Upload
luci99
View
47
Download
0
Embed Size (px)
DESCRIPTION
Surface Dressing
Citation preview
THE ROAD SURFACE TREATMENTS ASSOCIATION
Surface Dressing & Micro-Surfacing
Dr Howard RobinsonChief Executive
1www.rsta-uk.org
Surface Dressing Long History of Use
www.rsta-uk.org
Performs 2 functions which relate directly to the essential requirements in the European CPD
Safety Skid ResistanceIncreases macro & micro texture with minimum usage of scare high quality aggregate
Durability Preventative Maintenance Seals underlying surface from ingress of water and air
3
Surface Dressing
www.rsta-uk.org
Single Dressing
Racked-In
Double Dressing
Sandwich Dressing
4
Surface Dressing techniques
www.rsta-uk.org
Carriageways
Footways
Cycleways
Car parks
5
Surface Dressing Applications
www.rsta-uk.org
Treatment composition kg/m2
Material Single Dressing
Double Dressing
40mm Asphalt
SurfacingBinder 1.0 1.5 6.0
Aggregate 12.0 21.0 93.0
6www.rsta-uk.org
Finite Resource ConsumptionFinite Resource Consumption
Comparative Costs and Life
www.rsta-uk.org
Type Application /m2+/10%
ExpectedLifeyears
6mmSingleSurfaceDressing Estateroads,ruralareas 1.50 7 10
10&6mmRackedInDressing Urbanroads,quieter 1.80 7 10
14&6mmDoubleSurfaceDressing(relativelynew)
Busyurbanroads,higherstress,gradient,bend
2.20 7 10
Prepatchingadditionalcost Rural,urbanroads 1.00 1.50 n/a
MicroAsphalt14mm MainlyUrbanlocations 3.00 7 12
Microasphalt+regulating+ironworksraised
MainlyUrbanlocations 3.50 4.00 7 12
HighFrictionSurfacing Highstressareas 9 12 5 10
Retexturing bushhammer Anywhereexposedaggregates
2 3 3 5
GilsonitePreservative Anywhere 0.8 1 3 5
AsphaltReinforcementGeocomposites/Geotextiles
Urban,trunkroads 5 8 Increaseslifebyfactorof4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Years
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Years
O v era ll cond ition
O vera ll cond ition
G ood
G ood
P oor
P oor
S urface d ressing
S urface d ressing
D e fects v is ib le
P a tch ing
R econstruction
S urface d ressingS urface d ressing
Source : Aspha lt S urfac ings, S teven S t John
8
Surface DressingExtending time to structural maintenance
www.rsta-uk.org
Work ongoing at University of Nottingham to develop process maps and capture energy data for a range of surface treatments that can then be fed into asPECT
Asphalt Pavement Embodied Carbon Tool
9
Carbon Footprint
www.rsta-uk.org
www.rsta-uk.org
Quality ControlQuality Control
Chipping Spread Rate Test
www.rsta-uk.org
www.rsta-uk.org
Binder Spread Rate Test
www.rsta-uk.org
Carpet Tile Spray Bar Test
www.rsta-uk.org
SpecificationSpecification
SHW Clause 922SHW Clause 922BSEN 12271BSEN 12271
PD6689PD6689
Procurement
Method 1 Specified by end product performance - Cl 922 of SHW
Method 2 Specified by recipe - Cl 919 of SHW
Method 1 defines a product and therefore the Construction Product Regulation applies and BSEN12271
www.rsta-uk.org
Clause 922
Thecontractormust... Produceadesigntoachievealevelofperformancee.g.
