796Reinforcement in headwalls and pedestals shall consist of reinforcing bars and

723.03 General Requirements 90

Excavation and disposal shall be in accordance with the applicable requirements of 206. Waterproofing of the designated areas shall be in accordance with 702.23. All underground drains encountered during excavation for the structure shall be perpetuated as dictated by field conditions. Drainage openings through masonry shall be in accordance with 702.16. Handling of three-sided structures shall be in accordance with 907.05. Handling of wingwalls and spandrel walls shall be in accordance with 907.06. For precast three-sided structures, the ma nufacturer’s representative shall provide technical instruction and on-site technical assistance to the Contractor during the 100 erection of the members. The three-sided structure, headwalls, wingwalls, and footings shall be designed and constructed in accordance with the dimensions shown on the contract plans. Construction joints shall not be used with in the cross-section of precast three-sided structures unless shown on the contract plans.

723.04 Design Requirements A three-sided structure shall be designed for HL-93 loading in accordance with

AASHTO LRFD Bridge Design Specifications. 110 The three-sided structure, headwalls, wingwalls, footings, and spandrel walls shall be designed in accordance with the soil parameters shown in the contract documents. Headwalls, wingwalls, and spandrel walls shall be designed based on a minimum equivalent fluid pressure of 40 lb/cu ft. If flowable backfill is to be used, the Contractor shall consider the effects of hydrostatic pres sure on the structure. Weep holes shall be provided in all wingwalls. Horizontal pressures shall be increased for sloping backfill surfaces and live load surcharge. Head wall connections, wingwall footings, and 120 spandrel walls shall be checked for sliding and for overturning. 723.03 A headwall with guardrail mounted on top, the anchorage of the headwall or spandrel wall to the structure section, or a moment slab with bridge railing, shall be designed for the bridge railing test level shown on the plans. Continuity shall be established between the structure footing and the wingwall footing.

723.05 Manufacture The structure sections, headwalls, wingwalls, footings and spandrel walls shall be

free of fractures. Headwalls, wingwalls, and spandrel walls shall be given a finish in 240 accordance with 702.21. The structure units shall not be stored in an upright position until the designated handling and storage compressive strength, as shown on the working drawings, has been achieved.

723.06 Rejection

Structure sections, wingwalls, footings, or spandrel walls will be rejected due to the following conditions.

723.07 Repairs

Structure sections, headwalls, wingwalls, footings, or spandrel walls shall be repaired, when necessary, due to imperfec tions in manufacture, handling damage, or construction. Repairs will be acceptable if it is determined that the repairs are sound, properly finished and cured, and if the repaired structure section headwall, wingwall, footing, or spandrel wall is in acco rdance with the requirements herein.

723.08 Trench Compaction 270

The soils in the bottom of the excavation shall be compacted to 95% of the maximum dry density in accordance with 203.23. If 95% of the maximum dry density cannot be obtained in the bottom of the excavation or in other areas, the Office of Geotechnical Services shall be contacted for additional recommendations. If during construction, soft soils are encountered at depths that make removal impractical, the Office of Geotechnical Services shall be contacted for additional recommendations.

723.09 Footings All footings shall be give n a smooth float finish. Footing concrete shall reach a

compressive strength of 2,000 psi or flexural strength in accordance with 702.24(c) 280 prior to placement of the structure sections or wingwalls. The surface shall not vary more than 1/4 in. in 10 ft when tested with 10 ft straightedge. An 8 in. layer of coarse aggregate No. 8 in accordance with 301 shall be placed under the full width of the footing. Precast footings shall be made into a continuous strip footing using closure pours between the precast units. Closure pours shall be as detailed in the working drawings and sha ll be designed to accommodate the design loads. 723.10 Pedestals 290 Where a reinforced concrete pedestal is required between the base of the structure leg and the top of the footing to provide the required rise and low structure elevation as shown on the contract plans, the Contractor shall have the option of providing a structure with extended legs or constructing the pedestals. 723.11 Placement of Structure Sections and Wingwalls For three-sided arch-topped structures and three-sided flat-topped structures, the structure sections shall be set on masonite or steel shims. Each wingwall that is not precast as one unit with the f ooting shall be set on masonite or steel shims. A minimum gap of 1/2 in. shall be provided between the footing and the bottom of each section or 300 wingwall. Once the wingwalls or structur e sections are placed, the space underneath the wingwall or structure leg section to the top of the keyway sides shall be filled with prepackaged grout in accordance with ASTM C1107, or conventional or self- consolidating fine grout in accordance with ASTM C476, except as modified herein. If conventional fine grout is used, it shall be troweled into the keyway and mounded on one side of the leg or wingwall. The m ound of conventional fine grout shall be vibrated until it passes through to the ot her side of the leg or wingwall. After 723.07 801 completing this process on one side, if the conventional fine grout has not passed through to the other side, the process shall be repeated on the other side. Conventional or self-consolidating fine grout shall be from a prepackaged source or composed of 310 one of the following mixtures: (a) 930 lb/cu yd Type I portland cement with No. 23 natural sand or mortar sand.

