Canada's “Rock to Road” Magazine

May/June 2006 Issue

• Canada’s Top 25 operations
• Planning pays off for Texada Quarrying
• Capital Paving workshop provides unique forum
• Construction show beats targets
• What’s new in conveyors

For a copy of the issue that contains these articles with colour photos, click here.

Canada’s Top 25 operations

By Robert L. Consedine, Editor & Andy Bateman, Engineering Editor

     Aggregates and Roadbuilding Magazine has taken a different approach for our 2006 report on the country’s top aggregate operations. This year’s listing shows the Top 25 operations ranked by size based on 2005 production, rather than previous reports showing the Top 20 quarries and Top 20 sand and gravel operations separately.

Top 25 Table

      The new approach yields some interesting results, showing eight quarries and two sand and gravel pits making up Canada’s Top 10 biggest operations. Also striking is the fact that the four of the country’s five biggest operations are water-based, with two located on the Pacific coast, one on the Great Lakes and one on the Atlantic coast.
     B.C. water-based operations occupy the top two spots with Texada Quarrying Ltd.’s Texada Quarry and Construction Aggregates Ltd.’s Sechelt Pit in the number one and two spots respectively. Third place goes to the Lafarge Canada operation on Manitoulin Island serving Great Lakes markets, while Martin Marietta’s Porcupine Mountain quarry in Nova Scotia is in fifth place with reported 2005 production of 4.2 million tonnes. The only operation in the top five relying exclusively on trucks to deliver products is Lafarge Canada’s Dundas quarry near Hamilton Ont., with 2005 reported production of 4.24 million tonnes. It is also interesting to note that rapid growth has, with the exception of Dundas, taken the water-based operations ahead of the traditional truck delivery quarries serving Ontario and Quebec. Based on these trends, it seems likely that water based operations will occupy most of the top spots ten years from now, as Canadian producers at existing and new water based operations develop additional export and domestic markets.
     Generally speaking, water-based operations are located in relatively remote or rural locations and the economics of water shipment enable them to compete in distant markets. Land locked operations, on the other hand, are located relatively close to their customers, usually rely on trucks for product delivery and are subject to the higher land use pressures of more densely populated areas.
     According to data compiled by Aggregates & Roadbuilding Magazine, there are now some forty operations across Canada with annual production of one million tonnes or higher. Annual production of two million tones or higher will generally put an operation into the Top 15 operations and production of three million tonnes or more will take it into the Top 10. The reported volumes also reflect the westward shift in economic growth across the country from Ontario to B.C. and Alberta. While most provinces show some at least some growth, the numbers for Ontario are flatter with some operations reporting slight downturns.
      Many operators appear to be optimistic about the future of their businesses, with this optimism reflected in continuing capital investment. At Texada Quarrying Ltd., the country’s biggest aggregate operation and biggest quarry, operations manager Harold Diggon reports 2006 delivery of two Caterpillar 777 haul trucks as well as a Caterpillar 385 excavator. Diggon explains that the two trucks, valued at $2.5 million, will be on primary haul duty while the excavator is on trial to help achieve better separation of the rock types present in this deposit. Diggon states: “The rock types present here include chemical grade limestone, cement grade limestone and granite. The granite dykes were formed when molten granite, an igneous (volcanic) rock forced its way into cracks and fissures in the existing limestone.
     “The granite is extremely hard and provides the main feed material for high quality aggregates, but must be kept separate from the limestone shipped as cement or lime raw feed. The dykes vary in thickness between 50 mm and 12.2 m and, with this variation in width, it can be challenging to efficiently separate the limestone and granitic rock types. Up to now, the sorting process has been completed by 9.1 m3 wheel loaders and we are hoping that the large excavator will provide more effective separation”.
     Still on mobile equipment, Diggon reports no problems with obtaining truck tires, adding that a lot of effort has gone into anticipating demand for both tires and conveyor belting to avoid future shortages. Spares are kept on hand and the operation has standardised belt widths wherever possible to reduce inventory requirements. That said, tire availability remains near the top of the list of operational issues (along with fuel costs) and is likely to stay there for some time.
