503CONCRETE CATCH BASINS

543 502- 4 Method of Measurement: Structural plate pipe, pipe- arches, and arches will be measured either by the linear foot, or by the lump sum for each structure, installed in place, completed, and accepted. If measurement is made by the linear foot, measurement will be made along the invert center line for pipe and pipe -arches and the average of the springline lengths for arches. Structural concrete and reinforcing steel used for headwalls and footings will be measured by the cubic yard and by the pound, respectively. Structural excavation and structure backfill for footings will be measured in accordance with the requirements of Subsection 203- 5.04 of the specifications. 502- 5 Basis of Payment: The accepted quantities of work under this section, measured as provided above, will be paid for at the contract lump sum price or the contract unit price per linear foot for the different sizes and thickness of structural plate pi pe, pipe -arches and structural plate arches designated in the bidding schedule, complete in place, including excavating and furnishing, placing , and compacting backfill material. Payment for structural concrete used in footings and headwalls will be made as provided in Subsection 601- 6 of the specifications. Payment for reinforcing steel used in footings and headwalls will be made as provided in Subsection 605- 5 of the specifications. Payment for structural excavation and structure backfill for footings w ill be made as provided in Subsection 203- 5.05 of the specifications. 503- 1 Description: The work under this section shall consist of furnishing all materials and constructing or reconstructing concrete catch basins, including excavation, concrete removal , and backfill. Work shall be done at the locations designated on the project plans and in accordance with the details shown on the plans and the requirements of these specifications. 503- 2 Materials: 503- 2.01 Concrete: Portland cement concrete shall conform to the requirements of Section 1006 of the specifications for Class B concrete. TABLE OF CONTENTS INDEX 544 503- 2.02 Reinforcing Steel: Reinforcing steel bars or mesh shall conform to the requirements of Section 1003 of the specifications. 503- 2.03 Masonry Mortar: Masonry mortar shall be composed by volume of one part Portland cement, two parts fine aggregate, one- fifth part hydrated lime, and sufficient water to provide a plastic mixture. The lime shall be considered as an addition to and not as replacing any cement. Fine aggregate shall conform to the requirements of ASTM C144. Portland cement and water shall conform to the requirements of Section 1006 of the specifications. Hydrated lime shall conform to the requirements of ASTM C207, Type N. Mortar that has been mixed more than one hour shall not be used. Retempering of mortar will not be permitted. 503- 2.04 Structural Steel: Structural steel parts shall conform to the requirements of Section 1004 of the specifications. 503- 3 Construction Requirements: 503- 3.01 Catch Basins: Excavation and backfill for the catch basin shall be performed in accordance with the requirements of Subsection 203- 5 of the specifications. Catch basins shall be cast -in-place or, at the option of the contractor, may be precast units. A list of approved precast units may be found on the Department’s Approved Products List (APL), available on the internet from the Arizona Transportation Research Center (ATRC), through its PRIDE program. The "H" dimension for catch basins shall be determined in the field prior to casting. The contractor is advised to acquaint itself with conditions peculiar to the project which might limit the use of precast items. Cast -in-place catch basins shall be constructed in accordance with the requirements of Section 601 of the specifications and reinforced where called for on the plans in accordance with the requirements of Section 605 of the specifications in reasonably close conformity to the lines and grades shown on the plans and shall meet adjacent sidewalk, curb, or gutter surfaces with no appreciable offsets. Catch basin grates and TABLE OF CONTENTS INDEX SECTIO N 503 545 frames shall be fabricated and installed so that the bearing surfaces of the grate rest securely on the bearing surfaces of the frame. Proper equipment shall be provided for lowering the precast sections to position. The tongue end of the section shall be placed in contact with the base structure unless otherwise directed. Not more than two holes shall be cast or drilled in the shell of each section for the purpose of handling and placing. If such holes are provided, they shal l be filled and finished with mortar after placing the catch basins. Immediately before joining precast sections, mortar shall be placed continuously around the circumference of the receiving section's contact surface. Any precast section damaged during handling or placing shall be repaired or replaced at the option of the Engineer and at no additional cost to the Department. When specified on the project plans, aprons shall be constructed in accordance with the details shown on the plans. Aprons shall be constructed from Portland cement concrete or from asphaltic concrete. When specified on the project plans or ordered by the Engineer, corrugated metal pipe shall be installed as temporary drain for the roadway. The pipes shall be subsequently filled wit h concrete. Backfilling of the completed structure shall be in accordance with the requirements of Subsection 203- 5 of the specifications. Preformed bituminous joint filler shall be installed where the catch basin concrete will meet new or existing concret e curb pavement. 503- 3.02 Reconstruct Catch Basins: Catch basins shall be reconstructed in reasonably close conformity to the lines and gr ades shown on the plans. The existing frame and grate shall be carefully removed and cleaned. After removal of the frame, the top of the catch basin shall be trimmed to provide a suitable foundation for the new material. Frames and grates shall then be reinstalled according to the requirements of Subsection 503- 3.01 of the specifications. Where reconstruction of a catch basin requires partial removal of concrete, sufficient concrete shall be removed to permit new reinforcing steel to be spliced to existing reinforcing steel in accordance with the requirements of Subsection 605 -3.02 of the specifications. Existing reinforcing incorporated into the new work shall be thoroughly cleaned of all adhering material before being embedded in new concrete. N ew concrete shall be placed according to the requirements of Section 601 of the specifications. TABLE OF CONTENTS INDEX