Oral Presentation of the Past

Without the past what would we become?  

Whilst searching the archives of Aran’s technical papers this week we located a transportation planning study for Brisbane City, published in 1965. The insights into population growth and infrastructure development demands were surprisingly accurate.

Planned projects, costed to pounds and pence, with grade and alignment designs, many of which have been constructed in various forms. Some are still needed. Some abandoned for the preservation of urban lifestyle. It was fascinating to reflect on Aran’s contribution to the development of Brisbane’s road network for over 40 years.  Click the pic for the 2004 Program.

Click Here for the Full Oral History Report.

This interview is an excerpt from a Report which was commissioned by the New South Wales State Road Authority (RTA Roads and Traffic Authority) in Australia. This report was commissioned in 1997 to investigate various topics, based on 28 hours of digitally recorded interviews from 23 participants. Trevor Dunstan, Aran Founder, was interviewed to talk about the introduction of mobile pugmills.

Today, Aran’s legacy has been paved around the world and continues to be a reliable contributor to the world’s building infrastructure.

Continuous Volumetric Metering

Aran Mixer Effectiveness Index History and Report

The history and origination of the Continuous Mixer began in the mid 1980’s.

Aran was founded on a solid focus of excellence in engineered solutions. This is not only apparent in the robust design of the equipment, but a collaborative scientific approach to developing industry standards and construction methods. One example of this is the development of a rationale and equation to objectively measure the effectiveness of mixer types for mixing cementitious materials.

1985, Dutch Stephenson, founder and owner for Stephensons Construction of Washington, bought the second Aran ASR200 mobile pugmill to be used in the USA. Dutch was a pioneer in mixing RCC and CTB, with his first project at the Burlington Northern Railroad in Denver. RCC was still in its infancy in 1985, with some contractors attempting to produce RCC with inadequate equipment. Some projects were poorly completed. It was necessary to prove that the Aran pugmill and material metering feeders had the accuracy and mixing effectiveness necessary to produce a quality RCC mix. Collaborating with Aran and the Portland Cement Association (PCA) Stephenson tested the Aran pugmill in Tacoma, WA with several mix designs. The testing proved the Aran plant could not only produce RCC, but also various traditional designs of slump concrete. Stephenson raised the challenge to Aran to develop a plant primarily focused on Concrete.

In 1986 Aran released the ASR280C (C for Concrete) mobile pugmill. This machine included many new features to improve its capability of material dosing and mixing concrete. These features included a larger cement metering feeder with negative pressure silo, improved aggregate hopper and metering feeder and most importantly, the mixer with a new blade phasing arrangement and various other flexible operating features. To prove the new design Aran invested in ~$300,000 testing program at the Monnier Hard Rock Quarry in Redbank, QLD Australia. Construction Testing Pty Ltd of Brisbane were engaged in June 1986 to test materials produced by the new Aran ASR280C pugmill. The results were also reviewed and ratified by Golder Associates.

Testing included the following samples:
10-30mpa Pavement Type Concretes to assess the following plant performance metrics:

  • Consistency of mix over time, collecting material at 40 second intervals from the start to the end of a production cycle (Batch).
  • Consistency across the mixer and discharge belt from batch to batch. Samples taken at the centre and each edge of the static belt.
  • Consistency – short run reliability of mix at 15 second and 30 second batch run intervals.
  • Air Entrainment evaluation with samples taken at 10, 20, 30 then 15 sec intervals over 90 second total sample production runs, at 10-30mm slump and 50-60mm slump.
  • Water Reducing agent evaluation with the same intervals. 

A large database of records collect confirmed that Aran ASR280C:

  • Demonstrated uniformity of cement feed, whilst the silo was being filled and at various levels.
  • Demonstrated sufficient mixing time and mixing thoroughness by material testing and using colour additives
  • Demonstrated effectiveness of admixtures
  • Slump uniformity

During the trials, Aran tested several mixing blade phasing patterns, blade angles, mixer shaft speeds and entire mixing chamber angles. Some adjustments to mechanical or operational characteristics made very little difference, others made a significant difference in mix quality.

On the strength of these positive test results, Dutch Stephenson ordered another Aran machine, an ASR280C delivered in September 1986.

These testing program results aroused elevated interest in the unique Aran pugmill design and its capacity to produce high quality product, at high instantaneous production rates. It was important to prove the Aran pugmill credentials, differentiating it from other mixing systems traditionally employed.

