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

info@sabita.co.za

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

graham.harrison@meckow.com

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

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R

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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: info@sabita.co.za

www.sabita.co.za