FINE-GRAINED CONCRETE COMPOSITION FOR PROTECTIVE COAT OF PIPE INNER SURFACES Russian patent published in 2007 - IPC C04B41/50 F16L58/06 

FIELD: application of protective coats on inner surfaces of cast-iron pipes and pipe fittings, including high-strength cast iron with globular graphite; erection of water supply systems.

SUBSTANCE: proposed composition is used for pipes at large curvature of walls (inner diameter of 100-400 mm) which are used in erection of water supply systems, both for potable water and other non-aggressive aqueous media. Proposed concrete composition includes Portland cement ПЦ500-ДО, bank-run sand of 0.063-2 mm fraction and M= 1.55-1.9, potassium permanganate and superplasticizing agent C3 and/or modifying agent Linamix 73P-1 or Relamix and water at the following ratio of components, mass-%: Portland cement, 31.25-33.51; bank-run sand, 50.0-53.266; potassium permanganate, 1.67·10^-5-5.87·10^-5; superplasticizing agent C3, 0.09-1.06; C3 and linamix 73P-1, 0.09-1.06; Linamix 73P-1,0.0840.13; Relamix, 0.067-0.146; the remainder being water. Fine-grained concrete composition may additionally contain up to 3.2 mass-% of dry complex additive with sand of 0.05-0.16 mm fraction, Portland cement and superplasticizing agent at ratio of 2.24 : 0.95 : 0.01. Coats made from such composition acquire enhanced early flexural and compressive strength 3-4 h after heat and moisture treatment and final strength after 28 days of treatment.

EFFECT: enhanced efficiency and strength of coats.

2 cl, 1 tbl, 5 ex