Making our roads green matters, and it matters a lot. We may not realize it, but under that smooth, clean strip of asphalt we drive on — and the layers of rock and soil further down — lies an economic and environmental disaster that has been kept quiet for too long.
And yet, new technologies and new mindsets have begun evolving to help transform traditional blacktop. As the world turns its attention to addressing long overdue ecological and economic challenges, we have an unprecedented opportunity. Driving cleaner cars and commercial vehicles on dirty roads solves only a part of the problem — get ready for green roads.
The Status Quo
The global roads network is vast and growing at one of the fastest paces in history. In 97 percent of the continental U.S., you’re no more than three miles from a paved road of one kind or another, and the most recent CIA World Fact Book places the number of worldwide paved roads at 15.99 million kilometers.
By comparison, the moon is a mere 384,400 kilometers (almost 239,000 miles) away. China’s latest Five Year Plan calls for the building and renovation of 1.2 million kilometers (almost 746,000 miles), making good on its promise to build “a road to every village.” Brazil, Russia, India and even Africa are not far behind, each with plans to massively invest in long-needed road infrastructures.
The American Society of Civil Engineers says $186 billion is required to just improve the U.S. highways, and several thousand shovel ready projects are already benefiting from President Obama’s stimulus package.
A new road can reduce the travel time and distance for transporting people and products and other material from place to place. However, for each mile of these new but traditionally constructed roads, thousands of tons of materials such as aggregate rock, concrete, asphalt and steel are needed, let alone all of the diesel fuel required to power the construction equipment. One mile of two-lane asphalt road with aggregate base can require up to 25,000 tons of aggregate rock (aggregates are the most mined resource in the world and are almost entirely non-renewable).
In terms of greenhouse gas emissions, between the pavement and sub-base — all the mining, transporting, heating, earthwork and paving work — the average single lane-mile of freeway, will emit enough pollution to equal up to 1,200 tons of CO2. That’s about the same as the total annual emissions of 210 passenger cars. In 2007, the U.S. alone laid down close to 37,000 lane-miles of new road.
The environmental effects of a road do not stop when construction is complete. The new road affects local plant and animal life as well as the region’s water and soils. The road acts as a barrier that cuts through animal ranges and creates a crossing hazard, further diminishing wildlife habitats, especially if trees were cleared to make way for the road.
Increased travel through the area introduces invasive plant species to the existing vegetation. For as many as 1,000 meters from the road, water and soils must contend with increased heavy-metal and salt deposits from gasoline and de-icing, as well as changes to run-off patterns and underground flow rates that affect larger bodies of water further downstream. In addition, the heat island effect that is generated does not just threaten creatures such as birds and snakes. Cool rainwater that lands on hot roadbeds is heated and then runs off into nearby aquatic ecosystems, where the rapid temperature changes can put fatal stress on life in the water.
And in populated areas, the general rise in atmospheric temperatures in the vicinity of the new road creates greater human demand for cooling, increasing emissions of carbon dioxide, sulfur dioxide and mercury.
While it is highly encouraging to see new efforts to green the transportation infrastructure (cleaner cars, light rail, urban mass transit), most of the world still goes to work each day on a road designed and built with yesterday’s thinking.
Turning a Corner
So how can we reconcile the need for vastly improved and more extensive road infrastructure with the need to do so in a less damaging way?
A number of efforts are beginning to generate interest in and momentum for what can be called green roads. Combined efforts by the EPA and Federal Highway Administration through support for the Green Highways Partnership, a standards setting program called Greenroads, and the Recycled Materials Resource Center, as well as efforts by the road building industry itself, has led to the beginnings of a new framework for green roads. Though acceptance, while growing, is still its infancy.
The Green Highways Partnership was born in 2002 when the Federal Highway Administration, in consultation with the EPA, named environmental stewardship and streamlining to be one its vital few goals. The GHP operates through a network of private and public partnerships to study and implement best management practices for concepts such as: watershed management; reuse and recycling programs for products that include coal fly ash, slag cement and old asphalt; and conservation and ecosystem protection such as wildlife crossings.
Building a green road with ECOroads materials.
