BALLAST-specification used IN IR ZONE.pptx

BALLAST USED IN RAILWAY

1. * 1 BALLAST

2. L P Srivastava Assistant Professor Track IRICEN 7420041149 2

3. 3 What is Ballast Ballast is the selected crushed granular material placed as the top layer of the substructure in which the sleepers are embedded.

4. 4 DEFINITIONS BLANKET SUB - GRADE TRACK-FOUNDATION TRACK STR. FORMATION B A L L A S T CESS SUB - SOIL

5. 5 Important Functions of Ballast Resists vertical, lateral and longitudinal forces Provides resilience and absorbs energy Reduces formation pressure Facilitates track geometry correction Facilitates track drainage Provides voids

6. 6 Additional Functions of Ballast Inhibits vegetation growth Absorbs airborne noise Provides adequate electrical resistance

7. 7 Requirements of Track Ballast Tough and wear resistant Hard without getting crushed under moving loads Generally cubical having sharp edge Non-porous and non-absorbent of water

8. 8 Requirements of Track Ballast Resist Attrition Durable and should not get pulverized under weather condition Good drainage of water Economical in cost

9. 9 Ballast may be subdivided into following zones: Crib Shoulder Top Ballast Bottom Ballast Track Ballast

10. 10 Ballast Fouling Potential sources are Ballast breakdown Handling Tamping/packing Traffic Weathering CONTD..

11. 11 Fines from subgrade Mud pumping Seepage Fines from surface Droppings from trains Wind or water transported Ballast Fouling

12. 12 Effects of Fouling Impedes drainage Affects elasticity of ballast Tamping/ packing becomes difficult Reduces electrical resistance

13. 13 Remedial measures - fouling Shoulder screening : Preventive maintenance – Once in 3-5 yrs. (para 609 of IRPWM). All loops should be shallow screened once in 7 years (para 609 of IRPWM).

14. Remedial measures - fouling Deep Screening : This is speed and line dependent. 200 mm or 150 mm (para 636 (2) e of IRPWM). All loops should be deep screened once in 15 years (para 636 (2) e of IRPWM). 14

15. 15 DETAILED SPECIFICATIONS IRS GE – 1 JUNE 2004 Basic Quality: Ballast should be hard, durable and as far as possible angular along edges/corners, free from weathered portions of parent rock, organic impurities and inorganic residues. Particle Shape: Ballast should be cubical in shape as far as possible. Individual pieces should not be flaky and should have generally flat faces with not more than two rounded/sub rounded faces .

16. 16 Mode of Manufacture: Ballast for all BG main lines and running lines shall be machine crushed Hand broken ballast can be used in exceptional cases with prior approval of Chief Track Engineer/CAO/C. Such approval shall be obtained prior to invitation of tender. DETAILED SPECIFICATIONS

17. 17 Physical Properties Ballast sample should satisfy the following physical properties in accordance with IS:2386 Pt.IV-1963 when tested as per the procedure given in Annexure 1&2 BG, MG & NG (Planned/sanctioned for conversion) NG&MG(Other than those planned for conversion) Aggregate abrasion value 30% Max* 35% Max Aggregate Impact Value 20% Max* 30% Max DETAILED SPECIFICATIONS CONTD..

18. 18 In exceptional cases, on technical and/or economic grounds relaxable upto 35% & 25% respectively by CTE in open line and CAO/C for construction projects. The relaxation in Abrasion and Impact Values shall be given prior to invitation of tender and should be incorporated in the tender document. DETAILED SPECIFICATIONS

19. 19 The “Water Absorption” tested as per IS:2386 Pt-III – 1963 following the procedure, should not be more than 1%. This test however, to be prescribed at the discretion of CE/CTE in open line and CAO/Con for construction projects. The power of relaxing for water absorption limit should be delegated to CTE in open line and CAO/Con for construction for specified areas. However maximum water absorption in any case should not be > 2.5% DETAILED SPECIFICATIONS

20. 20 SIZE AND GRADATION: FULL RATE PAYMENT Retained on 65mm sq. mesh sieve - 5% Maximum Retained 40mm sq.mesh sieve For machine crushed ballast : 40% to 60% Retained on 20mm sq.mesh sieve Not less than 98% for machine crushed DETAILED SPECIFICATIONS

21. 21 OVERSIZE BALLAST - Reduced Rate Payments i) Retention on 65mm square mesh sieve A Maximum of 5% ballast retained on 65mm sieve shall be allowed without deduction in payment. In case ballast retained on 65mm sieve exceeds 5% but does not exceed 10%, payment at 5% reduction in contracted rate shall be made for the full stack. DETAILED SPECIFICATIONS

