Section 816 Section 816
816.04 Method of Measurement. Maintenance painting of structures and members will
be measured by the lump sum or per each as provided in the contract.
816.05 Basis of Payment. Maintenance painting of struct ures and members will be paid
for at the contract unit price per each or lump sum, which price w ill be full compensation for preparation of the surface, for furnishing and applying all materials and for all labor, tools, equipment and incidentals necessary to complete the work. Payment will be made under: 816-A: Maintenance Painting of Metal Structures - lump sum 816-B: Maintenance Painti ng of Metal Structure, Location / Description - per each 816-C: Maintenance Painting of Description - lump sum SECTION 820 - TIMBER STRUCTURES
820.01 Description. This work consists of construc ting timber structures in conformity
with these specifications a nd in accordance with lines, gr ades, dimensions, and details shown on the plans.
820.02 Materials.
820.02.1 Lumber and Timber. Lumber and timber shall conform to the requirements of
Section 718, and in the case of exposed perman ent structures shall be treated as set out therein. Certain portions of un treated timber shall be coated as set out hereinafter and as may be shown on the plans.
820.02.2 Rods, plates, Eyebars, and Shapes . Rods, plates, eyebars, and shapes shall be
of structural steel conforming to the requirements of Section 717.
820.02.3 Castings. Castings shall be cast steel or gr ay-iron, as specified, conforming to
the requirements of Subsections 716.02 or 716.04.
820.02.4 Hardware. Machine bolts, drift bolts, and do wels may be either wrought iron
or medium steel. Washers may be cast ogee or malleable castings, or they may be cut from medium steel or wrought iron plate, as specified. Unless otherwise specified, machine bolts shall have square heads and nuts. Nails shall be cut or round wire of standard form. Spikes shall be cut or wire spikes, or boat spikes, as specified. Nails, spikes, bolts, dowels, washers, and lag screws shall be galvanized unless otherwise specified.
820.03 Construction Requirements.
820.03.1 Storage of Material. Lumber and timber stored on the site shall be kept in
orderly piles or stacks. Untreated material sh all be open-stacked on supports at least 12 inches above the ground surface to avoid abso rption of ground moistu re and to permit air circulation, and it shall be so stacked and stripped as to permit free circulation of air between the tiers and courses. It will be advisable in particul ar cases for the Engineer to require protection from the weather by a suitab le covering. On glued laminated structural members that are not to be treated, an appr oved end sealer shall be applied after end trimming of each completed member.
820.03.2 Installing Timber Piling.
820.03.2 1--Driving Piling. Timber piles shall be driv en in accordance with the
requirements of Subsection 803.03.1.7, except as modified herein.
820.03.2 2--Pile Hammer Formulas. Pile hammer formulas shall be per the requirements
of Subsection 803.03.1.9.2, except the use of gravity or drop hammers shall be allowed. In the absence of loading test, sa fe bearing values for piles dr iven with a gravity or drop hammer shall be determined by the following formula: P=2WH S+1.0 for gravity or drop hammers
820.03.3 Timber Connectors. Timber connectors shall be one of the following types, as
specified on the plans: the split ring, the toothed ring, the sh ear plate, or the spike grid. The split ring and the shear plate shall be installed in pre-cut groov es of dimensions as given herein or as recommended by the manufacturer. The toothed ring and the spike grid shall be forced into the contact surf ace of the timbers joined by means of pressure equipment. All connectors of this type at a joint shall be embedded simultaneously and uniformly. Fabrication of all structures using connector s shall be done prior to treatment. When prefabricated from templates or shop details, bolt holes shall not be more than 1/16 inch from required placement. Holes for round drift bolts shall be bored w ith a bit 1/16 inch less than the bolt to be used. The diameter for square drift bolts shall be equal to the least dimension of the bolt. Holes for machine bolts shall be bored with a bit the same diameter as the bolt. Bolt holes shall be bored perpendicular to the face of the timber. Timber after fabrication shall be stored in a manner that will prevent changes in the dimensions of the members before assembly. Dimensions of material and details not otherwis e specified shall meet with the approval of the Engineer.
820.03.4 Treated Timber.
820.03.4 1--Handling. Treated timber shall be car efully handled without sudden
dropping, breaking of outer fibe rs, bruising, or penetrating the surface with tools. It shall be handled with rope slings. Cant hooks, peaveys, spikes, or hooks shall not be used. Prior to driving, the timber piling shall not be hand led in such a manner that it is subjected to excessive and undue abuse that might produce splitting, splintering or brooming of the wood.
