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Pavestech PST Limited

Report on Highway Retexturing Works – April 2010

for

MGWSP – Northamptonshire County Council

Richard Jenman MIAT

2

Contents

Section Title Page No.

1. Introduction 3

2. The Retexturing Process 4

3. Programme 6

4. A6 Burton Rd, Finedon 9

5. A421 Buckingham Rd, Brackley 12

6. A428 Spencer Bridge Rd, Northampton 15

7. A428 Grafton St, Northampton 18 8. Recycling Dust 21 9. Conclusions 22 10. Test Data Sheets & Maps 23

3

1. Introduction MGWSP are the Highway Maintenance Service Provider to Northamptonshire County Council and began working for Northamptonshire in April 2008. MGWSP is a Joint Venture Company of May Gurney and WSP. Examination of Countywide SCRIM Survey Results revealed a number of relatively recently resurfaced routes failing to meet expectations and falling below Intervention levels. This disappointing early life skidding resistance is a recognised issue in some situations and has a number of potential causes, where the road is otherwise in good condition. Conventionally, the three most obvious options for improvement at such sites would have been to, plane out the surface and lay a new surface course; an application of surface dressing or an additional thin wearing course; application of an Anti Skid/High Friction Surface coating. Apart from the obvious high financial costs these methods all use large amounts of newly quarried materials, significant amounts of bituminous resources, require large numbers of heavy vehicle movements, are time consuming, potentially disruptive to road users and residents and produce significant amounts of waste products.

Often the above options are the only viable alternative, however, after careful research into the alternative options available, MGWSP decided to consider Retexturing and specifically a trial of the HVIM (shot blasting) Retexturing process, at four sites which required improvement in both texture and skid resistance. The HVIM retexturing option has been much improved in recent years with advances in the equipment involved and in particular, dust containment and extraction, noise suppression, magnetic separation etc, and was therefore seen as an efficient, more cost effective, less disruptive and a very much more sustainable option; giving a longer working life to existing road surfaces. The locations chosen for this process/trial were identified by MGWSP as being representative of the type of challenge being experienced on the Northamptonshire road network. ( Though similar sites no doubt exist Nationwide ). The four sites chosen were :-

1. A421 Buckingham Road 2. A6 Burton Road 3. A428 Spencer Bridge Road 4. A428 Grafton Street

These sites being identified by routine SCRIM testing as being near or below Intervention Level, recently resurfaced and in generally good condition other than the SCRIM result, as described above. In addition the variety of Urban and Rural, 30mph to 60 mph, traffic volumes etc, mean the locations provide a good cross section sample of road types and conditions. Following a successful tender bid in late 2009, Pavestech PST Limited was appointed to carry out the works. This report details the sites, material types, textures and skid resistance before and after the retexturing works and a brief explanation of how the process works. Despite the considerable and widespread weather problems at the beginning of 2010 the works were carried out in a methodical manner, over nine productive night shifts, to time and within budget constraints, with a minimal impact on the travelling public. We are delighted with the demonstrable results achieved by this quiet, clean, effective, sustainable and economic process for carriageway retexturing, as can be seen in this report summarizing the work. Even the small amount of byproduct the process creates ( a dry evenly graded sand textured dust with a small amount of oxidized bitumen ) can be, and in fact was, wholly recycled into new blacktop mixes, leaving no waste. MGWSP would have no hesitation in using or in recommending "Pavestech" for such work in the future.

MGWSP – Northamptonshire Highways

4

2. The Retexturing Process

The High Velocity Impact Method (HVIM) of Retexturing Asphalt The basic shot blasting process has been around for over 100 years and the first mobile shot blasting process since the early 80’s. Recent developments in the efficiency of dust separation and blasting technology now means this HVIM (High Velocity Impact Method) is the most effective and environmentally sound way to re-texture highway asphalt surfaces. The HVIM system is a mechanical process which is designed to remove surface contaminants, surface imperfections and coatings. The process is fully controlled, safe and environmentally sound. It uses no water, no chemicals or solvents, emits no pollutants or dust to the atmosphere and the removed material can often be fully recycled. The steel shot impacts the surface and bounces off, as it does so material from the surface whether this is contaminants, coatings or the surface material itself is abraded and loose material together with the shot is drawn up into the machine by the airflow created by the vacuum unit. Brush seals enclose the blast head to the surface and air is drawn in through and under the brushes from the surface to ensure no shot or material from the blast head escapes to atmosphere. This is around 99% efficient but when the machine goes over any bumpy or uneven surface some shot particles can escape. The debris and shot is drawn up into the separation chamber and by a dual cyclone and magnetic separation process the debris is drawn off to the dust collector and the shot is recycled back to the blast head. The strength or degree of blasting required is infinitely variable and will depend on what the surface requires. Accurate control of the blast pattern and the degree of removal or the texture created is controlled using various machine settings and operational practices. These include: Shot type Shot size Shot delivery control valve setting Impellor / Rotor speed Dust collector vacuum (airflow) setting Forward speed of machine Number and direction of passes

Steel shot is fed by gravity through a control valve into an impellor. The impellor turning at high speed throws the steel shot through an adjustable opening at high velocity and at a specific angle on to the surface over which the self propelled machine is traveling.

Diagram HVIM / Blasting Head operation

S550 Hardened Steel Shot Before After

5

Truck mounted retexturing system at work on a Roundabout

After completing retexturing the road surface is swept using a magnet to ensure no steel shot is left on the surface

Any shot collected by the magnet is re-used.

6

3. Retexturing works programme

Although the works were originally planned to commence in January 2010, due to the extreme winter weather they were delayed until March 2010. All works were carried out at night between 2000 hrs and 0600hrs in order to keep traffic delays and inconvenience to public and commerce to a minimum. Works were completed in a total of 9 night shifts by early April.