     The major project on the drawing board is a reversing the shore conveyor belt with feed bins, slated for 2007. The design will be completed internally and will provide stockpile and material recovery capacity for Texada’s transhipping business. “Bulk materials such as coal and sand and gravel are brought by barge to Texada and reloaded into larger vessels, allowing customers such as the Quinsam Coal Corporation of Campbell River to take advantage of our ship loading capacity.” See also “Planning pays for Lafarge with new Texada Quarrying shiploader”.
     On the marketing side of the business, Diggon reports that total sales from the Texada operation are split about 60/40 between Canada and the U.S., respectively, with California and Hawaii still offering significant growth opportunities. U.S. volumes have been boosted in recent years by shipments to Ash Grove Cement, while domestic shipments to B.C.’s Lower Mainland have remained relatively flat.
     Construction Aggregates Ltd.’s Sechelt operation in B.C., is by far the largest sand and gravel operation in Canada at 5.1 million tonnes and is the country’s second biggest operation overall. Mine manager Rodger McLean reports that new capital equipment acquired in 2005 included a Komatsu PC 750-7 excavator and two sand dewatering decks. McLean explains that three primary extraction machines at Sechelt provide the required blend of plant feed material and include two Komatsu PC 750’s and a Caterpillar 375 excavator. The PC750 replaced its larger stable mate, a PC 1250-7, that was found to be overkill in this application.
     For 2006, the main objective of Sechelt’s $4 million capital spending program is to double primary surge pile capacity and obtain three shifts of primary screening from two shifts of primary extraction. The enlarged surge pile will be fed by a new 4000 tonnes/h capacity Ward Ironworks radial stacker, with reclaim capacity increased by extension of the reclaim tunnel and the installation of six new belt feeder gates.
     On the marketing side of the business, McLean explains that Sechelt’s volume growth is being driven by a very busy B.C. lower mainland market on top of the 1.5 to 2 million tonnes shipped annually to California.
     McLean is also mine manager for the Construction Aggregates Ltd.’s Producers Pit, a sand and gravel operation in Victoria B.C. that reached 11th position with 2005 production of 2.2 million tonnes. Here, mobile equipment acquired last year included a Komatsu WA600 wheel loader, while the $2 million capital investment program for 2006 includes a new jaw crusher and additional mobile equipment to support the pit’s final extraction and reclamation. This year’s equipment list includes Caterpillar D7 and D9 dozers and another Komatsu WA 600 loader. By the end of 2007, the Producers Pit will be depleted and McLean expects between 1 million and 1.5 million tonnes of its current sales to be transferred to Sechelt, taking the Sechelt operation another step nearer to its targeted annual production of 7 million tonnes.
     At the Lafarge Canada Manitoulin quarry on Lake Huron in Ontario, expenditures on new fixed and mobile equipment last year totalled nearly $4.8 million, including two Caterpillar D9T track dozers for stockpiling and reclaiming duty, an Ingersoll Rand DM 45 DTH production drill, a Caterpillar 992G production loader and a Simplicity 8x20 two-deck screen. Quarry manager Perry Newman explains that the purpose of the new screen deck is to enhance Manitoulin’s 50mm flux stone production line with the addition of a wash screen to produce a cleaner product. For the business as a whole, Newman sees a strong Canadian dollar, high fuel costs and low water levels in the Great Lakes as challenges faced by the Manitoulin operation in the upcoming year.
     It’s not just the biggest producers, however, who are making significant investments in the future of their businesses. Atlantic Minerals Ltd. is located at Lower Cove on Newfoundland’s Port au Port Peninsula and took the number 18 spot in our listing with 2005 reported production of 1.77 million tonnes.
     Company president William Fitzpatrick reports that the Lower Cove operation is replacing four R85B Euclid-Hitachi 85-tonne haul trucks with four Euclid-Hitachi 65-tonne haul trucks as the operation’s main production haul units and has also purchased two 2001 Euclid-Hitachi 65-tonne capacity haul trucks in the U.S. for use at Lower Cove.
     This replacement program has been motivated by the age of the R85’s but was accelerated due to difficulty in obtaining tires for the R85’s with their 1245 mm tires. The four R85’s will be maintained for yard-work, while the company has disposed of four 50-tonne capacity Caterpillar 773 haul trucks to allow it to standardize on Euclid-Hitachi units. At the face, a Hitachi EX 1200 excavator was purchased in spring 2004 to replace the 1994 Hitachi EX 1800 unit that was recently sold.