820.03.4 2--Placement. All cutting, framing, and boring of treated timber shall be done
before treatment insofar as practicable. When treated timbers are to be placed in waters infected by marine borers, untreated cuts, bo rings, or other joint framings below high water elevation shall be avoided.
820.03.4 3--Cuts and Abrasions. All cuts in treated piles or timbers, and all abrasions,
after having been carefully tr immed, shall be covered with two applications of a mixture of 60 percent creosote oil and 40 percent roofing pitch, or brush coated with at least two applications of hot creosote oil an d covered with hot roofing pitch.
820.03.4 4--Bolt Holes. All bolt holes bored after treatment shall be treated with creosote
oil by means of an approved pressure bolt hole treater. An y unfilled holes, after being treated with creosote oil, shall be plugged with creosoted plugs.
820.03.4 5--Temporary Attachment. Whenever, with the approval of the Engineer,
forms or temporary braces are attached to treate d timber with nails or spikes, the holes shall be filled by driving galvanized nails or spikes flush with the surface or plugging holes as required for bolt holes.
820.03.5 Untreated Timber. In temporary structures of untreated timber, the following
surfaces shall be thoroughly co ated with two coats of hot cr eosote oil before assembling: ends, tops, and all contact surfaces of sills, caps, floor beams, and stringers; and all ends, joints, and contact surfaces of bracing and truss members. The back faces of bulkheads and all other timber that is to be in contact with earth, me tal or other timber shall be similarly treated. Bolts passing through non-resinous wood shall be galvanized.
820.03.6 Treatment of Pile Heads. The heads of treated timber piles shall be protected
as specified on the plans. If not specified, th e fabric covering shall be used. The heads of timber piles, when the nature of the driving will unduly injure them, shall be protected by driving caps. When the area of the head of a ti mber pile is greater than that of the face of the pile hammer, a suitable cap shall be provi ded to distribute the blow of the hammer throughout th e cross section of the pile. Fresh head ing of a timber pile is recommended prior to driving. The head shall be cut square and shall be shaped or chamfered to prevent splitting at its periphery. Heads of all piling shall be sq uare and a driving cap shall be provided to hold th e axis of the pile in line with the axis of the hammer.
820.03.6 1--Cutting Off of Timber Piles. The tops of all piling shall be sawed to a true
plane, as shown on the plans, and at the eleva tion fixed by the Engineer. Piles that support timber caps or grillage shal l be sawed to conform to th e plane of the bottom of the superimposed structure. In general, the length of pile above the cut- off elevation shall be sufficient to permit the complete removal of a ll material injured by driving, but piles driven to very nearly the cut-off el evation shall be carefully adzed or otherwise freed from all broomed, splintered or otherwise injured material. Pile heads, after cutting to receive the caps and prior to placing the ca ps, shall be treated in accord ance with Subsection 820.03.6.
820.03.6 2--Defective Piles. All piles damaged because of internal defects or by improper
driving, driving out of the proper location, or driving below the specified elevation shall be corrected at no additional costs to the State by one of the following methods approved by the Engineer for the pile in question:
a.The pile shall be withdrawn and replaced by a new, and if necessary, a longer pile.
b.A second pile shall be driven adjacent to the defective or low pile.
c.A sufficient portion of the footing shall be extended to properly embed the pile. Timber piles shall not be spliced. All piles pushed up by the driving of adjacent piles or by any other cause shall be driven down again.
820.03.6 3--Metal Covering. The sawed surface shall be covered with three applications
of a mixture of 60 percent creosote oil and 40 percent roofing pitch or thoroughly brush- coated with three applications of hot creosote o il and covered with hot roofing pitch. Before placing the cap, a sheet of 12 gauge, 0.028- inch zinc of good co mmercial quality or a sheet of 26 gauge iron or steel of the qua lity of ASTM A 525 and galvanized each side shall be placed on each pile head. The sheet sh all be of sufficient size to project at least four inches outside of the pile, and it shall be bent down, neatly trimmed and securely fastened to the face of the pile with large headed galvanized roofing nails.
