7-36 After initial set, the temperature gain of the concrete shall n ot exceed 40 F per hour. Initial set shall be determined in accordance with ASTM C403, Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance; a strength gain of 500 psi indicates initial set. The maximum all owable concrete temperature shall be 160 F. Concrete temperature shall be measured during curing with recording thermometers. In order to qualify for accelerat ed cure, the concrete temperature shall attain a minimum temperature of 120 F; that temperature shall be maintained for a minimum of 8 hours and the concrete shall achi eve a minimum of 80 percent of design strength. The accelerated curing cycle shall be considered complete when the method of supplying heat is stopped and/or the concrete temperature drops below 120°F. Two cylinders shall be tested immediately upon completion of the ac celerated cure cycle. Products that have not achieved all of the above criter ia shall be moist cured until the concrete has achieved design strength. If the precast units have achieved 80 percent of design strengt h during the accelerated curing cycle, no further curing will be required. The forms shall remain in place until the concrete attains a mi nimum compressive strength of 3,000 psi. Concrete Testing Acceptance of structural precast units, for e ach day’s production, will be determined by the Department, based on compliance with this specification and satisfactory concrete testing results. At least once per week, the QAI will make 2 concrete cylinders (6 cylinders when the Contract includes permeability requirements) for use by the Dep artment; cylinders shall be standard cured in accordance with AASHTO T23 (ASTM C31). The Q AI will perform entrained air content and slump flow testing, determine water-c ement ratio and determine temperature of the sampled concrete at the time of cylinder cas ting. All testing equipment required by the QAI to perform this testing shall be in accorda nce with Standard Specification Section 502.041, Testing Equipment. In addition, the Contractor shall provide a slump cone meeting the require ments of AASHTO T 119. Providi ng and maintaining testing and curing equipment shall be considered incidental to the work and no additional payment will be made. Quality Control test cylinders shall be made and tested in acc ordance with the following standards: AASHTO T 22 (ASTM C39) Test Met hod for Compressive Strength of Cylindrical Concrete Specimens AASHTO T23 (ASTM C31) Practice for Making and Curing Concrete T est Specimens in Field AASHTO T141 (ASTM C172) Practice for Sampling Freshly Mixed Con crete AASHTO T152 (ASTM C231) Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method 7-37 AASHTO T196 (ASTM C173) Standard T est Method for Air Content of Freshly Mixed Concrete by the Volumetric Method ASTM C1064 Test Method for Temperature of Freshly mixed Portlan d Cement Concrete ASTM C1611 Standard Test Method for Slump Flow of Self-Consolid ating Concrete Tested concrete shall conform to the following:
a.Temperature shall be from 40 o F to 85o F.
b.Air content shall be 5.5% to 7.5%.
c.Slump flow shall be homogenous with no sign of segregation.
d.Visual stability index (VSI) of S CC shall not exceed 1; if a mo rtar paste halo is present it shall not exceed an average of 0.25 inch. The Contractor shall cast a minimum of 8 concrete test cylinder s for each continuous concrete placement, for QC purposes: 2 cylinders shall be stan dard cured in accordance with AASHTO T23 (ASTM C31) to be tested for 28 day strength; an d a minimum of 6 cylinders shall be field cured under the same conditions as the units and tested for stripping and design strength. Unit identification, entrained air conten t, water-cement ratio, slump flow and temperature of the sampled concrete shall be recorded at the time of cylinder casting. The Contractor shall perform all testing in the prese nce of the QAI. The QAI will designate the loads to be tested. If the Contractor fails to make enough cylinders to demonstrate that the product meets the Contract requirements, the product will be considered unacc eptable. The compressive strength of the concrete will be determined by averaging the compressive strength of two test cylinders made from the same s ample. For the purpose of determining design strength, the average of two cylinders shall meet or exceed the design strength, and the difference in strength between the two shall be no more than 10 percent of the higher strength cylinder. Perform compressive strength testing to determine stripping and design strength in the presence of the QAI. Cylinder tests not witnessed by the QAI w ill not be acceptable. All QC Inspectors performing concrete testing shall hold a curr ent ACI Field Testing Technician Grade I Certification, or other equivalent certifica tion. Surface Finish and Repairs. Exposed surfaces shall be