asphaltnews - asfaltblij...hse certification scheme launched 5 sabita council: new appointments 6...
TRANSCRIPT
volume 22
issue 2
JULY 2008
ASPHALTNEWS
In this issue
Cover picture: View of the recently constructed dedicated public transportlanes, featuring coloured asphalt, on the N3 in Durban. The construction is part
of infrastructure preparations being made for the 2010 soccer World Cup
Asphalt News is published by the Southern African Bitumen Association(Sabita), a non-profit organisation sponsored by its members to serve all
stakeholders through engineering, service and education.
The contents of this publication may be reproduced free of chargeprovided the source is asknowledged.
Editor: John Fensham
HSE certification scheme launched 5
Sabita Council: new appointments 6
Sabita Outstanding Achievement Award 2007 7
Sabita joins global alliance of paving associations 9
RPF resolutions 10
Roads sector skills needs critical initative 12
Bitumen durability protocol 14
Pay Factors for hot mix asphalt 17
Laboratory vs field density: A contractor's view 20
Bitumen rubber asphalt guidelines 21
Reclaimed asphalt pavements in HMA manufacture 22
Sabita publications 24
Sabita website 25
Thin layer asphalt guidelines launched 26
New members 28
Sabita membership 30
The rapid expansion in road sector
activity in recent years, and the
significant increase in roadspend at all
levels of government, has raised the
level of production and construction activity to
levels unseen for many years. The road
construction industry as a whole has, in fact,
become one of the top performers in the area of
infrastructure provision.
This in turn has generated a wide range of initiatives
aimed at introducing and entrenching global standards of
best practice, worker and environmental protection,
technology development and skills development in order
that we are better placed to meet the ever increasing
demands and challenges being placed on the bituminous
products industry in a growing market.
Sabita’s role in these developments has been one of
guidance in the service of its members, and one of the
most important tools in promoting the above initiatives is
communication aimed at ensuring an informed industry.
This has led Sabita to invest significant funding and
resources into the development of publications ranging
from manuals, codes of practice and guidelines to DVD
training material, its flagship publication the Sabita
Digest, and the Asphalt News, which is published three
times each year.
In recognition of the industry’s unabated need for
relevant, timely and comprehensive information, Asphalt
News has now been upgraded and re-designed. Its scope
and range has been expanded to incorporate a broader
range of both information and member service.
For example, members are encouraged to submit articles
on topical issues. Advertorials on proprietary products
and services will be considered for publication free of
charge, reaching a dedicated target audience of 2 000
local readers. A condition of such publication is that the
member company places an advertisement, which in turn
will assist Sabita in maintaining its output of cutting
edge information to the industry.
Comments on this new Asphalt News initiative, and
requests for advertising rates, should be directed to
3
Sabita CEO Trevor Distin
New image for Asphalt News to meet
expanding information needs
4
In its continuing initiative to ensure that the health
and safety of workers is protected, and that the
environmental impacts of industrial processes on
the environment are minimised, the Southern
African Bitumen Association (Sabita) has introduced a
certification scheme aimed at promoting global
standards of health, safety and environmental
conservation (HSE) in South Africa’s bituminous
products industry.
This latest move follows the launch at CAPSA’07 of
Sabita’s HSE Charter, which commits Sabita members
to the implementation of best available HSE techniques
during the handling and application of bituminous
products. The Charter underscores the internationally
accepted principle that the ongoing improvement of
mechanisms to ensure worker well being and
conservation of the fragile environment is an
obligation, not a choice.
Sabita CEO Trevor Distin said this week that the
intention of the certification scheme was to encourage
Sabita members and others in the bituminous products
industry to further develop their own HSE initiatives
by adopting those tools developed by Sabita to raise
the level of safety awareness in the bituminous
products industry.
“The benefits of the certification scheme are wide
ranging,” Distin said, “and include bottom-line gains
such as participation in government tenders, the peace of
mind linked to compliance with statutory requirements,
and the future sustainability of the industry through
protection of our people and environment.”
INCIDENT REPORTING
He added that a parallel initiative was the introduction of
a Bitumen Incident Reporting framework (Bitinrep) to
develop a database of incidents/accidents affecting the
health and safety of workers, and damage to the
environment. This scheme was designed to raise
awareness of potential hazards and to disseminate
information that would allow members to learn from the
mistakes of others.
The Bitinrep reporting form requires a comprehensive
report on every aspect of any incident involving the
handling of bituminous products, including:
• The type of incident (spillage, explosion, fire,
burns and foaming);
• Losses suffered (human, equipment, down time,
building damage, product);
• Activity underway when the incident/accident
occurred;
• Nature of the incident or injury sustained;
• Measures taken during and after the incident;
• Nature of injuries suffered;
• Cause of the incident.
DATABASE
Once completed, the form must be faxed or emailed to
Sabita, where the information will be used to build a
comprehensive database of incidents in the bituminous
products sector. This will be used to develop guidelines
to make the industry aware of potential hazards, and the
way in which these incidents can be prevented or
countered in the future.
“Both the certification and the incident reporting
schemes will foster a climate in which HSE performance
can be benchmarked and the re-occurrence of incidents
can hopefully be avoided. These initiatives will also
allow our industry to write and update specific codes of
5
Health and safety certification
system introduced to encourage
self-regulation
practice, and to develop specialised training material
aimed at preventing damaging incidents,” Distin said.
In terms of the certification scheme all Sabita members
will be sent a Pre-Audit Checklist (one for each
established site or facility) which will assist them to
identify and correct areas of non-conformance with the
minimum requirements of Sabita’s HSE Charter and/or
with occupational health and safety legislation. These
criteria will depend on the nature of the member’s
industrial activity.
In terms of the scheme a site is defined as a fixed facility
where the processing or storage of bitumen takes place
(such as a refinery, depot, emulsion plant, blending plant
or asphalt mixing plant), but also includes vehicles
involved in the transportation or application of
bituminous materials.
COMPLIANCE
“Once these checklists have been returned to Sabita,
we will notify an independent auditor to conduct an
audit of the member’s site or facility,” Distin said.
“Sites will be allowed up to three months to correct
any shortcomings noted by the auditor, who will then
make a second audit, following which the member will
be deemed either compliant or non-compliant.”
Sites which fully meet the minimum requirements will
be issued with a certificate of compliance, will be
allowed to use the logo and flag of Sabita’s Centre for
Occupational Safety, Health and Environmental
Conservation (COSHEC) on company stationery, and
their status as HSE certified companies will be published
on the Sabita website,” Distin said. “These certificates
will be valid for a period of 12 months from the date of
issue, and the certification process must be repeated
annually, with renewal of certification mandatory within
three months of the anniversary date of the previous
certificate issued.”
DYNAMIC CRITERIA
He added that compliance criteria were dynamic and
would change with time in step with revised
circumstances and legislation. Part of the process would
demand that Sabita keep members informed and up to
date with the latest legal requirements and best practices
in maintaining global standards of HSE.
“Sabita has developed appropriate tools and guidelines
to assist members in achieving compliance and
certification. These are available on the Sabita website
www.sabita.co.za for downloading and ordering. The
full Sabita HSE Charter is also available on the
website," Distin said.
6
At the special council meeting of 13 March
2008, Phillip Hechter, authorised
representative of Much Asphalt (Pty) Ltd, was
re-elected as chairman of Sabita Council. Mr
Hechter has filled this position unopposed since 2004,
and Sabita thanks him for his ongoing commitment and
dedication.
It is with regret that Sabita has accepted the resignation
from Sabita Council of Kevin Spence, authorised
representative of Spray Pave (Pty) Ltd. Mr Spence has
served the Association with distinction since 1988 when
he served a two-year stint as councillor representing
Rand Roads. He continued his service with Sabita from
1997 until his retirement from Spray Pave (Pty) Ltd at
the end of 2007. Sabita thanks him for his support and
wishes him well in his future endeavours.
Gary Catin of Rand Roads (a division of Grinaker-LTA
Ltd) was subsequently elected to fill the vacant position.
Mr Catin, initially technical manager and now general
manager of Rand Roads, has extensive technical
knowledge of both paving processes and hot mix asphalt
manufacture.