723.12 Extension of Existing Structure All applicable requirements of this specification shall apply to the extension of an

existing three-sided arch-topped structure with headwalls and wingwalls, a three-sided flat-topped structure with headwalls and wingwalls, or a true arch shape structure with 723.12 802 spandrel walls and wingwalls. Such portions of the existing structure designated for removal shall be removed. All portions of the existing structure which are to remain in place and are damaged shall be repaired or replaced as directed. Those portions left in place which are wholly or partially filled with debris shall be cleaned out. Material removed shall be disposed of in accordance with the applicable requirements of 202.02. 360 Before removing concrete from an existing structure with wingwalls, the Contractor shall saw around the perimeter of the removal area on the interior and exterior of the existing structure a depth of 1 in. All existing reinforcement in the top slab and sidewalls exposed after concrete removal shall be cleaned and straightened in preparation for lapping with reinforcemen t from adjacent new work. Where existing reinforcement has deteriorated or been damaged during the removal operation, holes shall be drilled into the face of the existing structure to provide embedment for replacement reinforcing bars. The holes shall be of the diameter and depth required by the chemical anchor system manufacturer. Th e holes shall be cleaned prior to placing 370 the chemical anchor system and the reinforcing bars. No concrete shall be removed from an existing structure that has a headwall but no wingwalls. Reinforcing bars to tie the existing structure to the new structure section shall be installed by drilling holes into the face of the existing structure to provide embedment for reinforcing bars. The diameter and depth of the holes shall be in accordance with the recommendations of the manufacturer of the chemical anchor system. The holes shall be cleaned prior to placing the chemical anchor system and the reinforcing bars. An existing structure shall be extended by means of one of the following methods. (a) Precast Reinforced Concret e Three-Sided Structure Extension A cast-in-place concrete splice shall be constructed as a transition between the existing structure and the precast structure extension. The splice reinforcement in the precast structure extension section that will abut the existing structure shall be exposed 18 in. on the tongue end of the precast structure extension section. It shall be lapped 18 in. with either exposed existing structure reinforcement, in the case of an existing structure with wingwalls, or newly installed reinforcing bars in the existing structure, in the case of an existing structure with a headwall only as shown on the plans. Existing 390 exposed structure reinforcement from an existing structure with wingwalls shall be cut off 1 in. from the face of the new precast extension. If the existing tongue or groove join t end is acceptable and matches the mating joint on the new precast reinforced concrete structure extension section, the new extension may be installed using the mating joint of the existing structure. No cutting of the structure or splicing of reinforcement is then required. The joint between the new precast structure extension and the existin g structure shall be sealed as directed below. 400 723.12 803 (b) Cast-In-Place Concrete Three-Sided Structure Extension The reinforcement for the structure extension shall be lapped with the exposed reinforcement of the existing structure as shown on the plans.

723.13 Blank

723.14 Precast Reinforced Concrete Three-Sided Structure Section Joints

907.07 and centered on the joint. The exterior surface of the concrete sectio ns shall be clean and dry before the joint

membrane is applied. The outside surfaces of the top slab and both walls of every joint shall be completely covered for the entire length of each joint. Where joining two sections of joint membrane material, or where two ends meet, a 3 in. overlap shall be provided. The overlapping strip shall be firmly pressed onto the end of the underlying 440 strip to seal the joint. Joints between structure sections and wingwalls, between wingwalls and spandrel walls, and between structure sections and headwalls or spandrel walls shall also be covered with a joint membrane. The joint membrane shall be maintained in its installed location centered on the joint. It shall not be damaged during the backfilling operation. 723.14 804 723.15 Backfilling Structure backfill shall be placed a nd compacted in accordance with 211. Structure backfill shall be placed and compact ed on each side of the structure to the 450 fill line shown on the plans. During the backfill operation, the difference in elevations of the fill on each side of the structure shall not exceed 24 in. Unless otherwise specified by the manufacturer on the working drawings, once the level of structure backfill reaches the top of the structure, two lifts shall be placed and hand compacted over the structure with out traversing the structure with heavy equipment. Compaction with heavy equipment will not be allowed until a minimum of two lifts have been placed, hand compacted, and accepted. The operation of equipment over the stru cture shall be in accordance with the 460 structure manufacturer’s recommendations.

723.16 Scour Protection When riprap is specified, geotextile shall first be placed on the in-situ soil in accordance with 616.11. Riprap shall then be placed in accordance with 616.