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Planning pays off for new Texada Quarrying shiploader

By Kathy Hannaford, Lafarge Canada
& Andy Bateman, Engineering Editor

     Located on Texada Island in British Columbia’s Strait of Georgia, the limestone and construction aggregate operation of Texada Quarrying Ltd. has seen rapid growth in recent years, reaching the top spot in this year’s Aggregates & Roadbuilding’s Top 20 Quarries report with 5.59 million tonnes. Back in spring 2005, operations manager Harold Diggon predicted in an interview with Aggregates & Roadbulding that the operation’s new 4000 tonnes/h capacity single quadrant shiploader would be in service by fall 2005. Diggon’s forecast was spot on, with the loading of the new shiploader’s first barge in October 2005, and its first ship a month later. Even with all its engineering and construction challenges, the project’s distinctive features included the time and effort devoted to the planning, design and project management to bring a project of this magnitude in on time and on budget.
     The new shiploader replaces a 1960 vintage installation that had become both expensive to maintain and a potential safety hazard. Equipped with 914 mm wide conveyor belts and two booms, the old unit provided a maximum load-out rate of 1000 tonnes/h, requiring two operators as well as a ground walker to operate. Frequent breakdowns kept the millwright ground walker busy, particularly with demurrage (ship detention) charges running in excess of $1800 per hour. On the marketing side of the business, the need for a replacement was underscored by increasing demand for aggregates along the west coast combined with a marketing thrust into the key growth markets of Los Angeles and San Francisco. With these considerations in mind, a special project team was formed and given the mandate to design and build a new world-class shiploader.
     One of the project team’s first actions was to engage a Vancouver-based engineering firm, Westmar, to produce a conceptual single quadrant design for an initial cost estimate and review. Following this review, a detailed request for proposal was issued to six short-listed consultants across North America whose proposals included single quadrant, dual quadrant and linear quadrant designs. After another round of detailed scrutiny, it was confirmed that the single quadrant design would meet the team’s performance criteria in a cost effective and relatively simple design. Westmar, now the project engineering firm, produced a preliminary design based on a 50 year shiploader life in line with the operation’s long term goals.
     The resulting design provides huge capacity, with 1.52 m wide conveyor belts and the ability to load a 70 000-tonne capacity Panamax ship in 20 hours without warping (moving the vessel). Even Cape-sized vessels with 120 000-tonne capacity would require only one move to load. Once this preliminary design was completed, detailed design drawings were prepared, and after a final team review, bid documents were prepared for tender.
     Project construction was broken down into the three major components of marine structure, shiploader, and land-side conveyors. At the new loading site, marine structure work included pile driving, the construction of a concrete quadrant beam and removal of the existing shiploader. Meanwhile, fabrication of the main loader structure was underway in Vancouver. Once ready, the 700-tonne structure was walked onto a 107 m long barge for the 144 km voyage to Texada where it was landed and walked a further 800 m to its final location. It was here that the time put into the laborious crosschecking of drawings paid off, as two independently constructed plates fitted together almost perfectly and allowed the loader to be secured onto the pivot and rail. Within one month, the remaining assembly tasks were complete and the shiploader was commissioned.
     A number of cost control measures were put in place for the overall project. Firstly, a design-tender-construct process was used as distinct from a design-build approach. As a result, the consultant worked for the owner rather than the contractor, allowing the owner to manage the project and ensure its requirements were met. Secondly, the contractor was required to sign off on any “extras” through legal documentation before any progress payment was made, thereby ensuring that there would be no unexpected major costs at the end of the project. Further measures included weekly budget updates to track purchase orders and invoices, as well as cost-to-date and cost-to-complete tracking compared to the construction budget. The project manager and project accountant signed off on all purchase orders, contracts and invoices, while the project vice president signed off on all extras. Senior management were also involved in monthly conference calls with the project team.
     Despite its size, the new shiploader requires only one operator who can, if required, use a remote control to load from the ship for closer monitoring of trimming the holds and barge drafts. Loading rates, potential mechanical problems and wind speed are all computer monitored. The wind monitoring system gives a warning when wind speeds reach 48 km/h and locks the loader at 72 km/h to protect against potential damage.
     For the short term, the new shiploader will be cruising in terms of capacity, as it is currently supplied from a feed system with a capacity of 1000 tonnes/h. That will soon change with the installation of a reversing shore belt, allowing the load-out rate to be increased to 2500 tonnes/h. Future site development will also see the installation of a 2.4 km long overland conveyor connecting the operation’s limestone plant to its aggregate operations and the shiploader. This overland development will allow both limestone and aggregate to be loaded onto either barges or ships and also facilitate the sale of surplus dyke material from the limestone operation for marine fill projects.