The Sabita Council for 2008 is made up as follows (in
alphabetical order):
Angela Broom: Chairman, Urban Renewal and Rural
Development
Marius Cronje: Chairman, Finance Portfolio
Gary Catin: Chairman, Communications
Pieter Goosen
Phillip Hechter: Chairman, Council
Bob Hornsey: Chairman, Health Safety and the
Environment
Basil Jonsson: Vice Chairman and Chairman of the
Planning Committee
Daniel Mashatola
Thomas Pringle
Kevan Rocher
Dave Rose
Arthur Taute: Chairman, Technology Development
Chris Viljoen
Mike Winfield
Sabita 2008
Council: new
appointmentGary Catin, new
Sabita CouncillorKevin Spence, retired
Sabita Councillor
Sabita’s Award for Outstanding Achievement for
2007 was presented to Mpumalanga
businesswoman and contractor Violet Mphafudi
at the Sabita annual general meeting in Cape
Town on 13 March 2008.
Ms Mphafudi, managing director of Vioflo Services
(Pty) Ltd which is registered as a Grade Six contractor,
was cited for her “sterling employment of
labour-enhanced construction methods in upgrading
approximately 40 kms of gravel roads to surfaced
standard in the Hammanskraal and surrounding
townships … over the past nine months”.
Doubled workforce
A mother of three, Ms Mphafudi began her career as a
contractor when she undertook a three-year tender to
rehabilitate and maintain roads in the Hammanskraal and
Mabopane areas in May 2007. By using hand-operated
machinery and a surfacing methodology developed by
Johannesburg-based company Tarfix, she has been able
to employ a large number of workers from these areas,
and her original workforce of 42 people has doubled to
more than 80 – with women making up 40% of her staff
complement.
Independence
Vioflo Services, unlike many small contractors which
are dependent on larger contractors to perform specialist
functions such as surfacing, has become a completely
independent construction enterprise. This enables the
company to carry out all construction work on its own,
using its own plant and equipment. The citation noted
the vision of the City of Tshwane in specifying the
Tarfix methodology as a separate and dedicated element
of its tender programmes. This opened the doors to
smaller contracting companies to undertake work which
otherwise would have been done by larger and more
established contractors.
Without this vision emerging companies such as Vioflo
Services would have been denied the opportunity of
tendering and success.
7
Mpumalanga contractor Violet Mphafudiproudly displays her Outstanding
Achievement Award, presented to her atSabita's annual general meeting in March.
The award itself is shown below
Sabita's Outstanding AchievementAward for 2007 applauds successfullabour enhanced construction initiative
For Mphafudi, winning and fulfilling local government
tenders is nothing new. In 1997 she won her first
two-year contract from the City of Tshwane for
household refuse removal and street cleaning. In 2002
she tendered successfully for a three-month water and
sewer reticulation, which she completed in two months.
She then went on to complete further contracts for
sewer and water reticulation, re-gravelling and
maintaining rural roads, and maintaining road traffic
markings – a contract she still holds.
After her first refuse removal contract was completed,
Mphafudi was persuaded by an engineering friend to
move on to civil engineering projects, and today she
quips that “construction is my passion. It is with me
‘till death do us part.” However, she has had to
overcome challenges and stereotypes on her road to
success. Male counterparts and staff have questioned
her ability, as a woman, to function in a construction
environment. Her wisdom in employing women as
labourers was also doubted, but she believes she is
winning her detractors over.
Part of her success formula is to lead by example, and
Violet spends much of her working day on site. “I am
a hands-on operator and I am not afraid to get my
hands dirty. This includes pushing wheelbarrows. I do
not want my staff to think they are just making money
for me.”
Mphafudi’s award was acknowledged by guest
speaker Dr Ingrid Verwey, founder of South African
Women in Construction (SAWIC).
“SAWIC has played a vital role in empowering and
equipping women to take up and successfully
complete construction projects,” Mphafudi said, “and
it remains an important source of knowledge and
motivation in ensuring that women contractors are kept
informed of best practice in the industry.”
Dr Verwey noted that although 48% of the 44 100
construction enterprises registered with the Construction
Industry Development Board were owned by women,
only 5% of these were found in grades four and higher.
“This means that there is still a challenge to SAWIC and
those who share the interest and passion of promoting
women in construction. That is all the more reason to
applaud this wonderful initiative of Sabita for
acknowledging our women in construction champions.
“We likewise applaud the winner here tonight, Violet
Mphafudi. A shining example to all women contractors,
she joined SAWIC and through hard work and
dedication derived maximum benefit from the training
and other programmes offered by SAWIC and the
Development Bank of South Africa. True to her caring
and sharing nature as a woman, Violet not only takes
care of her business, her projects and her personal
growth, but still finds time to plough back her
knowledge and expertise to help others develop,”
Verwey said.
Sabita CEO Trevor Distin said Mphafudi was a role
model and an example of how emerging contractors
could make an enormous difference in the upgrading of
gravel roads to a surfaced standard while optimising
employment from local communities.
“We hope that by recognising and honouring Violet and
her endeavours we will inspire more entrepreneurs like
her, and also spur government into recognising the
immense value of labour-enhanced construction methods
in road provision. Every town needs a Violet, if not
several Violets,” he said.
8
Violet Mphafudi (centre,
wearing construction vest)
directs operations on one of
her construction sites in
Hammanskraal
Sabita was among a grouping of international
asphalt pavement associations which, during the
Conference on Asphalt Pavements for Southern
Africa held in Gaborone in September 2007,
formulated the concept of an alliance aimed at improving
cooperation and information sharing between such
associations worldwide.
Delegates participating in the development of the
proposal stressed that strategic global challenges in the
field of sustainable asphalt technology and its usage
could best be dealt with in a framework of international
cooperation which included systems for the exchange of
information and experience. This in turn would lead to
the development of common solutions.
A Global Strategic Alliance of Asphalt Pavement
Associations (GSAAPA) has now been formed, with the
following foundation members:
• Australian Asphalt Pavement Association (AAPA);
• European Asphalt Pavement Association (EAPA);
• Japanese Road Contractors Association (JRCA);
• National Asphalt Pavement Association (NAPA);
• Southern African Bitumen Association (Sabita).
The signing by representatives of the founder
organisations took place at a special function organised
by EAPA on the eve of the fourth Eurobitume and
Euroasphalt Congress recently held in Copenhagen to
formalise the Global Strategic Alliance of Asphalt
Pavement Associations. Alan McKenzie, Chairman of
EAPA, was elected the inaugural Chairman of GSAAPA
until the end of 2009 at a meeting of representatives of
the five founding associations held during the congress.
The representatives agreed that the first priority of
GSAAPA was to develop a position paper to identify
common strategic issues facing the global HMA
industry. To this end a work plan with time lines for the
preparation of the initial activities of the alliance, taking
into account the different interests and focus of the
alliance members, was drawn up.
The goals of the GSAAPA are to optimise the activities
of member associations through combined effectiveness
and cooperation, to promote international awareness of
agreed major issues, to create a structure for the
exchange of information, and to identify existing and
future developments that could have economic,
technological, legal or other impacts on the global
asphalt industry.
COMMON STRATEGIES
“The founding associations have accepted the inherent
effectiveness of forging common strategies to deal with
such developments and impacts on our industry,” Sabita
CEO Trevor Distin said, “and have identified seven key
strategic areas influencing the competitiveness and
sustainability, and thus the future wellbeing, of
GSAAPA constituents. These strategic areas will
provide the terms of reference for future discussions,
meetings and activities.”
He added that a targeted approach would be adopted to
deal with specific issues and agreed actions on the
following:
9
Signatories to the GlobalStrategic Alliance of AsphaltPavement Associations (l-r):
Alan McKenzie (EAPA)Tetsuya Shimoda (JRCA)Mike Acott (NAPA)John Lambert (AAPA)Trevor Distin (Sabita)
Sabita joins forces with global
partners to foster cooperation
• Environmental affairs;
• Occupational health and safety;
• Marketing and promoting asphalt to counter the
threat of alternative products;
• Awareness and implications of changes and
trends in global markets, with a specific focus on
bitumen and aggregates;
• Engineering and technology developments and
their implementation;
• Training and education of producers, contractors,
designers; and
• Research and development goals and objectives.
“The effective ongoing operation of GSAAPA will rely
heavily on foundation member commitment. Limited
resources will demand effective participation,
individually and as a group, to ensure currency and to
maintain member support,” Distin said.