22. 22 If ballast retained on 40 mm square mesh sieve (machine crushed case only) > 60%, payment at the reduced rates shall be made for the full stack in addition to the reduction worked out above. 5% reduction in contracted rates if retention on 40mm sq. mesh sieve is between 60% (excluding) and 65% (including) 10% reduction in contracted rates if retention on 40mm sq. mesh sieve is between 65% (excluding) and 70% (including). DETAILED SPECIFICATIONS OVERSIZE BALLAST- Reduced Rate Payments

23. 23 OVERSIZE: When the ballast retained on 65 mm sieve > 10 %. When the ballast retained on 40 mm sieve > 70 %. UNDERSIZE: When the ballast retained on 40 mm sieve < 40 %. Machine Crushed Ballast: When the ballast retained on 20 mm sieve < 98%. Hand Broken Ballast: When the ballast retained on 20 mm sieve < 95%. DETAILED SPECIFICATIONS REJECTION OF BALLAST ON GRADATION ACCOUNT

24. 24 METHOD OF SIEVE ANALYSIS While carrying out sieve analysis, the screen shall not be kept inclined, but held horizontally and shaken vigorously. The pieces of ballast retained on the screen can be turned with hand to see if they pass through but should not be pushed through the sieve. The percentage passing through or retained on the sieve shall be determined by weight with least count as 100 g . DETAILED SPECIFICATIONS

25. 25 CONDITIONS FOR SUBMISSION OF TENDER Each tenderer at the time of tendering shall submit the test report of Impact Value, “Abrasion Value, Water Absorption Value from approved laboratories and the list of these Laboratories shall be mentioned in the tender documents. The tenderer shall also furnish an undertaking as incorporated in the tender document that the ballast supply at all times will conform to Specifications for Track Ballast as specified by Railway. DETAILED SPECIFICATIONS

26. 26 STACK MEASUREMENT Stacking on a neat, plain, firm and well drained ground The height of stack shall not be less than 1 m, (hilly areas - 0.5 m ) but not more than 2.0 m. Top width shall not be less than 1 m. Top of stack shall be kept parallel to the ground plane. The side slopes should not be flatter than 1.5:1 (H : V). Cubical content of each stack shall normally be not less than 30 cum in plain areas and 15 cum in hilly areas. DETAILED SPECIFICATIONS

27. 27 WAGON MEASUREMENT A continuous white line should be painted inside the wagon The cubical content in cubic meter corresponding to white line should also be painted on both sides outside the wagon. In addition, short pieces of flats with cubical contents punched shall be welded at the centre of all the four sides as permanent reference. In case the supply is taken in general service wagons, actual measurements will be taken. DETAILED SPECIFICATIONS

28. 28 SHRINKAGE ALLOWANCE Payment shall be made for the gross measurements either in stacks or in wagons without any deduction for shrinkage/voids. When ballast supply is taken in wagons, shrinkage upto 8% shall be permitted at destination while verifying the booked quantities by the consignee . DETAILED SPECIFICATIONS

29. 29 Norms to be followed in respect of sampling, testing and acceptance: On supply of the first 100 cum, the tests for size gradation, Abrasion value, Impact value and water absorption (if prescribed) shall be carried out by Railways . Further supply shall be accepted only after this ballast satisfies the specifications for these tests. Railway reserves the right to terminate the contract as per GCC at this stage itself in case the ballast supply fails to conform with any of these specifications. DETAILED SPECIFICATIONS CONTD.. SAMPLING AND TESTING

30. 30 Subsequent tests : DETAILED SPECIFICATIONS CONTD.. Type of test Supply in stacks Supply in wagons (a) Size and gradation tests One for each 100 cum or part thereof in any stack One for each 100 cum or part thereof for quantity to be loaded in wagons (b) Abrasion value, Impact value and Water absorption value One test for every 2000 cum

31. Sampling procedure Care should be taken at the time of stacking to make sure that sufficient space for JCB/Power equipment is available. Three samples of 0.3 - 0.5 cum, two from sides and one from top should be drawn by JCB/Power equipment. 31

32. Gross sample All the three samples should be mixed thoroughly using JCB/Power equipment. In exceptional cases manual means for collection and mixing may be allowed duly incorporating in the tender document. 32

33. Test sample A test sample of .027 cum shall be drawn out of gross sample for carrying out size and gradation tests. 33