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Capital Paving workshop provides unique forum for Ontario’s hot mix paving buiness

     The Paving Professionals Workshop was held in mid-April at the University of Guelph, where attendees gained practical insights into asphalt laydown, handling, rolling, mix design, new technologies and testing equipment. Presented by Capital Paving Inc. in conjunction with Roadtec, the two-day workshop incorporated hands on training with an equipment review, as well as a tour of Capital’s asphalt plant and certified laboratory operation. What began as an in-house training session mushroomed into a major event where nearly forty employees from Capital’s paving crews, quality control, and management were joined by representatives from owners, government, supplier’s experts, industry associations and consultants. Government representation included the Ontario Ministry of Transportation, The Region of Waterloo, County of Wellington as well as the Cities of Burlington, Guelph, Hamilton and Kitchener.
    Brian Horner of E.D Etnyre & Co. opened the presentation sessions with Tack Coat 101, explaining that a tack coat ensures a good bond between an asphalt lift and the existing pavement while also helping to prevent water intrusion. As asphalt products are handled at many different temperatures (21C to 193C) and have different characteristics, knowledge of these products is essential for safe and productive use of an asphalt distributor truck. The function of each of the eight major components of an asphalt distributor namely tank, heating system, asphalt pump and circulating system, application control and metering system, spray bar, flushing and clean-out system, power source and chassis, was described together with guidelines for their proper use.
    Jim Hedderich, director of training for Roadtec, made a significant contribution to the workshop with presentations on paving principles, thermal imaging, smoothness and transverse and longitudinal joints.” Paving principles” covered the evolution of the asphalt lay down process, understanding the functions of the asphalt paver screed and choosing the right screed. Hedderich gave an overview of developments in paver design and described the function of the tractor and screed as the two major components of the paver. The components of a paver’s material feed system were explained along with the optimum material level in each area. Specifically, the hopper should be at least one-third full while the slat conveyors should be kept full. Most important, material in the augers should be kept level with the auger shaft, with the material flow gates set to maintain this material level in the auger and the augers themselves built to suit the width of the screed. In Hedderichs’ view, maintaining the correct control of the head of material in front of the screed is the most important thing we do in paving, adding that properly set up feed sensors to monitor the material level on the outboard of the augers are valuable operator aids. Sonic sensors have the advantage of non-contact with the material and should be set up perpendicular to the material face.
    The review of screed designs included variable width and fixed width screeds as well as extensions, heating systems and compaction. Major screed components were reviewed, with emphasis on the importance of correct setting for components such as the pre strike off shield. The advantages and disadvantages of diesel, propane and electrically heated screeds were compared, followed by an overview of the operation of a compaction screed.
    Building on this background information, the presentation on smoothness summarised what if takes to achieve a smooth mat, forces acting on the paver screed, and preventing segregation at the paver. Hedderich reviewed the operating principles of the screed, including self-levelling concepts, screed response versus paver travel distance and forces acting on a screed. All modern asphalt pavers employ a free-floating self levelling screed design where the screed can be thought of as a separate machine that is towed behind the tractor and free to float up or down independent of the tractor. The tractor’s self levelling characteristic is provided by the wheel base of the paver and as the tractor moves over a grade change the floating screed will naturally tend to fill in low points and cut off high points. A screed also inherently resists change and takes some time to respond to an adjustment. If for instance, a depth screw adjustment is made it will take approximately five lengths of the tow arm for the full effects of the change to be applied. As this distance is 15 m to 18 m or about 1-1⁄2 paver lengths, patience is required for the full reaction to take place as frequent changes to depth control can cause weaves or roughness. The key to good control is that the change should only be made after frequent depth and slope checks have been made over a 10 m to 15 m segment of the mat. Once a change is introduced the results should be rechecked before making any other corrections. Back on the theme of material level control, Hedderich stressed the importance of maintaining the head of material at the auger shaft level. The head of material is the mass of paving material that lies directly in front of and spans the entire width of the screed. It is estimated that 95 to 98 per cent of all mat flaws originate from paving with an improper head of material. For the mat itself, a rule of thumb is 25 per cent reduction in thickness from placement to final compaction.
    To consistently build high quality smooth riding roads, the paving speed must be at a constant rate, as speed changes can cause unwanted changes in the depth of the mat. The paving speed should be determined by the paving foreman and a common mistake is to allow the trucks to set the pace of paving. Paver bumping by reversing trucks is also to be avoided, as is material spillage in front of the paver. Other effects reviewed by Hedderich included fixed screed weight versus changing material weight, bearing pressure changes with a hydraulic extendable screed, mix gradation changes, aggregate size in relation to paving depth, changes in the mix, asphalt cement content and asphalt cement temperature.