macrotextureandalsoadesignlife
InstalladressingthatmeetsrequirementsofNHSS13a Provideaqualityplan BecompliantwithBSEN12271 Providea2yrguarantee Provideevidencehisspraytankerandchippingmachinecan
achievethedesiredrateandaccuracyofspread
ProduceaselfcertifiedTAIT
www.rsta-uk.org
BSEN 12271 EffectiveinUKfromJanuary2011 PD6689providesUKguidance Specifiesarangeofpropertiesandcategoriestoenableappropriatelimitingvaluestobesetforawiderangeofuses
CEMarkingcurrentlynotmandatoryinUK
www.rsta-uk.org
PD 6689 Constituent Materials
www.rsta-uk.org
Binders
UnmodifiedbindersmustconformtoBSEN13808emulsions
PMBsareproprietarymaterialsandClauses919and922requirethesetohaveBBAHAPAScertificates
BSEN12271includesameasureofbindercohesion(VialitTest)
www.rsta-uk.org
Modified BindersModified BindersVialitPendulumCohesion
Vialit Cohesion BS EN 13588
HA SHW Clause 939
Grades (minimum Peak Cohesion):
Super premium binder 1.4J/cm2
Premium binder 1.2J/cm2
Intermediate 1.0J/cm2
Unmodified* 0.7J/cm2
*threshold level for guidance only
www.rsta-uk.org
PD 6689 Aggregates
HD36adviseswhatPSVandAAVtobeusedonasitebysitebasis. ThePSVisrequiredtoensurethedurabilityofskiddingresistance
AggregatesusedinsurfacedressingshouldconformtoBSEN13043
RecommendationsforgradingsofchippingsareinPD66822:2009,Table4
BSEN13043alsorecommendsthat,forsurfacedressing,thefinescontentshouldbef1(i.e.notmorethan1%passing0.063mmsieve)
www.rsta-uk.org
PD 6689 Performance Criteria
PerformancecategoriesinPD6689havebeenchosenfromBSEN12271:2006,Table2
TheserecommendationsrelatetheHAUCroadtypestogetherwiththedesignclassificationsfromRN39
www.rsta-uk.org
EN 12271:2006(E) - Table 2
Type Approval Installation Trial (TAIT)
TAITsarethemeansbywhichaproducerdemonstratestheabilitytodesignandinstallagrouporfamilyofsurfacetreatmentsmeetingtherequiredperformancecharacteristics
TAITscanalsobeusedasthebasisforCEmarking
www.rsta-uk.org
Type Approval Installation TrialRecommended Portfolio
TAITs are the responsibility of the producer and must be verified by a notified body
www.rsta-uk.org
Factory Production Control (FPC)
BSEN12271specifiesaFPCsystem aroutetoCEmarking FPCensuresthedesignprocedureisdocumented,therelevantcontrols
andtestsarecarriedoutatminimumfrequencyandrecordsarekept
AllproducersaccreditedtoNHSS13amusthaveaQAsystemwhichmeetsFPCrequirementsandareaccreditedbynotifiedbodies
TheSectorSchemeisarequirementoftheSHWandrequiresproducerstodemonstratethecompetenceoftheirworkforce
ThereisascheduleofsuppliersaccreditedtoNHSS13amaintainedbyLantra
Theattestationofconformityis2+
www.rsta-uk.org
Surface Dressing Design Guide
SurfaceTemperatureCategory
RoadHardness
Traffic
Geometry
Chippingproperties
Design Input Data
www.rsta-uk.org
Surface Temperature Category
Table 7.2.1 - Approximate Surface Temperature Categories
www.rsta-uk.org
Road Hardness Category
www.rsta-uk.org
Road Hardness Category
very soft
soft
normal
hard
very hard02468
10121416182022
10 15 20 25 30 35 40
Road surface temperature (C)
P
r
o
b
e
p
e
n
e
t
r
a
t
i
o
n
(
m
m
)
Figure 7.2.2 Hardness categories from depth of penetration and road surface temperature for Different Surface Temperature Categories
Category B
Traffic
Table 7.2.3 Traffic Categories
Categories converted from msa to cv/l/d assuming a growth rate of 2% over the design life.
www.rsta-uk.org
Geometrics
Gradients
Bends
Junction and Crossings
= STRESS
www.rsta-uk.org
Chipping Properties
PSV refer to HD36/06 or Figure 7.3.1.
