5-121
518.01 Description This work shall consist of repairing existi ng structural concrete as
shown on the Plans and/or as dir ected by the Resident. Repair ing structural concrete shall include removal and disposal of deteriorated concrete, cleaning exposed reinforcing steel, cleaning of concrete surfaces in repair areas, application of b onding agent and placing and curing repair material. All work shall be in conformance with applicable provisions of Sections 202, 502, and 503. Upward Facing Surfaces are defined as any concrete surfaces whe re the slope is less than or equal to 15 percent from the horizontal. Overhead Surf aces are defined as any concrete surfaces where the slope is overhanging more than 15 p ercent from plumb. All other surfaces shall be defined as Vertical Surfaces.
518.02 Repair Materials A material that has been NTPEP tested and from the
Department’s Qualified Products L ist (QPL) of Rapid Setting Con crete Patching Materials may be used instead of concrete for any depth of placement, at the Contractor’s option, providing that all requirements of the manufacturer’s published recommendations are met. All materials used for repair of concrete or reinforcing steel shall meet the applicable requirements of Division 700 as specified in Standard Specifica tion Sections 502 and 503, respectively. When concrete is used as the repair material, it shall conform to the requirements of Table 1 of Section 502.05 for Class A Concrete. Where the depth of placement is less than 1 inch, the repair ma terial used shall be one of the products listed on the Department’s QPL of Rapid Setting Co ncrete Patching Materials. Where the depth of placement is equal to or greater than 1 inch , the Contractor may use concrete as the repair material. When concrete is used, the co arse aggregate shall conform to the requirements of the following tables. Thickness of Placement Coarse Aggregate Gradation Designation 1 to 3 inches 3 to 6 inc hes > 6 inches SP-1-7 x SP-1-78 x SP-2-8 x SP-2-89 x Class AA x Class A or AA x x Coarse Aggregate Gradation Designation Sieve Designation Percent By Weight Passi ng a Square Mesh Sieve ¾ in ½ in ⅜ in No. 4 No. 8 No. 16 No. 50 No.200 SP-1-7 100 90-100 40-70 0-15 0-5 - - 0-1.5 SP-1-78 100 90-100 40-75 5-25 0-10 0-5 - 0-1.5 SP-2-8 100 85-100 10-30 0-10 0-5 - 0-1.5 5-122 SP-2-89 100 90-100 20-55 5-30 0-10 0-5 0-1.5 A bonding material shall be used for bonding fresh concrete or patching material to existing hardened concrete. The bonding material shall consist of the following, except that, in the case where patching materials from the QPL are used in t he repair areas, the manufacturer’s published recommendations regarding application and use of bonding materials shall take precedence:
a.For repair of Upward Faci ng Surfaces, the bonding grout shal l have Portland cement and fine aggregate proportioned 3 to 1, respectively, by volume . The fine aggregate shall be from the same source as that used in the repair concrete. All material greater than ⅛ inch shall be removed from the fine aggregate. The sand and cement shall be measured separately in equal sized containers. The sand shall be added prior to the cement. Water shall be added during the mixing process a little at a time unt il sufficient water has been added to result in a workable consistency. A workable consiste ncy is defined as the minimum water necessary to allow flow of most of the grout with out segregation of the grout ingredients. Alternately, t he Contractor may use a produ ct from the Department’s QPL of Concrete Bonding Agents i n accordance with the manufactu rer’s published recommendations.
b.For repair of Vertical and O verhead Surfaces, the Contractor shall use a product from the Department’s QPL of Concrete Bonding Agents, in accord ance with the manufacturer’s published recommendations.
518.03 Removal of Unsound Concrete Removal of existing concret e shall be
accomplished without damage to the portion of the structure tha t is to remain. The deteriorated or delaminated concrete shall first be removed fro m areas designated by the Resident. The initial classification of an area as sound concr ete does not prevent its subsequent reclassification upon f urther inspection. After the initial removal of unsound concrete, the Resident shall inspect the area again to determin e whether additional areas of unsound concrete were revealed by removal operations and if add itional concrete removal is required in the areas to be repaired. This process shall conti nue until additional areas of unsound concrete are not revealed. After the Resident has dete rmined that the deteriorated concrete has been completely and satisfactorily removed, the pe rimeter of each cavity created by the removal of concrete shall be saw cut to a minimu m depth of ⅝ inch, unless a lesser depth is required to avoi d reinforcing steel. The saw c ut shall be approximately perpendicular to the original surface. Edges of the cavity sha ll not be feathered. Unless otherwise approved by the Resident, the equipment used f or removal of unsound concrete shall be chipping hammers weighing a maximum of 35 pou nds and only chisel point bits will be allowed. The surface area and depth of removal for concrete repairs shal l be subject to the approval of the Resident. 5-123 Deteriorated concrete shall be removed to one of the following depths, whichever is greatest:
a.Sound substrate. b) To the minimum depth required per the manufacturer’s recomme ndations, when a material from the Department’s QPL of Rapid Setting Concrete Pa tching Materials is used.
c.To the minimum depth indicated in the Thickness of Placement Table, when concrete is used, depending on the coarse aggregate gradation.
d.When reinforcing steel is exposed or encountered, the minimu m depth shall be 1 inch behind reinforcing steel f or Upward Facing Surfaces and 1- ½ inches behind reinforcing steel for Vertical and Overhead Surfaces.
