Part 1 — General
1.1 Section Includes
A.Concrete drainage structures according to the CB and DB Series Standard Drawings.
1.2 Related Sections
A.Section 02056: Embankment, Borrow, and Backfill
B.Section 2317: Structural Excavation and Backfill
C.Section 02635: Grates, Solid Covers, Frames, and Manhole Steps
D.Section 03055: Portland Cement Concrete
E.Section 03056: Self -Consolidating Concrete (SCC)
F.Section 03152: Concrete Joint Control
G.Section 03211: Reinforcing Steel and Welded Wire
H.Section 03310: Structural Concrete
I.Section 03390: Concrete Curing
1.3 References
A.AASHTO M 198: Joints for Concrete Pipe, Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants
B.AASHTO M 199: Precast Reinforced Concrete Manhole Sections
C.AASHTO M 213: Preformed Expansion Joint Fillers for Concrete Paving and Structural Construction (Non- extruding and Resilient Bituminous Types)
D.AASHTO M 235: Epoxy Resin Adhesives
E.AASHTO M 315: Joints for Concrete Pipes and Manholes Using Rubber Gaskets
F.ASTM A 775: Standard Specification for Epoxy -Coated Steel Reinforcing Bars
G.ASTM C 361: Reinforced Concrete Low -Head Pressure Pipe
H.ASTM C 443: Joints for Concrete Pipe and Manholes, Using Rubber Gaskets
I.ASTM C 478: Precast Reinforced Concrete Manhole Sections
J.ASTM A 1035: Deformed and Plain, Low -Carbon, Chromium, Steel Bars for Concrete Reinforcement
K.ASTM C 1107: Packaged Dry, Hydraulic -Cement Grout (Nonshrink)
L.ASTM C 1244: Concrete Sewer Manholes by the Negative Air Pressure (Vacuum) Test Prior to Backfill
M.UDOT Quality Management Plans
1.4 Definitions
A.Catch Basin/Drop Inlet – A structure accepting drainage from gutters or medians or other channels and discharging the water through a conduit.
B.Inlet – A grated surface connection to a closed conduit such as a storm drain. A structure at the upstream end of a cross culvert. The upstream end of any structure through which water may flow.
C.Manhole (access hole) – A circular structure for access and joining pipes.
1.5 Submittals
A.Repair P rocedure for review if precast Concrete Drainage Structures are damaged during shipping or handling.
1.Submit before performing any repairs. Refer to this Section, A rticle 1.6, paragraph B.
1.6 Acceptance
A.Repair or replace any structure that has the following:
1.Fractures or cracks passing through the wall except for a single end crack that does not exceed the thickness of the precast unit.
2.Defects showing improper proportioning, mixing, or molding.
3.Honeycombing and open texture.
4.Damaged or cracked ends that prevent joining manhole or inlets grade rings and sections.
5.Any continuous crack with a surface width of 0.01 inch or more that extends more than 12 inches anywhere on the wall.
6.Limit cracks or fractures for grade rings or similar structures. Refer to ASTM C 478.
B.Precast Structures
1.Furnish precast structures that are plumb and square within ⅛ inch per foot so that precast adjoining elements fit.
Part 2 — Products
2.1 Concrete
A.Wet cast – Class AA (AE). Refer to Section 03055.
B.Dry cast – Submit mix design for approval.
1.Minimum cement content 470 lb/yd
2.Maximum water/cementitious ratio 0.40
C.Self-Consolidating Concrete – Refer to Section 03056 .
2.2 Reinforcing Steel and Welded Wire
A.Refer to Section 03211.
B.Chromium reinforcing steel may be substituted for coated reinforcing steel .
1.Deformed low -carbon, chromium, steel bars
a.Alloy Type 1035 CM or 1035 CS
b.Grade 100
c.Refer to ASTM A 1035.
2.Use chromium steel as a direct substitute for coated reinforcing steel.
a.Use the same number and size of bars as shown for coated bars. b, Assume a yield strength of 60 ksi for design.
