19 of 49 Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 05: Earth Works, Pipe Works and Ground Improvement  This mortar shall be pre-shrunk by mixing it to a plastic consistency as far in advance of its use as pos- sible. Trial mixes shall be made and aged to determine the longest period the mortar’s use can be de- layed while retaining sufficient plasticity to permit good workmanship.  Immediately prior to the application of the mortar, the damp surface of the area to be repaired shall be  scrubbed thoroughly with a small quantity of neat cement ground, using a wire brush. Remaining  loose sand particles shall be swept away immediately before application of the mortar.  In applying the mortar, it shall be compacted into the space to be filled, care being taken to eliminate  air pockets and to secure bond at the edges. The surfaces shall be shaped and finished to correspond  with adjacent surfaces of the pipe.  Any holes and small areas of defects on the surface shall be repaired by using Dry-pack mortar as  specified in the herewith Employer’s Requirements, Section 6: Concrete and Steel Works.  The newly repaired surfaces shall be kept damp for 24 hours after the repair is completed. A mem- brane coating of an approved white-pigmented sealing compound shall then be applied.  5.3.5.3 Ductile iron pipes  Ductile cast iron pipes shall be used exclusively within the fields of water supply, sewerage and waste  water treatment works.  Pipes and fittings in ductile cast iron shall be in conformity with TS EN 545, DIN EN 598 and , TS  11565 EN 969, ISO 2531 and shall withstand successfully any test described therein.  Pipe connections of ductile Iron Pipes shall be tension proved sockets according to DIN 28603. All  bending points have to be provided with concrete abutments or anchorage in sub grade.  All pipes, and fittings and accessories shall be made from ductile cast iron, also called nodular or  spheroid graphite cast iron, characterized by the presence of graphite in the spheroid state in sufficient  quantities to impart the mechanical characteristics defined in the standard TS 11565 EN 969 or ISO  2531 to the material.  Pipes for water supply  Pipes for pumped wastewater  Pipes for water supply will be subjected to a maximum static head of 85 m of water column. Allowing  for friction losses and water hammer conditions, the maximum working pressure shall be 16 bar.  Pipes for pumped wastewater will be subjected to a maximum static head of 35 m of water column.  Allowing for friction losses and water hammer conditions, the maximum working pressure shall be 16  bar.  Ductile iron pipes for pumped wastewater shall be lined with an inner sulphate resistant cement lining  according to DIN 28610 and TS EN 545. The outer corrosion protection shall be in accordance to DIN  30674 and TS EN 598.  All pipes of ND 250 or smaller shall have an external electrolytic zinc protection. In addition all pipes  shall have an external coat of black varnish applied at the factory. Special external bitumen, having a  minimum thickness of 0.3 mm, shall be sprayed onto the pipes before laying to provide protection  against corrosion.  Coating of water supply pipes  Pipes for water supply shall be lined internally with spun cement mortar. The mortar shall contain no  toxic element or elements soluble in water, or any elements susceptible to impart any smell or odour to  the water. The characteristics of the mortar, its placing and control shall be in compliance with ISO  4179.  5_Vol3_d4.3_Section 5 Earth and pipe works_en_GIR_rev6.docx 