518.04 Reinforcing Steel All existing reinforcing steel expose d by concrete removal,
which is to remain in the structure , shall be cleaned of all l oose rust by sand blasting, wire brushing, machine wire brushing or other methods approved by th e Resident. Where reinforcing steel is to remain in the structure, care shall be taken to prevent damage to the reinforcing steel or its bond to the surrounding concrete. All existing main reinforcing steel which is broken, or has los t 25 percent, or more, of its original cross sectional area, shall be supplemented with new r einforcing steel. The total area of supplemental bars plus existing bars with section loss shall have the same total area as the original bar. Supplementary reinforcing steel shall be l ap spliced a minimum length of 30 bar diameters for bars with section loss of up to 75 percent of the original bar area, and per Section 503, Reinforcing Steel , for all other bars. Reinf orcing steel shall be wired to the existing steel or, where designated by the Resident, the ex isting reinforcing steel shall be cut and supplementary reinforcing steel spliced in with tension couplers.
518.05 Surface Preparation The surfaces to receive repair mate rial shall be free of oil,
solvent, grease, dirt, loose particles and foreign matter. Cle aning of repair areas shall be performed by sandblasting or other methods approved by the Resi dent. All surfaces receiving new material are to be sandblasted not more than 36 h ours ahead of the placement of the repair material, or as per the bonding agent manufacture r’s recommendations. Any sandblasted areas that have been rained on, exposed to high hum idity or fog, or contaminated in any other manner shall be sandblasted again bef ore the repair material is applied. All debris from the cleaning operations shall be thor oughly removed from the cleaned surfaces and adjacent areas using compressed, dry, air, prior to the application of repair materials. All air compressor lines used for cleaning o f repair areas shall be equipped with effective oil traps.
518.06 Application of Bonding Agent When bonding grout is used on repair of upward
facing surfaces the following shall apply, except that, in the case where products from the Department’s QPL of Rapid Setting Concrete Patching Materials a re used in the repair areas, the manufacturer’s published recommendations regarding a pplication and use of 5-124 bonding materials shall take precedence. Once a workable consi stency has been reached, additional water shall not be added. The grout must be used or discarded within 30 minutes of the time water is added to the mix. The grout shall be appl ied no greater than ⅛ inch thick with stiff bristled, nylon, street brooms. The Contracto r shall prevent the grout from drying by beginning the grout appli cation immediately prior to the concrete placement and limiting the area of grout application ahead of concrete placem ent. If the grout begins to dry prior to concrete placement, additional grout may be brushed on the area as directed by the Resident. Should the grout become thoroughly dry it shall be r emoved by sand blasting or other methods as approved by the Resident. When a product from the Department’s QPL of Concrete Bonding Ag ents is used, it shall be applied in accordance with the manufacturer’s publishe d recommendations.
518.07 Placing Repair Materials When concrete is used as the r epair material the
provisions of Section 502 shall apply. Additionally, concrete shall not be placed when either the ambient air temperature or the existing concrete tem perature is below 45 degrees Fahrenheit. When a patching material is used, the Contractor s hall follow the manufacturer’s published recommendations for mixing and placing the material. Forms shall be erected to the neat lines of the existing struct ure and the new concrete placed. For overhead and vertical repair areas, sufficient con crete shall be removed to ensure that air within the area to be patched can effectively e scape during the placement of the repair material.
518.08 Curing Curing of concrete sha ll conform to the requirem ents of Section 502. For
Overhead and Vertical Surfaces, curing compounds may be used, i n accordance with the manufacturer’s requirements. Patching materials shall be cured in accordance with the manufacturer’s published recommendations.
518.09 Inspection The Contractor shall make provisions to allo w safe access to the
work for the Resident in order to inspect the work, facilitate ongoing inspection of the work and to measure the work for payment purposes.
