Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

DIAMOND GRINDING OF CONCRETE PAVEMENTS

1,156 views

Published on

The presentation basically deals with the diamond grinding of concrete pavements . One can get a clear picture of the whole process of diamond grinding which has proved to be an efficient pavement preservation technique in the alst decade. It also looks into the 2 important aspects of diamond grinding i.e, improvement in skid resistance and reduction in noise emission.

Published in: Engineering
  • Be the first to comment

DIAMOND GRINDING OF CONCRETE PAVEMENTS

  1. 1. “DIAMOND GRINDING OF CONCRETE PAVEMENTS” 1
  2. 2. 2 OBJECTIVES:- TO UNDERSTAND THE PROCESS OF DIAMOND GRINDING OF CONCRETE PAVEMNETS TO BE AWARE OF THE VARIOUS ADVANTAGES OF ADOPTING DIAMOND GRINDING TO EVALUATE THE EFFICIENCY OF DIAMOND GRINDING IN 1. IMPROVING SKID RESISTANCE 2. REDUCING NOISE EMISSION
  3. 3. 3 WHAT IS DIAMOND GRINDING? Pavement preservation technique Restores rideability by removing surface irregularities Significant improvement in the smoothness of a pavement Considerable increase in surface macro-structure and consequent improvement in a) Skid resistance b) Noise reduction c) Safety
  4. 4. 4 WHY GRIND CONCRETE PAVEMENTS?? Poor quality and rapid deterioration of concrete pavements Resulted in an increase in Increase in road accidents their maintanence expenditure High mortality rates  Hence we need to adopt efficient pavement preservation techniques that correct a variety of surface imperfections on concrete pavements. Diamond Grinding is one such technique
  5. 5. 5 OTHER EFFECTS OF DIAMOND GRINDING Reduces pavement lift Improves drainage Reduces the potential for hydroplaning
  6. 6. 6 PROCESS •Involves removing a thin layer at the surface of hardened PCC using closely spaced diamond saw blades •Blade assembly is run at a predetermined level across the pavement surface, which produces saw cut grooves •The diamond blades are composed of industrial diamonds and metallurgical powder Enlarged schematic representation of cross section of diamond ground surface
  7. 7. 7 DIAMOND SAW BLADES SAW BLADES ASSEMBLED TO FORM CUTTING HEAD
  8. 8. 8 Typical configuration for grinding
  9. 9. 9 DIAMOND GROUND PAVEMENT SURFACE
  10. 10. 10 APPLICATIONS •Improve the skid resistance and evenness of concrete pavements •Improves or corrects surface imperfections i. faulting at joints and cracks ii. built-in or construction roughness iii. polished concrete surfaces exhibiting inadequate macrotexture iv. wheel path rutting caused by studded tyres v. unacceptable noise level vi. slab warping caused by moisture gradient and construction curling vii. inadequate transverse slope and splash and spray reduction •Texture pavement inorder to make them suitable for suitable for recreational activities such as bike riding or roller skating.
  11. 11. 11 ADVANTAGES 1) Provide smooth surface 2) Reduced road noise 3) Removes faults 4) Enhanced surface texture and skid resistance 5) Reduce accident rates 6) Does not significantly affect fatigue life 7) Diamond-ground surface is nearly always dry 8) Does not raise the pavement surface elevation 9) Can be accomplished during off-peak hours 10) Cost advantage
  12. 12. 12 DESIGN CONSIDERATIONS
  13. 13. 13 • major distresses of the pavement should be repaired Thoroughly evaluate the existing condition of the pavement,. Pavement evaluation is done in a multi-step process. i. design and condition data is collected ii. data is then evaluated iii. evaluation data is used to design a CPR strategy A full CPR job can restore structural capacity to levels near those of new construction. Diamond grinding restores ride by blending the old slabs with new repairs into a uniform profile Pavement joints resealed after diamond grinding
  14. 14. 14 FACTORS TO BE CONSIDERED WHILE SELECTING A DIAMOND GRINDING PROJECT • Actions should be taken to alleviate drainage or erosion •Transverse slab cracking and corner •Joints and transverse cracks •The hardness of the aggregate and depth of cut has a direct relationship on the cost of the diamond grinding. •Significant slab replacement and repair
  15. 15. 15 EQUIPMENTS Produced by running a series of saw blades which are gang-mounted on a drive shaft over the concrete surface The depth of grinding is between 3 and 5 mm Diamond-tipped grinding segments, variable in width are situated at the edge of the blades The separation of the blades is set by spacer disks and is at most 3 mm. Diamond ground texture consists of grooves and land areas.
  16. 16. 16 • Most important aspects of a grinding machine weight of the machine the horsepower available to the grinding head the grinding head • Front wheels pass over a bump or fault, which is then shaved off by the cutting head • Rear wheels follow the smooth path left by the grinding head • Cutting head width -> 910 - 970 mm • Spacing of diamond blades -> 164 - 194 / m of shaft • Uses water to cool the cutting head • Contain on-board wet vacuums to remove slurry
  17. 17. 17 RANGE OF VALUES (mm) HARD AGGREGATE (mm) SOFT AGGREGATE (mm) GROOVES 2.0-4.0 2.5-4.0 2.5-4.0 LAND AREA 1.5-3.5 2.0 2.5 HEIGHT 1.5 1.5 1.5 NUMBER OF GROOVES /m 164-194 174-194 164-177 Recommended dimensions for hard and soft aggregates:-
  18. 18. 18
