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1. Building connections shall be installed using the same construction and pipe joining
techniques as specified in Section 02085 POLYVINYL CHLORIDE GRAVITY PIPE
AND FITTINGS.

2. In general, connections shall be carried only to the property line. The end of the pipes
shall be closed with PVC stoppers jointed in place to ensure against infiltration into the
sewer line.

3. In general, the mainline sewer has been designed at depths to accommodate full
basement service for each building to be connected. Building connections must be
installed at the proper depth in every case that full basement service is possible for the
building. The CONTRACTOR will be required to excavate, remove, reinstall and
backfill any building connection improperly installed at his own expense. The
CONTRACTOR will demonstrate to the Inspector that all connections are properly
made.

4. In streets where building sewers must cross water mains, the CONTRACTOR will
install the building sewers at proper depths to maintain the vertical clearance between
the two pipes, as shown in the construction details. Building services shall be installed
beneath water mains.

B. DROP CONNECTIONS:

1. When the invert of a pipe entering a manhole is 24 inches or more above the invert of
the lowest pipe leaving the manhole, it shall be connected to the manhole with an
inside drop section.

2. The drop pipe shall be the same diameter, material, and class as the sewer pipe
entering the manhole, unless otherwise noted in the drawings. The drop connection
shall be constructed as shown on the City of Nashua Standard details.

3. All connecting hardware shall be stainless steel.

END OF SECTION

2019 CIPP Lining Project Building Connections and Drop Connections
Nashua, NH 02530-2

SECTION 02631
PRECAST MANHOLES
PART 1 - GENERAL
1.01 WORK INCLUDED:

A. This Section covers all precast sewer manholes complete, including, but not limited to,
bases, walls, cones, mortar, inverts, frames and covers.

B. Work shall comply with City of Nashua Standard Specifications for Sewers and Drains,
which are hereby incorporated by reference.

1.02 RELATED WORK:

A. Section 02300, EARTHWORK.

B. Section 02745, ROAD RESTORATION
1.03 SYSTEM DESCRIPTION:

A. Precast sections shall conform in shape, size, dimensions, materials, and other respects to the
details indicated on the drawings or as ordered by the Engineer.

B. All manholes shall have concrete bases. Concrete bases shall be precast unless otherwise
specified. Invert channels shall be formed of brick and mortar upon the base.

C. Riser and cone sections shall be precast concrete.

1.04 REFERENCES:
A. The following standards form a part of this specification as referenced:

American Society for Testing and Materials (ASTM)

ASTM A48 Gray Iron Castings
ASTM C32 Sewer and Manhole Brick
ASTM C144 Aggregate for Masonry Mortar
ASTM C207 Hydrated Lime for Masonry Purposes
ASTM C478 Precast Reinforced Concrete Manhole Sections
ASTM (C923 Specification for Resilient
2019 CIPP Lining Project Precast Manholes

Nashua, NH 02631-1

Connectors Between Reinforced Concrete
Manhole Structures and Pipes

ASTM C1244 Standard Test Method for Concrete Sewer Manholes by the

Negative Air Pressure (Vacuum) Test.

American Association of State Highway and Transportation Officials (AASHTO)
AASHTO M198Joints for Circular Concrete Sewer and Culvert Pipe Using
Flexible Watertight Gaskets
Occupational Safety and Health Administration OSHA 29 CFR 1910.27
Fall Prevention Protection

1.05 SUBMITTALS: IN ACCORDANCE WITH REQUIREMENTS OF GENERAL
SPECIFICATIONS, SUBMIT THE FOLLOWING:

A. — Six sets of manufacturer literature of the materials of this section shall be submitted to the
Engineer for review.

B. _ Tests reports as required shall be submitted to the Engineer.
PART 2 - PRODUCTS 2.01. PRECAST CONCRETE SECTIONS:

A. All precast concrete sections shall conform to ASTM C478 with the following exceptions
and additional requirements:

1. | The wall thickness of precast sections shall be as designated on the drawings,
meeting the following minimum requirements:

Section Diameter (Inches) Minimum Wall Thickness (Inches)
48 5
60 6
T2 7
84 8

2. Type II cement shall be used except as otherwise approved.

3. Sections shall be steam cured and shall not be shipped until at least five days after
having been cast.

4, Minimum compressive strength of concrete shall be 4000 psi at 28 days.