     On the perennial subject of joint construction, Hedderich began by pointing out that the best joint is no joint. The goal is for joints to fail at the same rate as the driving surface, but joints currently often fail much faster than the driving surface. The proper technique for constructing both types was explained in detail with examples of good practice as well as practices to avoid.
    In Application and use of Smoothness Testing Equipment, Max Pizzingrilli of M & L Testing Equipment (1995) Inc. explained that there is no standard definition of road roughness, although it is generally measured over an interval between two points. Vehicle ride comfort depends on a number of factors including human response to vibration, vehicle response to the road, and road roughness. The impact of vibration on various parts of the human body differs in intensity and its resultant perception of discomfort. The first attempts to measure road roughness utilized a sliding straightedge which later evolved into the rolling straightedge. However, the rolling straightedge tuned to certain wavelengths of roughness in the road while ignoring others. To overcome this limitation, the rolling concept was subsequently improved by the addition of an array of wheels. This design established a reference plane from which to measure deviations and remains with us today as the Profilograph. Early devices installed in vehicles were called road meters and recorded suspension stroke as a measure of roughness. In contrast, modern systems utilize a profiler that works independently from the host vehicle and combines reference elevation, height relative to the reference, and longitudinal distance. Pizzingrilli described a number of International Cybernetics Corporation (ICC) profilers fitted to different vehicles for high-speed data collection as well as smaller walking and lightweight units. Applications for profilers during construction include dump/dip identification and must-grind lines, while profilers are used upon road completion for network data collection and pavement evaluation. Profiler output can be used to determine ride quality, evaluate a pavement’s life cycle, locate problem areas, and help create a quality pavement. Currently, there is a move towards an international ride index (IRI) based specification for both construction and long term evaluation. The advantage of this approach is that the IRI is reproducible, portable, stable with time, a property of the true profile and measurable with any valid profiler.
    The future for roughness may include a complete adoption of inertial profiling equipment for both construction and monitoring purposes, as well as advanced algorithms for “bump detection” that maximize efficiencies in repair. In addition, future specifications may require contractors to warranty their work for multiple years.
    Turning to compaction, Chuck Deahl, national accounts manager for Bomag Americas, noted that proper compaction improves mechanical stability, improves resistance to permanent deformation, reduces moisture penetration and improves fatigue resistance.
    The mat should be at least 80oC to obtain the required density and smoothness and compaction should be at the highest temperature considering ambient conditions, climate and temperature as well as base temperature, mix design and lift thickness.
    Wherever possible, a test strip should be completed to develop optimum rolling patterns and travel speeds for a specified mix.
    The compaction train typically consists of breakdown, intermediate and finishing rollers. Breakdown rolling is usually completed by a double drum vibratory roller typically operating within 60 m of the paver and providing 90 to 95 per cent of the mix compaction. The mat temperature in this zone is usually between 150oC and 140oC. The extent of the breakdown rolling zone in a specific situation is determined by estimating and experience, recognising that the centrifugal forces generated by a vibratory mechanism increase with frequency (vibrations/minute) for a given amplitude. Compaction by vibration involves particle rearrangement and changes in drum vibration frequency will change the spacing of impacts on the mat for a particular travel speed. A minimum of 10 impacts per 0.3 m is recommended. Drum ringing is caused by too many vibratory passes and can be corrected by reducing the number of passes or lowering the drum vibratory force. Roller crawling or hopping is caused by applying too much force or the mat becoming hard.
     Intermediate compaction is normally completed by a pneumatic roller in the section of the mat 60 m to 120 m behind the paver, (the “tender zone,”), where the mat is 115oC to 95oC and has about 92 per cent of its Maximum Theoretical Density (M.T.D.) Here, the mix directly under the roller tire is confined by the base from below, adjacent mix at the sides and the tires themselves from above. As a result, the roller tires provide a kneading action to increase density and eliminate air pockets. The finishing roller is used where the asphalt has cooled to about 65oC and is typically a static drum roller or vibratory roller in static mode. Here, the objective is to leave the mat as smooth as possible, achieved by using a consistent rolling pattern and avoiding sudden starts, stops or sharp turns.