The following operational guidelines have been
formulated to streamline attendance and participation:
• Given the distances between participants,
meetings should, where possible, be linked to
appropriate international conferences. Where
necessary, conference call facilities will be made
available for all meetings to allow the
participation of those unable to attend;
• CEOs and chairmen of each association will be
invited to attend meetings to evolve strategies for
the attainment of operational objectives;
• All correspondence and meetings will be
conducted in English;
• The GSAAPA will be chaired by one of the CEOs
of the founding associations for a term of one
year, who in turn will be responsible for the
administration, coordination of meetings and
communiqués.
“In signing the agreement, the founding members
expressed their willingness to participate in a global
alliance that is expected to benefit all member
associations, and to work willingly towards a full, open
and productive partnership,” Distin said.
10
Resolution #1
That the sponsors of the RPF should continue to
pursue the establishment of a Roads Engineering
Coordinating Body (RECOB) in support of the Roads
Coordinating Body (RCB) and Road Infrastructure
Framework for South Africa (RIFSA).
Resolution #2
That a status report on the current condition of the
road network be presented at the next RPF by the
RCB (to be championed by Ian MacDonald).
Resolution #3
• That the "ASTM/CEM standards for
bituminous materials" working group establish
essential revisions to the current draft 3001 AS
methods for asphalt through:
� Analysis and evaluation of the current
methods proposed by SANS vis-à-vis
ASTM and EN standards:
� Identification of amendments to current
draft SANS methods in consultation with a
panel of experts.
• That the agreed proposals be submitted to Dave
Wright for further action as per established
protocol (RMC-SABS).
Resolution #4
That the RPF support the self regulation initiatives of
the bituminous, readymix concrete and aggregate
materials industries in HSEQ.
Resolution #5
The RPF to create and mandate an education and
training task group to communicate industry needs to
the various industry training bodies and actively
coordinate and participate on these bodies to achieve a
set of qualifications that are in line with the needs of
the country. This will be achieved by actively
engaging as an industry with ECSA, CETA, SAQA
and others at their committee levels.
Resolution #6
That RPF accreditation task groups are to actively
engage with SANAS to assist them in creating the
necessary accreditation systems in order that the
requirements of ISO 17025 are achieved.
The next meeting of the RPF will be held at the CSIR
Conference Centre, Gauteng, on 11 and 12 November
2008.
The final signature is added to theGSAAPA agreement
Resolutions of the 15th Road
Pavements Forum,
Mpekweni, May 2008
11
Urgent action to increase available skills and
capacity will be needed if the construction
industry, now entering a growth phase after
years of depression, is to meet the delivery
targets of the Medium Term Economic Framework
(MTEF).
This is the conclusion reached in a wide-ranging
paper, written by Les Sampson, CEO of the Asphalt
Academy, which examines possible scenarios to
correct the debilitating skills shortage, resulting from
changes in South Africa’s political dispensation and
the advent of alternative priorities and agendas, now
hampering infrastructure delivery.
The paper notes that, based on a five year investment
scenario in line with the MTEF, it is estimated that
there needs to be an average of 7% annual increase in
personnel, across all skills levels, over the next five
years. This translates to 9 230 extra people in year one
and approximately 47 000 over the five year period to
deliver on the planned investment. Of this number, an
additional 1 000 skilled professionals in year one,
increasing to 5 000 by year five, will be required to
manage the design, construction and maintenance of
South Africa’s road infrastructure.
The predicted increase in semi-skilled workers (3 600
in year one and 18 180 in year five) will place huge
demands on appropriate training interventions at that
level to ensure that the appropriate cost, quality and
timeous delivery of road construction and maintenance is
achieved.
It is anticipated that the industry will need at least a
15-year window to transfer knowledge and build a
vibrant and experienced work force that can sustain the
roads sector into the future. In addition, this will need to
be supported by sustained road infrastructure growth
strategies, with a reduction in the large fluctuations in
funding previously experienced. The World Cup in 2010
has been the catalyst for growth in the infrastructure
sector, and this must be used as a platform for growth
into the future. There is no point in building capacity
now if there is to be a large reduction of infrastructure
investment in five or ten years time.
The capacity at provincial and municipal level is
identified as a serious bottleneck to delivery, and will
require urgent attention, as shown in Table 1. The
question of whether three tiers of government and
responsibility for the road infrastructure is an effective
and efficient management structure also need to be
urgently reviewed and addressed. The question that must
be asked is: "Can the roads sector be better managed
with two tiers of responsibility by increasing the network
of the Road Agency and strengthening the municipalities
with remaining capacity from the provinces.
The capacity problems at provincial level were presented
in a survey of provincial transport departments carried
out by National Treasury in August 2006. The findings
12
Holistic, sustainable development plan
needed to resolve skills shortage in the
construction industry
Figure 1: The MediumTerm Expenditure
Framework perinfrastructure sector
for 2007-2010.With 21% of total
expenditure allocatedto the roads sector,
human capacity needswill be severely tested
By Les Sampson, CEO,Asphalt Academy
of the survey conclude that provincial DoT’s are
understaffed, with many of the existing staff being
under-qualified. Top management interferes in, rather
than guides, their provincial DoT’s by forcing
inappropriate staff members, consultants, contractors
and/or projects onto them. In addition, current legislation
creates a generally negative environment and
departmental systems need to be streamlined to improve
effective and efficient delivery.
Table 1: Skills profile in provinces and municipalities
Sampson’s paper concludes that a coordinated approach
to skills development and capacity building in the road
sector is an essential prerequisite to improving the
efficiency and effectiveness of road sector delivery.
Typical strategies that will need to be considered are:
• Recruitment of foreign professionals;
• Improving the throughput at tertiary institutions;
• Fast tracking mentoring towards professional
registration;
• Promotion of the industry to encourage the study
of engineering at schools level;
• Review of all qualifications and training
interventions at all levels to ensure they address
industry needs.
In the short term, the recruitment or secondment of
foreign experts through competitive remunerations
packages is a reality, and appears to be the only way to
meet the immediate demands placed on the industry.
The inescapable conclusion, as stated earlier, is that in
the longer term, a holistic, sustainable skills
development plan is required to satisfy the needs of both
the private and the public sector. While the plan should
be a national one mandated by the Department of
Transport and supported by all sectors of the industry,
from a realistic capacity perspective it is unlikely that
this will be developed and implemented quickly unless
driven by the private sector in support of government
objectives and targets.
13
Skills categoryProvinces Municipalities
Percentage Number Percentage Number
Legislators, senior officials and managers 1,5 615 0,3 126
Professionals 1,1 451 1,2 504
Technicians and associate professions 5,2 2 132 7,0 2 940
Clerks 8,1 3 321 14,1 5 922
Semi-skilled workers 36,3 14 883 22,8 9 576
Elementary occupations 47,8 19 598 54,6 22 932
Total 100 41 000 100 42 000
Figure 2: The numberof universities,universities of
technology and CETAaccredited serviceproviders offering
courses andqualifications relatedto the roads sector
In its ongoing pursuit of excellence in bituminous
products Sabita will sponsor research for the
development of a test protocol to assess the long
term durability of binders. This action was
prompted by the generally acknowledged need to
develop such a test in addition to the short term ageing
assessments currently covered in the national
specification. Additionally, there appears to be no
current international standard readily transferable to
the South African situation, especially for spray seals.
The research project is conducted and managed by
Tosas with the assistance of Sasol Technology Fuels
Research and Natref.
This article examines the critical factors that influence
the durability of bitumen and which define the need
for undertaking such a project.
Properties of bitumen
Bitumen used for road construction is derived from the
refining of crude oil during which the more volatile
components are distilled into various fuel components.
The heavy residue from the atmospheric distillation
process is further distilled under vacuum into oily
fractions which are cracked and chemically converted
into high value fuel feedstock. The residue of the
vacuum distillation column is then typically classified
as straight run bitumen.
The properties of this vacuum residue are thus
dependent on the source of the crude oil and the nature
of the crude refining process. The viscosity or
hardness of the vacuum distilled residue is often
increased by air blowing or, at some refineries, by the
addition of propane precipitated asphaltenes - a
by-product of the lubricant refining process.
Consequently it is evident that bitumen manufactured
from different crude sources and/or by different
refineries will have unique properties.
Ageing
Bitumen’s behaviour changes over time as it ages.
Due to its chemical nature, bitumen stiffens
immediately after application and, on cooling down,
forms hydrogen bonds between the different
components. Also, over time, the more reactive
components are converted to form larger molecules,
thus increasing the hardness of the bitumen.
