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Per AASHTO LRFD Bridge Design Specifications, vehicle load deflection limits are not <br />required. However the Bridge Manufacturer will typically try to provide an anticipated <br />vehicle load deflection of approximately U500, expressed as the ratio of span length to <br />deflection. <br />5.2 Fracture <br />The main beams shall meet CVN values of 20 ft -lbs @ 40 -degrees Fahrenheit. <br />5.3 Wheel Load Distribution <br />4.25 -inch Bridge deck shall be designed to support the maximum wheel load from the <br />design vehicle. <br />6.0 MATERIALS OF CONSTRUCTION <br />6.1 Structural Steel <br />Structural steel shall meet ASTM A709 standards. <br />6.2 Deck Material <br />Decking to be 4.25 -inch Steel Bridge Deck, 9 -gage, placed transverse across the width of <br />the bridge. The height of the deck shall be 4.25' from top of the lower through to top of <br />the profile. Width of the plank shall be 12-13/16" with one 13/16" overlapping leg. <br />Decking shall be manufactured from pre -galvanized steel, ASTM A653 Grade 50 Class <br />with a minimum 2 oz. galvanized coating, Fy=50 ksi. Decking is to be welded to top <br />flange of stringers and to adjoining sheets. Welds to be treated with organic zinc -rich <br />coating meeting the material and performance requirements of ASTM A 780 (Standard <br />Practice for Repair of Damaged and Uncoated Areas of Hot -Dip Galvanized Coatings). <br />6.3 Wearing Surface <br />Timber (Treated) - Running (Ribbon) <br />Top of side dam shall be 3.5" above top of 4.25 -inch Big R Steel Bridge Deck for timber <br />wearing surface. Timber wearing surface shall be two ribbons of four planks each of <br />3x12 No. 2 or better, rough sawn, West Coast Region Douglas Fir, pressure treated ACQ <br />or equal to 0.4 pcf or refusal. Timber shall be attached to the 4.25 -inch Big R Steel <br />Bridge Deck utilizing %" diameter galvanized carriage bolts, two at each end of the planks <br />and one alternating every 4'-0" along the length of the planks. Some planks will be <br />shipped loose to allow access to the lifting lugs and the bolted stitch connection. <br />6.4 Fasteners <br />Structural bolts used to field splice, or connect; all main members shall be ASTM A325, in <br />accordance with the Specification for Structural Joints using ASTM A325 orA490 Bolts. <br />The nuts for these structural bolts shall be ASTM A563. One flat hardened washer <br />meeting ASTM F436 shall be supplied with all bolts. All bolts, nuts and washers shall be <br />galvanized and shall be furnished in an amount of 5% in excess of the number required <br />for each size and length. <br />Non-structural bolts shall be ASTM A307, '/." diameter carriage bolts, zinc plated or <br />galvanized. <br />Page 4 of 7 <br />