2019 CIPP Lining Project Precast Manholes
Nashua, NH 02631-2

5. No more than two lift holes may be cast or drilled in each section.

6. The date of manufacture and the name or trademark of the manufacturer shall be
clearly marked on the inside of each precast section.

7. Acceptance of the sections will be on the basis of material tests and inspection of the
completed product.

8. Circumferential steel reinforcement in walls and bases shall be a minimum of 0.12 sq.
in/lin. ft. for 4-foot diameter sections and 0.15 sq. in/lin. ft. for 5- and 6-foot
diameter sections. Reinforcing shall extend into tongue and groove.

B. Conical reducing sections shall have a wall thickness not less than 5-inches at the bottom
and wall thickness of 8-inches at the top. Conical sections shall taper from a minimum of 48-
inches diameter to 30-inches diameter at the top, as shown on the drawings.

C. Except where insufficient depth of cover dictates the use of a shorter base, bases shall be a
minimum of 4 feet in height.

D. Slab top sections and flat riser sections (Grade Rings) shall conform to the contract
drawings, with particular attention focused upon the reinforcing steel and be designed to
meet or exceed an H-20 Loading requirement.

E. The tops of the bases shall be suitably shaped by means of accurate ring forms to receive the
riser sections.

F. __ Precast sections shall be manufactured to contain wall openings of the minimum size to
receive the ends of the pipes, such openings being accurately set to conform with line and
grade of the sewer or drain. Subsequent cutting or tampering in the field, for the purpose of
creating new openings or altering existing openings, will not be permitted except as
directed by the Engineer.

G. —_"Drop-over" manholes shall be placed where indicated on the drawings. The Contractor
shall accurately measure the diameter of the existing outlet pipe and inform the
manufacturer of its size, so that the "Drop-over" type opening can be cut into the precast
manhole base. The bottom shall be cast in place by the Contractor in accordance with
Section 03302, FIELD CONCRETE. The invert channel shall be formed of brick and
mortar, as specified in this specifications section. The sub-base shall be a compacted, level
foundation of crushed stone, at least 6-inches thick, as specified in Section 02300
EARTHWORK, but shall vary to the depth necessary to reach sound undisturbed earth.

H. deleted

I. The Engineer reserves the right to reject any unsatisfactory precast section and the rejected
unit shall be tagged and removed from the job site immediately.

J. The Engineer may also require the testing of concrete sections as outlined under Physical

2019 CIPP Lining Project Precast Manholes
Nashua, NH 02631-3

Requirements in ASTM C478 with the Contractor bearing all testing costs.

2.02 BRICK MATERIALS:

A. _ Brick shall be sound, hard, and uniformly burned brick, regular and uniform in shape and
size, of compact texture, and satisfactory to the Engineer. Bricks shall comply with ASTM
C32, for Grade SS, hard brick, except that the mean of five tests for absorption shall not
exceed 8 percent by weight.

B. Rejected brick shall be immediately removed from the work and brick satisfactory to the
Engineer substituted.

C. Mortar shall be composed of portland cement, hydrated lime, and sand in which the volume
of sand shall not exceed three times the sum of the volumes of cement and lime. The
proportions of cement and lime shall be as directed and may vary from 1:1/4 for dense
hard-burned brick to 1:3/4 for softer brick. In general, mortar for Grade SS Brick shall be
mixed in the volume proportions of 1:1/2:4-1/2; portland cement to hydrated lime to sand.

D. Cement shall be Type II portland cement as specified for concrete masonry.

E. Hydrated lime shall be Type S conforming to ASTM C207.

F, The sand shall comply with ASTM C144 specifications for "Fine Aggregate," except that all
of the sand shall pass a No. 8 sieve.

2.03 FRAMES, GRATES AND COVERS:

A. Castings shall be of good quality, strong, tough, even-grained cast iron, smooth, free from
scale, lumps, blisters, sandholes, and defects of every nature which would render them unfit for
the service for which they are intended. Contact surfaces of covers and frame seats shall
be machined to prevent rocking of covers.

B. All castings shall be thoroughly cleaned and may be subject to a careful hammer inspection at
the Engineer's discretion.

C. Castings shall be ASTM A48 Class 30B or better.

D. The surface of the manhole covers shall have a diamond pattern with the cast words
"SEWER".

E. Manhole frames with 32-inch covers for 30-inch openings shall be 500 pounds minimum by
E.L. LeBaron Foundary Co., No. LC328; Quality Water Products, Style 47; Neenah
Foundry Co., R1740B or approved equal.