finished and repaired in conformance with the reference d specification. If the finish is not specified, then surfaces shall have a uniform appearance; make repairs to remove and ble nd fins, patch minor spalls, tie holes, handling device recesses, entrapped air pockets, hon eycombing, ragged or irregular edges and other non-structural or cosmetic defects us ing a patching material from the Department Qualified Products List (QPL). The repair, inclu ding preparation of the repair area, mixing and application and curing of the patching material, shall be in accordance with the manufacturer's product data sheet. Corners not exposed in the final product may be ground smooth with no further repair necessary, if the depth of the defect does not exceed one-half inch. Remove form ties and other hard ware to a depth of not less 7-38 than one inch from the face of the concrete and patch the holes using a patching material from the Department QPL. Repair of structural defects: Structural defects include, but are not be limited to, exposed reinforcing steel, cracks in bearing areas, through cra cks and cracks 0.013 inch in width that extend more than 12 inches in length in any directio n. Repair structural defects only with the approval of the Fabrication Engineer. Submit a no nconformance report (NCR) to the Fabrication Engineer wit h a proposed repair procedure. D o not perform structural repairs without an NCR that has been reviewed by the Fabricatio n Engineer. Give the QAI adequate notice prior to beginning any structural repairs. Tolerances Dimensional tolerances shall be in conformance with the applicable referenced specification or the established industry standards for the product being produced. Documentation The producer of the structural precast units sha ll keep accurate records of aggregate gradations, concrete batching, testing, curing, an d inspection activities, verifying that forms, reinfor cing and unit dimensions conform t o these requirements. Copies of reports s hall be furnished to the Depa rtment. Marking The date of manufacture, production lot number and ty pe of unit shall be clearly and indelibly inscribe d by the Contractor on a rear or unexposed portion of each unit. Handling, Storage and Shipping The Contractor shall handle, st ore, and ship units in such a manner as to prevent chipping, cracking, fractures, and excessive bending stresses. Damaged units shall be repaired or replaced.
712.07 Catch Basin and Manhole Frames, Grates and Covers, Drai nage, Sewer,
Utility, and related castings shall conform to the plan dimens ions and shall be gray iron or ductile iron castings conforming to t he requirements of AASHTO M 306.
712.08 Corrugated Metal Units The units shall conform to plan dimensions and the
metal to AASHTO M36/M36M. Bituminous coating, when specified, s hall conform to AASHTO M190 Type A.
712.09 Catch Basin and Manhole Steps Steps for catch bas ins and for manholes
shall conform to ASTM C478M [ ASTM C478], Section 13 for either of the following material:
a.Aluminum steps-ASTM B221M, [ASTM B211] Alloy 6061-T6 or 600 5-T5.
b.Reinforced plastic steps Steel reinforcing bar with injecti on molded plastic coating copolymer polypropylene. Polypropylen e shall conform to ASTM D 4101.
712.23 Flashing Lights Flashing Lights shall be power op erated or battery operated
as specified.
a.Power operated flashing lights shall consist of housing, ad apters, lamps, sockets, reflectors, lens, hoods and other necessary equipment designed to give clearly visible signal indications within an angle of at least 45 degrees and from 10 to 300 ft under all light and atmospheric conditions. 7-39 Two circuit flasher controllers with a two-circuit filter capab le of providing alternate flashing operations at the rate of not less than 50 nor more th an 60 flashes per minute shall be provided. The lamps shall be 650 lumens, 120 volt traffic signal lamps wi th sockets constructed to properly focus and hold the lamp firmly in position. The housing shall have a rotatable sun visor not less than 7 in ches in length designed to shield the lens. Reflectors shall be of such desi gn that light from a properly f ocused lamp will reflect the light rays parallel. Reflectors shall have a maximum diameter a t the point of contact with the lens of approximately 8 inches. The lens shall consist of a round one-piece convex amber materi al which, when mounted, shall have a visible di ameter of approximately 8 inche s. They shall distribute light and not diffuse it. The distribu tion of the light shall be asy mmetrical in a downward direction. The light distribu tion of the lens shall not be uni form, but shall consist of a small high intensity portion with narro w distribution for long distan ce throw and a larger low intensity portion with wide distribution for short distance thr ow. Lenses shall be marked to indicate the top and bottom of the lens.
