Section 805 Section 805 round bars of the same nominal size as shown in the table of areas and masses in Section 711. The weight of mesh will be computed from th e theoretical weight of plain wire. If the weight per square foot is given on the plan, that weight will be used. The weight of plain or deformed bars, or ba r mat, will be computed from the theoretical weight of plain round bars of the same nominal size as shown in the table of area and weights in Section 711. The weight for payment of structural steel re inforcement, incorporated in the work and accepted, will be the theoretical weight of the material used. The weight of reinforcement used in railings measured on a linear foot basis will not be measured. The weight of reinforcement in precast piles and other items where the reinforcement is included in the contract pric e will not be measured. No allowance will be made for clips, wire, sepa rators, wire chairs, an d other material used in fastening the reinforcement in place. If ba rs are substituted upon th e Contractor's request and as a result more steel is used than specif ied, only the bars specified will be measured. When splices, other than those shown on the plans, are made for the convenience of the Contractor, the extra steel will not be measured.
805.05 Basis of Payment. Reinforcement will be paid fo r at the contract unit price per
pound, which shall be full compensation for completing the work. Payment will be made under: 805-A: Reinforcement - per pound 805-B Reinforcement, Epoxy Coated - per pound 805-C Reinforcement, Corrosion Resistant - per pound SECTION 806 - PRECAST CONCRETE BRIDGE CAPS, SPANS AND WINGS
806.01 Description. This work consists of furnis hing and installing precast concrete
caps, precast concrete spans co mplete with post, bridge railing or concrete barrier rail and precast wings for bridges in accordance with th ese specifications and in reasonably close conformity with the dimensions and design i ndicated on the plans and placed on a prepared substructure to the lines and grad es established by the Engineer.
806.02 Materials. The materials used in this cons truction, in additi on to the general
requirements of these specifications, shall co nform, unless otherwise stipulated, to the requirements prescribed in Division 700, Material and Tests, for the particular kind and type of material specified.
806.02.1 Sampling and Testing. As referenced in Subsection 106.03, approval of the
source of supply of cement, fine and coarse aggregate, water, reinforcement and other materials used in the construction of the caps, slabs and wings and the results of tests showing their suitability for use shall be obtained prior to th eir use in any construction. Samples shall be submitted as directed. The Contractor/Manufacturer without extra compensation, shall supply the Engineer's plant inspector with the necessary materials and representative concrete mix for making a minimum of one test cylinder of concrete for each seven caps, slabs, or wings or a minimum of one test cylinder per day if less than seven caps, slabs, or wings are constructed. Other test cylinders may be required by the Engineer to establish strength for handling slabs or caps. Cylinders are to be cured with the same method used in curing the caps, slabs, or wings, as the case may be. Only those caps , slabs, or wings bearing identification marks of acceptance by the Department or approved laboratories will be permitted for use in the construction. The acceptance of any precast concrete member at the production plant shall in no way be final and further inspection will be made at the structure site before and after the member has been placed in its final position.
806.03 Construction Requirements.
806.03.1 General. The methods of construction shall conform, unless otherwise
stipulated, to the provisions and requirements prescribed in these specifications and indicated on the plans for the several items that constitute the complete structure.
806.03.2 Substructure. The substructure shall be constr ucted in conformi ty with Section
803 and as indicated on the plans. Paymen t for same will be made under Section 803, unless otherwise indicated. The piles shall be so driven that the cap may be placed in its proper location without excessive manipulation of the piles.
806.03.3 Precast Caps, Slabs, and Wings.
806.03.3 1--Proportionin g and Mixing Concrete. The composition, proportioning and
mixing of the concrete used in this construc tion shall be as specifi ed in Section 804, Concrete Bridges and Structures, and shall be the class concrete specified on the plans.
806.03.3 2--Rein forcing Steel. Reinforcing steel shall be of the quality, type, and size
specified on the plans and placed as indicated. It shall meet the requirements set out in Subsection 711.02, as applicable. Separate payment will not be made for reinforcing steel.
806.03.3 3--Forms. All forms shall be of metal or wo od. They shall be built mortar-tight
and of sufficient rigidity to prevent any distortion due to pressure of the concrete and other loads incident to the construction operations. The forms shall be subs tantial and unyielding and shall be so designed that the finished concrete will conf orm to the proper dimensions and contours. The design of the forms shall take into account the effect of vibration of concrete as it is placed. Forms shall be filleted at all sharp corners and shall be given a bevel or draft in the case of all projections to en sure easy removal. All forms shall be set and maintained true to the lines designated until the concrete is sufficiently hardened or for periods as hereinafter specified. Forms shall be treated with oil immediately before placing conc rete in them. Any material that will adhere to, or discolor, the concrete shall not be used. Extreme care shall be exercised to make sure that no oil gets on the reinforcing steel.
