Following findings that poor compaction levels are being achieved at a significant number of road projects, the South African National Roads Agency Limited (Sanral) has implemented a compaction management drive to tackle the problem, construction equipment manufacturer Dynapac business line manager Bill Jenkins tells Engineering News.

“The level of compaction during road construction is a critical aspect in the outcome of the quality of the road being constructed and Sanral has raised concerns about the current quality, which is below industry standards,” he states.

To deal with this issue, the company, which is part of the Atlas Copco group, has introduced its Dynapac Compaction Management real-time documentation systems for roller operators, which comprise three units for soil or asphalt analysis. These are the Dynapac Compaction Optimiser, the Dynapac Compaction Meter with Dynapac Compaction Analyser (DCA), which is a palm-based system, and the Dynapac Compaction Meter with DCA-Global Positioning System (GPS), which features a computer screen mounted on the roller.

Dynapac’s Compaction Man-agement Systems for roller operators have three main parts, which deal with the sensor or accelerometer, the process unit and the display instrument.

The sensor registers the vibratory movement of the roller and this information is then transferred to the processor unit, where it is analysed.

On the basic or Optimiser system, the analysed information is presented on the display instrument as a digital value measured as a compaction meter value (CMV), which can be selected with a switch on the instrument panel.

The compaction meter provides a relative measurement of the rigidity of the surface, which increases with a rise in the compaction and is reflected in a rising CMV.

The accelerometer continuously measures the compaction forces that occur as the vibratory drums work the surface.

The Dynapac Compaction Meter analyser registers all the CMV data and enables the compaction results to be viewed in two forms. The palm-based system will enable the engineer to view the compaction results live without a GPS tracking system. On the Dynapac Compaction Meter with DCA-GPS, the results can be viewed live on the com- puter screen by the operator.

Variations in the CMV are indicated in different colours on the computer screen, making it easy to identify weaker areas and take the required action.

“The DCA indicates precisely which areas require additional compaction, which enables the engineers to inform the operator where to make additional runs over an area to achieve satis- factory compaction; however, some areas may need to be improved through established methods such as stabilisation,” says Jenkins.

Meanwhile, the top-of-the- range Dynapac Compaction Meter with DCA-GPS docu- ments all the passes, which gives the roller operator a visual indication of the compaction achieved over the entire area. It also shows the position of the roller in relation to a selected reference line for the section.

Further, the analysis function can review compaction work, enabling operators and site engineers to assess if the roller has been used efficiently or if the rolling pattern needs to be changed to achieve optimised compaction.

Understanding market trends in terms of future demand, which is imperative for having the right type and amount of stock, is a major challenge that the capital equipment industry faces, says Jenkins.

“The tender process leaves contractors in a precarious position, making it difficult for them to plan for the equipment they will need to buy. This has a knock-on effect on us, as it makes it hard for us to know what products to bring into the market,” he explains.

Further, he says, because the tendering process is under scrutiny as a result of irregularities, as well as the uncertainty in the awarding of projects, contractors and the capital equipment industry are experiencing frustration.

“There seems to be an imbalance between open tenders and awarded tenders.

“Further, the emergence of smaller black economic- empowerment (BEE) contractors, who seem to be awarded the bulk of the tenders, changes the dynamics of the industry from two perspectives. Firstly, the larger contractors are seeking work beyond our borders, which brings its own challenges for maintenance and logistics for them and us.
“

The other perspective is the challenges associated with the emerging BEE contractor sector; skills, knowledge and finance are challenges that hamper the growth prospects of the small BEE contractor.”

However, Jenkins says he believes that both the capital equipment and the construction industries can make significant progress if the tender processes and policies are drafted with the intent to evenly disseminate contracts, and provide opportunity and employment for all.

Meanwhile, he welcomes the announcement by government regarding the acceleraton of infrastructure spend, but says this needs to be approached with cautious optimism.

“The need for infrastructure development, whether new or upgraded, is blatantly obvious, but the question of funding is never far away. Where the funding will come from is the challenge. The highs and lows we have seen in the construction industry over the past decade need to be smoothed out to allow for sustainable growth in the industry and to ascertain whether the announcement [will matrialise],” Jenkins adds.

Although he admits that the proposals by government are a step in the right direction, he says it must be noted that government has some good ideas surrounding infrastructure, such as ports and rail infrastructure; however, what is needed is work on the implementation of these plans.

Going forward, Dynapac will focus on major developing regions, such as Africa, Asia and South America, with the ever- increasing expansion in production facilities in Asia and China.

Jenkins says the company will soon introduce onto the South African market an 11.6 t single-drum roller that will give the compaction of a standard 12.5 t drum roller. “This machine will address the dilemma of not knowing whether to buy a 10 t or a 12 t roller.

Further, 15 t and 19 t machinery will be introduced in the beginning of the third quarter.”

A new paver range, along with a new planer range, will also be launched onto the South African market towards the end of the third quarter.

Meanwhile, Jenkins points out that Dynapac has doubled the number of employed technicians at its major branches to give clients easier access to service and maintenance personnel.

The company has also implemented a parts delivery improvement and monitoring scheme, and says it has consistently achieved a 95% turnaround time on the delivery of service parts.

Further, Jenkins says the company will be rolling out a programme that will demonstrate the low life cycle cost of a Dynapac machine to clients before they buy it. “The programme will highlight to the buyer the full cost of running a Dynapac machine over a period and the low life cycle cost associated with that product.”

Source: www.engineeringnews.co.za