Traffic Management

Mobile traffic lights were used on both the A6 and A421 which meant the operation could move continuously along the full length of the site, giving maximum production rates and negating the need for reversing against the traffic. Lane closures were used on the A428 sites with one direction being completed and then the TM changed over.

Testing Programme The following test programme was carried out both before and after the retexturing works in order to establish the effects of the process and assess the potential benefits achieved. Skid Resistance Testing - Griptester. Using MK2 Griptester to BS 7941-2:2000 Surface friction of pavements test method for measurement of surface skid resistance using the Griptester braked wheel fixed slip device. Skid Resistance -Pendulum Test - BS EN 13036-4:2003 This test method was used at specific locations in both directions at each site. The advantage of this test is that it can be done immediately after the retexturing machine has passed the test spot and provide a check to ensure the results being obtained are achieving the specification and if not carry out any adjustment necessary. Surface Texture Depth (Macrotexture)- Volumetric Patch Method, (Sand Patch) BSEN 13036 - 1:2002 This test method was used at specific locations in both directions at each site. Hydroconductivity - Surface Texture Drainage- Outflow Meter Method, ASTM E2380-05 This test method was used at specific locations in both directions at each site.

Full test data sheets and location maps are given on pages 23 to 48

Google mapping of all Griptester results is available electronically.

7

Notes regarding testing SCRIM (Sideways-force Coefficient Routine Investigation Machine) testing was carried out at these sites by others in 2008 and the results are included as background information. It is worth noting that the testing before retexturing was carried out at the end of a period of extreme winter weather and significant levels of salting and gritting had been carried out. This is likely to have temporarily improved some of the SF levels. Mark 2 Griptester The Griptester has two drive wheels and a single friction measuring wheel which is mechanically braked in relation to the drive wheels causing a 15% relative slip. The horizontal drag and vertical load are continuously measured and their quotient, the coefficient of friction, is calculated and stored. The friction coefficient, known as the Grip Number, is calculated for every 1metre travelled. The distance travelled and GPS locations are also measured and recorded. The towing vehicle is fitted with a water tank, pump, pipework and automatic control system for self-watering in front of the measuring wheel. Example Data:

<RESULTS>Chainage GN Load Speed Flow EM Name IL Level Latitude Longitude Altitude Quality No. Satellites

1 0.65 496 0 1.2 053:20.0511N 006:33.8063W 75.5 1 92 0.62 533 5 1.1 053:20.0511N 006:33.8063W 75.5 1 93 0.6 487 9 1.1 053:20.0511N 006:33.8063W 75.5 1 94 0.56 497 11 1.1 053:20.0512N 006:33.8073W 75.6 1 95 0.52 420 12 1.5 053:20.0512N 006:33.8073W 75.6 1 96 0.55 456 13 1.5 053:20.0512N 006:33.8073W 75.6 1 97 0.55 563 14 1.5 053:20.0512N 006:33.8073W 75.6 1 98 0.54 544 15 1.5 053:20.0511N 006:33.8097W 75.5 1 99 0.56 554 17 0.5 053:20.0511N 006:33.8097W 75.5 1 9

0

0.5

1

1.5

1 25 49 73 97 121

145

169

193

217

241

265

289

313

337

361

385

409

433

457

481

Grip nu

mbe

r

GN

IL Level SCNE

8

The terms SCRIM Reading (SR) and SCRIM Coefficient (SC) relate specifically to data obtained from a SCRIM sideway-force road friction survey. The friction measurement recorded by SCRIM is known as the SCRIM Reading (SR). The SR value is equivalent to the friction ratio (sideways-force divided by load, also generally referred to as Sideway-Force Coefficient, SFC) multiplied by 100 and is expressed as a positive, unsigned integer. SR = SFC x 100 GRIPTESTER SURVEY DATA The friction coefficient measured by Griptester is called the Grip Number (GN). The TRL have confirmed a strong linear relationship between measurements of skid resistance made by SCRIM and by Griptester at 50km/hr. It is recommended that GripTester survey results should always be reported in terms of GripNumber, with a statement of whether a Mark 1 or Mark 2 machine has been used. When comparing results with a standard Investigatory Level based on SCRIM Coefficient, it is recommended that an Equivalent GripNumber Investigatory Level is calculated using the equation below, rather than convert the measured GripNumber to equivalent SC. It is recommended that when users of the Mark 2 GripTester need to compare measured GripNumbers with SCRIM Coefficient, the correlation of SC = 0.85 x GripNumber should be used. The Griptester used in this testing programme is a Mk2 “D” type Serial No GT433 Measuring Surface Hydroconductivity Hydroconductivity is a measure of the road surface’s ability to dispel water from under the tyre. Readings can vary from just 3 seconds on a surface with good texture and fully interconnected voids to 30 seconds+ on surfaces with low texture depth and/or poor void connectivity.

The hydrotimer is a self contained outflow meter. It is a hands-off operation with consistently accurate results regardless of the operator as long as the tests are performed in accordance with instructions. The base sealing ring simulates a tyre footprint. A measured volume of water is released in the centre of the sealing ring while an electronic timer indicates how long it takes the water to pass through the surface texture. The test also provides a graphic visual display of escaping water.

9

4. A6 Burton Road, Finedon.

Map 1. Location of Burton Road Location is rural area, but a major route with high traffic volumes approximately 1200 linear metres towards Burton Latimer with 3.6m lane width. 8200m2. Road has several bends and is 60mph national speed limit.

Material: HRA 20mm PCC, Estimated age 3yrs+.

Surface Condition: Generally sound with no evidence of deformation or cracking. Surface of aggregates polished with loss of microtexture. Reasonable macrotexture overall but with significant areas/patches of poor texture depth and poor void connectivity potentially giving poor surface hydroconductivity and increasing skidding risk in wet conditions.

