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4. Materials and Manufacture

4.1 General material requirements for precast reinforced

concrete manhole products are presented in

4.1.1 – 4.1.9

. Other

materials or additional requirements for a product, if any, are

covered in the Part II section for that specific product.

4.1.1

Reinforced Concrete—

Reinforced concrete shall con-

sist of cementitious materials, mineral aggregates, and water, in

which steel reinforcement has been embedded in such a

manner so that the steel reinforcement and concrete act

together.

4.1.2

Cementitious Materials:

4.1.2.1

Cement—

Cement shall conform to the requirements

for portland cement of Specification

C150

, or shall be portland

blast-furnace slag cement or portland-pozzolan cement con-

forming to Specification

C595

, except that the pozzolan

constituent of the Type IP portland-pozzolan cement shall be

fly ash.

4.1.2.2

Fly Ash—

Fly ash shall conform to the requirements

of Class F or Class C of Specification

C618

4.1.2.3

Slag Cement—

Slag cement shall conform to the

requirements of Grade 100 or 120 of Specification

C989

4.1.3

Allowable Combinations of Cementitious Materials—

The combination of cementitious materials used in the concrete

shall be one of the following:

4.1.3.1 Portland cement only,

4.1.3.2 Portland blast-furnace slag cement only,

4.1.3.3 Portland pozzolan cement only,

4.1.3.4 A combination of Portland cement and slag cement,

4.1.3.5 A combination of Portland cement and fly ash, or

4.1.3.6 A combination of Portland cement, slag cement (not

to exceed 25 % of the total cementitious weight) and fly ash

(not to exceed 25 % of the total cementitious weight).

4.1.4

Aggregates—

Aggregates shall conform to Specifica-

tion

C33

, except that the requirements for gradation shall not

apply.

4.1.5

Admixtures and Blends—

The following admixtures

and blends are allowable:

4.1.5.1 Air-entraining admixture conforming to Specifica-

tion

C260

;

4.1.5.2 Chemical admixture conforming to Specification

C494/C494M

;

4.1.5.3 Chemical admixture for use in producing flowing

concrete conforming to Specification

C1017/C1017M

;

4.1.5.4 Chemical admixture or blend approved by the

owner.

4.1.6

Steel Reinforcement—

Reinforcement shall consist of

wire and welded wire conforming to Specification

A1064/

A1064M

; or of bars conforming to Specification

A615/

A615M

, Grade 280 or 420, or Specification

A706/A706M

Grade 420.

4.1.7

Water—

Water used in the production of concrete shall

be potable or non-potable water that meets the requirements of

Specification

C1602/C1602M

4.1.8

Secondary Synthetic Fiber—

Collated fibrillated poly-

propylene virgin fibers shall not be prohibited when used in

steel reinforced concrete manholes as a non-structural manu-

facturing enhancement. Only fibers designed and manufactured

specifically for use in concrete and so certified by the manu-

facturer shall be accepted.

4.1.9

Other Materials—

Other materials required for a prod-

uct and not covered in Section

will be covered in the Part II

section for that specific product.

5. Design

5.1 Design requirements for a product are prescribed in the

specific Part II section for that product.

5.1.1 The minimum compressive strength of concrete man-

hole products covered by this specification shall be 27.6 MPa

unless specified otherwise in Part II of this specification.

5.2

Modified or Special Design:

5.2.1 Manufacturers are not prohibited from submitting to

the owner, for approval prior to manufacture, designs other

than those prescribed in the specific section for a product. If

such approval is obtained, then the product shall meet all the

tests and performance requirements specified by the owner in

accordance with the appropriate sections on manufacture and

physical requirements.

5.2.2 If permitted by the owner, the manufacturer is not

prohibited from requesting approval of designs of special

sections, such as reducers, tees, and bases.

6. Reinforcement

6.1 This section presents requirements for reinforcement

cover, continuity, laps, welds and splices. Other reinforcement

requirements are presented in Section

and any additional

requirements are given in the Part II section for a specific

product.

6.2

Cover—

The exposure of the ends of reinforcement,

stirrups or spacers used to position the reinforcement during

placement of the concrete shall not be cause for rejection.

6.3

Continuity—

The continuity of the circumferential rein-

forcement shall not be destroyed during the manufacture of the

product, except when lift holes or pipe openings are provided

in the product.

6.4

Welded Steel Cage Laps. Welds, and Splices:

6.4.1 If splices are not welded, the reinforcement shall be

lapped not less than 20 diameters for deformed bars, and 40

diameters for plain bars and cold-drawn wire. In addition,

where lapped cages of welded wire fabric are used without

welding, the lap shall contain a longitudinal wire.

6.4.2 When splices are welded and are not lapped to the

minimum requirements in

6.4.1

, there shall be a minimum lap

of 50 mm and a weld of sufficient length such that pull tests of

representative specimens shall develop at least 50 % of the

minimum specified tensile strength of the steel. For butt

welded splices in bars or wire, permitted only with helically

wound cages, pull tests of representative specimens shall

develop at least 75 % of the minimum specified tensile strength

of the steel.

6.5

Steel Hoop Splices—

When splices are welded and not

lapped to the minimum requirements in

6.4.1

, there shall be a

minimum lap of 50 mm and a weld of sufficient length such

that pull tests from representative specimens shall develop at

least 50 % of the minimum specified tensile strength of the

C478M − 15

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