AAV Not greater than 14
www.rsta-uk.org
Other Data Required
General Surface Condition
Season
Shade
Local Traffic
Noise
www.rsta-uk.org
Season
Figure 7.3.2 Surface Dressing Season
Tree Shade
www.rsta-uk.org
Noise
Increasing texture depth
I
n
c
r
e
a
s
i
n
g
n
o
i
s
e
(
d
B
A
)
6mm
10/6mm
10mm
14/6mm
14mm
www.rsta-uk.org
Designing the Dressing
Site Suitability
Sections within the Site
Choosing the Dressing type and Binders
Using the Design Proforma
Selecting the Rate of Spread
www.rsta-uk.org
Site Suitability
Figure 8.1 - Effect of Existing Road Surface Characteristics on Achievable Performance Levels
Choosing The Right Dressing
Figure 8.3aSelection of Type of Surface
Dressing for Lightly-Trafficked Sites
Binder Rate of Spread - Table 9.2.2
Racked In Dressing
Relatively low cost and high productivity Extends road life and delays major maintenance spend Reduced traffic management costs and road user costs Efficient use of aggregates/binder and minimal waste Up to 10 year life if properly designed and executed A strategic option for de-carbonising roads Can help to prevent potholing
www.rsta-uk.org
Surface DressingBenefits
Better,tougherbinders=betterchipretention Lowtemperatureemulsions(undertrial) Betteremulsionbreakcontrol Bettermobileplant improvedspraying/spreadingaccuracy Closerattentiontoachievinggoodcompaction Closerliaisonwithhighwayauthorities Improvedaftercare BettertrainedoperativeswithCSCScards(SectorScheme13a)
Surface DressingInnovation
www.rsta-uk.org
MicroMicro--SurfacingSurfacing
www.rsta-uk.org
Micro-Surfacing
Apolymermodifiedcoldpavedasphalt
Thickness6to15mm
Uses
rutfilling/levellingcourse
sealing
fillingpotholes
correctsravelling/bleeding
improvesskidresistance(highervolumeroads)
www.rsta-uk.org
Micro-Asphalt Description
Slurrysurfacingintroducedinthelate1950s Primarilyusedasapreservativetreatmentforairfield
runwaystypicalaggregatesizeforslurrysurfacing03mm Slurrysurfacingnowmorewidelyknownasmicroasphaltsor
microsurfacingwithtypically06mmaggregates Microasphaltisamixtureof:
Aggregates(coarseandfine) PMBemulsion Water Cementorhydratedlime Possiblyfibres Chemicalbreaking agent
Theblendofmaterialsisbatchedinsituandlaidbyapurposebuiltselfpropelledmicroasphaltpaver
www.rsta-uk.org
Slurry Seal and Micro-Asphalt
Footwayslurrysealismechanicallymixedandhandappliedusingabrushtoprovidesurfacetexture.Nonpolymermodifiedbitumenemulsionandaggregatesizesof03mm
Thincarriagewayandairfieldslurrysealisusuallylaidupto5mmthickusinga03mmaggregateandnonpolymerbitumenemulsion.Laidmechanicallyandissuitableforurbanareasandairfieldtaxiways
Microasphalts firstlayerregulatesandreprofilestheexistingpavement secondlayerprovidesadensesurfacewithgoodtexturedepthand
wetskiddingresistance.
www.rsta-uk.org
SLURRY / MICROSURFACING
Composition
Aggregates
Mineralfiller
Water
Bitumenemulsion
Fieldcontroladditive
www.rsta-uk.org
Aggregate selection
Strong,durable
100%crushedparticles
Typeofrock
Reactivityoffines critical!
www.rsta-uk.org
Aggregate Gradation
Sieve size mm
Slurry Micro- surfacing
5.0 100 100 70-90 2.36 95-100 75-100 45-70 1.18 70-95 55-90 28-50 .600 55-75 35-70 19-34 .300 30-50 20-45 12-25 .075 5-15 5-15 5-15
www.rsta-uk.org
Mineral Fillers
Portlandcement
Hydratedlime
Modifyflow&settingcharacteristics
www.rsta-uk.org
Bitumen Emulsion Selection
www.rsta-uk.org
Polymer
Purposes
reducestemperaturesusceptibility
improvesstiffness
Types
latex(liquid)
solids
www.rsta-uk.org
Field Control Additive
Affectsbreaktime
temperature&aggregatereactivity
Typeandamount
amines(0.1%)
www.rsta-uk.org
Surface Curing
Mixtime
timeremainingfluid(30180s)
Settime
expulsionofclearwater&initialdevelopmentofcohesion
Traffictime
sufficientcohesionfortraffic(20minto4hrs)
www.rsta-uk.org
Mix Design Criteria
Mixingtests
Cohesiontest
Testsforbindercontent
Performancerelatedtests
www.rsta-uk.org