Retexturing: Retexturing works were carried out over 3 night shifts 9th 10th 11th March. Total

area retextured was 7300m2 and this produced 14.5 tonnes of removed material.

Before After Polished Aggregate Chip Retextured Aggregate Chip

10

Test Data A6 Burton Road, Finedon Summary of test results. Test Results Summary ‐ A6 Burton Rd Finedon

Before After Before After Before After Before After Before After1 North B236 A567 0.37 0.44 0.6 71 90 1.1 2.2 1.88 2.58 2.5 1.62 North B564 A878 0.37 0.6 0.57 71 82 1.1 2.3 1.83 2.37 2.6 1.83 North B833 A1143 0.37 0.46 0.61 71 82 1.1 2.2 1.61 2.19 3.2 2.04 North B1113 A1429 0.37 0.53 0.69 67 78 1.1 2.6 1.41 2.71 4.0 1.55 North B1265 A1584 0.20 0.46 0.68 75 81 1.1 2.1 1.55 2.19 3.4 2.06 South B2111 A2113 0.42 0.59 0.69 70 87 1.1 1.9 1.53 1.99 3.5 2.37 South B2468 A2280 0.42 0.54 0.69 77 85 1.1 2.2 1.48 2.37 3.7 1.88 South B2566 A2567 0.37 0.48 0.61 74 83 1.1 2.6 1.75 2.47 2.8 1.79 South B3014 A2824 0.42 0.38 0.61 68 83 1.1 2.1 1.38 2.37 4.2 1.810 South B3337 A3148 0.37 0.45 0.67 76 86 1.1 2.2 1.16 2.58 6.0 1.6

Hydro. Texture Hydro. SecondsGrip NumberTest Point References Mssc 2008

Pendulum Sand Patch

SCRIM: SCRIM data from 2008 shows the majority of the area at 0.35 to 0.399 Mssc with some

sections lower and some higher. Graphic map detail P24-25 Griptester:

0.3

0.4

0.5

0.6

0.7

0.8

1 37 73 109

145

181

217

253

289

325

361

397

433

469

505

541

577

613

649

685

721

757

793

829

865

901

937

973

Grip Num

ber

Chainage

Griptester ‐ A6 Burton Rd ‐ Nbnd

Before

After

0.3

0.4

0.5

0.6

0.7

0.8

1 37 73 109

145

181

217

253

289

325

361

397

433

469

505

541

577

613

649

685

721

757

793

829

865

901

937

973

Grip Num

ber

Chainage

Griptester ‐ A6 Burton Rd ‐ Sbnd

Before

After

11

Pendulum:

Sand Patch:

Hydroconductivity:

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10

Pend

ulum

Num

ber

Test Location

Pendulum ‐ A6 Burton Rd

Before

After

1

1.5

2

2.5

3

1 2 3 4 5 6 7 8 9 10

Texture Dep

th m

m

Test Locations

Sand Patch ‐ A6 Burton Rd

Before

After

0.01.02.03.04.05.06.07.0

1 2 3 4 5 6 7 8 9 10

Second

s

Test Locations

Hydroconductivity ‐ A6 Burton Rd

Before

After

Test Data Sheet on page 31

Test Data Sheet on page 32 Note: Sand patch testing before was not possible at time of testing on this site due to weather. The before figures are from testing outside of the retexturing area at each end of the site when the after testing was done.


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5. A421 Buckingham Road, from A43 Barleymow Rbt , East to Oxfordshire County Boundary.

Map 2. Location of Buckingham Road Location is in rural area, but is a major route with high traffic volumes and high speeds approximately 1800 linear metres and 4m lane width. 14000m2. Road is mainly straight with one bend and is 60mph national speed limit, it has central right turn areas at junctions which should be included in the retexturing works.

Material: 14mm SMA TSC Estimated age 3yrs+ & 400lm HRA + 20 PCC

Surface Condition: Both the SMA and HRA are generally sound with no evidence of deformation or cracking. Surface of aggregates very polished with significant loss of microtexture. Reasonable macrotexture.

Retexturing: Retexturing works were carried out over 3 night shifts 15th - 17th and one day time shift for the turning lanes. Total area retextured was 13,375 m2. 22 tonnes of material removed from surface.

13

Test Data A421 Buckingham Road. Summary of test results. Test Results Summary ‐ A421 Buckingham Rd

Before After Before After Before After Before After Before After1 West B90 A285 0.37 0.60 0.73 72 96 1.7 3.2 1.88 3.23 2.5 1.22 West B523 A718 0.37 0.61 0.74 71 89 2.2 2.9 1.88 3.03 2.5 1.33 West B947 A1142 0.47 0.74 0.80 73 89 1.6 2.1 1.53 1.93 3.5 2.44 West B1351 A1546 0.47 0.77 0.82 72 88 1.7 2.6 1.88 2.05 2.5 2.25 West B1585 A1780 0.47 0.75 0.79 67 89 1.1 2.2 1.53 2.58 3.5 1.66 East B1748 A1757 0.47 0.60 0.72 71 97 1.0 2.3 1.16 2.05 6.0 2.27 East B1514 A1523 0.47 0.48 0.70 70 93 1.2 2.3 1.33 2.19 4.5 2.08 East B1110 A1119 0.47 0.72 0.80 77 92 1.4 2.3 1.53 1.88 3.5 2.59 East B686 A695 0.37 0.65 0.72 80 86 1.8 3.2 1.75 2.37 2.8 1.810 East B253 A260 0.42 0.65 0.80 78 91 2.2 2.9 1.83 2.86 2.6 1.4

