NZQA registered unit standard
28707 version 1
Page 1 of 3
Title
Demonstrate knowledge of mix design fundamentals and treatment
selection for slurry surfacings
Level
4
Credits
6
Purpose
People credited with this unit standard are able to demonstrate
knowledge of mix design fundamentals and treatment selection
for slurry surfacings.
Classification
Infrastructure Works > Bitumen Surfacing Construction
Available grade
Achieved
Explanatory notes
1
Assessment against this unit standard must be based on the fundamental principles
of treatment selection in the following references:
RNZ 9806, Specification for Slurry Surfacings, RNZ 9806: June 2010, Roading
New Zealand, available at http://www.nzcontractors.co.nz;
ISSA A105 Recommended Performance Guideline for Emulsified Asphalt Slurry Seal
A105 (Revised February 2010) International Slurry Surfacing Association available at
http://www.slurry.org;
ISSA A143 Recommended Performance Guideline For Micro Surfacing A143
(Revised February 2010), International Slurry Surfacing Association available at
http://www.slurry.org.
2
Definitions
Job Mix Formula is the combined aggregate particle size distribution and total
bitumen content that falls within the SME and produces a mix that complies with
specified volumetric and mechanical criteria.
Slurry surfacing is the generic term for a mix of asphalt emulsion binder, crushed
aggregate, and stabilising filler. A development of slurry using a polymer modified
binder and selected aggregates is known as micro surfacing.
SME stands for Specified Mix Envelope or the asphaltic concrete particle size
distribution and effective bitumen content limits, which are set out in Section 5 of
NZTA Specification M10 Specification for Dense Graded and Stone Mastic Asphalts
available at http://www.nzta.govt.nz.
Infrastructure ITO
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
28707 version 1
Page 2 of 3
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of mix design fundamentals for slurry surfacings.
Evidence requirements
1.1
Slurry and micro surfacings are defined and their components are described in
accordance with RNZ 9806.
Range
1.2
Performance requirements for slurry and micro surfacing design are described
in accordance with RNZ 9806.
Range
1.3
wet track abrasion, wet striping, wet cohesion, binder content,
gradation.
Slurry and micro surfacing design is explained in terms of factors that affect the
performance of these surfacings.
Range
1.4
binder content, mineral aggregates, fillers, potable water,
additives, modifiers, sand equivalent.
grading, aggregate moisture content, residual binder content,
application depth, mix and set times, climatic conditions, time of
day, weather, wind speed, humidity.
A slurry surfacing Job Mix Formula is described in terms of what it contains and
why.
Range
recipe, emulsion content, cement content, aggregate content,
moisture content, dope content.
Outcome 2
Demonstrate knowledge of treatment selection for slurry surfacings.
Evidence requirements
2.1
Treatment selection for slurry surfacings is explained in terms of determining
the condition and composition of the existing surface.
Range
Infrastructure ITO
SSB Code 101813
determination from – records, site visit;
surface conditions – deflections, cracks, flushing, skid resistance
requirements, traffic stresses, traffic times, tack coat, rolling,
surface shape.
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
2.2
28707 version 1
Page 3 of 3
Treatment selection for slurry surfacings is explained in terms of selecting
appropriate systems for different situations and specific requirements.
systems – slurry, micro surfacing, cape seal, rut filling;
situations – traffic stress, cracking, deflections, traffic loading,
rutting, flushing, polishing, unravelling;
specific requirements – texture, skid resistance, colour, noise
level.
Range
Planned review date
31 December 2019
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
19 February 2015
N/A
Consent and Moderation Requirements (CMR) reference
0101
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
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 (CMRs). 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 the Infrastructure ITO qualifications@infrastructureito.org.nz if you wish to
suggest changes to the content of this unit standard.
Infrastructure ITO
SSB Code 101813
 New Zealand Qualifications Authority 2016