing of the overlay.
1.Visible moisture on the prepared deck at the time of placing the overlay is unacceptable. Identify moisture in the deck by taping a plastic sheet to the deck for a minimum of 2 hours (ASTM D 4263).
2.Rain will not necessarily cont aminate the surface. However, ta ke care so no contamination has occurred. Traffic adjacent to the prepared su rface during a rain will contaminate the surface.
3.Follow all manufacturer/supplier suggested safe ty precautions while mixing and handling polymer components.
4.Apply High Molecular Weight Methacrylate Prim er, if required, at application rates shown in TABLE
729-1 , or as directed by the mate rial’s manufacturer/supplier.
5.Place the overlay in 2 separate co urses at application rates shown in TABLE 729-2 for the system being placed.
6.Use notched squeegees or mechan ical application equipment to place the prepared polymer on the deck immediately and uniformly at the prescribed rate. 729 - MULTI-LAYER POLYMER CONCRETE OVERLAY 700-111 (7) If mechanical application equi pment is used, take 2 ounce samples for each 100 gallons of resin placed to verify mix ratios and curing times. Place samples on the bridge rail or deck and note time to cure.
8.The bridge deck and all polymer and ag gregate components must be at least 60 F at the time of application.
9.Apply the dry broadcast aggregate to cover the polymer uniformly and completely within 10 minutes of application.
10.Remove and replace any first course areas that do not receive enough aggregate before gelling of the polymer.
11.Vacuum or broom excess aggregate from the first course after sufficiently cured. If damage or tearing occurs, stop brooming or vacuuming and allow additional curing time. See TABLE 729-3 for curing guidelines.
12.Do not open the first course to traffic. (13) Place the polymer and aggregate fo r the second course at the prescribed rate and in the same manner as the first course. The second course can be placed immedi ately after brooming of the first course is completed.
14.Recoat second course areas that do not receive enough aggreg ate before gelling of the polymer with additional polymer and aggregate.
15.Locate any longitudinal joints along lane lines, or as approved by the Engineer . Keep the joints clear of wheel paths as much as practical.
16.Produce and place the overlay w ithin the specified limits in a c ontinuous and uniform operation.
17.Correct completed surface variations exceeding ⅛ inch in 10 feet, unless directed otherwise by the Engineer.
18.Tape all construction joints to provide a clean st raight edge for adjacent po lymer concrete placement. This includes joints between previously pl aced overlay material s and at centerline.
19.Finish the exposed edges at the ends of the bridge and at expansion joints to minimize bridge deck roughness.
20.Apply a bond breaker to all expansion joints. (21) Vacuum or broom excess aggregat e from the bridge deck after the pol ymer is sufficiently cured. If damage or tearing occurs, stop brooming or vacuuming and allow additional curing time.
e.Face of Curbs, Barriers , and Corral Rail Posts. Use a paintbrush or roller to apply the polymer resin on the face of curbs, barrier s, and corral rail posts. On bridges with a corral rail, apply the polymer resin to the front face and adjacent sides of all posts. On bridges with curbs apply the polymer resin to the top of the curb face. On bridges without curbs apply the polymer resin to the edge of the deck. On bridges with continuous concrete barrier rails, apply the polymer resin to the first break in the geometry of the barrier or a minimum of 6 inches , uniform. Protect areas above the break line (or minimum of 6 inches) from resin. Apply so the top threshold of the resin follows a uniform line along the rail. This work is subsidiary to the bid item Multi-Layer Polymer Concrete Overlay. Apply primer (if required) and polymer to the curb or barrier as each of the overlay applications are performed.
f.Application Rates . Place epoxy and polyester materials at the same rate. Place primer (if required) at the application rate shown in TABLE 729-1 . Place the overlay in 2 separate cour ses at application rates shown in TABLE 729-2 . TABLE 729-1: HIGH MOLECULAR METH ACRYLATE PRIMER APPLICATION RATES for MULTI-LAYER POLYMER CONCRETE OVERLAYS Primer Each Coat Not Less Than 0.09 gal./sq yd TABLE 729-2: APPLICATION RATES for MULTI-LAYER POLYMER CONCRETE OVERLAYS Course Polymer Rate Aggregate Rate * 1 Not Less Than 0.22 gal./sq yd 10 lbs./sq yd 2 Not Less Than 0.45 gal./sq yd 14.5 lbs./sq yd *Apply enough aggregate to completely cover the polymer. 729 - MULTI-LAYER POLYMER CONCRETE OVERLAY 700-112 g. Curing.