The reactivity of the bitumen components increases
when exposed to oxygen, ultra violet light and high
temperatures. The bitumen’s durability can thus be
expressed in terms of the change in the flow properties
or stiffness over time (Figure 1). While a certain amount
of hardening is necessary to limit deformation under
severe loading and elevated temperatures, an optimum
balance is required to minimise temperature
susceptibility over time.
The durability of bitumen is generally regarded as a
critical factor in the satisfactory performance of spray
seals and asphalt layers, and often premature fatigue and
thermal cracking of a bituminous layer is ascribed to
inadequate durability of the bituminous binder.
Test methods
To simulate the ageing that takes place during
production of hot mix asphalt, bitumen is aged in the
laboratory by exposing thin films to high temperatures
and oxygen. As is the case with AASHTO and CEN,
this is achieved by carrying out the Rolling Thin Film
Oven Test (RTFOT), which is also a requirement of the
SANS 307 specification.
Long term ageing is not addressed in this test, and other
laboratory testing protocols are required to simulate the
in-service ageing that occurs over years on the road.
SUPERPAVE and the PG specification system in the
USA introduced the Pressure Ageing Vessel (PAV), and
in Europe the Belgian Road Research Centre developed
the Rotating Cylinder Asphalt Tester (RCAT) to assess
the durability of bitumen in-service. The ageing
mechanism employed in the PAV was found to differ
from those actually occurring on the road, and places a
question mark over the usefulness of this test.
While it is widely believed that the RCAT method
reflects more closely in situ ageing in the pavement, it
has a disadvantage with regard to time i.e. it takes longer
to perform than the PAV test. Despite the usefulness of
the RCAT, CEN has yet to adopt parameters for
durability in the EN bitumen specifications.
One should always note that the tests described above
relate to the ageing of bituminous binders in asphalt
layers. As the majority of surfaced roads in South Africa
consist of spray seals, a suitable method related to the
mechanisms and consequences of ageing for this type of
application may need to be developed. Australia has
recognised this need and has adopted an ageing protocol
that simulates ageing in seals as opposed to asphalt.
They claim to have developed a reliable prediction
model based on 25 years of field and laboratory studies
that can differentiate between bitumen with poor and
14
Sabita funds research to develop a
bitumen durability protocolBy Johan Muller, Technical Manager, Tosas
adequate durability properties.
Other factors affecting durability
Apart from the chemical characteristics of the bitumen,
which are crude dependent and process related, the
conditions under which it is handled will also affect its
durability. Notwithstanding the production of durable
bitumen at the refineries, the following practices, to
name but a few, could have an adverse impact on the
durability of the bitumen:
Modification
Modification of bitumen, as in the case of bitumen
rubber, has been shown to increase the durability of the
bituminous binder used in asphalt and seal applications.
In the latter case, the carbon black which is present in
the rubber crumbs is known to improve the durability of
the binder. Also, given that bitumen rubber is a highly
viscous binder, it allows a much higher binder content to
be applied with a lower risk of bleeding, which in turn
renders a much thicker binder film.
Durability protocol for South Africa
Research work has recently been conducted by the CSIR
to develop a bitumen durability test for South Africa.
The protocol developed will be validated in a further
project and, if necessary, refined. The project entailed a
comparison of the ageing of 60/70 bitumen, subjected to
the RTFOT and the PAV tests. The results obtained
require a modification to the RTFOT procedure to
correlate the results with the requirements of the PG
classification system. Verification and comparison of
the chemical composition of the aged residues from
these tests and actual in-service aged bitumen will
shortly be conducted. This assessment will provide
valuable guidance for the future direction of this
research project, which will ultimately enable the
Industry to adopt a test protocol for measuring bitumen
durability in the laboratory that is validated by field
experience. To this end discussions are under way with
the Australian Road Research Board for joint
cooperation given their past work experiences with
binder durability in seals.
15
Conceptual ageing simulation to identify binder suitability
• Prolonged exposure to high temperatures during
heating;
• The type of heating system used e.g. thermal hot
oil versus flame tubes;
• The dwell-time that the bitumen is directly
exposed to the heat source;
• The duration of mixing bitumen with super
heated aggregate during asphalt production;
• The design of the asphalt mixing system with
respect to air flow and heat transfer;
• Asphalt mixes which have low binder contents,
thin binder film thickness and high air void
contents
16
17
Incentive to Contractors
Pay Factors are increasingly being used in the USA and
elsewhere to improve the quality of HMA. The intention
of the introduction of Pay Factors is to provide
additional payment as an incentive to contractors who
provide a superior quality product, while at the same
time penalising substandard work by reduced payments.
The application of a system of Pay Factors is also central
to an improved process for submitting and approval of
HMA mixes and facilitating the process of modifying
mix composition dictated by variations in supplies
of aggregate.
It is envisaged that the process of implementation
will initially provide a set of rules for the
calculation and application of Pay Factors in
practice, followed by possible adjustments and
amendments – depending on the outcomes
achieved and further desired outcomes.
The intention is that the Pay Factors will be
calculated based on the results of tests that form
part of the current requirements of specification
and approval processes, and will be incorporated in
the payments by the client to the contractor.
Intermediate arrangements between paving
contractors, hot mix manufacturers and aggregate
producers will be subject to their own
inter-company arrangements.
Scope
In South Africa the application of pay factors to
date has been limited to bonus penalty schemes
applied to the evenness or riding quality of the
HMA surface.
However, typical South African specifications also
provide for partial payment where certain specification
limits are only partially met. Whereas these schemes
could be considered to be a form of Pay Factor, they
lacked in providing an incentive of additional payment
for superior quality asphalt.
Four Pay Factors are proposed:
• Riding Quality – not covered in this article;
• Density – to deal with both the uniformity and
degree of compaction achieved;
• Binder content – to cover uniformity and degree
to which the binder content complies with the mix
design target values;
• Aggregate gradation – to accommodate the
uniformity and degree to which the total grading
envelope differs from the target grading
developed for the mix. The system assumes that a
single uniform source is used for the project and a
different mix design and related targets must be
set if more than one source will be used for the
duration of the project.
It is felt that the Pay Factors mentioned cover all key
elements of the final product and related quality. In this
sense “voids in the mix” are not included as they
represent a result of the aggregate grading (and other
characteristics) and binder content.
DENSITY
Figure 1 illustrates a range of suggested Pay Factors for
density which are non-linear for three groups depending
on the variability of the test results. At this stage it is
suggested that the standard deviations of the percentage
relative compaction for the grouping of Low, Medium
and High variability for each lot be set as follows:
Low: <1,3
Medium: >1,3 <1,7
High: >1,7
It should also be noted that the proposed Pay Factor cuts
off at 103% of target density, which in normal practice
would be approximately 96% of maximum theoretical
density (MTD). It is debatable whether a bonus should
be paid for densities higher than that value, as this may
encourage over-compaction and possibly crushing of the
Proposed pay factors for hot mix asphalt
quality control
Figure 1: Existing and proposed Pay Factors - Density
By Arthur Taute, MD, Vela VKE Consulting Engineers
aggregate. In particular, at 98% of MTD there would be
insufficient voids for expansion of the binder and
increased deformation would result.
If any individual value in the lot is less than 98% of the
minimum specified density, no Pay Factor in excess of 1
will be applied.
BINDER CONTENT
Figure 2 shows the proposed payment categories for
different variability classes.
These graphs can be represented by the formula below
for a range of binder content deviations and standard
deviations:
PFb = 1.15 - 0.25Sb – (2+2.75Sb) B2
(max 1.1 min 0.85)
where:
PFb = Pay Factor for binder,
Sb = standard deviation of binder content
for the Lot
B = average binder content deviation of the Lot
from specification.
The present COLTO specification allows for conditional
acceptance with a minimum payment of 67%. However,
it is felt that in such cases the quality of the asphalt will
be sufficiently poor to justify rejection and replacement;
hence the Pay Factor cut-off shown above has been
increased to 85%.
While the Pay Factor applies to average values, the
problem of individual values lying outside the required
range needs to be addressed. It is proposed that, if any
individual value within a lot lies outside +- 15% of the
target binder content, no Pay Factor in excess of 1 will
apply. Furthermore, for continuously graded asphalt, if
more than 15% of the test values are outside a 0.4%
deviation the lot should be rejected as per the current
COLTO specification.
AGGREGATE GRADING
The process proposed involves the determination of a
weighting between 1 and 2 for each of the sieves being
controlled for the mix with the sum of all the weightings
being equal to 12.
The standard deviation of the percentage passing each
sieve for the lot is multiplied by its selected weighting.