34. Method for drawing test sample Gross sample shall be scooped into a cone shaped pile. Flattened by pressing and cut into quarters by two lines. Any two diagonally opposite quarters are taken for testing. 34

35. 35 METHOD OF SIEVE ANALYSIS Sieve sizes are nominal sizes. The following tolerances shall be permitted: 65mm square mesh sieve plus minus 1.5mm 40mm Square Mesh Sieve Plus Minus 1.5mm 20mm Square Mesh Sieve Plus Minus 1.0mm Mesh size of the sieves should be checked before actual measurement. The screen shall not be less than 100cm in length, 70cm in breadth and 10cm in height on sides. DETAILED SPECIFICATIONS

36. 36 Aggregate abrasion value test APPARATUS: LOS-Angele’s abrasion testing machine. The charge shall consist of 12 spheres of cast iron or steel of approximately 48 mm dia. And each weighing between 390-445 grams ensuring the total weight as 5000 ± 25 grams. IS sieves: 50, 40, 25 and 1.7 mm.

37. 37 Aggregate abrasion value test SAMPLE: Passing through 50 mm and retained on 40 mm =5000 gm. Passing through 40 mm and retained on 25 mm = 5000 gm. Total = 10000 gm. The sample should be dried in oven at 100 -110 o C to a constant weight and weighed (A).

38. 38 Aggregate abrasion value test PROCEDURE: The test sample along with the charge is put in machine for a 1000 revolution at the speed of 20-33 revolution / minute. At the completion, the material is drawn out and sieved through 1.7 mm. Material retained on 1.7 mm sieve shall be washed, dried in oven at 100-110 o C to a constant weight and weighted (B).

39. 39 Aggregate abrasion value test OBSERVATION: The difference between the original weight and the final weight of the test sample shall be expressed as a percentage of original weight of the sample. A - B Aggregate abrasion value = --------- x 100 A   Note: Permissible abrasion value is 30%.

40. 40

41. 41

42. 42 Water absorption test APPARATUS: Wire basket with hangers for suspension in the container. Water tight container. Dry soft absorbent cloth 75 X 45 cm size (2 nos.). Shallow tray of minimum 650 cm 2 area.

43. 43 Water absorption test SAMPLE: Ballast 2000 gm. PROCEDURE: Ballast should be thoroughly washed to remove dirt / dust, drained and then put in the wire basket and immersed in the distilled water at a temperature between 22-32 o C. After immersion the basket should be lifted 25 times in 25 seconds to remove the entrapped air. Sample is kept immersed for a period of 24 ± ½ hours.

44. 44 Water absorption test Procedure continues…… Basket having sample is removed from water and allowed to drain for few minutes. The ballast shall be emptied on a dry cloth and gently surface dried with cloth. Sample is then spread on to a second cloth to atmosphere (away from direct sun light) until appears completely surface dry.

45. 45 Water absorption test Procedure continues…… Sample then weighed (A). The aggregate shall than be put in oven at a temperature 100 – 110 o C for 24 hours. The aggregate shall be removed cooled and weighed (B).

46. 46 OBSERVATION: A - B Water absorption = --------- X 100. B Two such tests shall be conducted and the mean result shall be reported.   Note: Water absorption should not be more than 1%.

47. 47 Aggregate impact value test APPARATUS: Impact testing machine conforming IS 2386 part IV – 1963. IS Sieves: 12.5, 10 and 2.36 mm. A cylindrical metal measure of 75 mm dia and 50 mm depth. A tapping rod of 10 mm dia and 230 mm long.

48. 48 Aggregate impact value test continues…. SAMPLE: Sample should be prepared out of track ballast. Passing through 12.5 mm 100%. Retaining on 10 mm 100%.

49. 49 Aggregate impact value test continues…. PROCEDURE: Sample is dried in oven for 4 hours at 100 – 110 o C and cooled. Measure shall be filled 1/3 rd level and tamped 25 times. Filled again to 2/3 rd level and tamped 25 times. Filled to full level and tamped 25 times. Surplus if any should be struck off and net weight is taken (A).

50. 50 Sample is filled in the machine’s cup and tamped 25 times. Hammer shall be raised at 380 mm height above the upper surface and allowed to fall. Sample is subjected to 15 blows. Material is drawn and sieved through 2.36 mm sieve. Material passing through 2.36 mm sieve weight (B). Material retained on 2.36 mm sieve weight (C).

51. 51 Aggregate impact value test continues…. OBSERVATION: B Aggregate impact value = ----- X 100 A Note: Should not be more than 20%.

52. 52

53. 53

54. 54 THANKS !