820.03.6 4--Fabric Covering. The heads of all piles shall be covered with alternate layers
of hot pitch and loosely woven fabric similar to membrane waterproofing, using four applications of pitch and three layers of fabric. The cover shall measure at least six inches more in dimensions that the diameter of the pile and shall be neatly folded down over the pile and secured by large headed galvanized nails or by binding or serving with not less than seven complete turns of galvanized wi re securely held in place by large-headed galvanized nails and staples. The edges of the fabric projecting below the wire wrapping shall be trimmed to presen t a workmanlike appearance. The heads of untreated piles shall be given one of the following treatments, as may be specified or directed by the Engineer: (a) The sawed surface shall be thoroughly brus h-coated with two applications of hot creosote oil.
b.The sawed surface shall be heavily coated with paint, after which it shall be covered with cotton duck of a least eight-ounce weight, which shall be folded down over the sides of the pile and firmly secured thereto with large-headed roofing nails. The edges of the duck sh all be trimmed to give a workmanlike appearance. The duck shall then be waterproofed by being thoroughly saturated and coated with one or more applications of red lead paint.
820.03.7 Holes for Bolts, Dowels, Rods and Lag Screws. Holes for ro und drift bolts
and dowels shall be bored with a bit 1/16 inch less in diameter than the bolt or dowel to be used. The diameter of holes for square drif t bolts or dowels shall be equal to the least dimension of the bolt or dowel. Holes for machine bolts shall be bored with a b it the same diameter as the bolt, except as otherwise provided in Subsection 820.03.3. Holes for rods shall be bored with a bit 1/16 inch greater in diameter than the rods. Holes for lag screws shall be bo red with a bit not la rger than the body of the screw at the base of the thread.
820.03.8 Bolts and Washers. A washer, of the size and type specified, shall be used
under all bolt heads and nuts that would otherwise come in contact with wood. The nuts of all bolts shall be effectively locked after they have been finally tightened.
820.03.9 Framing. All lumber and timber shall be accurately cut and framed to a close
fit in such manner that the joints will have even bearing over the entire contact surfaces. Mortises shall be true to size for their full de pth, and tenons shall fit snugly. No shimming will be permitted in making joints , nor will open joints be accepted.
820.03.10 Pile Bents. Pile bents shall be constructe d in accordance with applicable
provisions of Section 803.
820.03.11 Framed Bents.
820.03.11 1--Mud Sills. Untreated timber used for mud s ills shall be of heart cedar, heart
cypress, redwood, or other durable timber. Mu d sills shall be firmly and evenly bedded to solid bearings and tamped in place.
820.03.11 2--Concrete Pedestals. Concrete pedestals for the support of framed bents shall
be carefully finished so that th e sills or posts will take even b earing on them. Dowels of at least 3/4-inch diameter and projecting at leas t six inches above the tops of the pedestals shall be set in them when they are cast for anchoring the sills or posts.
820.03.11 3--Sills. Sills shall have true and even-bearin g on mud sills, piles, or pedestals.
They shall be drift-bolte d to mud sills or piles with bolts of not less than 3/4-inch diameter and extending into the mud sills or piles at l east six inches. When po ssible, all earth shall be removed from contact with sills so that there will be free air circulation around them.
820.03.11 4--Posts. Posts shall be fastened to pedest als with dowels of not less than 3/4-
inch diameter extending at leas t six inches into the posts. Posts shall be fastened to sills by one of th e following methods, as in dicated on the plans: (a) By dowels of not less than 3/4-inch diam eter extending at least six inches into posts and sills.
b.By drift bolts of not less th an 3/4-inch diameter driven diagonally through the base of the post and extending at least nine inches into the sill.
820.03.12 Caps. Timber caps shall be placed, with ends aligned, in a manner to secure
an even and uniform bearing over the tops of the supporting posts or piles. All caps shall be secured by drift bolts of not less than 3/4-inch diameter extending at least nine inches into the posts or piles. The drift bolts shall be approxima tely in the center of the post or pile.
820.03.13 Bracing. The ends of bracing shall be bolted through the pile, post or cap with
a bolt of not less than 5/8-inch diameter. In termediate intersections shall be bolted, or spiked with wire or boat spikes, as indicated on the plans. In all cases spikes shall be used in addition to bolts.
820.03.14 Stringers. Stringers shall be sized at bear ings and shall be placed in position
so that knots near edges will be in the top portions of the stringers. Outside stringers may have butt joints with the ends cut on a taper, but interior stringers shall be lapped to take bearing over the full width of the floor beams or cap at each end. The lapped ends of untreated stringers shall be separated at least 1/2 inch for the circulation of air and shall be securely fastened by dr ift-bolting where specified . When stringers are two panels in length the joints shall be staggered. Cross-bridging between stringers shall be n eatly and accurately fra med and securely toe nailed with at least two nails in each end. All cross-bridging me mbers shall have full bearing at each end against the sides of stri ngers. Unless otherwise specified in the contract, cross-bridging shall be placed at the center of each span.