These weighted standard
deviations for each sieve are
summed to obtain the Sum
Weighted Standard Deviations
(SWStd) which are categorised as
follows:
SWStd <12 - low variability
SWStd 12-17 - medium variability
SWStd >17 - high variability
The absolute value of the
differences between the lot
average of percentage passing
each sieve and the target value for
each sieve is then multiplied by
the weighting determined above.
The weighted differences for all
sieves are then summed to obtain
the weighted sum of the
differences (WD).
CALCULATING THE PAYFACTOR
The relevant Pay Factor is then determined by using the
graph illustrated in Figure 3, or by applying the
following formulas:
High variability PFg= 1.06 – 2 x WD (max 1.0 min 0.85)
Medium Variability PFg= 1.12 - 2 x WD (max 1.05 min 0.85)
Low variability PFg= 1.20 – 2 x WD (max 1.10 min 0.85)
It is proposed that where more than one Pay Factor is
applied to the Lot the final Pay Factor should be the
product of the Pay Factors being applied. This final Pay
Factor should be applied to the amount calculated from
the rate tendered for paving HMA and the quantity in the
lot being assessed.
This will mean that a maximum Pay Factor will be 1.33
where all three individual Pay Factors are equal to 1.1,
which is considered to be substantial.
ADJUSTMENT FOR PROJECTVARIABILITY
An inconsistency may occur where individual lots with
high Pay Factors are followed by poorer quality lots with
much lower Pay Factors which will ultimately have an
adverse effect on the life of the facility.
18
Figure 2: Proposed and existing Pay Factors - Binder Content
In this regard it is proposed that
the Pay Factors applied for all
lots within each lane kilometre be
assessed, and that the combined
Pay Factor for each lot within that
lane kilometre be multiplied by
the minimum combined Pay
Factor for all lots within that lane
kilometre where such minimum is
less than 1.
Table 1:
Proposed density Pay Factors
19
As measured average
relative compaction equal
to or less than
As measured standard deviation of relative
compaction
�1,3>1,3
�1,7>1,7
104,00
103,01
103,00
102,60
102,00
101,80
101,60
101,40
101,20
101,00
100,80
100,60
100,40
100,30
100,20
100,00
99,90
99,80
99,70
99,60
0,800
0,800
1,000
1,080
1,100
1,096
1,090
1,080
1,071
1,060
1,049
1,035
1,020
1,010
1,000
0,950
0,925
0,895
0,850
0,000
0,800
0,800
1,000
1,060
1,080
1,076
1,070
1,062
1,053
1,043
1,032
1,018
0,995
0,975
0,950
0,895
0,850
0,000
0,000
0,000
0,800
0,800
1,000
1,040
1,055
1,051
1,044
1,036
1,026
1,014
0,990
0,950
0,895
0,850
0,000
0,000
0,000
0,000
0,000
0,000
Figure 3: Proposed Pay Factors - Aggregate Grading
Local Events
BitSafe Train-the-Trainer course: 4-6 August, Gauteng.
Eastern Cape Roads Summit, 6 - 8 August, Qunu, Eastern Cape.
SAT report-back seminar on 4th E&E Congress, 20 August, Pretoria.
SAT report-back seminar on 4th E&E Congress, 3 September, Cape
Town.
SAT report-back seminar on 4th E&E Congress, 4 September,
Durban.
Bitumen Quality Management Course, 7 - 9 October, Vanderbijlpark.
IMESA Conference, 28 - 31 October, Bloemfontein.
RPF, 11 - 12 November, CSIR Conference Centre, Pretoria
International Events
13th AAPA HSE Conference, 10 - 12 August 2008, Melbourne,
Australia.
ISAP International Symposium on Asphalt Pavements and
Environment, 18 - 20 August, Zurich, Switzerland.
4th International Symposium on Asphalt Emulsion Technology, 24 -
26 September,Virginia, USA.
International Warm Mix Asphalt Conference, 11 - 13 November
Nashville, Tennessee, USA.
LOCAL AND INTERNATIONAL EVENTS - 2008
Notwithstanding several death sentences, the
Marshall mix design method is still alive and
well, and often continues to confound
common sense, especially in correlating field
and laboratory densities over a range of paved layer
thicknesses.
Discrepancies that need to be (but often are not) taken in
account are:
• Laboratory briquettes are compacted to a finished
thickness of 63.5mm; wearing courses are paved
in much thinner layers, while bases are paved
much thicker;
• Laboratory specimen preparation takes place
under impact compaction while confined in a
mould at a temperature in the region of 140oC
(for 60/70 penetration grade bitumen); on site
roller compaction takes place on a mat that offers
little confinement while the temperature may
range from 140oC to as low as 80
oC.
As the measured in-place density is compared with the
laboratory density, we have to establish a correlation
between the laboratory density results and what is
achievable on site. The well-known COLTO correlation
of 97% Rice's VIMs was established by experience of
what should be possible on site for a 40mm thick
wearing course.
However, this is a loose correlation that will change with
different mat thicknesses, for the following reasons:
• Thick mats are easier to compact than thin ones
for two reasons:
� They retain heat longer;
� There is less internal friction.
• Better lubrication i.e. higher bitumen contents are
thus needed for thin vis-à-vis thick layers.
How does this influence a fixed correlation such as 97%
Rice's VIMs? For thick mats it is easy, but for thin mats
much more difficult.
Site experience shows that:
• It is easy to get 94% of maximum theoretical
densities (MTD) on thick BTB;
• It is more difficult to get 92% MTD on 40mm
COLTO medium; and
• It is even more difficult to achieve this density
when COLTO medium is only 35mm thick.
Suggested density specifications:
Specifying a fixed density correlation such as 97%
Rice's VIMs in COLTO is flawed, because for thick
mats it is (too) easy, but for thin mats it is (very)
difficult.
20
A paving contractor's view of
laboratory density vs field densityBy Julian Wise, Director, Zebra Bituminous Surfacing
REQUIREMENTS
It is becoming more common to ignore the COLTO
requirements and specify the following requirements:
1. A set minimum density for a particular application,
e.g. 93% of MTD for 40mm wearing course, to
ensure a consistently dense mat, with low
permeability. The mixes must of course be designed
so that this density is achievable;
2. A higher minimum density for thick mats, based on
what experience has proven attainable, e.g. 93.5%
Rice's for 80mm BTB or LAMBS;
3. A maximum density for thick mats, e.g. 96.5% of
MTD for 80mm BTB, to prevent over-compaction;
4. For thin wearing course mats e.g. 25mm, low
permeability is essential. Thus a minimum of 92% of
MTD is desirable, but again the mixes must be
designed to achieve the inter-related properties of
good density and low permeability.
Sabita has revised its best practice guideline on
the design and construction of bitumen rubber
asphalt wearing courses.
The original document, known as Sabita Manual 19,
was compiled by the Modified Binders Technical
Committee of the Bituminous Material Liaison
Committee headed by Bob Kingdon, and first
published in 1997. While the original manual was
designed as a specification document, the revised
document has been written as a best practice guideline
to assist practitioners with the design, manufacture,
handling and construction of bitumen rubber asphalt.
WET BLEND
The manual only covers the ‘wet- blend’ method of
preblending the rubber crumb into the bitumen prior to
mixing with heated aggregate, and not the ‘dry-blend’
method of adding the rubber crumb as a filler during
the asphalt mixing process.
The document incorporates the latest specifications on
bitumen rubber as per the latest revised Technical
Guideline 1 on modified binders. It also makes
recommendations on asphalt gradings and properties for
continuously, open and semi-open graded mixes based
on latest field experience.
The manual covers the following areas with regard to
bitumen rubber asphalt:
• Component material requirements;
• Occupational health, safety and environmental
issues;
• The design process including quality control;
• Mixing and application plant requirements;
• General precautions with regard to handling and
application.
The draft revised manual is available on the Sabita
website. This document was workshopped in Pretoria,
Durban and Cape Town through the Society for Asphalt
Technology (SAT) during May and June this year.
The valuable feedback received during these workshops
will be incorporated into the draft before the second
revision is published in the second half of 2008.
21
Bitumen Rubber Asphalt: draft best
practice guideline now available
The Road Pavements Forum Task Team on
recycled asphalt pavements (RAP) has
agreed on an action plan to facilitate a
paradigm shift in the roads sector's approach
to optimising the use of RAP in the manufacture of
new mixes.
