SECTION 610: CATTLE GUARDS
610.1 Description
This Work consists of construc ting precast concrete cattle gua rds or steel frame cattle guards.
610.2 Materials
610.2.1 General
The Contractor shall provide cattle guards and grids in accorda nce with the Contract. The Contractor shall provide individual cattle guards with grid s of identical type having the same shapes, dimensions, and we ight of the steel members. The Contractor shall use steel frame cattle guards as an altern ate to precast concrete cattle guards at turnouts or at oth er locations in accordance w ith the Contract. The Contractor shall permanently cap all vertical metal pipes. If the Contract specifies precas t concrete cattle guards, the D epartment will not allow substitutions.
610.2.2 Precast Concrete Cattle Guards
The Contractor shall use Class AA concrete in accordance with S ection 510, “Portland Cement Concrete.” The Department will reject cattle guards with cracks, chips, sp alls, or honeycombed or patched areas in excess of 30 in²; or those that fail to meet t he minimum strength requirements. The Contractor shall provide s hop drawings in accordance with S ection 105.2, “Plans and Working Drawings” of the New Mexico State Department of Transpo rtation Standard Specifications for Highway and Bridge Construction Current Edit ion, and in accordance with the current edition of the ACI Detailing Manual. The Contractor shall fabricate precast concrete cattle guard st eel grids and other steel appurtenances in accordance with Section 541, “Steel Structures .”
610.2.3 Steel Frame Cattle Guards
The Contractor shall provide steel frame cattle guards from app roved manufacturers listed on the Department’s Approved Products List.
610.2.4 Reinforcing Steel
The Contractor shall use Grade 60 reinforcing steel deformed bars in accordance with Section 540, “Steel Reinforcement.” The Contractor shall provide welded wire fabric in accordance w ith AASHTO M 55.
610.2.5 Cattle Guard Grids and Hardware
The Contractor shall provide tr affic grill units, warning devic es, bolts, tie bolts washers, Section 610: Cattle Guards Page 671 hardware, and other Materials in accordance with Section 541, “Steel Structures.” The Contractor shall provide gr id units in accordance with AASH TO M 183. The Contractor shall provide aluminum members in warning device s in accordance with the ASTM Specifications listed in Table 610.2.5:1, “Aluminum Members Warning Devices Standards.” Table 610.2.5:1 Aluminum Members Warning Devices Standards Description ASTM Alloy Temper Tubing B 429 6061 T-6 Fence angle B 221 6061 T-6 Base plate B 209 6061 T-6
610.3 Construction Requirements
610.3.1 Concrete Footings and Foundations
The Contractor shall excavate or build with Embankment, level, and compact foundations for cattle guards before installing the cattle guard. The Cont ractor shall excavate wide enough to compact and test Material adjacent to the cattle guard, or b ackfill with flowable fill at no extra cost to the Department. The Contractor shall finish uneven foundation surfaces to ensur e full bearing of cattle guard units. The Contractor shall compact Subgrade foundations in accordance with Section 207, “Subgrade Preparation.” If the Contractor finds unstable Material in footing foundation s, the Contractor shall stabilize, or remove and replace with Material approved by the Project Manager. The Contractor shall place a three (3) inches thick bedding of fine aggregate over the Subgrade and compact it to at least 95% of the maximum density in accordance with AASHTO T 180 (Modified Proctor), Method D (TTCP Modified). The Contra ctor shall place the cattle guard unit on the fine aggregate bedding. The Contractor shall finish the tops of concrete footings so th at stringer-bearing surfaces receive the full bearing under each stringer.
610.3.2 Placement Requirements
The Contractor shall place the concrete cattle guards in accord ance with Section 511, “Concrete Structures.” The Contractor may splice reinforcing b ars over 30 ft long using a minimum 24-bardiameter lap. The Contractor shall chamfer exposed edges of concrete ¾ inch. The Contractor may use used steel members that are free of bend s and in good condition, as approved by the Project Manager. The Contractor shall fabricate grids so that the bottoms of the stringers are in a plane surface.
610.3.3 Protective Coating
The Contractor shall provide cattle guards with a protective c oating in accordance with Section 545, “Protective Coati ng of Miscellaneous Structural St eel.” The Contractor shall stripe warning devices with two (2) coats of black coating Material in accordance with the Contract.
610.3.4 Backfill
The Contractor shall perform the excavation, placement, and com paction of select backfill in accordance with Section 206, “Excavation and Backfill for Cu lverts and Minor Structures.”
610.4 METHOD OF MEASUREMENT—Reserved 610.5 BASIS OF PAYMENT
Pay Item Pay Unit Cattle Guard ( ____ ft) Each
610.5.1 Substitutions
The Department will not adjust th e Bid price for weights of rai ls greater than the specified minimum.
610.5.2 Work Included in Payment
The following Work and items, except when otherwise specified, will be considered as included in the payment for the main items, complete in place a s detailed in the Contract, and will not be measured or paid for separately: 1. Subgrade preparation, excavat ion, replacement of unstable Su bgrade, placement and compaction of select backfill; 2. All steel reinforcement (Including welded wire fabric); 3. All Structural Steel, bearing pads, all connecting hardware and associated components; and 4. All warning devices, all field painting, and all appurtenanc es necessary to complete the Work. Section 613: Cleaning of Culverts and Drainage Structures Page 673