b.Battery operated flashing lights shall be self- illuminated by an electric lamp behind the lens. These lights shall also be externally illuminated by reflex-reflective elements built into the lens to enable it to be seen by reflex-reflection of t he light from the headlights of oncoming traffic. The batteries must be entirely enclosed in a case. A locking device must secure the case. The light shall have a flash rate of not less than 50 nor more than 60 flashes per minute from minus 20 °F to plus 150 °F. The light shall ha ve an on time of not less than 10 percent of the flash cycle. The light beam projected upon a surface perpendicular to the axis of the light beam shall produce a lighted rectangular proj ection whose minimum horizontal dimension shall be 5 degrees each side of the horizo ntal axis. The effective intensity shall not have an initial value greater than 15.0 can delas or drop below 4.0 candelas during the first 336 hours of continuous flashing. Th e illuminated lens shall appear to be uniformly bright over its entire illuminated surface when viewed from any point within an angle of 9 degrees each side of the vertical axis and 5 degr ees each side of the horizontal axis. The lens shall not be less than 7 inches in diameter incl uding a reflex-reflector ring of ½ inch minimum width around the periphery. The lens shall be ye llow in color and have a minimum relative luminous transmittance of 0.440 with a luminan ce of 2854° Kelvin. The lens shall be one-piece construction. The lens material shall be plastic and meet the luminous transmission requirements of this specification. The case containing the batteries and circuitry shall be constructed of a material capable of wit hstanding abuse equal to or greater than 1.21 mm thick steel [No. 18 U.S. Standard Gage Ste el]. The housing and the lens frame, if of metal shall be properly cleaned, degreased an d pretreated to promote adhesion. It shall be given one or more coats of enamel which, when dry shall completely obscure the metal. The enamel coating shall be of such quality that when the coated case is struck a light blow with a sha rp tool, the paint will not chip or crack and if scratched with a 7-40 knife will not powder. The case shall be so constructed and cl osed as to exclude moisture that would affect the proper operation of light. The case shal l have a weep hole to allow the escape of moisture from condensation. Photoelectric controls, if provided, shall keep the light operating whenever the ambient light falls below 215 lx [ 20 foot candles]. Each light shall be plainly marked as to the manufacturer's name and model number. If required by the Resident, certification as to conformance to these specifications shall be furnished based on results of tests made by an independent t esting laboratory. All lights are subject to random inspection and testing. All necessary ra ndom samples shall be provided to the Resident upon reque st without cost to the Depar tment. All such samples shall be returned to the Contr actor upon completion of the test s.
712.32 Copper Tubing Copper tubing and fittings shall co nform to the requirements
of ASTM B88M Type A [AS TM B88, Type K] or better.
712.33 Non-metallic Pipe, Flexible Non-metallic pipe and pipe fittings shall be
acceptable flexible pipe manufactured from virgin polyethylene polymer suitable for transmitting liquids intended for human or animal consumption.
712.34 Non-metallic Pipe, Rigid Non-metallic pipe shall be Schedule 40
polyvinylchloride (PVC) that meets the requirement of ASTM D178 5. Fittings shall be of the same material. 712.341 Metallic Pipe Metallic pipe shall be ANSI, Stand ard B36.10, Schedule 40 steel pipe conforming to the requi rements of ASTM A53 Types E o r S, Grade B. End plates shall be steel conforming to ASTM A36/A36M. Both the sleeve and end plates shall be hot dip galvanized. Pip e sleeve splices shall be welded splices with full penetration weld before galvanizing.
712.35 Epoxy Resin Epoxy resin for grouting or sealing s hall consist of a mineral
filled thixotropic, flexible epoxy resin having a pot life o f approximately one hour at 50°F. The grout shall be an approved product suitable for ceme nting steel dowels into the preformed holes of curb inlets and adjacent curbing. The seala nt shall be an approved product, light gray in color and s uitable for coating the surfa ce.
712.36 Hot Mix Asphalt Curb The performance graded asphalt bi nder for hot mix
asphalt curb shall meet a PG 58-28 or a PG 64-28. The aggregat e shall conform to the requirements of Subsection 703.07. The coarse aggregate portio n retained on the No. 8 sieve may be either crushed rock or crushed gravel. The mineral constituents of the hot mix asphalt shall be sized and graded and combined in a composite blend that will produce a stable durabl e curbing with an acceptable texture. 7-41 Hot Mix Asphalt for curb shall meet the requirements of Sectio n 403 - Hot Mix Asphalt Pavement.
