All precast products will be manufactured in a plant especially for that purpose. All units will confirm to the design shown on the drawings and all work shall be done under strict plant controlled supervision and testing.
Design loads shall consist of dead load, live load, impact, an in addition, loads due to water table and any other loads which may impose upon the structure. Live loads shall be for H-20 and/or H-20-s16 per A.A.S.H.T.O Standard specifications for highway bridges with revisions. Design wheel load shall be 16 kips. The live load shall be that load which produces the maximum shears and bending moments in the structure.
All forms used in placing concrete shall be metal and sufficiently designed and braced to maintain their alignment under pressures of the concrete during placing.
Aggregates: All aggregates shall confirm to specifications outlines by ASTM
C-33-64. Aggregate shall be graded in a manner so as to produce a homogeneous concrete mix. All materials are to be accurately weighed at a central batching facility for mixing.
Cement: All cement shall be portland cement confirming to ASTM C150, or
Type III. Cement content shall be sufficient top produce a minimum strength of 4500 psi in 28 days or other strength required. Slump shall be two to four inches. Strength test will be made in accordance with ASTM C39 using molded concrete cylinders.
Placing: All concrete shall be handled from the mixer or transport vehicle to the place of final deposit in a continuous manner, as rapidly as practicable and without segregation or loss of ingredients until the approved unit operation is completed. Concrete shall be placed in layers not over two feet deep. Each layer shall be compacted by mechanical internal or external vibrating equipment. Duration of the vibration cycle shall be limited to the time necessary to produce satisfactory consolidation without causing objectionable segregation.
All reinforcing steel, including welded wire mesh, shall be in size and the location shown on the plans. All reinforcing shall be sufficiently tied to withstand and displacement during the pouring operation. All bars shall be intermediate or hard grade billet steel conforming to ASTM A615. Bars other that 1/4″ round, or smaller shall be deformed in accordance with ASTM A305.
Using our catalogs or approved drawings to obtain dimensions, the owner or his contractor shall prepare the excavation for the correct elevation after the base has been properly installed. The depth of the base and the material used for the same shall meet the specified requirements for the type of soil at the setting location. The base shall be compacted and level. After having received at least 24 hours notice we will deliver the manhole sections to the specified excavation. It will be necessary for the contractor to furnish the labor necessary to install the joint sealant and t assist our crane operator with the installation. We will furnish the sealant specified to seal the joints unless grout is to be used. If grout is to be used to seal the joints, it shall be furnished and installed by the contractor.
Material should be free flowing and placed in lifts of approximately two (2) feet around the manhole so as not to shift the manhole sections. Compaction, per owners requirements.
Sanitary Sewer Manholes
Pre-cast sanitary sewer manhole will consist of a bottom, variable riser sections, and a cone or lid. Concrete used will CLASS A, 4000 p.s.i. properly vibrated and inspected to assure quality. Reinforcing steel will meet ASTM specifications.
Inside base height is 16″ to 42″ inches with a 7″ floor below the pipe. PRESS SEAL GASKETS will be installed with compression to insure no leakage. Sizes of gaskets are determined by pipe sizes. PRESS SEAL GASKETS meet or exceed ASTM-923 specifications.
Riser sections range from 12″ to 48″ in height. A recess is provided on the spigot end at the joint for a PRESS SEAL O-RING GASKET to insure leak proof joints. PRESS SEAL O-RING GASKETS meet or exceed ASTM C-316A and ASTM C-443-85A specifications.
Invert channels are constructed to insure smooth uniform flow. A smooth and uniform floor is poured on a 1/2 inch per foot slope to the edge of the invert channel.
Contractor should remove all loose dirt and provide a cushion of 6″ crushed stone or suitable non-cohesive bedding material placed uniformly under the base extending 6″ beyond the side walls.
Cone sections are 18″, 24″, and 32″ inches high. The bottom is 48″ inside diameter and tapers to 24″ inside diameter at the top to accept grade rings and frame/cover. All riser and cone sections are CLASS A concrete and steel reinforced to meet or exceed ASTM specifications.
All sections and base come equipped with lift inserts for easy installation.