670 Page 467670 DROP INLETS
670.1DESCRIPTION
This work consists of furnishing materials and the construction of drop inlets.
670.2MATERIALS
Materials will conform to the following sections. A.Concrete: Class M6, Section 462. For precast drop inlets cast at a facility regularly producing other precast concrete items under Section 560 or Section 990, the concrete will conform to Section 560. B.Castings: Unless otherwise specified, frames and grates will consist of approved gray iron castings meeting the requirements of AASHTO M 105, Class 35. Grates will fit the frames with which they are to be used. Inaccuracies of bearing will be corrected by machining before use or replaced with new assemblies. C.Steel Reinforcement: Section 1010 . D.Mortar: Mortar will consist of one part Portland cement and two parts mortar sand conforming to Sections 750 and Section 810 respectively. As an alternate, a commercially available grout conforming to Section 460.2 K may be used. E.Curing Compound: Section 821.
670.3CONSTRUCTION REQUIREMENTS
A.General Requirements: Concrete for drop inlets will be proportioned, mixed, hauled, and placed in accordance with Section 462. For precast drop inlets cast at a facility regularly producing other precast items under Section 560, the concrete proportions, slump, and air content will conform to When the foundation for a drop inlet is in new embankment, the embankment will be constructed to an elevation at least 1 foot above the footing before the foundation for the drop inlet is prepared. The foundation will be compacted as specified for the adjacent embankment. Castings will be set in full mortar beds or secured as specified. Castings will be set accurately to the correct elevation so subsequent adjustment will not be necessary. Inlet and outlet pipe connections will be of the same size and kind and will meet the same requirements as the pipe they connect. Pipe sections will be flush on the inside of the structure wall and project outside sufficiently for proper connection with the next pipe section. Masonry will fit neatly and tightly around the pipe. Grouting of the pipe connection may be required as directed by the Engineer if voids exist after form removal. 670 Page 468Drop inlets will be either cast in place or precast. Precast drop inlets will be defined as those drop inlets cast outside of the project limits. Drop inlets cast within the project limits will be considered cast in place. B.Cast In Place Drop Inlets: The foundation excavated for drop inlets will be thoroughly moistened immediately prior to placing concrete. Moisture will be applied without forming pools of water. Steel reinforcement will be placed in accordance with Section 480. Concrete will be protected and cured in accordance with Section 460.3 M. The minimum curing time will be 72 hours. The finished surface of the concrete will present a neat and smooth appearance. Upon completion and curing of the unit, the sheeting, bracing, forms, and falsework will be removed, and the excavation backfilled. The unit will not be backfilled until the completion of the 72 hour curing period, or until the concrete reaches a minimum compressive strength of 3000 psi. Backfill will be placed in loose layers not exceeding 6 inches thick and compacted to the same degree as specified for the adjacent embankment. Installations will be completed and left in a neat appearing condition. C.Precast Drop Inlets: Precast drop inlets will conform to the following requirements: 1.Notification: The Contractor will notify the Engineer 48 hours in advance of all concrete pours for inspection and observation of Contractor testing. 2.Design: Precast drop inlets will conform to the configurations of the standard plates. Variations from the standard plates may be accepted provided the AASHTO materials, design, fabrication specifications, and the requirements of this section are complied with. Precast drop inlets will be designed to specified load conditions. The design Engineer of the drop inlets must be a Professional Engineer registered in the State of South Dakota. The design will conform to the AASHTO design requirements for the depth of fill, including surfacing, as well as live load or other specified loading. The Contractor will furnish a checked design with the shop plans. A checked design will include the design calculations and check design calculations performed by an independent Engineer registered in the State of South Dakota. 3.Shop Plans: If using a design that varies from the standard plates, the Contractor will submit shop plans in accordance with this section. Prior to fabrication, the Contractor will submit shop plans to the Department for the Department’s opportunity for review. Any review by the Department of the shop plans is limited to general conformance with the contract plans and specifications only. The Contractor will send an email with the shop plans attached as a PDF to the Project Engineer and Office of Bridge Design. Upon request, the Project Engineer will provide the Contractor the appropriate email addresses. Within 14 calendar days of receiving the shop plans, the Office of Bridge Design will respond to the Contractor in one of the following ways: 1) No Exceptions Noted; 2) Returned for Revision; or 3) Not Required for Review. If the Department’s response states, “Returned for Revision”, the Contractor must make the revisions and resubmit the 670 Page 469shop plans for review as specified above. The Contractor will not begin fabrication or construction of the work contained in the shop plans until the Department has confirmed, in writing, a completed review with a response of “No Exceptions Noted” or “Not Required for Review”. The shop plans will consist of fabrication details including reinforcing steel and spacer placement and configurations, total quantities for the complete item, and all information necessary for fabrication and installation. 4.Forms: The forms will be designed to withstand the fluid pressure of the concrete and the added forces due to vibration and impact without distortion. The forms will be mortar tight and free from warp. The form surface area in contact with the concrete will be treated with an approved form oil or wax before the form is set in position. The forms will be thoroughly cleaned of all other substances. 