In October 1986, Trevor Dunstan developed, what is now known at the Mixer Effectiveness Equation or Mixer Effectiveness Index (MEI). Written as an appendix to his white paper titled “Continuous Volumetric Metering of Concrete Ingredients, The Aran Equipment Approach to Accuracy – How it Works”. This paper was presented at various conferences and industry meetings in Australia, USA, China and Europe during the remainder of the 1980’s and early 1990’s. The MEI was later updated in 2006 to include other input data necessary to give a reliable measure for applications when mixers are processing slurries and clays. The original Mixer Effectiveness Index is still used by many designers and contractors today.

Site Visits, Inspections and Condition Reports

Aran performs routine Site Visits for a variety of purposes and is regularly called to perform plant inspections & condition reports, where customers recognize the manufacturer has the best understanding of the equipment. As we are the original continuous mixing manufacturer Aran ensures user equipment is configured for trouble free operations and personnel are adequately trained to ensure owners get the production & durability they have come to expect from their continuous mixing equipment.  These visits not only enable customers by providing them with the tools to improve mixer output and overall performance but Aran utilizes information collected to continue to innovate our continuous mixing equipment, staying ahead of the industry. From parts to training Aran extends their services beyond the scope of just a sale.

Construction materials get a new life in western Sydney

Construction materials get a new life in western Sydney

See how equipping for growth early will cement your position as an industry leader.

Boral Recycling use an Aran Modumix mixing plant to deliver pavement construction materials to Sydney projects with a solid respect for the environment.

Western Sydney is the recycling center for Australia’s largest city.  Receiving many thousands of tonnes each day of old construction materials from building and pavement demolition sites, Boral will crush, screen and stockpile materials for reuse.    These processed materials are later delivered to new projects either as fill or stabilised road construction material.  The Aran mixing plant is a key to the success of this business.

Road construction specifications require very accurate dosing of binders and water to produce a constructed pavement with consistent density and strength.  This can be challenging to achieve with recycled materials containing residual cement.  Boral elected to install an accurate, high production mixing plant in 2008 to service the rapidly growing need for recycled material in Sydney and beyond.  Considerably larger that what was needed in 2008, Boral identified the growth in Sydney would demand a high production plant for the future and purchased a second hand Aran Modumix II modular mixing plant.   With a proven history of mixing large volumes of material very accurately, this was the perfect choice for Boral.  In  years prior, this mixing plant, along with an identical twin plant, produced over one million cubic yards of Roller Compacted Concrete for a dam in South Carolina, USA.   Prior to installing the plant in Sydney, Aran refurbished the machine, including the installation of a new control system and a third silo and metering system.

I recently visited this machine just after its 13th year, with 7 years operating at Boral’s facility in Sydney.   This machine is operating every day, producing material at rates of 420 cubic meters per hour or greater, with binder contents of 0-11 percent.   The accuracy of the cement metering is an impressive 0.033% variance across milestone targets.  This is easily within the specified guidelines and a good example of the Aran SiloFeed system to perform on a 13 year old machine.  This accuracy gives clients confidence they are receiving a quality product and Boral the confidence that they are not only producing a product on specification, but doing so efficiently.

High production rates is not only geared for processing orders for material quickly, it also allows Boral to charge trucks very rapidly and maintain a clear traffic flow around the plant.  Speed and efficiency helps this site run smoothly and successfully.

Learn more about how Aran can help you attract more customers along with improving: your production rates and efficient use of material.  Get in touch and tell us your story.


 

Three potential binder blends give Boral the flexibility to meet demanding project specifications.

Three potential binder blends give Boral the flexibility to meet demanding project specifications.

High rates of production + fast truck charging and efficient operations.

High rates of production + fast truck charging and efficient operations.

 

 

Hobart, Tasmania

Year: 2007

Machine Number:
B022 – Flexiclean 610L Mixer complete with 55m3 Silo, Silo Feeder, Auxiliary Hopper and Feeder

Customer: Hazell Brothers
Location: Hobart, Tasmania

Job:
Reprocessing Zinc Refinery Waste Products. The Aran plant stabilized stockpiled waste product and reconditioned it suitable for shipping for reprocessing. Waste product had a typical particle size of less than 1mm. Production rates of approximately 300 cubic meters per hour were comfortably achieved.