Separate from the GHP work, EPA efforts include the new Tier 4 standards for non-road diesel engines, which are to reduce exhaust emissions by more than 90 percent and eventually reduce diesel fuel sulfur content from 3,000 PPM to 15 PPM. When fully applied, the agency says, “these reductions in NOx and PM emissions from non-road diesel engines will provide enormous public health benefits. The EPA estimates that by 2030, controlling these emissions would annually prevent 12,000 premature deaths, 8,900 hospitalizations, and one million work days lost.” Both Cummins and Caterpillar have promised to meet these aggressive new standards.
Universities are also in on the effort.
The University of Washington, in a joint effort with the global civil engineering and construction firm CH2MHill, has created the Greenroads Sustainability Performance Metric for design and construction of new, reconstructed or rehabilitated roads. This system of credits is similar in nature to the LEED rating system designed for buildings. Through its seven categories of sustainable design features, credits are awarded based on dozens of initiatives, including storm water management, bicycle and pedestrian access, reduced fuel use and paving emissions, recycled content and pavement technology.
The University of New Hampshire-Durham, in cooperation with the University of Wisconsin-Madison and the Federal Highway Administration, has created the Recycled Materials Resource Center. For over a decade, their efforts have focused on developing guidelines for — and promoting the use of — recycled materials in transportation infrastructure construction and maintenance. Currently, about 94 percent [PowerPoint] of the 3.2 billion tons of aggregates used every year are virgin aggregate rock while 20 percent of all hot mix asphalt and Portland cement concrete end up clogging landfills.
Adding ECOroads to windrows and sub base.
The paving industry, too, is not blind to its environmental record. Both the cement and lime industries have spent years working on productivity and efficiency gains. In the United Kingdom, manufacturers exceeded their targets of improving specific energy consumption by 26.6 percent over 1990 levels ahead of schedule, recording a reduction level of 33.7 percent, the Mineral Products Association said in a recent article on AggregateResearch.com. Manufacturers in the lime sector achieved a specific energy consumption of 940kW h/tonne against a target of 955kW h/tonne, the article said.
In the U.S. and Canada, the cement industry reduced energy consumption by 37.5 percent from 1972 to 2006, according to the Portland Cement Association. In addition, the industry has formed the Cement Sustainability Initiative. The initiative, consisting of 18 of the world’s major cement producers, promotes research into more efficient cement and has a created a framework of performance indicators for companies to keep track of their progress. The asphalt industry has also taken commendable steps to reduce its carbon footprint through the development of warm mix asphalt. This new asphalt requires substantially less heat and therefore consumes less energy and emits fewer greenhouse gasses.
Finally, a number of innovative and eco-friendly products are also beginning to emerge. Among the most promising are soil stabilizers and asphalt binders that provide the equivalent strength of aggregate base rock at a fraction of the cost and environmental impact. Many of these show promise in the green building space as well, proving that green roads innovations can provide benefits across the sustainability value chain. This could eventually lead to greener office buildings, residential developments, schools and the rest of the built environment.
Final shaping of the green road.
These innovators will have to contend with agencies and individuals wedded to the old way of doing things. The task is no easy matter, as these agencies can be burdened with bureaucratic inertia and bias toward existing industries and technologies. That said, several state departments of transportation are starting to recognize that the industry — and overall approach to road building — is due for a change, especially given an economy that is forcing most states and local governments to do more with less.
New York State Department of Transportation Commissioner Astrid C. Glynn said recently, “By encouraging sustainable transportation project designs, we are taking significant steps to conserve our natural resources, enhancing the quality of our lives and reaffirming our commitment to future generations.”
While there is still a long way to go, when all these concepts are implemented, the complete product is a road that reduces toxic and greenhouse gas emissions, protects watersheds, reduces landfill use, protects ecosystems and preserves space for recreation. It is an engineering, economic and public policy achievement that proves that infrastructure construction and environmental preservation do not have to be a zero-sum game.
The Time is Now
There remains one other reason why green roads are so important and require a solution now, not tomorrow. In order to compete in the 21st Century, the developing world has to build out its own highway infrastructure, as we’ve discussed, to the tune of several million kilometers over the next 10 to 20 years. Builders and public works officials in Africa, India, China, Russia and all over Latin America have a choice: blacktop or green, dirty or clean.