2019 CIPP Lining Project Precast Manholes

Nashua, NH 02631-4

SEWER MANHOLE ACCESSORIES:

A. Gasket materials shall be top grade (100% solids, vulcanized) butyl rubber and shall meet or
exceed AASHTO M-198.

B. Couplings at the manhole-pipe interface shall be made with a rubber seal system (with or
without stainless steel straps) meeting the requirements of ASTM C923 and recommended
for this type of connection.

C. — Stubs installed as specified and indicated on the drawings shall be short pieces of the same
class pipe as that entering the manhole and shall have either stoppers or end caps as shown on
the drawings. Stoppers or end caps shall be especially designed for that application.

PART 3 - EXECUTION
3.01 INSTALLATION:

A. PRECAST SECTIONS:

1. Precast bases shall be supported on a compacted level foundation of crushed stone, as
specified in Section 02300 EARTHWORK, at least 6-inches thick, but shall vary to
the depth necessary to reach sound undisturbed earth.

2. Precast reinforced concrete sections shall be set vertical and with sections in true
alignment.

3. Butyl rubber joint sealant shall be installed between each concrete section.

4. All holes in sections used for handling the sections shall be thoroughly plugged with
mortar. Mortar shall be one part cement to 1-1/2 parts sand, mixed slightly damp to
the touch (just short of "balling"), hammered into the holes until it is dense and an
excess of paste appears on the surface, and then finished smooth and flush with the
adjoining surfaces.

B. BRICK WORK:

1. _ Bricks shall be moistened by suitable means, as directed, until they are neither so dry
as to absorb water from the mortar nor so wet as to be slippery when laid.

2. Each brick shall be laid as a header in a full bed and joint of mortar without requiring
subsequent grouting, flushing or filling, and shall be thoroughly bonded as directed.

3. The brick inverts shall conform accurately to the size of the adjoining pipes. Side
inverts shall be curved and main inverts (where direction changes) shall be laid out in

smooth curves of the longest possible radius which is tangent to the centerlines of
adjoining pipe.

2019 CIPP Lining Project Precast Manholes
Nashua, NH 02631-5

C. CASTINGS:

L.

Cast iron frames, grates and covers shall be as specified. The frames and covers
shall be set by the Contractor to conform accurately to the grade of the finished
pavement, existing ground surface, or as indicated on the drawings. Frames shall be
adjusted to meet the street surface.

Cast iron manhole frames and covers not located in paved areas shall be set 6-inches
above finished grade, at a height as directed by the Engineer, or as indicated on the
drawings. The top of the cone shall be built up with a minimum of 1 course and a
maximum of 5 courses of brick and mortar used as headers for adjustment to final

grade.

Frames shall be set concentric with the top of the concrete section and in a full bed of
mortar so that the space between the top of the concrete section or brick headers and
the bottom flange of the frame shall be completely filled and made watertight. A
thick ring of mortar extending to the outer edge of the concrete shall be placed all
around the bottom flange. The mortar shall be smoothly finished to be flush with the top
of the flange and have a slight slope to shed water away from the frame.

Covers and/or grates shall be left in place in the frames, for safety reasons, except
while work is being performed.

D. ACCESSORIES:

l.

2.

Accessories shall be installed in accordance with manufacturer's instructions.

Stubs shall be set accurately to the dimensions indicated on the drawings. Stubs
shall be sealed with suitable watertight plugs.

3.02 LEAKAGE TESTS:

A. Leakage tests shall be made by the Contractor and observed by the Engineer on each
manhole. The test shall be by vacuum or by water exfiltration as described below:

B. VACUUM TEST:

1.

The vacuum test shall be conducted in accordance with ASTM C1244. Test results
will be judged by the length of time it takes for the applied vacuum to drop from 10
inches of mercury to 9 inches. If the time is less than that listed in Table 1 of ASTM
C1244, the manhole will have failed the test. Test times from Table 1 are excerpted
below.

TABLE | Minimum Test Times for Various Manhole Diameters

Diameter (Inches)
Depth (Feet) 48 60 72

2019 CIPP Lining Project Precast Manholes

Nashua, NH

02631-6

Times (Seconds)

0-12 30 39 49
12-16 40 52 67
16-20 50 65 81
20-24 59 78 97
26-30 74 98 121

If the manhole fails the initial test, the Contractor shall locate the leaks and make
proper repairs. Leaks may be filled with a wet slurry of accepted quick setting
material. If the manhole should again fail the vacuum test, additional repairs shall be
made, and the manhole water tested as specified below.