Hydro. SecondsTest Point References Mssc 2008

Grip Number Pendulum Sand Patch Hydro. Texture

SCRIM: SCRIM data from 2008 shows a range of levels from 0 to 0.499 Mssc. Graphic map detail P 26,27,28 Griptester:

0.4

0.5

0.6

0.7

0.8

0.9

1

1 64 127

190

253

316

379

442

505

568

631

694

757

820

883

946

1009

1072

1135

1198

1261

1324

1387

1450

1513

1576

1639

1702

Grip Num

ber

Chainage

Griptester ‐ A421 Buckingham Rd West bnd

Before

After

0.4

0.5

0.6

0.7

0.8

0.9

1

1 64 127

190

253

316

379

442

505

568

631

694

757

820

883

946

1009

1072

1135

1198

1261

1324

1387

1450

1513

1576

1639

1702

Grip Num

ber

Chainage

Griptester ‐ A421 Buckingham Rd ‐ East bnd

Before

After

14

Pendulum:

Sand Patch:

Hydroconductivity:

6065707580859095

100

1 2 3 4 5 6 7 8 9 10

Pend

ulum

Num

ber

Test Location

Pendulum ‐ A421 Buckingham Rd

Before

After

1

1.5

2

2.5

3

3.5

1 2 3 4 5 6 7 8 9 10

Texture Dep

th m

m

Test Locations

Sand Patch ‐ A421 Buckingham Rd

Before

After

1

2

3

4

5

6

1 2 3 4 5 6 7 8 9 10

second

s

Test Locations

Hydroconductivity ‐ A421 Buckingham Rd

Before

After




15

6. A428 Spencer Bridge Road, Gladstone Rd to Muscott St.

Map 3. Location of Spencer Bridge Road Location is in a residential area approximately 350lm and 7m width 2400m2. A straight section with junctions and traffic lights 30mph.

Material: 14mm SMA TSC Estimated age 6yrs+

Surface Condition: Generally sound but areas with slight deformation and cracking, several patches with good joint condition. Surface of aggregates very polished with significant loss of microtexture. Reasonable macrotexture. Line markings generally worn in particular cycle lane markings, these will require reinstating after any retexturing works. Some access covers requiring attention but will not be affected by retexturing

Retexturing Works: The smallest of the four sites with 2400m2 being retextured in a single 6 hour night shift. 3500kg of material removed from surface.

16

Test Data A428 Spencer Bridge Road. Summary of test results. Test Results Summary ‐ A428 Spencer Bridge Road

Before After Before After Before After Before After Before After1 East B402 A132 0.20 0.51 0.74 69 93 1.1 2.3 1.53 2.05 3.5 2.22 East B497 A231 0.47 0.60 0.70 63 82 1.1 1.4 1.16 1.67 6.0 3.03 West B2244 A1973 0.20 0.54 0.73 75 82 1.1 1.7 1.33 1.61 4.5 3.24 West B2340 A2069 0.42 0.49 0.77 71 79 1.2 1.6 1.46 1.67 3.8 3.0



SCRIM: SCRIM data from 2008 shows levels from 0 to 0.349 Mssc. Graphic map detail P29 Griptester:

0.30.40.50.60.70.80.91

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121

127

133

139

Grip Num

ber

Chainage

Griptester ‐ A428 Spencer Bridge Rd ‐ East bnd

Before

After

0.4

0.5

0.6

0.7

0.8

0.9

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106

113

120

127

134

141

148

155

162

169

176

183

190

Grip Num

ber

Chainage

Griptester ‐ A428 Spencer Bridge Rd ‐West bnd

Before

After

17

Pendulum:

Sand Patch:

Hydroconductivity:

6065707580859095

100

1 2 3 4

Pend

ulum

Num

ber

Test Locations

Pendulum ‐ A428 Spencer Bridge Rd

Before

After

11.21.41.61.82

2.22.4

1 2 3 4

Texture Dep

th m

m

Test Locations

Sand Patch ‐ A428 Spencer Bridge Rd

Before

After

2.0

3.0

4.0

5.0

6.0

1 2 3 4

second

s

Test Locations

Hydroconductivity ‐ A428 Spencer Bridge Rd

Before

After




18

7. A428 Grafton Street, St Andrews Rd to Regent Sq.

Map 4. Location of Grafton street Location is in a commercial and residential area just off the town centre, approximately 700 linear metres and 7m width. Road is straight but on a significant gradient. The area is interdispersed by several sections of HFS and several pedestrian refuge islands, hatching and Pelican Crossings, giving the effect of an urban dual carriageway. Total area for retexturing is approximately 4000m2.

Material: 14mm SMA TSC Estimated age 6yrs+

Surface Condition: Generally sound, surface of aggregates very polished with significant loss of microtexture. Reasonable macrotexture.

Retexturing: Retexturing works were carried out using 2 gangs and both the large truckblaster unit and the smaller mobile unit were used on this site, the smaller unit being more manouverable could work in the centre sections at the same time. The work was completed in one night shift on 17th March. Area retextured was 4215m2 which produced 6.7 tonnes of removed material.