Final compaction of the green road.
To use the same old construction methods would lead to unprecedented environmental impact and further contribution to global warming, all while incurring great economic costs to the budget. Now is the time for decision makers to embrace a new way to design, plan, build and maintain their road infrastructure, consistent with green road building practices, leveraging new technologies and know-how, and preparing their countries to take a leadership role in environmental stewardship and infrastructure development.
In the developing world, every single mile of road built is associated with a significant economic return, as reduction in travel times and costs improve all factors of life. Poverty can be reduced, as it was in Laos. Access to healthcare improves, lessening risks to pregnant woman and children, as occurred in India. School enrollment can increase as it did in Morocco. Income and employment opportunities rise as new businesses are created along the roads, and better access to financial services increases investment towards non-agricultural industry. Land values go up, further increasing access to capital and stimulating entrepreneurial investment. And, according to the Asian Development Bank, in China’s Shaanxi province “for every CNY10,000 invested in roads, 3.2 poor people are lifted out of poverty; and for every 1 percent increase in kilometers of road per capita, household consumption increases by 0.08 percent.”
Of course all of this development does not just happen in the rural countryside. From Sao Paulo to Lagos to Delhi, by 2050 the world’s cities will see their populations expand by 3.1 billion new residents. All that growth will bring with it a massive new demand for infrastructure. Green roads in conjunction with modern power grids, cleaner cars, large and dependable public transportation systems and sewage treatment facilities will help to greatly reduce the per capita carbon footprint of these thriving mega-urban regions.
As growth proceeds apace, it is also important to note that shifting a supply chain to another part of the globe merely moves the source of the smog to a new region. Instead of improving environmental impacts, the change can make things worse: A significant new part of the pollution over American soils now originates in China. That said, expanded infrastructure in the developing world will lead to significant improvements in supply-chain efficiencies of Western companies, leading to cost reductions and a smaller carbon footprint per unit of product — a tangible benefit for companies, employees, and customers in the developed world.
The End of the Road as We Know It…
The old ways are fading and new approaches to road construction are finally catching up with the times. A standard four-lane highway should not consume, over its lifetime, 2,600 barrels of oil worth of energy per kilometer. Just as the green building movement has finally reached the spotlight and gone mainstream, the green roads movement is not far behind.
By: Omri Dahan and Alex Goykhman
The eyes of the world, it seems, are on a $1.4 million paving project in Shoreview.
Construction groups, civil engineers and public works officials are touring the job site. Just the other day, a group from Sacramento, Calif., flew in to take a look at the project. Media types from Miami to Bakersfield are asking questions. There’s even an eye-catching video on Youtube.
“We have been talking to people from New York to California about this thing,” said Mark Maloney, Shoreview’s public works director. “It is very unusual to be involved with an infrastructure project that has that much national attention.”
The fuss is about “pervious concrete,” a green technology that allows water to pass through instead of running off the surface, thus reducing the need for expensive storm water retention ponds and other infrastructure. Pervious concrete also provides a natural filter for polluted “run-off” – such as petroleum products – that would otherwise flow unimpeded into lakes, streams and rivers.
Pervious concrete isn’t new; it has been used in Minnesota for at least five to 10 years, mostly on walkways, parking lots and the like. However, Shoreview is using the technology on a three-quarter-mile residential roadway – the first time, in Minnesota at least, that this type of concrete has been applied to a project of this size.
The project, which began in July and is just wrapping up, features a seven-inch bed of pervious concrete on top of 18 inches of aggregate.
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The concrete doesn’t contain fine sands. Instead, it’s made up of a “concrete matrix” that’s specially designed to allow water to pass through, according to Mendota Heights-based Cemstone, which is supplying 1,800 cubic yards of concrete for the project.
“The water goes through the pervious concrete, gets in this layer of crushed aggregate, and naturally filters into the soil,” said John Lee, a sales manager with Cemstone. “For lack of a better analogy, it looks like a Rice Krispies bar.”
It’s not a cookie-cutter concept. In fact, the concept runs afoul of the traditional view of concrete used in cold climates.