For concrete base slabs, concrete shall be placed in accordance with 702.

723.17 Method of Measurement

Precast reinforced concrete three-side d flat-topped structur es or structure 470 extensions, precast reinforced concrete three- sided arch-topped structures or structure extensions, precast reinforced concrete true arch structures or structure extensions, cast-in-place reinforced conc rete three-sided flat-toppe d structures or structure extensions, cast-in-place reinforced concrete three-sided arch-topped structures or structure extensions, and cast-in-place reinfo rced concrete true arch structures or structure extensions will not be measured. The accepted quantities for payment will be the quantities shown on the plans. Structure backfill will be measured in accordance with 211.09. Flowable backfill will be measured in accordance with 213.08. Geotextile and riprap will be measured 480 in accordance with 616.12. Field drilled holes will be measured in accordance with

702.27 Plain or coated reinforcement or WWR us ed in precast reinfor ced concrete three-

sided flat-topped structures or structure extensions, precast reinforced concrete three- sided arch-topped structures or structure ex tensions, precast reinforced concrete true arch structures or structure extensions, precast headwalls, precast wingwalls, cast-in- place reinforced concrete three-sided flat-t opped structures or structure extensions, cast-in-place reinforced concrete three-si ded arch-topped structures or structure extensions, cast-in-place reinforced concre te true arch structures or structure 490 extensions, cast-in-place headwalls, or cast- in-place wingwalls will not be measured for payment. 723.15 805 If the Contractor elects to provide a box structure in lieu of the three-sided structure shown on the plans, it will be measured in accordance with 714.11.

723.18 Basis of Payment

The accepted quantities of precast reinfor ced concrete three-sided flat-topped structures or structure extensions, precast re inforced concrete three-sided arch-topped structures or structure extensions, precast rein forced concrete true arch structures or 500 structure extensions, cast-in-place reinfo rced concrete three-sided flat-topped structures or structure extensions, cast-in-p lace reinforced concrete three-sided arch- topped structures or structure extensions, and cast-in-place reinforced concrete true arch structures or structure extensions, of the size specified will be paid for at the contract unit price per linear foot. Structure backfill will be paid for in accordance with 211.10. Flowable backfill will be paid for in accordance with 213.09. Geotextile and riprap will be paid for in accordance with 616.13. Field drilled holes will be paid for in accordance with 702.28. If the Contractor elects to provide a box structure in lieu of the three-sided structure shown on the plans, it will be paid for in accordance with 714.12. The Department will not incur additional cost for allowing the Contractor to substitute a box structure for the three-sided structure shown on the plans. Payment will be made under: Pay Item Pay Unit Symbol Structure Extension, Co ated Reinforced Concrete, 520 Three-Sided Sections, ____ in. x ____ in. .......................... LFT span rise Structure Extension, Reinforced Concrete, Three-Sided Sections, ____ in. x ____ in. .......................... LFT span rise Structure, Coated Reinforced Concrete, Three-Sided Sections, ____ in. x ____ in. .......................... LFT span rise Structure, Reinforced Concrete, Three-Sided Sections, ____ in. x ____ in. .......................... LFT 530 span rise The cost of all design, coring, testing, pedestals or extended legs, excavation, repairs, plugging core and handling holes, mortar, grout, sealer, preformed flexible joint sealant, jo int membrane, cylinder molds, and necessary incidentals shall be included in the cost of the stru cture or structure extension. The cost of spandrel walls, concrete base slab, footings, and aggregate base under footings shall be included in the cost of the structure or structure extension. 540 723.18 806 The cost of precast concrete headwalls, precast concrete wingwalls, cast-in-place headwalls, or cast-in-place wingw alls shall be included in the cost of the structure or structure extension. The cost of plain or coated reinforcem ent or WWR used in precast reinforced concrete three-sided structures, precast re inforced concrete three-sided structure extensions, precast headwalls, precast wingw alls, cast-in-place reinforced concrete three-sided structures, cast-in-place rein forced concrete three-sided structure extensions, cast-in-place headwalls, or cast- in-place wingwalls shall be included in the cost of the structure or structure extension. 550 The cost of concrete used in a cast-in-p lace splice shall be included in the cost of the structure extension. The cost of footings for wingwalls and aggregate base under the wingwall footings shall be included in the cost of the structure or structure extension. The quantities for payment shall remain as shown on the plans whether the Contractor installs the three-sided arch-topped structure or structure extension, the three-sided flat-topped structure or structure extension, or the true arch shape structure 560 or structure extension. No additional payment will be made fo r carrying an underground drain through a structure or structure extension. However, no deduction will be made for the volume of concrete occupied by the drain pipe in a cast-in-place structure or structure extension. No additional payment will be made for the repair or replacement of existing concrete damaged by Contractor operations. 570