2403Wood Bridge Construction

2403.1DESCRIPTION

This Work consists of constructing wood Bridge Structures, or portions of Bridge Structures made of timber and lumber.

2403.2MATERIALS

A Structural Wood Components A.1 Component Grading and Symbol Designations Provide stress-rated timber and lumber in accordance with 3426, “Structural Wood,” for the grade specified. Provide lumber for laminating meeting the following requirements:

Contract

Structural Glued Laminated Timber B Preservative Treatment Provide wood treated with preservative in accordance with 3491, “Preservatives and Preservative Treatment of Wood Products,” unless otherwise required by the Contract. C Adhesives Provide adhesives meeting the requirements for wet-use (waterproof) in accordance with ANSI/AITC A190.1, Standard for Wood Products – Structural Glued Laminated Timber and AITC 405, Adhesives for Use in Structural Glued Laminated Timber. D Dowels Provide dowels made of hot rolled steel in accordance with 3306, “Low-Carbon Structural Steel,” and galvanized in accordance with 3394, “Galvanized Structural Shapes.” E Plank for Laminated Floors Provide plank strips for laminated floors surfaced on one side to a uniform thickness no greater than 3 inches (S1S). Unless the Plans show otherwise, the Department will not require surfacing to a uniform width.

Provide 50 percent of the strips at least 16 feet long. Use strips at least 6 feet long, except to fill skews. Provide strips in variable lengths to ensure joints on one stringer are no closer than each third strip. F Railings Provide timber and lumber for railings free from blemishes that detract from the appearance of the finished work. Surface timber and lumber for railings on four sides (S4S). G Hardware Galvanize hardware, including nails, spikes, and wood connectors after fabrication in accordance with 3392, “Galvanized Hardware.” Provide bolts in accordance with 3391.2C, “Bolts for Wood Construction,” unless otherwise shown on the Plans. Provide drift bolts with counter-sunk heads and chisel points, lag screws, and rods in accordance with 3306, “Low-Carbon Structural Steel.” Provide properly proportioned plate washers to develop the full strength of the bolt . Provide round washers with diameters, and square washers with side dimensions, at least 3 1/2 times the diameter of the bolt and with a thickness of at least one-half the diameter of the bolt, unless otherwise shown on the Plans. The Contractor may cut washers for bolts no greater than 1/2 inch in diameter from medium steel plate. Provide wood connectors of standard manufactured products in the size and type as shown on the Plans.

2403.3CONSTRUCTION REQUIREMENTS

A Cutting and Framing Cut, frame, and bore treated wood before treatment. Drive nails and spikes to set the heads flush with the surface of the wood . The Engineer may reject wood pieces or members with deep or frequent hammer marks in exposed wood surfaces. B Handling and Storage Handle, transport, and store wood without damaging portions that will remain in the completed Structure. Do not split or damage the surfaces and edges. Do not puncture the treated surface of treated wood with pointed tools, temporary bolts, or spikes. C Framing Accurately cut and frame lumber and timber, true and exact to a close fit to construct the joints with an even bearing over the entire contact surfaces. Do not shim the joints or construct open joints. C.1 Holes in Untreated Wood Bore holes in untreated wood with diameters in accordance with the following types of hardware:

Table 2403.3-1 Holes in Untreated Wood Hardware Type Bore Hole Diameter Round driftbolts and dowels 1/16 inch less than the diameter of the bolt or dowel Square driftbolts or dowels Equal to the least dimension of the bolt or dowel Machine bolts Same diameter as the bolt Rods 1/16 inch greater than the diameter of the rod Lag screws No larger than the body of the screw at the root of the thread C.2 Holes in Treated Wood Bore holes in treated wood at least 1/16 inch larger than the holes specified in Table 2402.3-1. D Field Treatment Carefully trim and coat the following in treated piles and timbers with a preservative in accordance with 3491, “Preservatives and Preservative Treatment of Wood Products,” and meeting the requirements of AWPA M4, Standard for the Care of Preservative-Treated Wood Products:

Wait at least 2 hours between each application. For pile cut-offs, treat the tops of treated timber piles used in wood Bridge construction with three applications in accordance with the requirements in this section. E Piling Provide timber piling in accordance with 2452, “Piling.” F Sills Finish concrete pedestals, where required for the support of framed bents, to ensure even load bearing transfer to sills or posts placed on the pedestals . Extend the dowels for anchoring the sills at least 9 inches above the tops of pedestals. Set dowels while casting pedestals. Provide sills with true and even bearing on piles or pedestals . Drift-bolt sills to the piles using bolts extending into the piles at least 9 inches. Remove earth from around the sills to provide free air circulation. Use dowels extending at least 6 inches into posts and sills to fasten posts to sills. G Caps Place timber caps to obtain an even and uniform bearing over the tops of the supporting posts or piles and to provide an even alignment of their ends. Use driftbolts extending at least 9 inches into posts or piles to secure caps, except wing pile caps. Place the driftbolts in the center of each post or pile. H Bracing Fasten bracing to the pile or post and cap using bolts at least 3/4 inch in diameter in tandem with split or tooth ring connectors. Use wire spikes, boat spikes, or spike grid connectors to bolt and spike intermediate intersections as shown on the Plans.