In northern climates, the industry has typically designed concrete to keep water out, thereby preventing freeze-thaw damage. So it’s not surprising that there’s some skepticism about the future of pervious concrete on Minnesota.
The jury is still out on the Shoreview project; a lot more will be known about its durability after it gets past its first winter.
But Lee said the early indications are promising. In a recent demonstration that’s documented on Youtube, crews put the concept to test by dumping 2,000 gallons of water on a finished portion of the street.
The water “disappeared in about a minute,” according to Lee.
“When we go to the site, appearance-wise, the concrete looks remarkably well,” Lee added. “The contractor [Ramsey-based North Country] has done an absolutely fabulous job. The appearance looks very uniform. As far as driving on it, and walking on it, it feels like a regular pavement.”
The pavement isn’t cheap; its upfront cost is about 50 percent more than traditional concrete, Lee noted. But he hastened to add that it’s cost-effective considering that “you are getting a storm water management system” instead of just a driving surface.
Maloney concurs.
“When you net out what you don’t have to build – mainly ponds and piping and catch basins and manholes – when you consider the cost of those things, it is almost a break-even,” Maloney said. “We would not be doing the project if that weren’t the case.”
As more contractors become familiar with the product, and learn how to apply it with the proper tools and techniques, the price is likely to come down.
Maloney said the city’s construction bids specified that experience with pervious concrete, including the proper certification, is a must.
Ramsey-based North Country is a paving subcontractor for general contractor Veit Cos. on the project.
“It’s the largest project we as a company have completed as far as pervious goes,” North Country project manager Cliff Swenson said. “It’s a pretty big undertaking for us.”
From a construction standpoint, pervious concrete differs from standard concrete paving, Swenson noted. Tools and techniques are different. For example, crews must take care not to over-compact, a mistake that could prevent the all-important water infiltration.
The curing is “really, really important,” Swenson said.
“The process – it is pretty critical. You don’t have a lot of time. You need to get it down, rolled and cured as quickly as you can.”
Swenson credits Shoreview officials for “taking a risk with a fairly new material, even though we have been working with it for years. They have put a lot of faith in us and the supplier and general contractor, Veit, to give them a good product.
“And we feel we have. … We want to make sure it’s successful, not just for ourselves, but we feel we are working for the industry as a whole.”
Maloney said the project has “evolved into a partnership that is very, very different than the typical model that has delivered infrastructure. It has been a very positive experience, with all these different market sectors pulling in the same direction to advance something.
“For a city of our size, we don’t normally get involved in projects where that’s the case.”
Caterpillar Inc. was named to the Dow Jones Sustainability Indexes for the ninth consecutive year, the company announced.
Caterpillar also retained its Sustainable Asset Management Gold Class position in the Industrial Engineering sector, it said in a news release.
Launched in 1999, the annual DJSI process involves an analysis of economic, environmental and social performance, assessing issues such as corporate governance and citizenship, risk management, climate strategy, standards for suppliers, product stewardship and occupational health and safety.
“As Caterpillar continues on its sustainability journey, our ongoing inclusion on the DJSI exemplifies our progress in aligning our sustainability efforts with our business strategy,” said Doug Oberhelman, Caterpillar group president, in the news release.
Caterpillar the past year has focused on its 2020 goals for products, services and solutions, as well as operations. Caterpillar continues to look for opportunities to improve efficiencies in operations and products and services offerings, increase recycling and remanufacturing, as well as increasing life cycle value throughout its product line, the release said.
“Our employees, dealers and suppliers continue to work together to help our customers achieve improvements in material and energy efficiency, emissions reductions and job site safety,” said Oberhelman. “At the same time, energy efficiency continues to be a key focus in our facilities; and we continually challenge ourselves to find innovative ways that will increase efficiency while reducing emissions.”
Caterpillar’s annual Sustainability Report can be read on the company’s Web site at http://www.cat.com.
CEMEX UK, building materials provider, is currently trialling an innovative transport solution, Iso-veyors, to transport pulverised-fuel-ash from West Burton power station to Tilbury, for the production of blended cements.