The plan emerged from a meeting of the Task Team in
Durban on April 24 2008, its first meeting since a
resolution was passed at the RPF in November 2007.
The initiative to develop best practice guidelines for
the use of RAP in HMA was promulgated at
CAPSA'07 and a series of SAT seminars.
The outline objectives of this paradigm shift are to:
• facilitate the treatment of RAP as a valuable asset
of the State;
• promote RAP as a viable alternative aggregate
source - i.e. a linear quarry;
• stockpile RAP for general use on future projects;
• optimise the use of RAP;
• promote RAP as a material providing a
competitive advantage.
ACTION PLAN
The task team adopted the following plan of action to
achieve the above objectives:
• Use the draft TRH21: Hot mix recycling (1996) as
the base guideline document and update it with
the latest international best practice;
• Identify appropriate international best practice
documents for consideration as reference
documents;
22
CONCERTED MOVE TOWARDS
OPTIMISING THE USE OF RAP
IN HMA MANUFACTURE
• Agree on the content of TRH21, and confine the
scope of the document review exclusively to the
recycling of RAP in the manufacture of HMA.
The document will not contain contract
specifications, which would be incorporated into
a revised COTO document. However, it was
agreed that SANRAL would incorporate new
proposals in their pro forma project
specifications;
• Sabita has appointed Tony Lewis Consulting to
review the references and draft changes, and to
re-write the document. Specialist peer reviewers
will review each section of the document.
MISCONCEPTION
"There is a perception that HMA manufactured using
RAP is inferior to that made using virgin aggregate,"
Sabita CEO Trevor Distin said. "This is completely
untrue, and part of the task team's job will be to correct
this misconception."
It has therefore been decided that HMA should be
divided into three categories based on, inter alia, the
percentage of RAP used in any mix, namely:
• <15% RAP;
• >15 - <30% RAP;
• >30 % RAP
Each category of HMA would
have a regime of asphalt end
properties irrespective of the
percentage of RAP in each
class. The risk, application,
constraints and protocols for
each class would be defined to
assist the specifier or client.
Protocols will
now be
developed for
reclaiming,
stockpiling and
processing
RAP, and
should focus
on the
following:
Milling of RAP
• Investigate in situ layers;
• Selected premilling.
Stockpiling of RAP
• Demarcate dedicated stockpiles;
• Minimise moisture content of RAP;
• Avoid segregation and consolidation.
Processing of RAP
• Screen RAP into different sizes;
• Fractionating of RAP when using >15%;
• Plant limitations
� Type of plant;
� Where the RAP is fed into the mixing process.
The final content of the document should cover the
following (peer reviewers are shown in brackets):
• Introduction;
• Pavement recycling;
• Use of RAP in HMA plant recycling;
• Feasibility of recycling (Dennis Rossmann & Rob
Lindsay);
• Mix design (Eric Denneman, Derick Pretorius &
Herman Marais);
• Reclaiming of RAP (Wolf
Reusch & Gary Catin);
• Stockpiling of RAP (Eric
Lathleiff & Wynand Nortje);
• Mixing & plant (Bennie
Greyling & Gary Catin);
The first draft of the new TRH21
is scheduled for presentation at
the November 2008 meeting of
the RPF, and for publication as a
best practice guideline by January
2009. Feedback from the industry
on the document
will be sought
through
workshops to be
organised by the
Asphalt Academy.
23
Client
Dennis Rossmann
Adreo Brits
Rob Lindsay
Eric Lathleiff
Krishna Naidoo
Engineers
Derick Pretorius
Tony Lewis
Nicol van der Walt
Benoit Verhaeghe
Manufacturers/
Contractors
Bennie Greyling
Herman Marais
Wynand Nortje
Gary Catin
Membership of the RPF Task Team on HMA recycling, classified as
representative of client bodies, engineers and manufacturers/contractors,
was confirmed as:
Promoting
RAP as a
viable alternative
aggregate source
24
The Sabita website, developed in 2000, was
recently revised and updated in line with the
reimaging of Sabita’s corporate identity. The
site has been redesigned to maximise
information transfer and communication, and to
facilitate an informed bituminous products industry.
The website consists of the home page which carries a
short précis of Sabita’s activities, as well as breaking
news items. Prominently on the home page is an article
worthy of attention on the signing of the Global
Strategic Alliance Pavement Associations agreement.
The “About Sabita” page handles statutory
information as well as a list of members and a
regularly updated “Members Benefit” document,
which also contains a membership application form.
Council bulletins with snippets of information about
recent council meetings, held as well as Members
Briefs, are also available on this page.
The “HSE” page contains a full transcript of the Sabita
HSE Charter, to which all Sabita’s members subscribe
and adhere. Bitumen safety training information and
information on the incident reporting (BitInRep) and
certification (BitCert) schemes can also be found here.
Copies of previous Digests, Asphalt News and Annual
Reports can be downloaded from the “Publications”
page. Of all the manuals produced by Sabita to date,
pdf copies of manuals 2, 5, 6, 7, 11, 12, 14, 17, 18,
19(draft), 22, 24, 25, 26 and 27 are also downloadable
free of charge. Using the order form, copies of all
manuals, DVDs and other training aids can be ordered
directly off the web.
The “News/Reports” page contains information on new
members, upcoming events, articles on HSE and delivery.
Copies of Sabita technical papers and reports are also
available, as well as statistics on the local yearly bitumen
volumes backed up by EAPA information on asphalt
volumes in Europe.
The “Links’ page provides links to the web pages of national
and international bodies relevant and of interest to the
southern African bituminous product industry.
Also available is a “Contact Details Updater” which
enables interested persons to update their contact details
for insertion into the Sabita database. This function is
invaluable in keeping the Sabita database up-to-date, and
readers are urged to make use of this function.
The “Members Only” section, available to Sabita
members only, requires a username and password for
access. This page carries the SAFCEC newsletters and
daily tender documentation, the Sabita Safety file (draft)
and research documentation not yet in the public domain.
Readers are urged to contact Sabita with items they
would like to see on the website as well as any
constructive criticism. Any advice will receive Sabita’s
attention and if feasible will be acted upon. With the
assistance of interested persons, the Sabita website can
only be improved upon.
25
Sabita website upgraded to
maximise information transfer
26
Sabita’s Digest 2007, a comprehensive review of
the proceedings and presentations of
CAPSA’07, is now being prepared for
publication.
As is now customary, the issue of the Sabita Digest
following the holding of a Conference on Asphalt
Pavements for southern Africa (CAPSA) features the
content and outcomes of the conference. Whereas in the
past the topic matter covered a summary of papers and
discussions, highlighting important outcomes, this issue
differs in that it attempts to present the conference
content in terms of the goals set within the context of the
conference theme Consolidating Best Practice. This
issue therefore endeavours to analyse the outputs of
CAPSA’07 and assess how well the southern African
practice has progressed in finding solutions to specific
questions raised over the decades since inception of
CAPSA in 1969.
New publications
With the increasing use of thin layer asphalt to surface
residential streets, Sabita has now developed and
published Manual 27: Guidelines for thin layer hot
mix asphalt wearing courses on residential streets.
This follows a series of workshops hosted by SAT to introduce the
alternative methods and procedures to practictioners before
finalising the guideline document for publication as a best practice
Sabita manual.
The purpose of this manual is to present a set of general guidelines
to assist clients, consultants, paving contractors and asphalt
manufacturers to design, construct and manage the quality of thin
layer hot mix asphalt wearing courses on streets carrying light
(predominantly passenger car) traffic, mostly in residential areas.
In these locations the layers would normally be expected to meet
functional requirements, rather than to contribute significantly to
the structural capacity of the road pavement.
The guidelines presented in this document do not cover high speed,
high volume applications served by e.g. stone mastic asphalt, or
proprietary products such as ultra-thin friction courses. While it is
evident that such proprietary products, possibly accredited by
Agrément South Africa and covering a wide range of service
applications, are increasingly entering the SA market, it is not the
intention of this manual to capture such practice.
The current application in the design and construction of thin layer
asphalt of procedures more germane to layers that contribute to
structural capacity are critically appraised and, where appropriate,
alternative methods and procedures proposed in pursuit of a more
uniform, rational approach to the design and construction of such layers.
Currently in South Africa the majority of thin layer asphalt has
been laid at thicknesses of between 20mm and 30mm. More
recently proprietary products have been laid at thicknesses of less
than 20mm in a variety of applications.
