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Title / Design chipseal surfacings using polymer-modified binders
Level / 5 / Credits / 5
Purpose / This unit standard is for people who design chipseals and surface treatments.
People credited with this unit standard are able to: assess site requirements for use of polymer-modified binders; describe the design of polymer-modified chipseals; and design polymer-modified chipseals.
Classification / Pavement Surfacing > Chipseal Surfacing
Available grade / Achieved
Entry information
Critical health and safety prerequisites / Unit 21664, Design chipseal surfacings and pretreatments; and Unit 17670, Demonstrate knowledge of hot polymer-modified binders and their use in chipseal construction; or demonstrate equivalent knowledge and skills.
Explanatory notes
1The following requirements apply to this unit standard, and must be complied with:
AGPT04F-08 Guide to Pavement Technology Part 4F: Bituminous Binders(Austroads Guidelines), Austroads, available for purchase at:
Chipsealing in New Zealand, New Zealand Transport Agency, available at
The Bitumen Safety Handbook, Roading New Zealand, available for purchase at
Any requirements superseding any of the above will apply, pending the review of this unit standard.
2Assessment against this unit standard may be based on evidence from workplace and/or provider contexts.
3Evidence is required of at least four designs.
4Definitions
Company procedures refers to all documented policies, procedures, and methodologies of the candidate’s employer at the time of training including but not limited to those relating to health, safety, environment, quality, and operations.
PMB means polymer-modified binder.
Outcomes and evidence requirements
Outcome 1
Assess site requirements for use of polymer-modified binders.
Evidence requirements
1.1Pavement use and condition are assessed in accordance with Austroads Guidelines and company procedures.
Rangetraffic stress, texture, cracking, deflections, flushing;
influence of PMB on rate of redevelopment of flushing.
1.2Factors that need to be given special consideration to ensure that polymer-modified binder adhesion and cohesion are achieved are assessed in accordance with site conditions, company procedures, and contract requirements.
Rangeincludes but is not limited to – pavement surface cleanliness, chip cleanliness, climate, shade, moisture, pavement surface temperature, binder viscosity, cutter use, adhesion agent use.
Outcome 2
Describe the design of polymer-modified chipseals.
Evidence requirements
2.1Seal selection suitability for site conditions is described.
Rangeseals – single coat, two coat, multilayer, sandwich, racked-in.
2.2Reasons for using different binder types and degrees of modification are described in accordance with Austroads Guidelines.
Rangemodification includes but is not limited to – diluents, adhesion agent, hot-sprayed PMB, emulsified PMB;
three reasons.
2.3Reasons for pretreating chip are described.
Rangecleaning, preheating, precoating.
2.4Tests that confirm properties specified in manufacturer’s technical data sheets are described.
2.5The influence of PMB on the rate flushing is described.
Rangepolymer type, polymer concentration, bitumen grade.
Outcome 3
Design polymer-modified chipseals.
Rangehot binder, emulsified binder.
Evidence requirements
3.1Seals are selected in accordance with site conditions.
Rangemay include but is not limited to – road geometry, climatic conditions, traffic loading, and stresses.
3.2Chip is selected in accordance with site and binder requirements.
3.3Pretreatments are selected in accordance with site requirements.
Rangepavement surface, chip, texturizing.
3.4Binder type and degree of modification are determined in accordance with site requirements.
3.5Residual binder application rates are determined in accordance with binder properties, surface texture, chip size, traffic volumes, and surface hardness.
3.6Field application rates for hot binder are determined in accordance with spraying temperature and quantity of diluents.
3.7Chip application rates are determined through the designs in accordance with chip average least dimension and site requirements.
3.8Designs are completed in accordance with client requirements and contract specifications.
Rangemay include but is not limited to – road and traffic noise, loose chip, type of end user e.g. cyclists, pedestrians.
Planned review date / 31 December 2016Status information and last date for assessment for superseded versions
Process / Version / Date / Last Date for AssessmentRegistration / 1 / 25 November 2000 / 31 December 2013
Review / 2 / 27 October 2005 / 31 December 2013
Review / 3 / 15 March 2012 / N/A
Consent and Moderation Requirements (CMR) reference / 0101
This CMR can be accessed at
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA, before they can report credits from assessment against unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and which are assessing against unit standards must engage with the moderation system that applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies to this standard are outlined in the Consent and Moderation Requirements (CMR). The CMR also includes useful information about special requirements for organisations wishing to develop education and training programmes, such as minimum qualifications for tutors and assessors, and special resource requirements.
Comments on this unit standard
Please contact Infrastructure if you wish to suggest changes to the content of this unit standard.
Infrastructure ITOSSB Code 101813 / New Zealand Qualifications Authority 2018