C. WATER EXFILTRATION TEST:

lL.

After the manhole has been assembled in place, all lifting holes shall be filled and
pointed with an approved non-shrinking mortar. All pipes and other openings into the
manhole shall be suitably plugged and the plugs braced to prevent blow out. The test
shall be made prior to placing the shelf and invert. If the groundwater table has been
allowed to rise above the bottom of the manhole, it shall be lowered for the duration
of the test.

The manhole shall be filled with water to the top of the cone section. If the
excavation has not been backfilled and observation indicates no visible leakage, that is,
no water visibly moving down the surface of the manhole, the manhole may be
considered to be satisfactorily water-tight. If the test, as described above, is
unsatisfactory as determined by the Engineer or if the manhole excavation has been
backfilled, the test shall be continued. A period of time may be permitted if the
Contractor so wishes, to allow for absorption by the manhole. At the end of this
period, the manhole shall be refilled to the top of the cone, if necessary, and a
measuring time of at least 8 hours begun. At the end of the test period, the manhole
shall be refilled to the top of the cone, measuring the volume of water added. This
amount shall be extrapolated to a 24-hour loss rate and the leakage determined on the
basis of depth. The leakage for each manhole shall not exceed one gallon per
vertical foot for a 24-hour period. If the manhole fails this requirement, but the
leakage does not exceed 3 gallons per vertical foot per day, repairs by approved
methods may be made as directed by the Engineer to bring the leakage within the
allowable rate of one gallon per foot per day. Leakage due to a defective section or
joint or exceeding the 3 gallon per vertical foot per day, shall be cause for rejection of
the manhole. It shall be the Contractor's responsibility to uncover the rejected
manhole as necessary and to disassemble, reconstruct or replace it as directed by the
Engineer. The manhole shall then be retested and, if satisfactory, interior joints shall be
filled and pointed.

No adjustment in the leakage allowance will be made for unknown causes such as
leaking plugs, absorption, etc. It shall be assumed that all loss of water during the
test is a result of leaks through joints or through the concrete. Furthermore, the

2019 CIPP Lining Project
Nashua, NH

Pr

Contractor shall take any steps necessary to assure the Engineer that the water table is
below the bottom of the manhole throughout the test.

4. Ifthe groundwater table is above the highest joint in the manhole, and there is no
leakage into the manhole, as determined by the Engineer, such a test can serve to
evaluate water-tightness of the manhole. However, if the Engineer is not satisfied
with the results, the Contractor shall lower the water table and carry out the test as
described hereinbefore.

3.03 CLEANING:

All new manholes shall be thoroughly cleaned of all silt, debris and foreign matter of any
kind, prior to final inspection. Debris shall be decanted and disposed of at the City landfill.

END OF SECTION

2019 CIPP Lining Project Precast Manholes
Nashua, NH 02631-8

12 ee won

EXHIBIT A
TABLE OF CONTENTS
GENERAL CONDITIONS

DEFINITIONS

PROFESSIONAL ENGINEER STATUS
STANDARD OF CARE

CITY OF NASHUA REPRESENTATIVE
CHANGES TO SCOPE OF WORK
CITY OF NASHUA COOPERATION

DISCOVERY OF CONFLICTS, ERRORS, OMISSIONS, AMBIGUITIES, OR

DISCREPANCIES
TERMINATION OF CONTRACT

DISPUTE RESOLUTION

NO DAMAGES FOR DELAY

INSURANCE

INDEMNIFICATION

FISCAL CONTINGENCY

COMPENSATION

COMPLIANCE WITH APPLICABLE LAWS
NONDISCRIMINATION

ENDORSEMENT

ASSIGNMENTS, TRANSFER, DELEGATION, OR SUBCONTRACTING
CITY INSPECTION OF CONTRACT MATERIALS
DISPOSITION OF CONTRACT MATERIALS

PUBLIC RECORDS LAW, COPYRIGHTS, AND PATENTS
FINAL ACCEPTANCE

TAXES

NON-WAIVER OF TERMS AND CONDITIONS

RIGHTS AND REMEDIES

PROHIBITED INTERESTS

THIRD PARTY INTERESTS AND LIABILITIES
SURVIVAL OF RIGHTS AND OBLIGATIONS
SEVERABILITY

MODIFICATION OF CONTRACT AND ENTIRE AGREEMENT
CHOICE OF LAW AND VENUE

TIME IS OF THE ESSENCE

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