Often layers of specified thickness of 25mm or less are referred to
as ultra-thin layers. As these are also expected to serve functional
needs, they are considered in this guideline as a subset of thin layer
asphalt.
This document covers the following topics:
• A review of current practice in the design and construction
of thin layer asphalt in SA and abroad, and
recommendations on appropriate applications for such
layers,
• The influence of existing pavement conditions;
• A review of risks involved;
• Guidelines on mix selection and design;
• Guidelines on construction; and
• Quality control pertinent to thin layer asphalt.
Copies of Manual 27 may be ordered from the Sabita offices, but a
pdf version may also be downloaded free of charge from
www.sabita.co.za
Sabita launches guideline
for thin layer asphalt
The issue includes a
comprehensive analysis of the
road sector’s human capacity
needs, and examines methods to
counter the skills shortage which
increasingly hampers delivery.
Included in this edition is a
closing chapter offering
recommendations, based on the
outcomes of CAPSA’07, on the
way forward.
27
The Working safely with bitumen DVD, now
available from Sabita, has been designed to introduce
both new and experienced workers to the hazards of
working with bitumen and how these hazards can be
avoided.
The DVD is supplementary to COSHEC’s already
comprehensive range of materials and publications
aimed at entrenching global standards of safety, health
and environmental conservation in our industry. It
should be used in conjunction with the BitSafe
materials detailed on Sabita's website,
www.sabita.co.za
The DVD clearly explains the need for the diligent use
of Personal Protective Equipment, worker
understanding of warning signs, the dangers of using
cutters with hot bitumen, the proper use of fire
extinguishers and many more procedures vital to worker
health and safety.
New DVD identifies hazards of
working with bitumen
August4 - 7 Materials Testers Course - Aggregates Gauteng
4 - 6 BitSafe Train-the-trainer course Gauteng
12 - 13 Manufacture application and construction of HMA KZN
19 - 21 Design application and construction of seals KZN
26 Bituminous binders for road construction and maintenance -
Introductory course Nelspruit
27 - 28 Bituminous products in practice Nelspruit
September1 - 4 Materials Testers Course - Aggregates KZN
2 Bituminous binders for road construction and maintenance -
Introductory course Cape Town
9 - 10 Manufacture application and construction of HMA Port Elizabeth
29 - 2 October Materials Testers Course - Aggregates Western Cape
October
7 - 9 Quality management of bitumen Vaal Emerald Casino
28 Bituminous binders for road construction and maintenance -
Introductory course Port Elizabeth
27 - 31 Materials Testers Course - Concrete Gauteng
November
4 - 6 Design application and construction of seals Nelspruit
24 - 28 Materials Testers Course - Concrete KZN
All Asphalt Academy course information is available on the website http://asphaltacademy.co.za
ASPHALT ACADEMY COURSE SCHEDULE:
AUGUST - DECEMBER 2008
Aseries of integrated
DVDs, presenting the
combined video, audio
and PowerPoint
presentations of the best practice
papers published at CAPSA'07 is
now available through the Asphalt
Academy.
The series, which contains
outstanding educational material,
will be distributed to tertiary
educational institutions free of
charge.
Those who attended CAPSA'07 can
use the series to relive and
remember the excellent papers and
presentations given at the
conference. Those who could not
attend can now, for the first time,
experience at first hand the
excellent material presented at the
conference.
As an interim conference, CAPSA'07 was organised to
provide a unique benchmark of current best practice in
the following four focus areas through the presentation
of invited papers by local and international experts:
• Structural pavement design;
• Hot mix asphalt;
• Surfacing seals;
• Bitumen stabilisation.
The compilation of the individual lectures provide a
unique collection and record of practice as at September
2007. The DVDs may be ordered through the Asphalt
Academy website at: www.asphaltacademy.co.za
28
CAPSA'07 DVD series now available
29
NEW
MEMBERS
Letaba Lab (Pty) Ltd is a civil engineering
laboratory established in 1986. It has grown
into a company with branches in Nelspruit,
Lydenburg and Polokwane.
Now registered in Mozambique, the company originated
by sourcing its personnel from various geotechnical and
consulting engineers, and is affiliated to The South
African Association of Civil Engineering Laboratories.
Services rendered include geotechnical and structural
pavement designs and the testing of materials for design
and construction purposes. Typical projects are: Centre line
investigations; borrow pit exploration; concrete and asphalt
mix designs; road pavement designs; site laboratories;
geotechnical investigations; site supervision; soils mapping;
aggregate investigations and seismic refraction surveys.
Letaba Lab employs and trains local personnel in the
field-testing methods such as nuclear density meters, soil
replacement tests and drop weight cone penetrometer
tests. Local laboratory personnel are trained in all
aspects of laboratory testing, and casual labour used
during field work are employed from local communities
to promote skills development and employment
opportunities.
The various labs are linked and readily make resources
available to one another. Specialist support can be called
for by any of the branches if required. Letaba Lab also
has standing arrangements with consultants specialising
in engineering, surveying, geotechnical and other civil
engineering related disciplines. These include specialised
testing by other supporting organisations such as SABS,
CCI and CSIR.
Letaba Lab Nelspruit is in the process of acquiring ISO
17025:2005 accreditation.
Established in 2003, Meckow Ltd specialises in
the sourcing and supply of plant, equipment and
spare parts for the construction and
infrastructure industry in the developing world.
Recent African experience has Meckow dealing with:
• asphalt plants, asphalt pavers and bitumen
handling equipment;
• concrete plants and concrete pavers;
• water filtration systems;
• crushing and screening equipment for the
aggregate market; and
• spare parts and supply of safety-related
equipment.
Meckow has close relationships with a wide range of
European and American suppliers which ensures the best
prices and lead times for our customers.
Meckow also offers consultation services to customers
who require project evaluation or audits of plants, and
are able to recommend measures to improve production
and reliability.
Meckow can also provide spare parts packages to solve
plant and equipment problems.
In 2007, Meckow SA was established and is proud to
have been accepted into Sabita's membership.
Meckow currently has a wide customer base in Western
and Central Africa and looks forward to continuing its
forays into the southern African market.