Mixing & Cohesion Tests
Mixtime&settime Handmixedfor30s
Partpouredout.Clearwaterexuded settime
Partstirreduntilstiff mixtime
Cohesiontest Rolledintoball&droppedonfloor
www.rsta-uk.org
Tests For Binder Content
Wettrackabrasion(WTAT) BS434aggregatetest(max500g/m)
Loadedwheeltest
www.rsta-uk.org
www.rsta-uk.org
www.rsta-uk.org
Site Selection Client Side
Highwayclientslooktomicrosurfacingtoimprove:
Appearance coveringsurfacedefects Profiling regulationofthesurface SkidResistance replacescontactsurface SubsurfaceProtection sealingtheroadagainstwateringress
www.rsta-uk.org
A Potential Micro-Surfacing Site
www.rsta-uk.org
Micro-Asphalt Paver
www.rsta-uk.org
WATER
BITUMEN
AGGREGATE
SPREADER BOX
Computer Controlled Batching
www.rsta-uk.org
Applied through the Spreader Laying box
www.rsta-uk.org
Compaction using a Pneumatic Tyre Roller (PTR)
www.rsta-uk.org
After Care
Readyfortrafficafter20minutes Sweepafter24hours RaiseIronworknextday Applyroadsafetymarkingsafter72hours Removetrafficmanagementsigns
www.rsta-uk.org
Slurry-Micro SurfacingApplications
Carriageways
Footways
Cycleways
Car parks
Playgrounds
Airfield runways
Reservations and Islands
73www.rsta-uk.org
Benefits
Restorationofinstantaneousskiddingresistanceandtexturedepthlevels
Quickinstallation,withminimumdisruptiontotrafficflows
Environmentallyadvantageouswithlittleornotoxicemissionsandnoheatenergyrequired
Financialcostbenefits
www.rsta-uk.org
BSEN 12273 Micro-Surfacing
UK guidance contained in PD 6689 BSEN 12273 will be implemented in UK in
January 2011 By that time all contractors must have in place:
BSEN ISO 9001 QA systems, FPC, TAITs UK specification controlled by SHW Cl.918
contractors must be compliant with Sector Scheme 13b
www.rsta-uk.org
Specification Requirements
Aggregates to BS EN 13043 Binders to BS EN 13808 Cationic Bitumen
Emulsions Mix design declared by producer 1 year after installation:
visual assessment of defects surface macro-texture
www.rsta-uk.org
BS EN 12274 Test Methods
1. Sampling
2. Residualbindercontent
3. Consistency mixdesign
4. Cohesionofmix mixdesign
5. Wearing(wettrackabrasion) mixdesign
6. Rateofapplication
7. Shakingabrasion(binder/aggregateaffinity)mixdesign
8. Visualassessment
www.rsta-uk.org
Clause 918
Contractordesign RegistrationtoSectorScheme13B TAITtoBSEN12273 Aggregatemin.PSV&max.AAV(FI20 omitted) Performancerequirements
Assessmentofdefects¯otexture 2yearguarantee(macrotextureinitially,1&2years) Normally1yearfornontrunkroads
Specifieshowtoexecutetheworks BBAHAPAScertificationformodifiedbindernolonger
required Bondcoatspecified
www.rsta-uk.org
Notes for Guidance on Clause 918
Clause 942 thin surfacing applicable to micro-surfacing for roads carrying > 250 cv/l/d or allowing speeds > 60 mph
Categories given for visual assessment of defects from lightly trafficked roads (Cat. 1) to dual
carriageways (Cat. 4)
www.rsta-uk.org
Performance RequirementsRequirement Unit Category
0 1 2 3P1 bleeding, etc. % NPD 8 2 0.5
P2 delamination, aggregate loss, etc.
% NPD 8 2 0.5
Macrotexture mm NPD 0.2 0.4 0.6
Noise (macrotexture) mm Declared maximum
ConstituentsBinder cohesionAggregate PSV
Aggregate micro-Deval
J/cmDeclared class/category
(AAV in UK)Slurry type Defined by maximum aggregate
size & binder type
Design Manual for Roads and BridgesVolume 7 Section 5 Part 2 HD37/99
SHW Series 900
Clause 918 - Slurry Surfacing
Clause 919 - Surface Dressing Recipe
Clause 922 - Surface Dressing Performance
Clause 927 - Micro-surfacing
EN 12271 Surface Dressing (FPC + test methods)
EN 12273 Slurry-Micro Surfacing (FPC + test methods)
PD6689: 2009 Surface Treatments
NHSS 13a Surface Dressing and 13b Slurry-Micro Surfacing
Road Note 39 and RSDA Code of Practice
81
Guidance
www.rsta-uk.org
THANKS FOR LISTENING!
Visitwww.rstauk.org forourcalendaroftrainingcourses
www.rsta-uk.org