    In “What you need to know about making the right choice”, Vince Aurilio of Bitumar focussed on Superpave and SMA mix design and application. Steps in applying the Superpave system include materials selection, design of the aggregate structure, design of the binder content and a moisture sensitivity test. Information needed to develop a Superpave mix design includes design traffic and compaction level (a function of traffic and depth of layer), binder performance grade, mix size, pavement mat thickness and aggregate quality characteristics. Aurilio also reviewed applicable Superpave standards and described the process for selecting the appropriate binder grade for a particular application, the required aggregate properties and aggregate test equipment. Mix design considerations include the cost of the mix, aggregates availability, design lift thickness, binder type, project type and time of year. Superpave mix size is determined by the lift thickness and should be three to four times the nominal maximum size of aggregate in the mix. Aurilio explained the use of the gyratory compactor and the relationship between the compactive effort criteria for the gyratory compactor and the road design ESAL’s (equivalent single axle loads). A moisture sensitivity test must be completed on the proposed aggregate blend and asphalt content in accordance with AASHTO T 283. After reviewing Ontario guidelines for using reclaimed asphalt pavement (RAP), Aurilio described areas of concern and possible solutions for some Ontario HMA producers with respect to Superpave mixes. These include the difficulty of producing category C or higher mixes without importing aggregates. In addition some mixes are being produced with a low asphalt cement content. Possible “made in Ontario” specification changes being considered include lowering the design air voids from 4.0 to 3.5 per cent for low volume applications and lowering the gyration numbers at N design. Examples were given where U.S. state Departments of Transportation have started to adopt similar changes to their specifications.
     Turning to Stone Mastic Asphalt (SMA), Aurilio described SMA’s history, characteristics, development and applications, adding that owners have the choice of using Superpave and SMA mixes not only in super highways but also in less challenging applications such as low volume roads, commercial applications or parking lots.
     Aurilio concluded with an overview of some topical QC/QA issues including quality testing, laboratory certification, technician training and qualification, sampling, Superpave gyratory compactors and education. On technician training, for instance, it was noted that new training methods require technicians to relearn some aspects of laboratory testing including the splitting of larger samples, familiarity with gyratory compactors, close attention to mix temperature and knowledge of Superpave criteria.
    Don Wilgosh of Troxler presented “Understanding nuclear density testing equipment” which described compaction control methods for pavements including cores, nuclear gauges and non-nuclear gauges. Wilgosh compared these different density testing methods and their results, the theory and practise of nuclear and non-nuclear gauges, the importance of correct test procedures and factors that can impact test results and cause errors. Now that pay and penalties are determined by density test results, the role of QC/ QA technician has changed to “density cop”. Problems facing QC inspectors today include obtaining the required density, accurate gauge measurements and correct density results. According to Wilgosh, Superpave has added to density measurement problems and achieving density on these mixes has proven to be much more difficult.
    Nuclear gauges, used to measure asphalt densities for over forty-five years, are widely-accepted proven QC/QA tools that provide easy correlation between mixes and cores, with recent improvements in gauge design providing more accurate test results.
    Non-nuclear gauges were developed less than ten years ago and provide a quick method of measuring asphalt density without requiring a licence or training certification. Non-nuclear gauges also provide accurate results with proper correlation to cores or nuclear gauges, but are recommended for QC only. No matter which type of gauge is used, correct operation is required for accurate measurements. Wilgosh then outlined how nuclear gauges work and the factors that can affect density test results. Some of these factors, such as insufficient rolling cannot be controlled by the QC technician, while others such as surface roughness can affect gauge test results. However, the largest single factor impacting test results is improper gauge operation and Wilgosh illustrated some of the problems and solutions associated with gauge operation. For instance, the use the control strip density method and accurate correlation to cores will result in accurate test measurements. Common mistakes in gauge use include improper source rod positioning, mix build-up on the bottom of the gauge and material on the source rod. The asphalt core has been used for acceptance testing for many years, although it is not the perfect test and has the potential for many errors. Cores are also relatively costly at nearly ten times a nuclear test and their results are often too late for corrections to the mix. Again, it is essential to follow proper site and laboratory test procedures. Site factors that can affect density results include improper or insufficient rolling, surface and air temperature (including wind chill), and temperature segregation both in the truck and behind the paver.
     Material transfer vehicles (MTV’s) provide a more uniform mix gradation and temperature, normally resulting in better densities.
    Roadtec’s Jim Hedderich was back in the hot seat again to continue the MTV theme, explaining the use of an infrared camera in thermal imaging (thermography) to assess temperature uniformity and identify any “cold” spots in a newly laid mat. Uniform mat temperature leads to consistent road densities which in turn lead to a smooth long lasting pavement. Roadtec’s Shuttle Buggy, when used properly, eliminates thermal and physical segregation by remixing the hot mix asphalt. By providing site storage, it also eliminates paver stop and starts as well as truck delays to improve initial ride quality.
     Kevin English, Head of Quality Assurance at the MTO provided a ministry perspective in “What the MTO is looking for in longitudinal joints.” English emphasized that contractors are to construct joints in accordance with OPSS 313.07.01.12. This provincial specification states that longitudinal joints shall be properly set up with the back of a rake or lute at proper height and grade prior to rolling. Contractors can propose alternate methods to set up the joint, while MTO/CA’s are reminding contractors of joint requirements at pre-pave meetings. English provided examples of both good and poor joint construction methods, outlining common problems and their solutions.