Highly Manouvreable small mobile blaster 500mm Width Blast Head Large Truckblaster unit 1.14m blast head width

19

Test Data A428 Grafton Street. Summary of test results. Test Results Summary ‐ A428 Grafton Street

Before After Before After Before After Before After Before After1 East B1026 A750 0.37 0.49 0.88 65 85 0.9 1.5 1.05 1.41 7.5 4.02 East B1188 A911 0.42 0.52 0.71 62 85 0.8 1.9 0.96 2.05 9.5 2.23 East B1314 A1037 0.37 0.50 0.89 67 90 0.9 1.4 1.19 1.67 5.6 3.04 West B1436 A1164 0.42 0.53 0.73 74 83 1.2 1.7 1.28 1.93 4.8 2.45 West B1578 A1315 0.37 0.53 0.73 79 90 1.1 2 1.26 2.19 5.0 2.06 West B1738 A1467 0.20 0.49 0.79 64 75 1.1 1.8 1.23 1.88 5.2 2.5



SCRIM: SCRIM data from 2008 shows various levels from 0 to 0.499 Mssc. See P30 Griptester:

0.30.40.50.60.70.80.91

1 15 29 43 57 71 85 99 113

127

141

155

169

183

197

211

225

239

253

267

281

295

309

323

337

351

365

379

Grip Num

ber

Chainage

Griptester ‐ A428 Grafton St ‐ East bnd

Before

After

0.4

0.5

0.6

0.7

0.8

0.9

1

1 13 25 37 49 61 73 85 97 109

121

133

145

157

169

181

193

205

217

229

241

253

265

277

289

301

313

325

Grip Num

ber

Chainage

Griptester ‐ A428 Grafton St ‐West bnd

Before

After

20

Pendulum:

Sand Patch:

Hydroconductivity:

6065707580859095

100

1 2 3 4 5 6

Pend

ulum

Num

ber

Test Locations

Pendulum ‐ A428 Grafton St

Before

After

0.50.70.91.11.31.51.71.9

1 2 3 4 5 6

Texture Dep

th m

m

Test Locations

Sand Patch ‐ A428 Grafton St

Before

After

1.0

3.0

5.0

7.0

9.0

1 2 3 4 5 6

Second

s

Test Locations

Hydroconductivity ‐ A428 Grafton St

Before

After




21

8. Recycling Dust

The total weight of material removed over all 4 sites was 46700 kg. The material removed is a fine dust,typical grading and analysis is:

SIEVE SIZE PERCENT PASSING 2mm 100 1mm 99 0.5mm 96 0.25mm 86 0.125mm 59 0.063mm 35 BINDER CONTENT 6% STEEL CONTENT 0.2%

In terms of depth of surface removed it calculates at less than 1mm. The material is classified as “Bituminous Arisings” with an EU code No 17-03-02 .

The material is very suitable for recycling into new asphalt as it acts as a fines material with a bitumen content. All the 46.7 tonnes has been recycled and incorporated in an asphalt base course locally, leaving no waste product at all and saving an equivalent amount of virgin quarrying.

22

9. Conclusions

Significant improvements in both macrotexture (texture depth) and microtexture (skid resistance) has been achieved at all 4 sites. This improves the safety of the surface, gives it a renewed working life and can have significant effects on reducing the risk of skidding accidents, especially in wet conditions.

The process has achieved these benefits without the need for laying any new materials, conserving natural resources. Also the process is more sustainable as all of the removed surface material has been fully recycled locally.

Average improvements by site are as follows:

SITE Skid Resistance Texture Depth Hydroconductivity

A6 Burton Rd +39% +52% +50%

A421 Buckingham Rd +16% +64% +45%

A428 Spencer Bridge +40% +56% +36%

A428 Grafton St +27% +72% +57%

With the ever increasing demands on our highway infrastructure, engineers are constantly reviewing methods of construction and maintenance, looking for more cost effective and sustainable solutions in order to deliver the essential highway maintenance required for a safe efficient road network. This trial has clearly demonstrated that the HVIM retexturing process offers the highways maintenance engineer a very cost effective, sustainable alternative to planing out and resurfacing or surface dressing, the main benefits being:

Reduced Cost

No new primary aggregates used

No bitumen used

Massive reduction on heavy vehicle movements

Significant reduction in contract time / disruption time

No waste materials – fully recycled byproduct

Significant improvements in skid resistance & texture

In situations where the main concern is low skid resistance due to polished aggregate and or low texture but the surface is structurally sound and otherwise in good condition this process can be a very effective improvement option.

31

On Off Hours

1 2 3 4 5 6 7 8 AirWet

Surface

1 70 75 70 68 70 71 7.0 6.0

2 72 72 72 72 69 71 7.0 6.0

3 73 72 68 70 70 71 6.0 6.0

4 70 69 68 67 66 62 65 67 6.0 5.0

5 77 75 75 75 74 73 74 75 6.0 6.0

6 72 70 70 70 68 70 5.0 6.0

7 80 79 78 76 76 72 76 75 77 5.0 6.0

8 75 74 74 73 75 74 5.0 6.0

9 70 70 65 66 68 70 68 5.0 5.0

10 78 78 77 76 75 75 75 75 76 5.0 5.0

1 2 3 4 5 6 7 8 AirWet

Surface

1 90 90 90 90 88 90 7.0 7.0

2 82 85 83 81 79 82 9.0 10.0

3 80 84 82 82 80 82 9.0 8.0

4 75 80 79 79 78 78 9.0 8.0

5 83 84 78 82 80 81 9.0 8.0

6 90 86 86 87 85 87 7.0 7.0

7 85 85 86 82 85 85 8.0 7.0

8 80 88 82 82 85 83 7.0 6.0

9 85 82 83 80 85 83 8.0 7.0

10 80 89 89 86 86 86 8.0 7.0

Date:

Date:

R.Jenman

SJ & SM

HRA + 20mm PCC

A Route - Single - 60mph SK 1081

Skid Resistance -Pendulum Test - BS EN 13036-4:2003

A6 Burton Road, Finedon, Northampton - 293/1727

Pendulum Ref:

Site / Contract*:

Material:

Surface Category

Cold-Wet / Dry - Cold TRRL

06/03/2010 - 12/04/2010 C2543Calibration Cert:

Slider Type:

Mean

N/A

5 ° / 9 °

N/A

* The number of individual tests and locations should be agreed with the client / overseeing authority prior to commencing work.

Mean

Pendulum Values taken before treatment.