I Stringers and Bridging Size stringers at bearings. For stringers one panel long, place with knots near the edges in the top portion of the stringers. For stringers two panels long, place with knots near the edges in the compression edges of the stringers and stagger lapped joints over the supports. Provide outside stringers with butt joints. Provide lapped interior stringers to take bearing over the full width of the floor beam or cap at each end. Toenail or bolt to fasten lapped ends of stringers as required by the Contract. Accurately frame cross bridging members with bevel cut ends. Place cross bridging members providing full bearing at each end against the sides of stringers . Use two nails at each end to hold each cross bridging member securely. Set the cross bridging before placing the floor. Tightly set and nail the top ends home. Nail the lower ends only enough to hold the bridging in place. After placing the floor and wearing surface, readjust the lower ends of cross bridging, draw tight to the face of the stringers, and fully nail as required by the Contract. Place block or header bridging before laying the subfloor. Fully nail the blocks at the top and only temporarily nail at the bottom. After placing the entire floor, complete nailing of the bridging. If using bolts or lag screws to fasten block bridging as shown on the Plans, do not final tighten the bolts or lag screws until after placement of the entire floor. Cut block bridging square and to the accurate length to avoid the need for shims . If end shims are necessary, use zinc or galvanized sheet steel. Use end shims the size of the end of the block, with additional width to allow nailing along one side of block. Use galvanized roofing nails to hold shims in place. Place cross bridging at the center of each span unless otherwise shown on the P lans. J Prefabricated Wood Panels Provide and install nail or glue laminated wood panels for use in B ridge Superstructures in accordance with the following: J.1 Nail Laminated Panels Cut individual wood members for use in the panels to the proper length and drill dowel holes. Treat members with preservative in accordance with 3491, “Preservatives and Preservative Treatment of Wood Products.” Fabricate members into panels. Provide panels fabricated as shown on the Plans and assemble at the fabrication plant before delivery to the Project. Match mark the panels before shipment. Provide panel lengths with a tolerance of 1/8 inch of the dimension shown on the Plans. Install the panels to provide an overall deck width within 1/4 inch of the panel dimension shown on the Plans. J.2 Glued Laminated Deck Panels Provide and install glued laminated deck panels as shown on the P lans and meeting the requirements of this section, the ANSI/AITC A190.1, “Standard for Wood Products-Structural Glued Laminated Timber,” and AITC 405, “Adhesives for Use in Structural Glued Laminated Timber.” Provide shop details to the Engineer. Do not begin fabrication Work until the approval of the shop details by the Engineer in accordance with 2471.3C, “Shop Drawings.” J.2.a Appearance Grades Surface finish the panels meeting the requirements of AITC 110-2001, Standard Appearance Grades for Structural Glued Laminated Timber, except the Department will not require finishing the Roadway surface of the panels. Place individual planks to achieve the maximum corrugation on the Roadway surface.

J.2.b Dowel Holes Drill dowel holes 1/16 inch greater in diameter than the dowel and 1/2 inch deeper than necessary to provide the planned dowel projection before the preservative treatment process. J.2.c Marking and Protection Match mark the panels before shipment. Do not end seal, surface seal, or wrap the panels. J.2.d Preservative Treatment Fabricate glue-laminated desk panels; remove excess glue from all panel surfaces, except on Roadway surfaces, before treating with preservative. J.2.e Inspection .............................................................................................. 3491.3 Provide an independent commercial inspection agency’s Certificate of Compliance, including the test results, and an approval certification mark on each panel, showing conformance with the requirements of section 2403, “Wood Bridge Construction.” J.2.f Assembly Verify dowel projection and conformance with dimensions as shown on the Plans at the Project Site before assembly. K Railings Frame railings as shown on the Plans. Ensure accurate railing alignment during erection. L Hardware Place driftbolts in the Structure with the chisel point at right angles to the grain of the unbored sections of the connected pieces. Use plate washers for bolts at least 1/2 inch in diameter, unless using bolt heads and nuts that provide an equivalent bearing surface and strength. Provide wood connectors of the type shown on the Plans. Install the split ring and the shear plate in precut grooves of the dimensions as shown on the Plans or as recommended by the manufacturer. Use pressure Equipment to force the toothed ring and the spike grid into the contact surfaces of the joint . Simultaneously and uniformly imbed connectors of this type at a joint . Install the claw plate using a combination of precut grooving and pressure Equipment.

2403.4METHOD OF MEASUREMENT

A Treated or Untreated Wood The Department will separately measure treated wood and untreated wood by the unit of measure based on Nominal sizes and lengths incorporated in the Structure. The Engineer will not provide allowance for waste except beveled ends. The Department will measure panels by the number of acceptable units of each type provided and installed, including panel hardware. B Hardware The Department will measure hardware by weight if the Contract includes a specific Contract Item for hardware. The Department will include of the cost of nails, dowels, or panel hardware with other relevant Contract Items.

2403.5BASIS OF PAYMENT

The Department will pay for wood Bridge construction on the basis of the following schedule: Item No. Item Unit

2403.502 Prefab Wood Panels Type ___ each

2 Glued Laminated Deck Panels Type __ each

8 Hardware pound

2403.522 Untreated Wood MBM

2 Treated Wood MBM