2.3 Precast Concrete Drainage Structures
A.Use a Department prequalified supplier of precast concrete products according to the UDOT Quality Management Plan 505 – Precast/Prestressed Concrete Structures
B.Furnish structures free of voids, cracks, and with beveled corners and edges. Securely attach all inserts in the proper location.
1.Prevent cold joints in the structure.
2.Field verify the fit and function at structure locations before manufacturing.
C.Manholes
1.Furnish precast concrete manholes according to ASTM C 478 and use self -centering watertight joints that meet ASTM C 443. Refer to CB Series Standard Drawings.
a.Meet AASHTO M 199 requirements.
b.Cure wet cast members according to Section 03390.
D.Grade Rings/Catch Basin Grade Sections
1.Furnish according to ASTM C 478 with anchor bolt -holes as shown on the CB Series Standard Drawings.
a.Cure wet cast members according to Section 03390.
E.Precast Inlets and Boxes
1.Furnish structures according to CB or DB Series Standard Drawings.
a.Attach and secure all inserts at the place of manufacture such as wall sleeves, gaskets or piping, sumps, steps, access hatches, and any other inserts as shown on CB or DB Series Standard Drawings.
2.Manufacture structures according to applicable requirements of ASTM C 858 and as modified by this Section. a. Meet AASHTO M 199 and ASTM C 857 requirements.
b.Cure wet cast members according to Section 03390.
3.Provide sufficient lifting points for a safe installation.
a.Locate lifting devices to avoid interference with the reinforcing steel.
4.Do not ship precast units until after 28 day minimum compressive strength has been attained.
a.Protect the unit from damage.
5.Furnish structures with appropriate openings for connecting pipe.
a.Cast or cut structure openings. Do not expose reinforcing steel or reduce reinforcing steel covering at openings.
b.Do not modify precast units in the field by cutting or enlarging holes or by making any other changes without the manufacturer’s and Engineer’s approval.
c.Modify precast units only according to manufacturer requirements.
2.4 Joints and Sealers
A.Preformed Joint Filler . Refer to AASHTO M 213 and AASHTO M 198.
2.5 Waterstops
A.Refer to Section 03152 for materials requirements.
2.6 Non- Shrink Grout
A.Use non- shrink grout according to ASTM C 1107.
2.7 Forms
A.Use plywood, wood, metal, glass, or a combination of these materials.
2.8 Gaskets and Joint Sealants for Connecting Precast Sections
A.Furnish gaskets for sealing precast sections that meet ASTM C 443 requirements.
B.Furnish gaskets for sealing precast concrete manholes that meet AASHTO M 315.
C.Furnish epoxy resin adhesive. Refer to AASHTO M 235.
D.Furnish “O” Ring according to ASTM C 361 as shown in the CB Series Standard Drawings.
2.9 Manhole/Frame Gasket
A.Place ¾ inch diameter minimum extruded rope Type B flexible plastic gaskets between the manhole frame and the concrete risers according to AASHTO M 198 requirements.
2.10 Jointing Mastic
A.Furnish water -resistant elastic jointing mastic of plastic bituminous materials and inert fillers that do not lose slump or plasticity when applied to a vertical metal surface and heated to 120 degrees F.
B.Furnish joint mastic that can be applied evenly and adhere at temperature range of 40 to 120 degrees F or higher.
2.11 Grates, Solid Covers, Frames, and Manhole Steps
A.Refer to Section 02635.
2.12 Granular Backfill Borrow
A.Refer to Section 02056.
Part 3 — Execution
3.1 Excavati On, Bedding and Backfill
A.Refer to Section 02317.
B.Excavate to at least 4 inch below the bottom of the structure.
C.Place a bedding of at least 4 inch of granular backfill borrow or as shown.
1.Add as needed, a sand- leveling course no greater than 2 inch in depth to the backfill material.
2.Excavate the area to the appropriate depth to accommodate the bedding and leveling course, when used.
C.Backfill structure using granular backfill borrow.
D.Furnish structures free of voids, cracks, and with beveled corners and edges. Securely attach all inserts in the proper location.
1.Prevent cold joints in the structure.