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Construction show beats targets

     Intermat 2006, France’s largest construction equipment exposition in terms of size, broke all attendance records when more than 209,000 visitors from 160 countries and 1400 exhibitors from 42 countries participated in the five-day event from April 24th to the 29th at the Parc des Expositions site adjacent to Paris’ Charles de Gaulle Airport.
     According to show organizers, Intermat 2006 attracted 16 per cent more visitors than the last exhibition held in 2003 and the percentage of international visitors was up 21 per cent compared to the previous show. Rotating every three years with BAUMA in Germany and Conexpo-Con/Agg in Las Vegas, Intermat is one of the world’s three leading exhibitions of equipment and services for the civil engineering, construction and building materials industries. Intermat 2006 was the seventh Intermat exhibition.
     This year’s record attendance figures consolidated Intermat’s position as the world’s second largest construction industry event after BAUMA. The 1400 exhibitors at Intermat 2006 used a total of 375 000 m2 of space to display the latest machinery and technological developments in worksite equipment. The earthmoving sector (with 36 per cent of the total area) and the lifting sector (with 15 per cent of the total area) occupied the largest areas of the exhibition. Among the European exhibitors, a total of 200 Italian companies used 30 000 m2 of space or roughly 10 per cent of the total stand space while exhibitors from Belgium, Korea, Spain, Switzerland, the U.S. and Canada significantly increased their stand space over the 2003 show. Two demo areas, encompassing a total of 30 000 m2, were used to demonstrate a wide range of earthmoving, paving and quarrying equipment under actual jobsite conditions.
     Intermat 2006 officials credited the growth in the European construction equipment marketplace as the primary reason behind the success of this year’s exhibition. The construction equipment market was up 10 per cent in 2005 over the previous year with a record 21 billion euros in sales.
     All the world’s leading manufacturers and suppliers of equipment and services for civil engineering, construction and the building materials industry were present at Intermat 2006. Included among the major exhibitors were Komatsu, Volvo CE, John Deere, Liebherr, JCB, Caterpillar, Terex, Wirtgen, Astec, Hitachi, Sandvik and Metso Minerals.
     Some 15 Canadian companies exhibited their products and services at the show including Ritchie Bros. Auctioneers of Richmond, B.C., Blackcat Blades Ltd., of Edmonton and Breaker Technology Inc., of Thornbury, Ont.

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Belt lifters ease conveyor roller replacement
     The time-consuming and often difficult task of replacing conveyor rollers is claimed to be easier and safer with Prok belt lifters from Sandvik Mining and Construction.
     According to the manufacturer, Prok belt lifters are designed to make roller replacement a simple and easy, one-person operation, without risk of injury to the operator or damage to the conveyor belt. The belt lifters are lightweight (typically weighing less than 20 kg), which reduces the risk of back injuries during roller replacement operations.
     The belt lifters are available in a range from 762 mm 1524 mm and rated for a safe lift of 400 kg. The Heavy Duty range is available in 1066 mm to 1524 mm and is rated for a safe lift of 800 kg. Also available is an Extra Heavy Duty range unit for 1828 mm belt size with a safe lift limit of 1000 kg. Each unit is lightweight, as well as economical, easy and safe to use, yet are very strong and extremely durable.
     To begin the roller replacement, the operator typically selects the lifter’s position between the frames on the main conveyor support beams, making sure the lifter is centered under the belt and has full contact with the support beams. The handle is connected to the lifter mechanism and turned in a clockwise direction until the belt is lifted to the required height for roller replacement. Standard belt lifters are designed based on the standard CEMA idler mounting dimensions and are suitable for use on 95 per cent of all conveyor applications.
     Non-standard belt lifters can be manufactured upon a customer’s request to suit non-standard requirements.
All belt lifters are tested and certified at the time of manufacture and are supplied as a set (trough and return) complete with operating instructions, WLL Test Certificate, spare parts booklet and training video. They are also available individually, as either trough side or return side.
www.smc.sandvik.com/us