820.03.15 Plank Floors. Unless otherwise specified, planks used in this construction
shall conform to the re quirements set forth in Subsection 820.02.1. Single plank floor shall consist of a single th ickness of plank supported by stringers or joists. The planks shall be laid heart side down, with 1/4-inch open ings between them for seasoned material and with ti ght joints for unseasoned material. Each plank shall be securely spiked to each joist. The planks sh all be carefully graded as to thickness and so laid that no two adjacent planks shall va ry in thickness by more than 1/4 inch. Two-ply timber floors shall consist of two layers of flooring supported on stringers or joists. The lower course shall be pressure treated with cr eosote oil. Th e top course may be laid either diagonally or parallel to the centerline of road way as specified, and each floor piece shall be securely fastened to the lower cour se. Joints shall be staggered at least three feet. If the top flooring is placed parallel to the centerline of the roadway, special care shall be taken to securely fasten the ends of th e flooring. At each end of the bridge these members shall be beveled.
820.03.16 Laminated or Strip Floors. The strips shall be of the grade required in Section
718. The strips shall be placed on edge at right angles to the cente rline of the roadway. Each strip shall be spiked to the preceding st rip at each end and at approximately 18-inch intervals with the spikes driven alternately near the top and bottom edges. The spikes shall be of sufficient length to pass through two st rips and at least hal f-way through the third strip. If timber supports are used, every other strip shall be toe-nailed to each timber support. The size of the spikes shall be as shown on th e plans. When specifi ed on the plans, the strips shall be securely attached to steel supp orts by the use of appr oved galvanized metal clips. Care shall be taken to have each st rip vertical and tight against the preceding one and bearing evenly on all the supports.
820.03.17 Wheel Guards and Railing. Wheel guards and railing shall be accurately
framed in accordance with the plans and erected true to line and grade. Unless otherwise specified, wheel guards, rails and rail posts sha ll be surfaced four sides, S4S. Wheel guards shall be laid in sections at least 12 feet long.
820.03.18 Countersinking. Countersinking shall be done wherever smooth faces are
required. Horizontal recesses formed for count ersinking shall be pain ted with hot creosote oil, and after the bolt or screw is in place, shall be filled with hot pitch.
820.03.19 Painting. Rails and rail posts of untreated timber, or timber treated with
preservative salts, shall be painte d with three coats of paint. Parts of the structure, other than rails and rail pos ts, that are to be painted, will be designated on the plans or in th e special provisions. Metal parts, except hardware, shall be given one coat of shop paint and after erection two coats of field paint as specified on the plans.
820.04 Me thod of Measurement. Timber remaining in the structure will be measured
by the thousand feet board measure (MBM) which shall include the cost of all hardware, galvanizing, paint and painting. Computations of the amount of lumber and timber in the structure will be based on nominal sizes and the lengths indicat ed on the plans. Piling will be measured in accor dance with Subsection 803.04. Metal parts, other than hardware, will be measured in accordanc e with Section 810.
820.05 Basis of Payment. Timber will be paid for at the contract unit price per thousand
feet board measure, which price shall be full compensation for co mpleting the work. Acceptable piling will be paid for at the respective contract prices per linear foot for the types and sizes specified, whic h price shall be fu ll compensation for completing the work. Payment will be made under: 820-A: Treated Timber - per MBM 820-B: Untreated Timber - per MBM 820-C: Untreated Timber Piling - per linear foot 820-D: Treated Timber Piling - per linear foot SECTION 822 - NEOPRENE EXPANSION JOINTS
822.01 Description. This work consists of furnishi ng and installing neoprene expansion
joints in accordance with these specifica tions and details shown on the plans.
822.02 Materials. Expansion joints shall meet the requirements of Subsection 707.07.
822.03 Construction Methods. Expansion joints shall be installed in accordance with
the manufacturer's recommendations. The expans ion material shall seal the deck surface, gutters and curbs to prev ent moisture or other co ntaminants from leaki ng through the joints. Anchor bolts shall be cast-in -place or drilled and grouted at a spacing recommended by the manufacturer. The expansion material shall be installed in such a manner that the top
Source: Mississippi Standard Specifications for Road and Bridge Construction, 2017 Edition. Pages 1082–1087 of 1,113.