NZQA registered unit standard
28708 version 1
Page 1 of 5
Title
Demonstrate knowledge of equipment and processes for
constructing slurry surfacings
Level
4
Credits
6
Purpose
People credited with this unit standard are able to demonstrate
knowledge of: equipment used; pre-construction processes;
construction processes; and post-construction processes for
slurry surfacings.
Classification
Infrastructure Works > Bitumen Surfacing Construction
Available grade
Achieved
Explanatory notes
1
Competence in this unit standard requires knowledge of the current editions of 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
Assessment against this unit standard must be based on evidence from a workplace
context.
3
Evidence is required from working on three contracts covering each of – slurry, cape
seal, rut filling.
4
Definitions
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.
Maintenance period means the period of time from the removal of temporary speed
restrictions until final acceptance by the engineer, during which time the contractor
may have corrective action obligations specified in the contract specifications.
Operating manuals refers to the plant operating manual and manuals written for
specific components or items of plant and equipment that may be published by the
manufacturer or the company.
Protection period means the period of time from the completion of construction until
the removal of temporary speed restrictions, during which time the contractor may
have corrective action obligations specified in the contract specifications.
Infrastructure ITO
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
28708 version 1
Page 2 of 5
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.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of equipment used for constructing slurry surfacings.
Evidence requirements
1.1
Slurry machine is described in terms of its components and functions.
Range
1.2
Slurry machine is described in terms of effects of machine faults on the quality
of the surfacing.
Range
1.3
faults – blocked filters, incorrect calibration of feeders, emulsion
flows, addition of water, poor mixing, runs into channel too thin;
The limitations and alternatives to slurry machines are identified.
Range
1.4
components – mixing box, weigh feeders, volumetric feeders, flow
meters, fibre dispenser, storage hopper, emulsion tank, dope tank,
control system, secondary strike off, rut box, crane, pump augers;
functions – loading, proportioning, mixing, spreading, screeding.
limitations – size, weight, width;
alternatives – smaller machine, chute and wheelbarrow, concrete
mixer.
Other slurry surfacing equipment is described in terms of when it is needed.
Range
where tack needed, where sprayer needed, where rolling needed,
type of roller needed.
Outcome 2
Demonstrate knowledge of pre-construction processes for slurry surfacings.
Evidence requirements
2.1
Checks to be made prior to accepting a site for laying bituminous mixes are
explained in terms of meeting contract requirements.
Range
2.2
checks – pre-seal repairs completed, site suitable for surfacing,
site extent marked out;
examples of checks are given from two different sites.
Pre-construction processes are described in terms of general site preparation
requirements for slurry surfacings.
Infrastructure ITO
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
Range
2.3
testing – mix design, aggregate, emulsion, slurry, aggregate
grading, sand equivalent, aggregate moisture content, binder
content, slurry gradation, cement, additives, dope.
Pre-construction processes are described in terms of identifying and notifying
affected parties.
Range
2.8
tack coat applicator, sprayer, slurry machine, loader, roller.
Pre-construction processes for slurry surfacing are described in terms of
scheduling sampling and testing to meet contract requirements.
Range
2.7
pre-treatment types – cleaning, sweeping, pre-levelling, tack coat;
membrane seal;
factors – pavement condition, treatment type, site constraints,
resources.
Pre-construction processes are described in terms of determining and
confirming plant, equipment, and labour resources for slurry surfacing.
Range
2.6
site safety, public safety, pavement shape, geometric constraints,
live load limitations, access, obstructions, radio, drop off area,
location of ancillary services, climate.
Pre-construction processes for slurry surfacing are described in terms of pretreatment types and factors to take into account when determining pretreatment requirements.
Range
2.5
programming pavement repairs, hazard identification and control,
environmental protection, temporary traffic management, loading
sites, stockpile site, parking and unloading areas, ends and widths
marked out, location on road marked.
Pre-construction processes are described in terms of complying with site
specific instructions.
Range
2.4
28708 version 1
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identify at least four affected parties and any four methods of
notification.
Pre-construction processes are described in terms of identifying, recording, and
protecting service overs, road furniture, and adjacent surfaces.
Outcome 3
Demonstrate knowledge of construction processes for slurry surfacings.
Evidence requirements
3.1
Transport of slurry surfacing plant, equipment, and materials to laying site is
explained in terms of logistics.
Infrastructure ITO
SSB Code 101813
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
Range
28708 version 1
Page 4 of 5
aggregate stockpiles, emulsion trailer, emulsion tanker, slurry
machine, roller, loader.
3.2
Surface preparation is explained in terms of cleaning and masking requirements
and methods.
3.3
Surface preparation is described in terms of tack coat and membrane seal
timing, types, and methods.
3.4
Slurry surfacing is described in terms of construction processes, checks, and
adjustments.
Range
processes – mixing, starts and stops, butting, lapping, tapering,
managing product viscosity, managing screed, control of break
and cure with dope;
checks – emulsion quality, aggregate quality, contamination,
moisture content of aggregate, stockpile cover, excessive cement;
adjustments – feeder rates, truck speed, feed to high side, auger
speeds.
3.5
Slurry surfacing construction is described in terms of when hand work is
required and hand work methods.
3.6
Site safety and traffic management are explained in terms of site requirements,
lane closures, and adjustments required during slurry surfacing construction.
Outcome 4
Demonstrate knowledge of post-construction processes for slurry surfacings.
Evidence requirements
4.1
Slurry site clean-up processes are explained in accordance with company
procedures.
Range
4.2
Protection of a road surface during the protection period is described in
accordance with company procedures.
Range
4.3
roadmarking, removing start finish paper, removing service
protection, waste disposal.
timing, traffic loads, traffic speed, positive traffic control.
Monitoring the newly laid surfacing for the maintenance period is described and
corrective actions are explained in accordance with company procedures.
Range
Infrastructure ITO
SSB Code 101813
monitoring for – aesthetics, texture, abrasion loss, skid resistance,
deformation, unravelling, flushing.
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
Planned review date
28708 version 1
Page 5 of 5
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