Team Leader: / Gregory Sanders / Chris Riney / Gene Houchins
Team Members: / Doug Thomas / Ken Shamet / Mike Gill
(Rationale: There are not many changes made to this specification. It was felt that the limited amount of methodology that was or is written into the spec should remain intact as a convenience to either MoDOT inspectors or the contractors doing the work. It is believed the amount of methodology is minimal and irreducible in terms of eliminating lines without adversely affecting the desired result we expect to get in the field. The method of measurement and basis of payment were not changed. The contractor we had on our team felt these were essential for them. In order to incorporate a widely used Bridge Unit Job Special Provision “Mechanical Bar Splices” into this Standard Specification, it has been given Sec 706.3.3 entitled “Mechanical Bar Splices” which includes Sec 706.3.3.1 through 706.3.3.5.)
10/28/03 - Revised per meeting of (10/06/03) with and at request of Kevin Keith.
Sec 706.3.1 - Deleted sentences (nos. 9 and 10) describing manufacturing, placing, and load and spacing requirements of plastic bar supports. Deleted part of sentences (nos. 14 and 15) stating that placed reinforcement be inspected before concrete pour and that inspection does not relieve contractor of their responsibility.
Sec 706.5.1 - Added that cost of mechanical bar splices shall be included with cost of epoxy coated reinforcing steel.
Sec 706.5.2 - Deleted.
SECTION 706
REINFORCING STEEL FOR CONCRETE STRUCTURES
706.1 Description. 1This work shall consist of furnishing and placing reinforcing steel of the shape, size and grade requiredas shown on the plans.
706.2 Material.
706.2.1 2All material shall be in accordance withconform to Division 1000, Materials Details, and specifically as follows:
Item
/ SectionReinforcing Steel for Concrete / 1036
706.2.2 3Reinforcing steel shall be accurately cut and bent to the dimensions and shapes shown on the plans, preferably at the mill or shop. 4Cutting and bending tolerances for reinforcing steel shall be in accordance with the Concrete Reinforcing Steel Institute's mManual of sStandard pPractice. Flame-cutting of uncoated reinforcing steel will be permittedallowed.
706.3 Construction Requirements.
706.3.1 5Reinforcing steel shall be protected from damage at all times. 6When placed in the work and before concrete is placedoured, reinforcing steel it shall be free from dirt, oil, paint, grease, loose mill scale, thick rust, any dried mortar and other foreign substances. 7A thin layer of Thin powdery rust need not be removedmay remain. 8All reinforcing steel required for superstructure concrete, such as slabs, girders and beams and top slabs of concrete box culverts withof more than a 4-foot (1.2 m) span, shall be held securely in correct position by means ofwith approved metal or plastic bar supports and ties. 9These Ssupports shall be manufactured and placed in accordance with the typical details shown on the plans for the various types of superstructures. 10Plastic bar supports shall meet or exceed the load carrying capacity of, and use the same spacing as, metal bar supports, and shall be molded in a configuration that does not restrict concrete flow and consolidation around and under the bar support. 11Reinforcing bars shall be positively secured against displacement. 12For bridge decks and top slabs of culverts, bars in the top mat shall be firmly tied with wire at each cross or lap. 13At other locations, the bars shall be firmly tied at the alternate crossings, or closer. 14The steel shall be tied in correct position with proper clearance maintained between the forms and the reinforcement. and shall be inspected before any concrete is placed. 15Such inspection will shall not relieve tThe contractor shall beof the responsibleility for constructing the unit in accordance with the plans. 16Care shall be exercised to maintain proper clearance between the forms and the reinforcement. 17Measurements to reinforcing steel shall be made to the centerline of bar, except where clear distance from face of concrete is shown on the plans.
18Before concrete is placed, any dried mortar shall be cleaned from the reinforcing steel.
706.3.2 19Bars shall not be spliced except as not be spliced except where shown on the plans or as directedpermitted by the engineer.
706.3.3 Mechanical Bar Splices.
706.3.3.1 Mechanical bar splice systems, as shown on the plans, shall be capable of developing 125% of the specified yield strength of the bar being spliced and shall be installed in accordance with the manufacturer's specifications and as modified herein.
706.3.3.12 The contractor shall furnish to the engineer a manufacturer's certification stating that the mechanical bar splice systems meet all requirements of this specification. The certification shall include or have attached specific results of tests showing yield and ultimate tensile load capacities.
706.3.3.23 The splicing system may attach directly to the bars being coupled or may be of a type that provides reinforcing bars of like size that lap with the bars being joined. A threaded type splice system will be required where clearance considerations require the splicing device to be placed flush to the face of the construction joint for the initial concrete placement.
706.3.3.34 Reinforcing bar lengths shown in the Bbill of Rreinforcing Ssteel may require modification to accommodate the specific mechanical bar splice system that will be used. The contractor shall determine the actual rebar lengths to accommodate the manufacturer's recommendations for installation of the mechanical bar splices.
706.3.3.45 For mechanical bar splice systems that require laps with the reinforcement, the minimum lap length on each side of the joint shall be as shown in the tables below. Mechanical bar splice systems that require laps with the reinforcement shall not be used for voided slab and solid slab bridges. Systems that require laps shall be Grade 60 [420] deformed bars in accordance with Sec 1036. Epoxy coated bars shall have epoxy coated mechanical bar splices.