518.10 Method of Measurement Repair of structural concrete is divided into repair
areas less than 8 inches in depth and repair areas 8 inches in depth or greater. The repair depth shall be considered the a verage thickness of an individua l repair area. The Resident shall make the final determination as to whether the average de pth of repair is less than 8 inches, or 8 inches or greater. Concrete repair will be measured for payment by the square foot of all surfaces repaired where the average depth of repair is less than 8 inches, comple te and accepted. Concrete repair will be measured for payment by the cubic yard for all repairs where the average depth of repair is 8 inches or greater, complete and ac cepted. The quantity will be determined from the theoretical yield of the design mix, or in the case of transit mixed concrete, by delivery ticket, as directed by the Resident. 5-125 Supplementary reinforcing steel will be measured for payment by the pounds of steel provided and installed and paid for under Item 503.12, Reinforc ing Steel, Fabricated and Delivered, and Item 503.13 Reinforcing Steel, Placing, respecti vely, except that Reinforcing Steel, Placing, will be measured for payment as 1.5 times the a ctual number of pounds placed. Reinforcing steel required to supplement reinforcing s teel damaged by the Contractor shall be supplied and installed at the Contractor’s expense. Tension couplers will be measured for payment as the number of splices satisfactorily installed and accepted. Payment will be made under Item 503.17 , Mechanical/Welded Splices. Couplers required to repair reinforcing steel damaged by the Contractor shall be provided and installed at the Contractor’s expense. Temporary support beams or girders required to repair bridge se ats or pier caps will be paid for separately, as approved by the Resident.
518.11 Basis of Payment The repair of structural concrete will be paid for at the
contract unit price as indicated i n the Schedule of Items for t he respective Contract item involved. The following will be included in the unit price for the respec tive concrete items, complete and accepted: Removal of existing concrete; cleaning of existing reinforcing steel to remain in the structure; cleaning of existing concrete surfa ces in repair areas; furnishing and installing bonding materials; providing, installing and rem oval of all formwork; furnishing and placing new concrete or other approved concrete patching materials in areas where existing concrete is removed; curing of concrete or patch ing materials; disposal of all demolition material and debris. Payment for any staging, platforms or lifts required by the Con tractor to gain access to the work in order to perform the work, or to provide access to the Resident in order to inspect or measure the work, shall be considered incidental to related Contract items unless the Contract provisions specify separate payment for such acces s devices. Fabrication, delivery and placing of reinforcing steel, and mec hanical couplers if required, will be paid for under separate Contract items. The payment for each Contract item will also be full compensati on for furnishing all materials, labor, equipment, and all other incidentals necessar y to complete the work. Payment will be made under: P a y I t e m P a y U n i t
518.50 Repair of Upward Facing Surf aces- to Reinforcing Steel Square Foot
< 8 inches 518.51 Repair of Upward Facing Surfaces- below Reinforcing Ste el Square Foot 5-126 < 8 inches
518.52 Repair of Upward Facing Surfaces > 8 inches C u b i c Y a r d
518.60 Repair of Vertical Surfaces < 8 inches S q u a r e F o o t
518.61 Repair of Vertical Surfaces > 8 inches C u b i c Y a r d
518.70 Repair of Overhead Surfaces < 8 inches S q u a r e F o o t
518.71 Repair of Overhead Surfaces > 8 inches C u b i c Y a r d
SECTION 519 - EXPANSION DEVICES – ASPHALTIC PLUG JOINT
519.01 Description This work consists of furnishing and insta lling asphaltic plug joint
systems at the locations shown on the Plans, in accordance with these Specifications, and as directed by the Resident. This work shall include furnishing, i nstallation, and removal of all bond breaking materials used to prevent asphalt pavement layers from adhering to waterproofing membrane, all temporary header(s) installed with the intent to form the asphaltic plug joint channel, and all preparation required for the installation of the asphaltic plug joint. This work shall also include ha ving the approved manufacturer p rovide a qualified technical representative to supervise the installation of the j oint systems. The representative shall instruct, train, and supervise the Contractor’s personnel in the proper methods of installation. All costs associated with this service shall be i ncluded in the unit price of the work.
519.02 Submittals Prior to construction, the Contractor shall submit the following to
the Resident for review and approval:
a.Complete and detailed Shop Drawings of the asphaltic plug j oint system. Shop Drawings shall include information covering materials, their pr operties, installation procedures, storage and handling requirements, and Safety Data Sheets.
b.The resume of the manufacturer’s technical representative, which shall include the representative’s experience installing the asphaltic plug joint system along with the names and telephone numbers of contact persons for recent projects wh ere technical assistance was provided.
c.Certified test reports of the asphaltic binder, closed cell foam backer rod, and the plastic compound.
d.Certificates of Compliance for bridging plates, centering n ails, and aggregate.
519.03 Materials An asphaltic plug joint system from Departme nt’s Qualified Products
List for Expansion Devices – Non- Modular (Asphaltic Plug Joints ) shall be used.
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 413–418 of 817.