2.3.2
Gaskets and Connectors
Gaskets for joints between manhole sections shall conform to ASTM C 443M
ASTM C 443. Resilient connectors for making joints between manhole and
pipes entering manhole shall conform to ASTM C 923M ASTM C 923 or ASTM C
990M ASTM C 990.
2.3.3
External Preformed Rubber Joint Seals
An external preformed rubber joint seal shall be an accepted method of
sealing cast iron covers to precast concrete sections to prevent ground
water infiltration into sewer systems. All finished and sealed manholes
constructed in accordance with paragraph entitled "Manhole Construction"
shall be tested for leakage in the same manner as pipelines as described in
paragraph entitled "Leakage Tests." The seal shall be multi-section with a
neoprene rubber top section and all lower sections made of Ethylene
Proplene Di Monomer (EPDM) rubber with a minimum thickness of 1.5 mm 60 mils.
Each unit shall consist of a top and bottom section and shall have mastic
on the bottom of the bottom section and mastic on the top and bottom of the
top section. The mastic shall be a non-hardening butyl rubber sealant and
shall seal to the cone/top slab of the manhole/catch basin and over the lip
of the casting. Extension sections shall cover up to two more adjusting
rings. Properties and values are listed in the following tables:
[Properties, Test Methods and Minimum Values for
Rubber used in Preformed Joint Seals
Test Methods
EPDM
Neoprene
Butyl mastic
Tensile, kPa
ASTM D 412
12,684
15,132
-
Elogation percent
ASTM D 412
553
295
350
Tear Resistance, N/mm
ASTM D 624
49
28
-
(Die B)
Rebound, percent,
ASTM C 972
-
-
11
5 minutes
(mod.)
Rebound, percent,
ASTM C 972
-
-
12]
2 hours
[Properties, Test Methods and Minimum Values for
Rubber used in Preformed Joint Seals
Test Methods
EPDM
Neoprene
Butyl mastic
Tensile, psi
ASTM D 412
1840
2195
-
Elogation percent
ASTM D 412
553
295
350
Tear Resistance, ppi
ASTM D 624
280
160
-
(Die B)
Rebound, percent,
ASTM C 972
-
-
11
5 minutes
(mod.)
Rebound, percent,
ASTM C 972
-
-
12]
2 hours
SECTION 02531
Page 26
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