Alternative materials for small scale pavement repairs

Transcription

1 Alternative materials for small scale pavement repairs Howard Robinson Chief Executive

2 Menu Very quick RSTA intro Look at 3 alternatives to hot-mix Quick look at new industry codes

3 RSTA Overview Formed in sectors 82 members 13 authority members Represents the full supply chain Developing guidance and training are two key outputs 100 million m 2 treated per annum

4 Road Surface Treatments

5 Alternative techniques 1. Thermal Road Repairs 2. Cold lay asphalt products (HAPAS) 3. Spray Injection Patching

6 Thermal Patch Repairs Introduced into UK from USA in 1980s Ideal for Surface Course defects, from 1m x 1m to 3m x 3m Technology has improved greatly over the past 5 years Carefully heats the surface to avoid binder carbonisation HAPAS certification and used to repair reinstatements

7 Thermal Patch Repairs Uses normal Chapter 8 TM cones and signs 4.5t vehicle carries more material compared to previous 3t System is powered off gas and electric, using a 2 man team Operating out of a transit sized vehicle, ideal for urban defects Ability to reinstate like-for-like materials in patches Typically carry out 25-30no. heat cycles per shift

8 Versatile Resolve high air voids in surface course by heating up the reinstatement then adding more material Resolve failed reinstatements due to over-banding by creating a thermal seamless bond Resolve consequential damage and scarring and avoid having to replace the surface course Replacing interim reinstatements particularly around the base of lamp columns. The thermal pole heater can fit around the base of the column to carry out a permanent reinstatement

9 Defective trench due to over-banding

10 Heating a defect using thermal heater

11 Checking the temperature with IR gun C target range prior to break out

12 Scarifying and reworking heated area Heater moved onto next area while heated area is reworked

13 Addition of anionic bitumen emulsion HAPAS approved anionic emulsion used in reworked area Operative uses experience to work out how much to use tends to be 1litre per m2 Added by hand lance or watering can Mix temp drops to about 140c after adding emulsion still sufficient heat to compact area

14 Additional asphalt added HAPAS approved DBM and SMA deferred set materials for reheating using onboard hot box on vehicle

15 Additional asphalt added Typically 12kg per repair added depends on extent of missing material

16 Temperature check prior to compacting

17 Compaction Bomag 55 used to compact SMA and AC. All equipment is winched into van no manual handling. Bomag 75 used for HRA.

18 Spot the join

19 Spray Injection Patching Varies from a 1 man to a 3 man operation Classed as mobile works just uses stop and go no cones, no signs Three manufacturers/ contractors: Jetpatcher, Velocity, Archway Always 3-6mm chippings open graded NOT used in a HAUC context

20 Spray Injection Patching - Grown in acceptance over the past 7 years - Notable increase in the amount of m 3 of repairs carried out on a year-by-year basis - Semi-permanent ( can last up to 2 yrs ) - Fast and economic alternative technique 9-12 / m 2 - Technique now incorporated into Sector Scheme 13 - Seasonal April to October

21 Spray Injection Patching - Can be operated as 1-3 man teams. Quality of end result is operator sensitive - Uses either hot or cold emulsion or hot bitumen - Aggregates selected dependent on end use, typically 56 PSV (mainly rural use) - Used to fill pot-holes, haunching, cracks and crazing and pre surface dressing patching

22 Spray Injection Patching - High volume low pressure air to clean the road surface defect

23 Spray Injection Patching - A bond coat of either hot or cold bitumen emulsion is applied or hot bitumen

24 Spray Injection Patching - Aggregate is then propelled, using high volume air at low pressure, before mixing it with the binder moments before it is self compacted as it is placed in the patch

25 Spray Injection Patching - No secondary compaction normally but the client often dictates whether additional compaction is required - Compaction by a vibrating plate is often used for heavier trafficked applications and on sites with turning traffic

26 Spray Injection Patching Same emulsion used to seal joints. Patching should be done a year ahead of surface dressing!

27 Spray Injection Patching Deep repair 75+ mm

28 Spray Injection Patching Haunching is built up in layers and usually relies on traffic to compact the material.

29 Cold Lay Asphalts Bagged products HAPAS certificated for use on footways and carriageways A small number of suppliers/products have HAPAS certification Growing market share mainly used on footway reinstatements

30 New Codes of Practice

31 Codes of Practice Lets have a quick look at one of the new Codes for Innovative Patching products

32 Patching products CoP Essentially covers Cold Lay Asphalts for temporary & permanent repairs published 2013 Available from /publications

33 Patching products CoP

34 Benefits

35 Spec

36 Technical details

37 More technical details

38 Surface Prep Some manufacturers recommend using a bond coat

39 Compaction

40 Technical details

41 What about the other Code? The CoP for Innovative Patching systems is similar in structure to the Products code

42 Patching Systems CoP

43 Breaking News Sector Scheme 23 will be published in 2015 for Small Scale Pavement Repairs Members: ADEPT, BBA, CITB, DRD Northern Ireland, HA, HTMA, MPA, RCMG, RSTA, TAG, TRL, TS, UKAS, ICoW, CECA

44 NHSS23 Scope a) asphalt pavements b) concrete pavements c) modular paving and block work refer to NHSS 30 d) surround to surface apparatus (including ironwork) e) surface treatments Including but not limited to the following techniques: 1. sealing pavement cracks and failed joints 2. spray injection patching refer to NHSS13 3. thermal road repairs

45 Questions? Thank you for your attention