712.37 Precast Concrete Slab Portland cement concrete fo r precast slabs shall meet
the requirements of Section 502 - Structural Concrete, Class A. The slabs shall be precast to the dimension shown on the plans and cross section and in accordance with the Standard Detail plans for Concrete Sidewalk Slab. The surface shall be finished with a float finish in accordance with Subsection 502. 14(c). Lift devices of sufficient strength to hold the slab while suspended from cable s shall be cast into the top or back of the slab.
712.38 Stone Slab Stone slabs shall be of granite from a n acceptable source, hard,
durable, predominantly gray in color, free from seams which imp air the structural integrity and be of smooth splitting character. Natural color variations characteristic of the deposit will be permitted. Exposed surfaces shall be free from drill h oles or indications of drill holes. The granite slabs in any one section of backslope must be all the same finish. The granite slabs shall be scabble dressed or sawed to an appro ximately true plane having no projections or depressions over ½ inch under a 2 ft s traightedge or over 1 inch under a 4 ft straightedge. The a rris at the intersection of th e top surface and exposed front face shall be pitched so that the arris line is uniform through out the length of the installed slabs. The sides shall be square to the exposed face unless th e slabs are to be set on a radius or other special condition which requires that the joints be cu t to fit, but in any case shall be so finished that when the stones are placed side by side no spa ce more than 3/4 inch shall show in the joint for the full exposed height. Lift pin holes in all sides will be allowed except on the expos ed face. SECTION 713 - STRUCTURAL STEEL AND RELATED MATERIAL
713.01 Structural Steel Highway bridge steel shall meet the r equirements of
AASHTO M 270.The grade of steel shall be as specified on the pl ans. Main load-carrying components subject to tensile stresses or st ress reversal shall meet the notch toughness requirements in AASHTO M 270M, Table 10, Zo ne 2, for non-fracture critical steel or Table 11, Zone 2 for fracture critical steel. Frequency of tension tests shall comply with the requirements of S1. Impact test sampling and testing procedures shall be in accorda nce with AASHTO T 243 M/T 243 and AASHTO T 244. 7-42 Steel for ancillary bridge products and steel structures shall conform to AASHTO M 270 or one or more of the following: ASTM A 36 ASTM A 572 ASTM A 588 ASTM A 53 ASTM A 500 ASTM A 595 Grade C ASTM A 786 ASTM A 847 ASTM A 992 Ancillary bridge products shall be as described below: (a) bearings (b) drainage components (c) expansion devices (gland seal, compression seal, finger jo int)
d.modular expansion devices (e) steel bridge rail (f) catwalks and inspection walkways 713.02 High Strength Bolts Bolts shall conform to the requirem ents of ASTM F3125, Grade A 325, Type 1 or Type 3. Type 3 bolts shall be supplied for all structures utilizing unpainted AASHTO M 270Mweathering steel. Nuts shall meet the requirement s of AASHTO M 291 or AASHTO M 29 2. Circular and beveled washers shall conform to the requirements of AASHTO M 293. Direct Tension Indicators (DTI’S) shall conform to the requirem ents of ASTM F 959. DTI’s for use with painted steel shall have a plain “as fabrica ted” finish. DTI’s for use with unpainted steel shall be galvanized to the requirements of AASH TO M 298 Class 50, Type I and have a fusion-bonded epoxy coating. DTI’s used with galvan ized steel, metalized steel and steel coated with a zinc-rich primer shall be galvanized to the requirements of AASHTO M 298 Class 50, Type I. “Twist Off” Type Tension Control Structural Bolt/Nut/Washer Ass emblies shall meet the requirements of ASTM F3125, Grade F1852. Bolts, nuts and washers specified to be galvanized may be galva nized by either hot dip galvanizing to the requirements of AASHTO M 232 Class C or mech anically galvanized to the requirements of AASHTO M 298 Class 50, Type I. All fastener (bolts and nuts), whether black or galvanized, sha ll be coated with a suitable lubricant. Galvanized nuts sha ll be lubricated with a lubrican t containing a visible dye.
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 741–747 of 817.