11-20-97
730-R-350
GRATED BOX END SECTIONS
The Standard Specifications are revised as follows:
SECTION 730, BEGIN LINE 1, INSERT AS FOLLOWS:
SECTION 730 -- GRATED BOX END SECTIONS
730.01 Description. This work shall consist of the fabrication of cast in place or precast grated box end sections in accordance with the dimensions and locations as shown on the plans.
730.02 Materials. All concrete shall be class A in accordance with 702. Concrete in precast units shall be air entrained. Reinforcing steel shall be Grade 60 and shall be in accordance with 703. Steel pipe and steel tubing shall be in accordance with ASTM A 53, Grade B or ASTM A 501. Such pipe and tubing shall be galvanized in accordance with ASTM A 123. Structural steel grates shall be ASTM A 36 M (ASTM A 36) for end sections having widths less than or equal to 0.9 m (3'-0"). Structural steel grates shall be ASTM A 572M grade 345 (ASTM A 572 grade 50) for widths greater than 0.9 m (3'-0"). All other related hardware shall be galvanized in accordance with ASTM A 153. Threaded inserts shall have a minimum pull-out capacity of 27 kN (6,000 lb). The M13 (1/2 in.) round bolts shall have hex heads, cut washers, and where necessary, shall be furnished with the grating. The aggregate leveling bed required for precast units shall be coarse aggregate size No. 8 in accordance with 904.02. The hardware cloth used to cover the weep holes, may be plastic with 6 mm (1/4 in.) mesh or galvanized steel wire No. 4 mesh with a minimum wire diameter of 0.8 mm (1/32 in.). It shall be firmly anchored to the outside of the structure and shall be centered on the holes.
Pipe with a 100 mm (4 in.) outside diameter and in accordance with ASTM A 513, Type 5, may be used as an alternate to the 100 mm (4 in.) outside diameter pipe specified. The pipe used as an alternate shall have a minimum wall thickness of 8 mm (5/16 in.) and a minimum yield strength of 345 MPa (50,000 psi). Steel tube of 100 mm by 100 mm by 9.5 mm (4 in. by 4 in. by 3/8 in.), and in accordance with ASTM A 500, Grade B, will also be permitted as an alternate to the 100 mm (4 in.) outside diameter pipe specified.
Pipe furnished as an alternate as described herein shall be covered by a type B certification in accordance with 916.
730.03 Construction Requirements. Grated box end sections shall be constructed according to the required pipe size and surface slope of the grated box end section specified at each location. Precast units shall be cast as a single complete unit except for the toewall which shall be cast in place. They shall be set and leveled on a 150 mm (6 in.) thick bed of coarse aggregate. If precast units are used and the adjoining pipe is to be field connected directly to the precast unit, the connection shall be made using a class A concrete collar of 150 mm (6 in.) minimum longitudinal and radial thickness. Inserts for approved lifting devices may be cast in the bottom slab of the precast sections. The number and location of lifting devices needed for handling shall be determined by the fabricator. All reinforcing steel shall have a minimum cover of 40 mm (1 1/2 in.) and shall have a minimum lap of 540 mm (21 in.). The type A construction joint between the floor and the wall is optional for cast in place units.
730.03.1 Pipe End Treatment. A grated box end section installed on a structure where differing smooth and corrugated interior pipe sizes are permitted will be considered to be a pipe end treatment.
730.04 Method of Measurement. Grated box end sections will be measured per each for the specified type, surface slope, and pipe size. Pipe end treatments will be measured in accordance with 715.11.
730.05 Basis of Payment. Grated box end sections will be paid for at the contract unit price per each for the specified type, surface slope, and pipe size. Pipe end treatments will be paid for in accordance with 715.12.
Payment will be made under:
Pay Item Pay Unit Symbol
Grated Box End Section, ____, _____, _______ mm..........................EACH
type slope pipe size
(Grated Box End
Section, ____, _____, ______ in..............................EACH)
type slope pipe size
The costs of concrete, grating, pipe tubing, reinforcing steel, aggregate leveling bed, hardware cloth, and necessary incidentals shall be included in the cost of this work.