5.Fabrication: Welding of mild reinforcing steel will not be permitted. Steel wire bar supports will be used to maintain proper reinforcement location and concrete cover. Cutting of reinforcement and bending to the form surface, for support, will not be permitted. Steel wire bar supports, in contact with the casting forms, will be stainless steel, hot dipped galvanized, or plastic tipped extending at least 1/2 inch from the form surface. The surface temperature of the forms and reinforcing steel, which come into contact with the concrete being placed, will be raised to a temperature above freezing prior to concrete placement. All deleterious material will be removed from the forms prior to concrete placement. For cold weather placements, concrete surfaces will be protected from freezing throughout the pour and until covered for the waiting period before application of live steam or radiant heat. The precast units will have sufficient strength to prevent damage to the units during removal of the forms and yarding. Precast units will have a minimum concrete compressive strength of 800 psi prior to form removal. Precast units will have a minimum concrete compressive strength of 3000 psi prior to yarding. The Engineer may approve a different minimum concrete strength for form removal and yarding, based upon fabricator demonstrated results or as shown on design details submitted and approved with the shop plans. 6.Concrete Cure: The concrete will be cured by low pressure steam, radiant heat, or as specified in Section 460.3 M. When curing in accordance with Section 460.3 M, the concrete temperature requirements of Section 460.3 N will apply. Low pressure steam or radiant heat curing will be done under an enclosure to contain the live steam or the heat and prevent heat and moisture loss. The concrete will be allowed to attain initial set before application of the steam or heat. The initial application of the steam or heat will be three hours after the final placement of concrete to allow the initial set to occur. When retarders are used, the waiting period before application of the steam 670 Page 470or radiant heat will be five hours. When the time of initial set is determined by ASTM C 403, the time limits described above may be waived. During the waiting period, the minimum temperature within the curing chamber will not be less than 50°F and live steam or radiant heat may be used to maintain the curing chamber between 50°F and 80°F. During the waiting period the concrete will be kept moist. Application of live steam will not be directed on the concrete forms causing localized high temperatures. Radiant heat may be applied by pipes circulating steam, hot oil, hot water, or by electric heating elements. Moisture loss will be minimized by covering exposed concrete surfaces with plastic sheeting or by applying an approved liquid membrane curing compound to exposed concrete surfaces. The top surface of concrete members for use in composite construction will be free of membrane curing compound residue unless suitable mechanical means for full bond development are provided. During the initial application of live steam or radiant heat, the concrete temperature will increase at an average rate not exceeding 40°F per hour until the curing temperature is reached. The maximum concrete temperature will not exceed 160°F. The maximum temperature will be held until the concrete has reached the desired strength. After discontinuing the steam or radiant heat application, the temperature of the concrete will decrease at a rate not to exceed 40°F per hour until the concrete temperature is within 20°F of the ambient air temperature. The test cylinders will be cured with the unit, or in a similar manner (similar curing method and concrete curing temperature, as approved by the Department’s Concrete Engineer) as the unit, until minimum compressive strength has been obtained. 7.Surface Finish and Patching: If a precast or prestressed item shows stone pockets, honeycomb, delamination, or other defects which may be detrimental to the structural capacity of the item, it will be subject to rejection at the discretion of the Engineer. Minor surface irregularities or cavities, which do not impair the service of the item, and which are satisfactorily repaired will not constitute cause for rejection. Repairs will not be made until the Engineer has inspected the extent of the irregularities and has determined whether the item can be satisfactorily repaired. If the item is deemed to be repairable, the repair method and procedures will be agreed upon by the Department and fabricator prior to the work commencing. Depressions resulting from the removal of metal ties or other causes will be carefully pointed with a mortar of sand and cement in the proportions, which are similar to the specific class of concrete in the unit. 8.Fresh Concrete Testing: The Contractor will be responsible for performing all fresh concrete testing in accordance with the Department’s Materials Manual. Tests will be documented on a DOT-54 form and submitted to the Engineer. 9.Concrete Compressive Strength: The Contractor will make a minimum of one group of test cylinders for each class of concrete for each day’s production, not to exceed 150 cubic yards per group of cylinders. At a minimum, a group of test cylinders will consist of the following: 670 Page 471a.Two test cylinders are required for the 28 day compression test. b.Two additional cylinders will be required for determining concrete strength, when the Contractor desires to make delivery and obtain acceptance by the Department prior to the 28 day compression test. Acceptance of the precast units will be in accordance with Section 460.3 B. except that the fabricator will be responsible for the sampling, preparing, and properly curing of all concrete cylinders for concrete compressive strength in accordance with the Department’s Materials Manual and the fabricator will be responsible for all costs. The precast units will be accepted when the minimum design concrete compressive strength requirements have been met. Accepted precast units represented by that test group of cylinders may be delivered to the project and will not require the 28 day cylinder test. The Engineer will be responsible for breaking of all concrete cylinders for concrete compressive strength in accordance with the Department’s Materials Manual.