Queries about Meckow services may be directed to
30
AG Thomas (Pty) Ltd P O Box 100 Manzini M200 Swaziland Tel +268 5184499 Fax +268 5186363
AJ Broom Road Products (Pty) Ltd P O Box 16421 Dowerglen 1612 Tel 011 4543102 Fax 011 4542790
Akasia Road Surfacing (Pty) Ltd P O Box 259 Bon Accord 0009 Tel 012 5620921 Fax 012 5620530
Asphalt Services cc P.O. Box 1765 East London 5200 Tel 043 7451014 Fax 043 7451245
Astec – Asphalt Technology P O Box 589 Rothdene 1964 Tel 016 3621310 Fax 016 3623024
Bitumen Constr. Services (Pvt) Ltd P O Box M78 Harare Zimbabwe Tel +263 4 305506 Fax +263 4 305507
Bitumen Supplies & Services (Pty) Ltd P O Box 1028 Sunninghill 2157 Tel 011 8039338 Fax 011 8039881
Brisk Asphalt Surfacing (Pty) Ltd P O Box 1055 Kloof 3640 Tel 031 5336883 Fax 031 5336695
Colas SA (Pty) Ltd P O Box 82 Eppindust 7475 Tel 021 5316406 Fax 021 5315514
Concor Roads & Earthworks (Pty) Ltd P O Box 8259 Johannesburg 2000 Tel 011 4952221 Fax 011 4952496
Javseal (Pty) Ltd P O Box 26317 Isipingo Beach 4115 Tel 031 9025988 Fax 031 9022457
Milling Techniks (Pty) Ltd P O Box 779 Gillits 3603 Tel 031 7929580 Fax 031 7004447
More Asphalt P O Box 2180 Durbanville 7550 Tel 021 9750784 Fax 021 9750792
Much Asphalt (Pty) Ltd P O Box 49 Eerste Rivier 7100 Tel 021 9004411 Fax 021 9004446
National Asphalt P O Box 1657 Hillcrest 3650 Tel 031 7362146 Fax 031 7361938
Nyanga Roads (Pty) Ltd P O Box 477 Botha’s Hill 3660 Tel 031 7771905 Fax 031 7771972
Phambili Road Surfacing (Pty) Ltd P O Box 145 Mkondeni 3204 Tel 033 3461982 Fax 033 3461995
Polokwane Surfacing (Pty) Ltd P O Box 288 Ladanna 0704 Tel 015 2931221 Fax 015 2931258
Power Construction (Pty) Ltd P O Box 129 Blackheath 7581 Tel 021 9071300 Fax 021 9056912
Rand Roads (div. of Grinaker LTA) Private Bag X030 Kempton Park 1620 Tel 011 9235304 Fax 011 3976294
Roadmac Surfacing (Pty) Ltd P O Box 8378 Bloemfontein 9300 Tel 051 4300404 Fax 051 4300400
Roadsmart (Pty) Ltd P O Box 30344 Tokai 7966 Tel 021 7130129 Fax 021 7130128
Roadspan Surfaces (Pty) Ltd P O Box 30550 Jet Park 1469 Tel 082 4112267 Fax 011 5188584
Spray Pave (Pty) Ltd P.O. Box 647 Alberton 1450 Tel 011 868 5451 Fax 011 900 1470
Tarspray cc Suite327,P.B.X09WeltevredenPark1715 Tel 012 6690003 Fax 012 6690110
Tarfix (Pty) Ltd P O Box 77354 Fontainebleau 2032 Tel 011 7084794 Fax 011 7084797
Tosas (Pty) Ltd P O Box 14159 Wadeville 1422 Tel 011 9021905 Fax 011 9022755
Van Wyk Tarmac cc P O Box 12535 Onderstepoort 0110 Tel 012 5611871 Fax 011 5611321
Zebra Bituminous Surfacing cc P O Box 14335 Kenwyn 7790 Tel 021 7613474 Fax 021 7971151
BP SA (Pty) Ltd
P O Box 1806, Durban 4000
Tel 031 2758867 Fax 031 2652701
Chevron SA (Pty) Ltd
P O Box 714 Cape Town 8000
Tel 021 4037242 Fax 021 4030380
Engen Petroleum Ltd
P O Box 1043, Jhb 2000
Tel 011 4806202 Fax 011 4806003
Sasol Oil (Pty) Ltd
P O Box 4211, Randburg 2125
Tel 011 8899773 Fax 011 8899859
Shell SA Marketing
(Pty) Ltd
6 Ipivi Road, Kloof 361
Tel 031 5711000 Fax 031 7646208
Total SA (Pty) Ltd
P O Box 579, Saxonwold 2132
Tel 011 7782376 Fax 011 6876381
SPONSOR MEMBERS
ORDINARY MEMBERS
31
S
A
B
I
T
A
M
E
M
B
E
R
S
Africon Engineering Int. (Pty) Ltd P O Box 905 Pretoria 0001 Tel 012 4272634 Fax 012 4272050
Afrisam SA (Pty) Ltd P O Box 6367 Weltevreden Park 1715 Tel 011 6705500 Fax 011 4759326
Arcus Gibb (Pty) Ltd P O Box 3965 Cape Town 8000 Tel 021 4699172 Fax 021 4245571
Asch Professional Services (Pty) Ltd P O Box 51121 V&A Waterfront 8002 Tel 021 4184988 Fax 021 4195187
BKS (Pty) Ltd P O Box 3173 Pretoria 001 Tel 012 4213667 Fax 012 4213679
CapePeninsulaUniv.ofTechnology P O Box 652 Cape Town 8000 Tel 021 4603074 Fax 021 4603710
Dick King Lab Supplies (Pty) Ltd P O Box 82138 Southdale 2135 Tel 011 4999400 Fax 011 4936349
GMH/CPP Cons. Eng. (Pty) Ltd P O Box 2201 Randburg 2125 Tel 011 4620601 Fax 011 4620672
Goba (Pty) Ltd P O Box 180 Sunninghill 2157 Tel 011 2363331 Fax 011 8078535
HHO Africa P O Box 6502 Roggebaai 8012 Tel 021 4252870 Fax 021 4194689
Iliso Consulting (Pty) Ltd P O Box 686 Gillits 3603 Tel 031 2662600 Fax 031 2662616
Jeffares & Green (Pty) Ltd P O Box 1109 Sunninghill 2157 Tel 011 8070660 Fax 011 8071607
Kantey & Templer (Pty) Ltd P O Box 3132 Cape Town 8000 Tel 021 4059600 Fax 021 4196774
Kaymac (Pty) Ltd T/A Kaytech P O Box 116 Pinetown 3600 Tel 031 7172300 Fax 031 7023173
Kwezi V3 Engineers (Pty) Ltd P O Box 36155 Menlo Park 0102 Tel 012 4256300 Fax 012 4601336
Lafarge Industries SA (Pty) Ltd P O Box 139 Paarden Eiland 7420 Tel 021 5088000 Fax 021 5088120
Lidwala Cons. Engineers (Pty) Ltd P O Box 2930 Nelspruit 1200 Tel 013 7532864 Fax 012 7532816
Namibia Technical Services cc P O Box 30623 Windhoek Namibia Tel +264 61 215324 Fax +264 61 215327
Ninham Shand (Pty) Ltd P O Box 1347 Cape Town 8000 Tel 021 4812400 Fax 021 4245588
PD Naidoo & Assoc. (Pty) Ltd P O Box 7786 Roggebaai 8012 Tel 021 4182929 Fax 021 4186440
Rankin Engineering Consultants P O Box 50566 Lusaka Zambia Tel +260 1 290562 Fax +260 1 293156
Sasol Technology Fuels Research P O Box 1 Sasolburg 1947 Tel 016 9604068 Fax 016 5224835
Sasol Wax SA (A div. of SCI) Chemcity 2 P O Box 1 Sasolburg 1947 Tel 016 9602126 Fax 016 5222063
Specialised Road Techn. (Pty) Ltd P O Box 15324 Westmead 3608 Tel 031 7004510 Fax 031 7003165
SSI Eng. & Env. Cons. (Pty) Ltd P O Box 867 Gallo Manor 2146 Tel 011 7986051 Fax 011 7986005
TPA Consulting (Pty) Ltd P O Box 1575 Westville 3630 Tel 031 7651907 Fax 031 7652551
Tshepega Engineering (Pty) Ltd P O Box 33783 Glenstantia 0010 Tel 012 6652722 Fax 012 6655597
Unitrans Fuel & Chem. (Pty) Ltd P O Box 31 Tableview 7439 Tel 021 5510636 Fax 021 5511996
Vela VKE Cons. Eng. (Pty) Ltd P O Box 72927 Lynnwood Ridge 0040 Tel 012 4813821 Fax 012 8034411
WSPSACivil&Struct.Eng.(Pty)Ltd P O Box 2330 Edenvale 1610 Tel 011 4502290 Fax 011 4502294
ASSOCIATE MEMBERS
Beosumbar & Associates cc P O Box 605 Westville 3600 Tel 031 2667494 Fax 031 2667404
DMV Harrimisth (Pty) Ltd P O Box 912 Harrismith 9880 Tel 058 6222676 Fax 058 6230271
Letaba Lab (Pty) Ltd P O Box 739 White River 1240 Tel 013 7527663 Fax 086 6754843
Luchrisdebar Surfacing cc 71 Westview Drive Millpark 6001 Tel 041 3730901 Fax 041 3730901
Mdubane Energy Services (Pty) Ltd P O Box 4876 Durban 4000 Tel 031 3042470 Fax 031 3019302
Meckow Ltd (SA) P O Box 12614 Mill Street 8010 Tel 083 7891565 Fax 021 4617783
MTTC (Pty) Ltd P O Box 912-387 Silverton 0127 Tel 012 8003018 Fax 012 8004381
N3TC (Pty) Ltd P O Box 2063 Bedfordview 2008 Tel 011 4543596 Fax 011 4540777
Salphalt (Pty) Ltd P O Box 234 Isando 1600 Tel 011 8232218 Fax 011 8262239
AFFILIATE MEMBERS
32
Asphalt News is published by the Southern African Bitumen Association (Sabita),a non-profit organisation sponsored by its members to serve all stakeholders
through engineering, service and education.
Sabita maintains cooperative and interactive links with similarassociations worldwide, including:
Australian Asphalt Pavement Association (AAPA)National Asphalt Pavement Association (NAPA)European Asphalt Pavement Association (EAPAJapanese Road Contractors Association (JRCA)
The contents of this publication may be reproduced free of charge,provided the source is acknowledged
Southern African Bitumen Association (Sabita)
Postnet Suite 56, Private Bag X21
Howard Place 7450
South Africa
Tel: +27 21 531 2718
Fax: +27 21 531 2606
email: [email protected]
www.sabita.co.za