Bar Size / Required Lap Length – Top Barsequal or greater than 12” (300 mm) of concrete below bar
Plain Reinforcing / Epoxy Coated Reinforcing
Bar Spacing Less Than 6” (150 mm) on Center / Bar Spacing More Than or Equal to 6” (150 mm) on Center / Bar Spacing Less Than 6” (150 mm) on Center / Bar Spacing More Than or Equal to 6” (150 mm) on Center
Inches (mm) / Inches (mm) / Inches (mm) / Inches (mm)
f’c = 3 ksi (21 MPa)
4 (13) / 29 (760) / 23 (610) / 35 (925) / 28 (740)
5 (16) / 36 (955) / 29 (765) / 44 (1160) / 35 (925)
6 (19) / 47 (1235) / 37 (990) / 56 (1500) / 45 (1200)
7 (22) / 63 (1690) / 51 (1350) / 77 (2050) / 61 (1640)
8 (25) / 82 (2225) / 66 (1780) / 100 (2700) / 80 (2160)
9 (29) / 105 (2815) / 84 (2250) / 127 (3415) / 102 (2735)
10 (32) / 133 (3575) / 106 (2860) / 161 (4340) / 129 (3475)
11 (36) / 163 (4385) / 131 (3510) / 198 (5325) / 159 (4260)
f’c = 4 ksi (28 MPa)
4 (13) / 29 (760) / 23 (610) / 35 (925) / 28 (740)
5 (16) / 36 (955) / 29 (765) / 44 (1160) / 35 (925)
6 (19) / 43 (1145) / 35 (915) / 53 (1390) / 42 (1115)
7 (22) / 55 (1460) / 44 (1170) / 66 (1775) / 53 (1420)
8 (25) / 71 (1925) / 57 (1540) / 87 (2340) / 69 (1870)
9 (29) / 91 (2435) / 73 (1950) / 110 (2960) / 88 (2365)
10 (32) / 115 (3095) / 92 (2475) / 139 (3760) / 112 (3005)
11 (36) / 142 (3800) / 113 (3040) / 172 (4615) / 137 (3690)
Bar Size / Required Lap Length – Other than Top Bars
less than 12” (300 mm) of concrete below bar
Plain Reinforcing / Epoxy Coated Reinforcing
Bar Spacing Less Than 6” (150 mm) on Center / Bar Spacing More Than or Equal to 6” (150 mm) on Center / Bar Spacing Less Than 6” (150 mm) on Center / Bar Spacing More Than or Equal to 6” (150 mm) on Center
Inches (mm) / Inches (mm) / Inches (mm) / Inches (mm)
f’c = 3 ksi (21 MPa)
4 (13) / 21(545) / 17 (435) / 31 (815) / 25 (655)
5 (16) / 26 (680) / 21 (545) / 39 (1020) / 31 (815)
6 (19) / 33 (885) / 27 (705) / 50 (1325) / 40 (1060)
7 (22) / 45 (1205) / 36 (965) / 68 (1810) / 54 (1445)
8 (25) / 59 (1590) / 47 (1270) / 88 (2380) / 71 (1905)
9 (29) / 75 (2010) / 60 (1610) / 112 (3015) / 90 (2410)
10 (32) / 95 (2555) / 76 (2045) / 142 (3830) / 114 (3065)
11 (36) / 117 (3135) / 94 (2505) / 175 (4700) / 140 (3760)
f’c = 4 ksi (28 MPa)
4 (13) / 21 (545) / 17 (435) / 31 (815) / 25 (655)
5 (16) / 26 (680) / 21 (545) / 39 (1020) / 31 (815)
6 (19) / 31 (820) / 25 (655) / 46 (1225) / 37 (980)
7 (22) / 39 (1045) / 32 (835) / 59 (1565) / 47 (1255)
8 (25) / 51 (1375) / 41 (1100) / 76 (2065) / 61 (1650)
9 (29) / 65 (1740) / 52 (1390) / 97 (2610) / 78 (2090)
10 (32) / 82 (2210) / 66 (1770) / 123 (3315) / 99 (2655)
11 (36) / 101 (2715) / 81 (2170) / 152 (4070) / 121 (3255)
20The use of splices shall be avoided at points of maximum stress. 21Where possible, splices shall be staggered and arranged to develop the full strength of the bar. 22Splices shall be made by lapping the bars a length at least equal to that shown on the plans or as authorized by the engineer.
706.44 Method of Measurement. 23Measurement of reinforcing steel will be made to the nearest 10 pounds (5 kg) for each structure. 24The weight (mass) paid for will be the plantheoretical weight (mass) of uncoatedplain bars, and no allowance will be made for thenot include mechanical bar splice systems, clips, wire, supports, and spacers or other fastening devices for holding the reinforcement in place. 25Allowances will not be made for an overrun in scale weights (masses) of bars. 26Final measurement will not be made except for authorized changes during construction, or where appreciable errors are found in the contract quantity. 27The revision or correction will be computed and added to or deducted from the contract quantity. Mechanical bar splice systems will be measured per each.
706.55 Basis of Payment.706.5.1 28The accepted quantity of reinforcing steel, including any approved mechanical bar splice systems, complete in place, will be paid for at the contract unit price.
706.5.2 The accepted mechanical bar splice systems, complete in place, will be paid for at the contract unit price per each. No adjustment of the plan weight (mass) of reinforcing steel for payment will be allowed for any bars coupled with mechanical bar splices.
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