806.03.3 4--Handling and Placing Concrete. Prior to the placing of any concrete, the
forms shall be thoroughly cleaned of any construction debris and extraneous matter and the reinforcing bars of the size and type indicate d placed and secured in the forms as indicated on the plans. Concrete sha ll not be deposited in the forms until the inspector has checked the placing of the reinforcement and has given approval to proceed. Ready mix concrete transported in a truck mixer or truck agitator shall be discharged at the site of the work and placed in its final po sition in the forms with in one hour after the introduction of the mixing water to the cement and aggregate or the cement to the aggregate whichever occurs first, except that in abnormal weat her, or under other conditions contributing to the quick stiffening of the concrete, the Engineer may make a determination of a lesser time for placement considering all f actors affecting initial set of the concrete. When mixed concrete is transported in approved non-agitating trucks, the concrete shall be discharged at the work site within thirty mi nutes after the introduction of the mixing water to the cement and aggregate. The concrete shall be placed so as to avoid segregation of the materials and the displacement of the reinforcemen t. Open troughs and chutes used shall be of metal or metal lined and shall be kept clean and free fr om coating of hardened concrete by flushing with water after each pour. Water used for flushing shall be discharged clear of the cap, slab, or wing forms.
806.03.3 5--Compaction. Concrete for the caps, slabs, and wings during and immediately
after depositing shall be thorough ly compacted by the use of vibrators and suitable spading tools. Vibration shall be applied at the point of deposit and in the ar ea of freshly deposited concrete. The vibration shall be internal and shall be of sufficient duration and intensity to thoroughly compact the concrete, but shall not be continued so as to cause segregation. Vibration shall not be continued at any one poin t to the extent that lo calized areas of grout are formed. The entire operation of depositing and consolida ting the concrete shall be so conducted that the concrete shall be smooth, dense and free from any honeycomb or pockets of segregated aggregates. The roadway surface of slabs and tops of caps and wings shall be finished with a wood float. Concrete in the precast caps, slabs and wings shall be placed in one continuous operation for each cap, slab, and wing.
806.03.3 6--Placing Bolts, Drains, Bolt Holes, etc. All bolts, drains, bolt holes, etc.,
indicated on the plans as necessary or desira ble shall be placed in the concrete at the locations indicated on the plans. They shall be formed by approved methods and operations and shall be such as to ensure proper connections.
806.03.3 7--Removal of Forms and Curing. Side forms for precast concrete bridge caps,
slabs and wings may be removed after the conc rete has attained sufficient strength to maintain a true section. The minimum time for removal, using alternate types of curing, is considered to be as follows:
a.With a minimum of three thicknesses of wetted burlap, cotton mats, or constant fogging with temperatures of more than 40°F and less than 80°F -- 24 hours; with temperatures 80°F and higher -- 20 hours. (b) Steaming in enclosures at temperatures of not less than 80°F and not more than 150°F -- 12 hours. When Type III Cement is permitted, side forms may be removed after 12 hours using all types of curing. Bottom forms shall remain in place until the concrete has obtained a minimum compressive strength of 2,500 psi as determ ined by cylinder tests. When the caps, slabs, or wings are moved, they shall be deposited directly on a level hard-surfaced true-plane area without stacking and shall remain undist urbed for seven days beyond the period of initial handling while the curing continues. Caps, slabs and wings shall be covered with wetted burlap immediately after the finishing operations. Liquid membrane curing may be used, but shall be white pigmented and applied at the rate of not less than one gallon per 150 square fe et of surface. The entire surface and exposed edges shall be sprayed with the membrane as so on as practicable after finishing is complete and as side forms are removed. The seal shall be applied to the surface as a fine mist that shall provide a continuous, un iform, water impermeable film. The bottom of the caps, slabs, or wings shall be sealed with the me mbrane when they are removed from the bottom supporting forms. The Contractor may use steam curing provide d the Engineer has gi ven written approval prior to casting operations. Steam curing sh all be according to stipulations set out in Subsection 804.03.22.4.2. The cap, slab, wing and rail un its shall not be shipped until th e concrete has obtained the specified minimum compressive strength as determined by cylinder tests.
806.03.4 Toleran ce of Dimensions .
806.03.4 1--Caps. The width and length of the caps shall not vary more than one-quarter
inch from the plan dimensions. The bottom of the cap shall be smooth and shall not vary more than one-eighth of an inch when tested with a straighte dge in a horizontal direction for any ten-foot length. The top of the caps shall not vary more th an one-sixteenth inch from the slope shown on the plans.
806.03.4 2--Slabs. The four sides of the slab shall no t vary more than on e-eighth inch for
the full depth of the slab when tested with a straightedge in a vertical direction, nor more than one-quarter inch in the fu ll length of the slab when test ed with a straightedge in a horizontal direction, nor shall the top of the sl ab vary more than one-eighth inch in any ten- foot length.