670.4METHOD OF MEASUREMENT
Drop inlets will be measured per each, or when specified, the materials for drop inlets will be measured under the following items: A.Cast Iron Frames with Grates: Drop inlet cast iron frames with grates will be measured as units. B.Concrete: Class M6 concrete will be measured in accordance with Section 462. C.Reinforcing Steel: Reinforcing steel will be measured in accordance with Section 480.
670.5BASIS OF PAYMENT
When payment for drop inlets is made per each, payment will be full compensation for excavation required to furnish and install the drop inlet; for furnishing and installing concrete and reinforcing steel; and for labor, equipment, and incidentals necessary. Cast iron frames with grates and the required mortar bed will be paid for in accordance with Section 670.5 A. Unless otherwise specified in the plans, the cost for removal of existing pipe, if necessary, to facilitate the installation of new drop inlets will be incidental to the associated drop inlet contract unit prices. When payment for drop inlets is not made per each, the various items will be paid for as follows: A.Cast Iron Frames with Grates : Drop inlet cast iron frames with grates will be paid for at the contract unit price each. Payment will be full compensation for furnishing and installing the cast iron frame and grate as a unit, inclusive of the required mortar bed. B.Concrete: Concrete will be paid for as Class M6 concrete, in accordance with Section 462. Payment will be full compensation for excavation required to furnish and install the drop inlet. C.Reinforcing Steel: Reinforcing steel will be paid for in accordance with Section 480.5 . 671 Page 472671 MANHOLES
671.1DESCRIPTION
This work consists of the construction or reconstruction of manholes.
671.2MATERIALS
Materials will conform to the following sections. A.Cast In Place Concrete: Class M6 Section 462. B.Brick: Clay or shale brick will comply with the requirements for building bricks as provided in ASTM C62. The brick will be Grade SW. C.Concrete Block: Concrete block masonry will conform to ASTM C139. The dimensions of the block may be any standard size which will produce the required dimensions in the completed structure. D.Precast Units: Precast manhole units will conform to AASHTO M 199 and Section 990.1 A.2 except that Section 990.1 A.2.h will not apply. E.Castings: Unless otherwise specified on the plans, frames and covers will consist of approved gray iron castings meeting AASHTO M 105, Class 35. F.Mortar: Mortar will consist of one part Portland cement and two parts mortar sand conforming to Sections 750 and Section 810 respectively. As an alternate, a commercially available grout conforming to Section 460.2 K may be used. G.Steel Reinforcement: Section 1010 .
671.3CONSTRUCTION REQUIREMENTS
Concrete for cast in place manholes will be hauled, placed, finished, cured, and protected in accordance with Section 460. When the foundation for a manhole is in new embankment, the embankment will be constructed at least 1 foot above the footing before the foundation is prepared. The foundation will be compacted to the same degree as specified for the adjacent embankment. Castings will be set in full mortar beds or secured as specified. Castings will be set to the correct elevation so subsequent adjustment will not be necessary. Inlet and outlet pipe connections will be the same size and kind and will meet the same requirements as the pipe they connect. Pipe sections will be flush on the inside of the structure wall and project outside for proper connection with the next pipe section. Masonry will fit neatly and tightly around the pipe.