Laserfiche WebLink
I <br /> 1 1 reinforcing steel. If this wire is used around epoxy-coated bars, it shall be coated with <br /> 2 plastic. <br /> 3 <br /> I4 Precast concrete supports may be accepted based on a Manufacturer's Certificate of <br /> 5 Compliance. <br /> 6 <br /> I7 In lieu of precast concrete supports, the Contractor may use metal or all-plastic supports <br /> 8 to hold uncoated bars. Any surface of a metal support that will not be covered by at least <br /> 9 1/2 inch of concrete shall be one of the following: <br /> I 10 <br /> 11 1. Hot-dip galvanized after fabrication in keeping with AASHTO M232 Class D; <br /> 12 <br /> I <br /> 13 <br /> 14 2. Coated with plastic firmly bonded to the metal. This plastic shall be at least 332 <br /> inch thick where it touches the form and shall not react chemically with the <br /> 15 concrete when tested in the State Materials Laboratory. The plastic shall not <br /> I <br /> 16 <br /> 17 shatter or crack at or above -5°F and shall not deform enough to expose the <br /> metal at or below 200°F; or <br /> 18 <br /> I19 3. Stainless steel that meet the requirements of ASTM A493, Type 302. Stainless <br /> 20 steel chair supports are not required to be galvanized or plastic coated. <br /> 21 <br /> I22 In lieu of precast concrete supports, epoxy-coated reinforcing bars may be supported by <br /> 23 one of the following: <br /> 24 <br /> 25 1. Metal supports coated entirely with a dielectric material such as epoxy or plastic, <br /> I 26 <br /> 27 2. Other epoxy-coated reinforcing bars, or <br /> 28 <br /> I 29 3. All-plastic supports. <br /> 30 <br /> 31 Damaged coatings on metal bar supports shall be repaired prior to placing concrete. <br /> I 32 <br /> 33 All-plastic supports shall be lightweight, non-porous, and chemically inert in concrete.All- <br /> 34 plastic supports shall have rounded seatings, shall not deform under load during normal <br /> 35 temperatures, and shall not shatter or crack under impact loading in cold weather. All- <br /> I 36 plastic supports shall be placed at spacings greater than 1 foot along the bar and shall <br /> 37 have at least 25 percent of their gross place area perforated to compensate for the <br /> 38 difference in the coefficient of thermal expansion between plastic and concrete. The <br /> I <br /> 39 shape and configuration of all-plastic supports shall permit complete concrete <br /> 40 consolidation in and around the support. <br /> 41 <br /> I <br /> 42 A"mat" is two adjacent and perpendicular layers of reinforcing steel. In bridge decks, top <br /> 43 and bottom mats shall be supported adequately enough to hold both in their proper <br /> 44 positions. If bar supports directly support, or are directly supported on No. 4 bars, they <br /> I <br /> 45 <br /> 46 shall be spaced at not more than 3-foot intervals (or not more than 4-foot intervals for <br /> bars No. 5 and larger). Wire ties to girder stirrups shall not be considered as supports. To <br /> 47 provide a rigid mat, the Contractor shall add other supports and tie wires to the top mat <br /> I 48 as needed. <br /> 49 <br /> 50 Unless noted otherwise, the minimum concrete cover for main reinforcing bars shall be: <br /> I <br /> 51 <br />