1.Epoxy. Minimum curing times are noted in TABLE 729-3 . TABLE 729-3: EPOXY CURE TIMES for MULTI-LAYER POLYMER CONCRETE OVERLAYS Course Average Temperature of Overlay Components, °F
55-59 60-64 65-69 70-74 75-79 80-85 85+
Minimum Cure Time (hours) 1 5 4 3 2.5 2 1.5 1 2 6.5 6.5 5 4 3 3 3 Cure the second course for 8 hours if the air temperature falls below 55 F during the curing period before opening to traffic.
2.Polyester. Proportion polyester courses so the cure times are between 30 and 120 minutes. Accelerators and inhibitors may be requ ired to achieve proper set times. Pr oportion all materials as recommended by the material supplier.
3.Plan and perform the work in such a way as to provide for the minimum curing times specified in this specification or as specified by th e material manufacturer/supplier.
h.Testing. Perform Polymer Concrete Overlay Bond Ev aluation as outlined in KT-70, Part V.
1.Place a polymer concrete test pa tch of not less than 0.5 square yards per lane or planned completed day’s work whichever is smaller. Submit a sequence plan to the Engineer. Test patches shall be full depth, placed by the normal construction sequence. Test patches should be representative of the work being performed.
2.Perform a minimum of 4 pull-off tests on each patch as outlined in KT-70, Part V.
3.Final acceptance will be based on the following re sults of the test outlined in KT-70, Part V: Type 1 – Failure in the concrete at a depth greater than or equal to ¼ inch over more than 50% of the test area for 3 out of 4 tests in the test patch. Type 2 – Failure in the concrete at a depth less than ¼ inch over more than 50% of the test area for 3 out of 4 tests in the test patch. Minimum Tensile Rupture Strength of 250 psi from an average of 3 out of 4 tests on a test patch regardless of depth of failure.
4.If failure in the concrete is at a depth less than ¼ inch and the Minimum Tensile Rupture Strength is less than 250 psi, or the failure in the concrete is less than 50% of the test area, ad ditional surface preparation is necessary.
5.A failure in the concrete below 250 psi and greater than ¼ inch deep indicates weak concrete, not poor overlay bond. No additional su rface preparation is required.
6.Do not perform tensile adhesion tests when ambient or deck temper atures are above 85°F.
i.Correction of Unbonded or Damaged Areas. Repair new overlay areas discovered to be unbonded by tapping or chaining and areas where the overlay was damaged by the Contractor’s operation. Saw cut the unbonded or damaged areas to the top of the deck surface, remove the overlay with small air t ools (15-pound class maximum) or shot blasting. Aggressively sandblast or shot blast the concrete bridge deck surface at the unbonded area to remove contaminants. Replace the overlay according to standard placement proc edures at no additional compensation.
j.Weather Limitations.
1.Epoxy. Do not place the overlay if the ai r temperature is expected to drop below 55 F within 8 hours of placement.
2.Polyester. Do not place any component of the overlay if the air or substrate temperature is at or expected to drop below 40 F during installation.
3.General. Do not place the overlay wh en the deck temperature will exceed 90 F. Do not place the overlay if gel time is less than 10 minutes. The overlay may be placed outside the specified temperature ranges with the approval of the Engineer and the material manufacturer/supplier. Discuss changes to temperature limitations at the preconstruction conference.
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 431–443 of 978.