3.2 Installation
A.Precast Inlets and Boxes
1.Refer to ASTM C 891. Comply with manufacturer installation guidelines.
a.Inspect precast drainage structures for defects before lowering into excavation.
b.Clean mating surfaces of all foreign materials such as dirt, mud, and stones and apply proper joint sealing material where applicable.
c.Assemble all joints tightly.
d.Use care when joining precast elements in cold weather. Do not force joints together with mechanical equipment.
e.Sufficiently warm all sealing materials to flow without causing damage to precast joint elements.
2.Do not place precast drainage structure in excavation that has water and frozen surfaces.
3.Plug lift insert recesses with a 1:1 sand to cement grout mix.
a.Finish flush with top , bottom , or both surfaces of concrete.
B.Cast-in-place concrete drainage structures.
1.Construct Cast -in-place structures free of voids, cracks, and with beveled corners and edges.
a.Securely attach all inserts in the proper location.
b.Prevent cold joints in the structure.
c.Refer to CB and DB Series Standard Drawings.
d.Construct according to Section 03310.
e.Cure according to Section 03390.
C.Clean and prepare the mating surfaces before assembly of pipes with structure.
1.Use one of the following methods to connect the pipes to the structure for Cast -in-place:
a.Pipe boot according to pipe manufacturer specifications for pipe type.
b.Non-shrink grout to seal the pipe connection.
3.3 Testing
A.Conduct either a vacuum test or ex -filtration test to verify the precast drainage structures are watertight at the direction of the Engineer upon failure of the visual inspection referenced in this Section, Article 1.6 .
1.Furnish all necessary equipment and materials for repair and re- test any structures that fail any tests .
2.Do not conduct vacuum and ex-filtration tests concurrently.
B.Vacuum Test – Follow the test procedure outlined below:
1.Vacuum test precast structures after assembly and before backfilling.
a.Form a seal between the vacuum base and the manhole rim/precast structure cover. Secure pipe plugs to prevent movement while the vacuum is drawn.
b.Draw a vacuum of 10 inches of mercury (Hg). Record the time for the vacuum to drop to 9 inches.
c.Passing drop rates for the time to drop to 9 inches are: Diameter/Width Time to Drop 1 inch Hg up to 4 ft 30 seconds 4 ft and larger 40 seconds
d.Make necessary repairs if the structure fails the test. Repairs and repair procedures must be acceptable to the Engineer.
e.Disassemble the manhole and replace the gaskets if preformed plastic gaskets are pulled out during the vacuum test.
C.Ex-filtration Test – Follow test procedure ASTM C 1244 as modified below:
1.Plug all pipes leading into or out of the precast structure for a watertight seal.
2.Fill precast structure with water to a level 3-4 inches below the casting rim or lid.
3.Let the water stand for two hours before beginning the test to allow absorption into the precast structure.
4.Place additional water to bring the water level back to 3 -4 inches below the rim or lid after the two hour stabilization .
5.Test for at least two hours and verify the leakage is less than shown on table 1. Table 1 Precast Structure Ex -Filtration Test – Allowable Leakage Water Depth (measured from invert to water level) Allowable water drop per hour Feet Maximum Horizontal Internal Dimension 4 ft.* 5 ft * 6 ft * (gals) (inches) (gals) (inches) (gals) (inches) 2 0.8 0.32 1.0 0.40 1.2 0.48 4 1.6 0.64 2.0 0.8 2.4 0.96 6 2.4 0.96 3.0 1.21 3.6 1.45 8 3.2 1.29 4.0 1.61 4.8 1.93 10 4.0 1.61 5.0 2.01 6.0 2.42 12 4.8 1.93 6.0 2.42 7.2 2.90 14 5.6 2.25 7.0 2.82 8.4 3.38 16 6.4 2.58 8.0 3.22 9.6 3.87 18 7.2 2.90 9.0 3.63 10.8 4.35 20** 8.0 3.22 10.0 4.03 12 4.84 * Adjust volume loss proportionally for different size not shown ** Provide an engineering analysis for equivalent ex -filtration rates for depths greater than 20 feet .
D.The Department will reimburse the Contractor for the actual cost of each passing test required by the Engineer to meet vacuum or ex -filtration requirements , not to exceed $500 per test .
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 394–402 of 1,331.