  19. 19. 19 CONSTRUCTION Traffic Control Field Operations Final Surface Finish
  20. 20. 20 TRAFFIC CONTROL Do not require shutting down adjacent traffic lanes An approved traffic control plan is essential Several machines works together (large projects) Contractors use only one machine and several passes for small projects The maximum overlap between passes should be 50 mm
  21. 21. 21 FIELD OPERATIONS Should begin after all repairs Should be performed continuously Should begin and end at normal to the pavement centerline Grinding is always longitudinal Should be performed across the entire lane surface Spot grinding is not recommended Grinding will provide a positive lateral drainage
  22. 22. 22 FINAL SURFACE FINISH Pavement surface shall be uniform in appearance Land area between the grooves shall be between 1.5 &3.5 mm Peak of ridges shall be 1.5 mm higher than bottom of grooves Pavement surface measured using A straight-edge requirement may be used to control bumps Transverse slope of the pavement shall be Transverse joints and random cracks shall be visually inspected Misalignment of the planes shall not exceed 1.5 mm per meter
  23. 23. 23 COMMON PROBLEMS AND SOLUTIONS Light vehicles and motorcycles experience vehicle tracking Reduce the spacing between the blades. Some areas are left without diamond- ground texture If the untextured area exceeds project specifications, regrind it Large amounts of concrete slurry are left on pavement surface Stop grinding operations and check the vacuum unit and skirt surrounding the cutting head Concrete fins fail to break off Reduce the spacing between the blades PROBLEMS SOLUTIONS
  24. 24. 24 EVALUATION OF SKID RESISTANCE ON DIAMOND GROUND PAVEMENTS diamond grinding increases skid resistance and safety Friction factor, f=F/L Skid Number: SN=100(f) where: F=frictional resistance to motion in plane of interface L=load perpendicular to interface friction resistance of most dry pavements is relatively high The number of accidents on wet pavements are twice as high as dry pavements Typical Skid Numbers Skid Number Comments <30 Take measures to correct ≥30 Acceptable for low volume roads 31 – 34 Monitor pavement frequently ≥35 Acceptable for heavily travelled roads
  25. 25. 25 CASE STUDY 1 (DoT ,TEXAS) DG utilized improve skid resistance Eleven DG projects were studied RESULTS ARE:- • IRI(I reduction of 0.95  m/km (40%) • Oldest DG section maintained an IRI reduction of about 36% after 8 years • Skid number (SN) increased by 5.6 (30%) • IRI increases by approximately 0.03  m/km each year& SN decreases 2.0 • After DG, the crash accidents had reduced by 62 and 46% for fatalities and incapacitating injuries
  26. 26. 26 EVALUATION OF NOISE EMISSION OF DIAMOND GROUND PAVEMENTS CASE STUDY 2 (BOING ACCESS ROAD ,WASHINGTON)
  27. 27. 27 RESEARCH IN GERMANY The relationship among surface texture, concrete composition and noise emission Composition of the concrete, the thickness and spacing of the diamond blades Texture characteristics and air flow resistance of textured surfaces Vibrations of tyres and the aero-dynamic processes AN ONGOING LABORATORY RESEARCH IN GERMANY (FEDERAL HIGHWAY RESEARCH INSTITUTE) INVESTIGATES :
  28. 28. 28 LABORATORY INVESTIGATIONS Noise emission was lower for segments widths of 2.8mm than for 3.2 mm Noise emission is lowest for surfaces produced with very low spacer widths No effect of concrete composition on the textural properties Concrete produced with rounded aggregate possessed similar textural properties, noise emission and fine roughness to concrete made with crushed aggregate.
  29. 29. 29 CONCERNS Faulting reoccur (load transfer is deficient) Does not correct any structural problems (e.g., slab cracking) or material problems (e.g. reactive aggregates). Reduces pavement thickness (pavement fatigue performance) [200-230 mm] Not all concrete pavements are good candidates for diamond grinding. May not be sufficient in all cases.
  30. 30. 30 CONCLUSION Improves skid resistance and reduces the risk of hydroplaning (safety) Investigations have shown that diamond grinding is a good alternative to exposed aggregate concrete for the production of low-noise pavement surfaces Experimental findings and researches indicate that diamond grinding is a viable and cost-effective rehabilitation measure when properly applied
  31. 31. 31 REFERENCES •Jens Skarabis and Ulrike Stockert (2015). Noise emission of concrete pavement surfaces produced by diamond grinding 2 ( 2 ) : 8 1 - 9 2 •Chen D and Hong F (2015). Long-Term Performance of Diamond Grinding. 29(1) pages 12-25. •Caltrans. (2013). Diamond grinding and grooving- California Dept. of Transportation (Caltrans) Vol 1,Issue 1 •Drakopoulos and Schmiedlin. (1998). Crash experience on tined and continuously ground Portland cement concrete pavements, Washington, DC Pages 140–146
  32. 32. 32 •Stubstad, and Tabet (2005). The effectiveness of diamond grinding concrete pavements in California . 73, 307-325 •Rao, and Darter, M. I. (1999). The longevity and performance of diamond— Ground pavements, research and development bulletin RD118, Portland Cement Association, Skokie. 112. •Federal Highway Administration, (2004) Pavement preservation design and construction of quality preventive maintenance treatments, National Highway Institute Course 13-20.
  33. 33. 33 THANK YOU….

×