for Highway Construction Page 366 of 71 5 SECTION 508 – CORRUGATED PLAT E PIPE
508.01 Description.
Provide and install a steel or aluminum corrugated plate pipe arch structure as detailed or as specified. The structure must be designed in accordance with the current edition of AASHTO LRFD Bridge Design Specifications .
A.Design Computations and Shop Drawings . Submit the manufacturer’s shop drawings and design computations, in accordance with 105.02, for Engineer approval before fabrication. Ensure the shop drawings and design computations are signed and sealed by an Idaho licensed professional engineer. Ensure shop drawings include a plate layout showing installation offsets and sequence from a common reference point for all stages of construction. For single pipe arch structures with a span length equal to or greater than 10 feet measured along the centerline of roadway or a combination of pipe arches with a total out to out length equal to or greater than 10 feet measured along centerline of roadway and the distance between centerlines of pipes less than one - half the span length of the smaller pipe arch, the structure must be designed at Strength II for a standard gauge tridem axle load of 120 kips (40 kips per axle) with 4.5 foot spacing between axles.
B.Initial Load Rating. For all pipe arch structures requiring Strength II design for tridem axel as defined in 508.01.A, the supplier is required to prepare a Load and Resistance Factor Rating (LRFR) in accordance with the Idaho Manual for Bridge Evaluation and provide a Load Rating Summary (LRS) form for approval by the Department at the same time as shop drawing submittal .
508.02 Materials.
Provide material as specified in 708.20. Meet minimum thickness for all steel plates as shown in the bridge plans.
508.03 Construction Requirements.
A.General. Curve each plate to the required radius and punch the bolt holes so the sections, except the end plates, are interchangeable in the erection process. Fabricate bolt holes in accordance with AASHTO M 167 Section 6. When the completed structure is to be a full -circle pipe , curve th e plates so when they are bolted together, they form true circles of the required diameter. When the completed structure is to be a multi -centered pipe or arch, curve the plates to the required radii. Cut plates for forming skewed or sloped ends to give the angle of skew or slope specified. Ensure burnt edges do not have oxide or burrs and present a well -made finish. Install the structure in accordance w ith the p roject plans and specifications and the manufacturer’s written instructions. for Highway Construction Page 367 of 71 5 B. Assembly. Assem ble the pipe in accordance with the manufacturer’s written instructions. Steel Structural Plate. Apply at least 100 foot -pounds but no more than 300 foot -pounds of torque to 0.75 inch diameter high strength steel bolt s (ASTM A449). Aluminum Structural Plate. Apply at least 100 foot -pounds but no more than 150 foot -pounds torque to 0.75 inch diameter aluminum bolts (ASTM F468) or standard strength steel bolt (ASTM A307) Exercise care in the use of drift pins or pry bars to prevent chipping or injury to the galvanized coating.
C.Backfill . Place backfill materials in symmetrical lifts on each side of the structure. Ensure the differential between the lifts on either side does not ex ceed 24 inches. Place each layer of soil in 6 to 8- inch loose lifts and compact to at least 95 percent of the maximum dry density as determined by Idaho T 74 and/or AASHTO T 99, and AASHTO T 310, Method B. Select equipment and methods to provide the specified backfill density without excessive movement or deformation of the structure.
508.04 Method of Measuremen t.
The Engineer will measure acceptably completed work by the foot. When the ends of a corrugated plate structure are cut on a skew or slope, the length of the structure will be the bottom length measured along the structure centerline and grade.
508.05 Basis of Payment .
The Department will pay for acceptable quantities at the contract unit prices as follows: Pay Item Pay Unit ____ Corrugated Plate Pipe Culvert ___ Thickness ............................... FT ____ Corrugated Plate Pipe Arch ___Thickness .................................... FT ____ Corrugated Plate Arch ___ Thickness ........................................... FT for Highway Construction Page 368 of 71 5 SECTION 509 – NONSTRUCTURAL CONCRETE
509.01 Description.
Provide nonstructural portland cement concrete . Nonstructural portland cement concrete is concrete used in curb, sidewalk , gutter, small sign post foundations, or other applications where long term s tructural durability is not critical. Submit a proposed mix design using ITD -0916 for approval. Use the concrete class as specified.
A.Classification. Provide Class 30 concrete unless otherwise specified. Use size No. 2a or 2b coarse aggregate for all c lasses of concrete. Provide concrete in accordance with Table 509.01- 1. Table 509.01 -1 – Basic Mix Design Parameters Concrete Class in 100 psi (28 day) (a) Maximum Water To Cement Ratio (b) Air Content Percent 35 and greater (c) 0.45 0 - 6 30 0.50 6.5 ± 1.5 22 0.60 0 - 6 15 0.60 0 - 6
a.Numerical part of class designation is the specified compressive strength when tested as specified in the applicable test listed in 509.02.
b.Cement plus secondary cementitious materials , if used.
c.Ensure concrete designated as: 1. Class A: the air content of 6.5 plus or minus 1.5 percent.
2.Class C: has a maximum water cement ratio of 0.38, water reducer required, and air content of 6.5 plus or minus 1.5 percent. Use SCM for concrete use when designated with an “F.” This designation shows a mix containing SCM and meeting the requirements for an “A” or “C” mix as specified when used with the above designations. Meet requirements of 714. If fly ash is used, d o not exceed 35 percent of the total cementitious material (fly ash + cement). If ground granulated blast furnace slag (GGBFS) is used, do not exceed 35 percent of the total cementitious materials. If a combination of GGBFS and fly ash is used, ensure the combination is at least 20 percent or more than 50 percent of the total cementitious materials. Use size Nos. 2a or 2b coarse aggregate in any class of concrete. Ensure the slump does not vary more than 1 inch from the average during placement. If an increase in slump is desirable for the concrete as batched, maintain the weight ratio of water to cement by either making proportional increases of cement with increases in water or by reducing the total weight of aggregates incorporated in the mixture.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 402–403 of 768.