All materials used in the manufacture of reinforced cement concrete pipes for use under this Contract shall conform to ASTM Designation C76-72a and also with the following specifications.

i) Cement

The Sulphate Resisting Portland Cement (SRPC) Portland cement which is required to be used in the manufacture of reinforced concrete pipes to be furnished and installed under this Contract shall conform to the requirements of BS 4027 and ASTM Designation C-150 (Type V) latest revision.

ii) Aggregate

The fully crushed coarse and fine aggregate and washed shall be used in the manufacture of concrete pipes to be furnished and installed under this Contract and shall be generally in accordance with the provisions of Chapter-6 of these Specifications.

iii) Steel Reinforcement

The material will conform to the Specifications contained in relevant Section of these Specifications in Chapter-5.

25.2.5 Mixing of Concrete

The proper types and amounts of Sulphate Resisting Portland Cement (SRPC), mineral aggregates and water shall be thoroughly mixed in an approved type of Concrete Batch Plant which shall be kept in perfect working condition. Admixtures in the concrete will only be permitted with the approval of the Engineer and as explained in Chapter-6.

25.2.6 Pipe Dimensions

(i) The internal diameters and wall thickness of reinforced concrete pipes under this Contract shall be as set forth in ASTM Designation C76-72a in Tables I through V for " Wall B " pipe as required and shown on the plans.
(ii) The lengths of reinforced concrete pipes under this Contract shall be as required to provide the designated laying length shall be in full, and shall not be less than 6 feet, nor more than 8 feet, unless otherwise approved in writing by the Engineer.
(iii) Only one laying length shall be permitted for each size of reinforced concrete pipe under this Contract and pipes not of the approved uniform laying length shall not be used in the work.

25.2.6 Lift Holes not permitted

Lift holes in the walls of reinforced cement concrete pipes will not be permitted under this Contract for the purpose of handling and laying. Other approved lifting methods shall be employed.

25.3 Certified Plans and Data Sheets

(i) The Contractor shall submit in triplicate, for approval by the Engineer, certified plans and data sheets as required to provide complete information on all concrete sewer pipes, dimensions, type and dimensions of pipe ends, joint details, proposed concrete design mix for each different strength Class of reinforced or non-reinforced concrete pipe and any other information needed to demonstrate full compliance with these Specifications.
(ii) No concrete sewer pipe shall be delivered to the work site until the Engineer has formally approved the plans and data sheets and until all test require¬ments called for in the respective ASTM Standard Speci¬fications C76-79 and C-14 have been met.

25.4 Joints for Concrete Pipe Sewers

25.4.1 General

Joints for concrete sewer pipes of more than 150mm diameter shall be Rubber Gasket joints as provided in the plans. No other types of joints will be permitted under this Contract. For pipes of 150mm internal diameters collar joints will be used.

25.4.2 Rubber Gasket Joints

(i) Rubber gasket joints shall be used for either tongue and groove or bell & spigot pipes.
(ii) Rubber gasket joints shall be made using specially designed rubber gaskets, made to fit the applicable tongue and groove or bell and spigot pipes and adequately tested under operating conditions. Special care must be taken in the selection and handling of the concrete pipes for use with rubber gasket joints, to ensure that pipe ends shall be smooth and concentric with tolerance which closely conforms to the requirements of the manufacturer of the rubber gaskets. The tongue or spigot end of each pipe shall be specially designed to perform groove or offsets to fit the manufacturer's rubber gasket design.
(iii) The rubber gasket joints shall conform to all applicable requirements of the latest revision of ASTM Designation C-443, entitled "Joints for Circular Concrete Sewer and Culvert Pipe, Using Flexible Watertight Rubber Type Gaskets", except that the test pressure need not exceed 10 feet of head at which the completed sewers shall meet the infiltration or exfiltration limits set forth hereinafter.
(iv) The groove end of tongue and groove pipes of either the reinforced or non-reinforced concrete type, shall have at least one line of wire reinforcing of 8 gauge size placed in the center of the groove.