Location of Test

Pendulum Readings

PST TC 001

Location of Test

Pendulum Readings

Date:

Weather:

Air Temp:

Times on Site:

Thermometer Ref:

N/A

Temp °C

Temp °C

Registered Office: 1 Wold View, Kilnwick Lane, Kilnwick, Driffield, East Riding of Yorkshire YO25 9JB Tel: 08456 44 70 33

Checked by: 06/03 & 12/04 - 2010

Pavestech PST Limited. Registered in England No 6201263. VAT Reg No 905 1364 49

Comments: Mean Pendulum Test Value (PTV

Testing Carried out by: 06/03 & 12/04 - 2010

Pendulum Values taken after treatment.

32

On N/A Off Hours* The number of individual tests and locations should be agreed with the client / overseeing authority prior to commencing work.

** Volume of measuring cylinder (V) should be obtained from the relevant equipment calibration records.

Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

240 240 180 170

255 230 165 170

245 250 160 170

230 230 170 160

175 170

175 165

155 155

140 170

160 190

170 180

190 180

190 170

160 190

170 160

170 150

135 170

165 180

175 170

170 170

170 170

Mean Texture Depth (mm): Mean Texture Depth (mm):Calculation: Volumetric Patch. Texture Depth = 4V/πD2 (where D = mean diameter of sand patch)

Date:

Date:

Material: HRA + 20mm PCC

Surface Category

Surface Texture Depth (Macrotexture)- Volumetric Patch Method, BSEN 13036 - 1:2002

Site / Contract*: A6 Burton Road, Finedon, Northampton - 293/1727

A Route - Single - 60mph Rule Ref: PST 001

Date: 12/04/2010 Vol Patch kit Ref: PST VP 001

Weather: Dry - Cold Cyl Vol (V)**: 50ml

Air Temp: 9 ° Thermometer Ref: PST TC 001

Times on Site: N/A N/A

Volumetric Patch Before Treatment Volumetric Patch After Treatment

Start Location: See Drawing attached Start Location: See Drawing attached

Diameter (mm)

Diameter (mm)

11 -8m nswt

241 1.1 1 +90m obnd nswt

171 2.2

12 LC71 +20m nswt

239 1.1 2 +260m Op LCT47

nswt

165 2.3

3 +250m Op LCT55 nswt

175 2.1

4 +250m nswt

171 2.2

155 2.6

183 1.96 inbnd LC T71 nswt

5 LC T71 nswt

7 +250m nswt

173 2.1

8 LC T55 nswt

170 2.2

156 2.6

170 2.2

12/04/2010

10 +90m nswt

9 LC T47 nswt


Checked by: SJ & SM 06/03/2010 & 12/04/2010


Comments: No sand patch tests carried ou before at this location due to wet surface conditions. One te

Testing Carried out by: R.Jenman

33

On N/A Off Hours

Distance from start

Distance from start

Mean Texture Depth (mm): Mean Texture Depth (mm):Calculation: Texture Depth from Outflow Meter Times = 3.114/OFT+0.636

Date:

Date:

Surface Hydroconductivity - Surface Texture Drainage- Outflow Meter Method, ASTM E2380-05

Site / Contract*: A6 Burton Road, Finedon, Northampton - 293/1727

Material: HRA + 20mm PCC

Surface Category A Route - Single - 60mph Outflow Meter Ref

Weather: Cold-Wet / Dry - Cold

Date: 06/03/2010 - 12/04/2010

HTC 313

Start Location: See Drawing attached Start Location:

Air Temp: 5 ° / 9 °

1.75

1 +90m obnd nswt

1.83

4 +250m nswt

Times on Site:

3 +250m Op LCT55

nswt

1.7 2.47

N/A N/A

Hydroconductivity Before Treatment Hydroconductivity After Treatment

Time (seconds)

See Drawing attached

Calculated Texture Depth (mm)

5 LC T71 nswt

5 LC T71 nswt

2.3

1.6 2.58



1.61

1.41

3 +250m Op LCT55

nswt

1.996 inbnd LC T71 nswt

6 inbnd LC T71 nswt

1.5 2.71

2 2.19

4 +250m nswt

1.55

1.53

2 2.19

8 LC T55 nswt

8 LC T55 nswt

2.8

1.48 1.8 2.37 7 +250m nswt

7 +250m nswt

1.8 2.379 LC T47 nswt

9 LC T47 nswt

1.38

10 +90m nswt

4.2

6 1.1610 +90m nswt

Comments

Testing Carried out by: R.Jenman 06/03 & 12/04 - 2010

2.5

2.6


1.6 2.58

1.8 2.37

1 +90m obnd nswt

Time (seconds)

1.88


3.2

4

3.4

3.5

3.7

Checked by: SJ & SM 06/03 & 12/04 - 2010


35

On Off Hours

1 2 3 4 5 6 7 8 AirWet

Surface

1 72 72 72 72 72 72 72 12.0 11.0

2 73 75 73 70 70 68 70 71 9.4 9.4

3 72 73 72 72 75 73 9.4 9.3

4 76 70 72 72 72 72 10.3 9.3

5 66 68 69 66 67 67 10.7 10.9

6 74 68 70 70 72 71 12.4 11.8

7 70 70 70 74 65 70 13.4 11.5

8 78 75 78 78 78 77 11.3 13.1

9 80 80 80 80 80 80 12.0 11.1

10 74 78 80 80 78 78 10.1 12.8

1 2 3 4 5 6 7 8 AirWet

Surface

1 96 95 100 96 95 96 11.0 11.0

2 90 93 90 86 86 89 11.0 10.0

3 90 88 89 87 90 89 11.0 10.0

4 86 88 86 90 90 88 8.0 9.0

5 90 88 90 90 87 89 12.0 11.0

6 96 99 97 97 96 97 10.0 9.0

7 94 92 92 94 93 93 8.0 8.0

8 92 94 92 90 90 92 8.0 8.0

9 87 86 86 88 85 86 8.0 8.0

10 92 90 90 92 89 91 9.0 8.0

Date:

Date:

R.Jenman

SJ & SM

14mm SMA & HRA + 20mm PCC

A Route - Single - 60mph SK 1081


A421 Buckingham Road, Brackley, Northampton - 293/1727

Pendulum Ref:

Site / Contract*:

Material:

Surface Category

Dry,Sunny, Cold - Dry, Cold TRRL

06/03 & 12/04 - 2010 C2543Calibration Cert:

Slider Type:

Mean

N/A

10 °

N/A


Mean


Location of Test

Pendulum Readings

PST TC 001

Location of Test

Pendulum Readings

Date:

Weather:

Air Temp:

Times on Site:

Thermometer Ref:

N/A

Temp °C

Temp °C


Checked by: 06/03 & 12/04 - 2010





36



Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

180 195 150 130

195 195 140 145

165 170 150 155

170 170 140 150

210 190 170 180

200 210 170 170

190 195 155 155

195 190 155 155

250 250 170 170

255 220 170 170

260 250 160 170

270 250 170 170

225 230 190 160

230 220 160 160

210 230 160 180

205 220 170 150

190 190 135 140

190 190 155 130

170 170 140 150

170 170 150 150


Date:

Date:

Material: 14mm SMA & HRA + 20mm PCC

Surface Category


Site / Contract*: A421 Buckingham Road, Brackley, Northampton - 293/1727

A Route - Single - 60mph Rule Ref: PST 001

Date: 06/03 & 12/04 - 2010 Vol Patch kit Ref: PST VP 001

Weather: Dry,Sunny, Cold - Dry, Cold Cyl Vol (V)**: 50ml

Air Temp: 10 ° Thermometer Ref: PST TC 001




Diameter (mm)

Diameter (mm)

1 +90m wbnd nswt

191 1.7 1 +90m wbnd nswt

141 3.2

2 +433m Rd info sign

nswt

169 2.2 2 +433m Rd info sign

nswt

149 2.9

3 +424m Ftpth nswt

203 1.6 3 +424m Ftpth nswt

170 2.2

4 +404m Tpole nswt

193 1.7 4 +404m Tpole nswt

173 2.1

155 2.6

168 2.3

5 +234 Rd info sgn nswt

244

6 eastbnd nswt

258 1.0 6 eastbnd nswt

1.1 5 +234 Rd info sgn nswt

7 eastbnd Tpole nswt

226 1.2 7 eastbnd Tpole nswt

140 3.2

8 east ftpth nswt

216 1.4 8 east ftpth nswt

168 2.3

165 2.3

148 2.9

06/03/2010 & 12/04/2010

9 Rd info sign nswt

190

10 eastbnd +90m nswt

170 2.2 10 eastbnd +90m nswt

1.8 9 Rd info sign nswt


Checked by: SJ & SM 06/03/2010 & 12/04/2010


Comments: 2 Tests at South East end (county Boundary) are on HRA then west sectio


37

On N/A Off Hours

Distance from start

Distance from start


Date:

Date:


Site / Contract*: A421 Buckingham Road, Brackley, Northampton - 293/1727

Material: 14mm SMA & HRA + 20mm PCC

Surface Category A Route - Single - 60mph Outflow Meter Ref

Weather: Dry,Sunny, Cold - Dry, Cold

Date: 06/03 & 12/04 - 2010

HTC 313


Air Temp: 10 °

1.53

1 +90m wbnd nswt

1.88

4 +404m Tpole nswt

Times on Site:

3 +424m Ftpth nswt

2.5 1.88

N/A N/A


Time (seconds)





2.2

1.4 2.86


nswt


nswt

1.53

1.88

3 +424m Ftpth nswt

2.056 eastbnd nswt

6 eastbnd nswt

2.2 2.05

1.6 2.58

4 +404m Tpole nswt

1.53

1.16

2.4 1.93

8 east ftpth nswt

8 east ftpth nswt

3.5

1.33 2 2.19 7 eastbnd Tpole nswt

7 eastbnd Tpole nswt

1.8 2.379 Rd info sign nswt

9 Rd info sign nswt

1.75

10 eastbnd +90m nswt

2.8

2.6 1.83 10 eastbnd +90m nswt

Comments


2.5

2.5


1.2 3.23

1.3 3.03

1 +90m wbnd nswt

Time (seconds)

1.88


3.5

2.5

3.5

6

4.5

Checked by: SJ & SM 06/03 & 12/04 - 2010


39

On Off Hours

1 2 3 4 5 6 7 8 AirWet

Surface

1 70 70 68 69 69 69 1.0 1.0

2 63 63 64 64 63 63 0.0 0.0

3 75 75 75 75 75 75 0.0 1.0

4 75 74 73 62 70 70 71 0.0 1.0

1 2 3 4 5 6 7 8 AirWet

Surface

1 86 92 94 96 95 93

2 82 86 84 79 80 82

3 84 84 81 80 82 82

4 82 76 79 80 77 79

Date:

Date:

R.Jenman

SJ & SM

14mm SMA TSCS

A Route - Residential 30mph SK 1081


A428 Spencer Bridge Road, Northampton - 293/1727

Pendulum Ref:

Site / Contract*:

Material:

Surface Category



Slider Type:

Mean

N/A

1° - 10 °

N/A


Mean


Location of Test

Pendulum Readings

PST TC 001

Location of Test

Pendulum Readings

Date:

Weather:

Air Temp:

Times on Site:

Thermometer Ref:

N/A

Temp °C

Temp °C


Checked by: 06/03 & 12/04 - 2010





40



Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

250 240 165 170

235 240 170 160

250 240 210 210

245 240 230 210

240 250 200 190

250 230 200 180

230 230 190 200

230 235 190 210


Date:

Date:

Material: 14mm SMA TSCS

Surface Category


Site / Contract*: A428 Spencer Bridge Road, Northampton - 293/1727

A Route - Residential 30mph Rule Ref: PST 001



Air Temp: 1° - 10 ° Thermometer Ref: PST TC 001




Diameter (mm)

Diameter (mm)

1 ebnd +50m nswt

241 1.1 1 ebnd +50m nswt

166 2.3

2 ebnd LC92 O/S Ln nswt

244 1.1 2 ebnd LC92 O/S Ln nswt

215 1.4

3 wbnd LC50 nswt

243 1.1 3 wbnd LC50 nswt

4 wbnd LC96 nswt


193 1.7

198 1.6

06/03/2010 & 12/04/2010


Checked by: SJ & SM 06/03/2010 & 12/04/2010


Comments:


41

On N/A Off Hours

Distance from start

Distance from start


Date:

Date:


Site / Contract*: A428 Spencer Bridge Road, Northampton - 293/1727


Surface Category A Route - Residential 30mph Outflow Meter Ref


Date: 06/03 & 12/04 - 2010

HTC 313


Air Temp: 1° - 10 °

1 ebnd +50m nswt

1.16

4 wbnd LC96 nswt

Times on Site:

3 wbnd LC50 nswt

N/A N/A


Time (seconds)





1.33

1.46

3 wbnd LC50 nswt


3.2 1.61

Comments


3.5

6


2.2 2.05

3 1.67

1 ebnd +50m nswt

Time (seconds)

1.53


4.5

3.8

Checked by: SJ & SM 06/03 & 12/04 - 2010


43

On Off Hours

1 2 3 4 5 6 7 8 AirWet

Surface

1 72 60 62 74 72 54 64 60 65 1.0 2.0

2 64 62 65 54 64 60 64 62 3.0 2.0

3 68 60 65 72 70 67 4.0 5.0

4 75 75 76 74 72 74 6.0 4.0

5 82 80 80 76 75 79 1.0 0.0

6 65 62 65 64 64 64 5.0 3.0

1 2 3 4 5 6 7 8 AirWet

Surface

1 82 86 86 86 83 85 10.0 9.0

2 88 78 86 75 90 86 89 85 10.0 9.0

3 90 89 90 90 90 90 10.0 10.0

4 82 85 82 82 82 83 9.0 9.0

5 90 90 90 90 90 90 9.0 9.0

6 75 75 75 75 75 75 8.0 8.0

Date:

Date:

Temp °C

Temp °C


Checked by: 06/03 & 12/04 - 2010





Location of Test

Pendulum Readings

Date:

Weather:

Air Temp:

Times on Site:

Thermometer Ref:

N/A

Mean

N/A

4° - 10 °

N/A


Mean


Location of Test

Pendulum Readings

PST TC 001

Material:

Surface Category



Slider Type:

R.Jenman

SJ & SM

14mm SMA TSCS

A Route - Residential 30mph SK 1081


A428 Grafton Street, Northampton - 293/1727

Pendulum Ref:

Site / Contract*:

44



Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

Distance from start

Mean Diameter

(mm)

Texture Depth (mm)

260 260 200 210

265 255 210 200

280 280 190 190

265 270 185 170

280 275 210 230

270 260 210 210

230 230 190 200

220 235 200 180

245 235 180 190

245 235 180 170

250 240 200 190

240 240 180 190


Date:

Date:


Checked by: SJ & SM 06/03/2010 & 12/04/2010


Comments:

Testing Carried out by: R.Jenman 06/03/2010 & 12/04/2010

5 wbnd LC57 nswt

240

6 wbnd LC 65 nswt

243 1.1 6 wbnd LC 65 nswt

1.1 5 wbnd LC57 nswt

215 1.4

193 1.7

190 1.8

3 ebnd LC51 nswt

271 0.9 3 ebnd LC51 nswt

180 2.0

4 wbnd LC50 nswt


205 1.5

2 ebnd petrol stn

nswt

274 0.8 2 ebnd petrol stn

nswt

184 1.9

Diameter (mm)

Diameter (mm)

1 ebnd sub stn nswt

260 0.9 1 ebnd sub stn nswt



Air Temp: 4° - 10 ° Thermometer Ref: PST TC 001





Surface Category


Site / Contract*: A428 Grafton Street, Northampton - 293/1727

A Route - Residential 30mph Rule Ref: PST 001

45

On N/A Off Hours

Distance from start

Distance from start


Date:

Date:


5.6

4.8

5

5.2

Checked by: SJ & SM 06/03 & 12/04 - 2010


7.5

9.5


4 1.41

2.2 2.05

1 ebnd sub stn nswt

Time (seconds)

1.05

Comments


3 1.67

1.886 wbnd LC 65 nswt

6 wbnd LC 65 nswt

2.4 1.93

2 2.19

4 wbnd LC50 nswt

1.26

1.23

5 wbnd LC57 nswt

5 wbnd LC57 nswt

2.5

2 ebnd petrol stn

nswt

2 ebnd petrol stn

nswt

1.19

1.28

3 ebnd LC51 nswt

3 ebnd LC51 nswt

N/A N/A


Time (seconds)




Air Temp: 4° - 10 °

1 ebnd sub stn nswt

0.96

4 wbnd LC50 nswt

Times on Site:

Surface Category A Route - Residential 30mph Outflow Meter Ref


Date: 06/03 & 12/04 - 2010

HTC 313


Site / Contract*: A428 Grafton Street, Northampton - 293/1727


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