Conveyor rollers designed to beat winter challenges
     The demands on conveying systems multiply dramatically during the winter season.
     Innoveyor, Inc. now offers a line of titanium-enriched PVC (polyvinylchloride) idler drums that are claimed to offer a number of features and benefits over conventional steel rollers, especially when snow and ice are the norm. These heavy-duty, lightweight rolls, branded YeloRoll® due to its colour, exceed CEMA D standards. According to the manufacturer, the unique roller design prevents snow and ice build-up that can damage the belt, slow productivity and eventually bring production to a halt. Its smooth, non-porous surface is rust and corrosion resistant.
     YeloRoll® t-PVC idler drums maintain a smooth, non-stick surface that also prevents belt misalignment in any weather condition. A 250 per cent longer shell life is claimed. The heart of the working end of all YeloRoll® rolls is a high-quality, double-sealed, self-lubricating ball bearing system. Unlike the taper bearings used in conventional steel can rolls, this runs smoother, cooler and quieter. Its carbon-fiber Combi-Cap aids in reducing noise as well as the shock and vibration encountered in steel can systems.
Unlike steel can systems, YeloRoll’s® unique t-PVC shells from Innoveyor are insulators, protecting against the transfer of heat and cold and thus condensation at the inner-working components while at the same time, reducing and actually preventing the risk of fire.
     These same inner components are kept clean and dry through the use of Combi-Cap system that protects the shaft ends. Its triple labyrinth seals keep dirt and other debris away from the roll and its critical inside components.
     Technician-friendly, even more so during the cold winter months, YeloRolls® weigh 60 per cent less than their same-sized steel can rolls.
www.innoveyor.us.

Metal conveyor covers offer high strength
     Curveline Inc. now offers custom fabrication of metal panel conveyor covers in an expanded choice of panels. The Curveline process turns standard metal building panels into highly rigid, self-supporting covers that may be used wherever covered conveyor systems are required for weather protection or dust control.
     Curveline can create customized covers from a choice of approximately 50 different fastener panels available from leading panel manufacturers. The company recommends a minimum of 24-gauge in 22 mm to 38 mm panel depths for most curved cover applications, although additional gauges and depths may be used depending on radius and span. Unfinished galvanized steel is the most common substrate, but pre-tinted panels in virtually any colour may be specified where aesthetics are of concern.
     Crimped-curved in to 180-degree applications, Curveline claims it can curve panels into any desired radii and angles of curvature using chord width and height dimensions provided by the customer.
     Based on 160-km/h wind factor, a single 24-gauge, Grade D (50 ksi) steel panel can be curved to form spans ranging from 1.84 m up to 3.61 m, depending on the profile chosen. With a 130 km/h wind factor, the clear span range is from 2.28 m to 4.47 m.
www.met-tile.com/curveline

Improved belt cutters offered
      Flexible Steel Lacing Co. (Flexco) has made improvements to two of its conveyor belt cutters that incorporate safety design features to protect users from accidents during and after cutting. Both the 840 Series and the Clipper® 845LD belt cutters have blades that remain fully enclosed during cutting procedures. The blades also now have a flat top design, providing protection from the tip when the upper beam is opened. Following use, the blades can be positioned in a protected area on either end of the cutter.
     Precision square and perpendicular cuts for belt thicknesses up to 25 mm are made quickly and accurately by simple turning the cutter’s handle. For added flexibility and ease-of-use, the belt cutters feature a chain tensioner for fast field adjustment. They are equipped with a specially designed drive wrench for chain tensioner belt adjustments. Removable clamp bars hold belts securely and can be lifted from either end to simplify routine operation and maintenance.
     The cutters are sized for a range of belt thicknesses and widths. The 840 Series cutters are designed for belts ranging from 10 mm to 25 mm thick and belt widths of 914 mm to 2133 mm. The Clipper®845LD cutters are designed for belts up to 12 mm thick and belt widths from 914 mm to 1828 mm.
www.flexco.com

Roll replacement
      Superior Industries has introduced an all new CEMA-rated idler line with a slotted shaft design that allows for quick and easy roll replacement in any idler frame.
     Superior idlers can help decrease costly downtime with fast delivery times and easy to install replacement rolls. CEMA B, C, D, and E idlers are available in all diameters and belt widths. This full line of replacement rolls offers a hex nut adaptor for those with hex nut brackets and frames.
     In addition to the slotted shaft design, the new idler features an innovative seal design for increased bearing protection and improved durability. Longer wear life and consistent reliability is achieved through the elimination of idler pinch points.
www.superior-ind.com

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May/June 2006 issue

Aggregates and Roadbuilding Magazine
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