806.03.4 3--Wings. The width and length of the wings shall not vary more than one-
quarter inch from the plan dimensions.
806.03.4 4--Concrete Barrier Rail. The width of the rail sha ll not vary more than one-
eighth inch and the length shall not vary more than one-quarter inch. The sides shall be smooth with no discolorations. In the event pa tching is required, the entire rail shall be given a Class 2 finish.
806.03.5 Handling and Placing Precast Caps, Slabs, Barrier Rail and Wings. The
precast caps, slabs, barrier rail, and wings sha ll be handled in such a manner that they will not be subjected to excessive and undue abuse producing crushing, spalling, or undue marring of the concrete. Injury to units may be cause for rejection whether the injury to the unit is apparent or not. Damaged units shall be replaced by the Contractor at no additional costs to the State. Where the caps, slabs, barrier rail, and wings are to be loaded or stored in tiers, the blocking between the tier should be in a vertical plane so that the wei ght of the upper caps, slabs or wings cannot produce bending in those of a lower tier. After the caps are set and doweled, welded, or grouted to the piling, the dowel holes shall be filled with grout or AC-1 3 before the slabs are set. Each section or unit shall be placed as closely as possible to its final position in the structure so that the use of bars or other tools that might mar the conc rete will be eliminated. The abutting edges of each slab unit shall be carefu lly cleaned of any concrete or extraneous matter in order that the longitudinal jo ints may be bolted tightly together. After the slab units are set, doweled and bolted in their final position, the keyways and dowel holes shall be filled with an approved non- shrink grout. Tr affic shall not be permitted on the spans for 24 hours and heavy construction type traf fic, or other loads exceeding 15 tons, will not be a llowed on the spans for a period of 72 hours af ter grouting. When epoxy grout is allowed, these time requ irements may be reduced to 12 hours. When a non-shrink commercial grout is used, the 72-hour time requirement may be reduced to 24 hours. Expansion material shall be placed between a ll bearing points of the slabs and surfaces of the caps. When not otherwise specifically provided, three layers of No. 15, Type I, roofing felt shall be used.
806.03.5 1--Transverse Joints. When a bridge consists of more than one span, bituminous
premolded joint filler, one-quarter inch in th ickness, shall be placed in the joint between spans. This join t filler shall be for the full thickness of the concrete, less one inch at the top of the slab, and for the full width of the structure, including curb. When the spans are completely in place and bolted the transverse jo ints shall be sealed with AC-13 or other joint sealer approved by the Engineer.
806.03.5 2--Railing. The bridge railing shall be installe d after all other work on the bridge
has been completed. The material used shall meet the dimensions and requirements specified on the plans and the railing shall be constructed in conformity with the details indicated and to the lines and grades established.
806.04 Me thod of Measurement. Precast concrete slab units, either interior or curb
units, precast barrier rail units and precast concrete caps either intermediate or end bent with winged abutment wall of the size and ty pe specified will be measured by the unit per each. Winged abutment walls, grout, tie rods, nuts, washers, bearing pads and other appurtenances will not be meas ured for separate payment.
806.05 Basis of Payment. Precast concrete slab units, precast barrier rail units and
precast concrete caps, measured as prescribed above, will be paid for at the contract unit price per each for the specified types and sizes. This price shall be full compensation for furnishing all materials, hauling and erectin g, equipment, tools, labor and incidentals necessary to complete the work. Payment will be made under: 806-A: ___’ Precast Concrete Slab Units, ___’ Interior - per each 806-B: ___’ Precast Concrete Slab Units, Curb - per each 806-C: ___’ Precast Barrier Rail Units - per each 806-D: ___’ Precast Concrete Ca ps, Intermediate Unit - per each 806-E: ___’ Precast Concrete Ca ps, End Unit with Wall - per each SECTION 808 - JOINT REPAIR
808.01 Description. All joints requiring repair sha ll be reconstructed with specified
materials according to details shown on the pl ans and instructions contained herein. All other requirements shall be in accordance with the applicable provisions of Sections 501 and 804 of the Standard Specifications.
808.02 Materials.
808.02.1 General. When materials from the Depart ment's current list of approved
materials are to be used, the Contractor sha ll submit documentation to the Engineer that the epoxy and all components meet the requirements of the contract. If the materials proposed for use are not from the Department's current list of approved materials, a sample of the epoxy and all components required for the epoxy mortar mix shall be submitted to the Engineer for evaluation and approval at least 30 calendar days prior to placement.
Source: Mississippi Standard Specifications for Road and Bridge Construction, 2017 Edition. Pages 1017–1021 of 1,113.