The new grinding and blending facility at Tilbury will be officially opened this month.
Iso-veyors, a more sustainable bulk transport system, were previously used by the company to transport materials to T5 at Heathrow airport. The system provides a logistical and flexible alternative to traditional silos providing storage for 28 tonnes of material per unit which can be transported by any combination of road, rail or ship.
The cylinder- shaped containers are filled at source, West Burton power station in Lincolnshire, and transported by rail approx 170 miles to Tilbury in East London. It is anticipated that this transport solution will save 600,000 road miles and 720 tonnes CO2, the difference between road and rail transportation, per annum.
Once at Tilbury, the 30ft containers, which have been constructed within the frame dimensions of a standard commercial container, are handled as standard ISO containers, utilising skeletal trailers and conventional rolling stock. They are placed on trucks to go into a storage area until required where they can be stacked three units high and moved using conventional lifting gear.
This system provides flexible weatherproof storage, eliminates cross contamination and reduces environmental damage.
“From an operations perspective, the Iso-veyors enables us to move far larger loads over greater distances in less time, giving environmental benefits. It also ensures that we always have a constant supply of P-FA. We are continually looking for innovations that are also more sustainable, Iso-veyors and the recent successful introduction of the Epod,(electronic proof of delivery) fulfill these criteria “, comments Graham Russell, Vice President Commercial, Logistics and Building Products.
Over a two-day period the lightweight concrete was poured to a depth of 650 millimetres and then topped up with granular material and asphalt. Within about two weeks the road was reopened compared to the several weeks it would have taken with traditional construction, says Barry Mulcahy, a project manager with Peel’s transportation division. “We’re always looking for innovative solutions,” says Mulcahy.
(Ontario, Canada) — Not only did it minimize the environmental impact on an adjacent wetland, what may be the first-ever application of a lightweight cellular concrete product on an Ontario road saved time and money and lessened inconvenience to adjacent residents, say Peel Region officials.
Some 950 cubic metres of the lightweight concrete was poured along a 120-metre-long stretch of Dixie Road in Caledon in late August by Calgary-based Cematrix Cellular Concrete Solutions, the proprietary developer.
Rather than pouring concrete from a waiting convoy of ready-mix trucks, the concrete was sprayed into place by assistant project manager Brad Garity operating a large hose attached to a mobile command mixing centre where water, a foaming agent, compressed air, and Portland cement—from an adjacent 30-ton silo — were mixed together.
Over a two-day period the lightweight concrete was poured to a depth of 650 millimetres and then topped up with granular material and asphalt. Within about two weeks the road was reopened compared to the several weeks it would have taken with traditional construction, says Barry Mulcahy, a project manager with Peel’s transportation division. “We’re always looking for innovative solutions,” says Mulcahy.
While not considered a hazard to the driving public, the peat moss conditions in the adjoining wetlands have been the source of settling problems for several years, he says.
Traditional construction would have required considerable dewatering, extensive peat removal, the erection of sheet piling and then replacing the peat with granular material, says Bob Bower, vice president of Delcan Corporation Engineers, the consulting engineer: “It (traditional construction) would have been very costly.”
While basically a test experiment for Peel Region and the first application in Ontario, the concrete has been successfully used in Western Canada.
“We’ve been at this for 10 years,” says Cematrix vice president Steve Bent. The lightweight concrete offers a cost-effective innovative solution to difficult and challenging road reconstruction in areas where there is weak soil, peat moss or where there is highly plastic clay, say Bent.
Other applications include lightweight back fill for retaining walls and bridge abutments.
In Alberta where the below ground frost level can range from 10 feet in Calgary to 14 feet in Fort McMurray, it has been used as an insulator for utility lines, says Bent.
Installation is rapid, with a capacity of from 20 to 150 cubic metres per hour in all conditions says Bent, noting the pouring hose can be extended a kilometre.
By: DAN O’REILLY
Where many coal-fired power plants see waste, researchers at Louisiana Tech University see an opportunity to curb greenhouse gas emissions, protect aquifers and change engineering forever.
The researchers, led by Erez Allouche, an assistant professor of civil engineering and associate director of the Trenchless Technology Center, and Sven Eklund, an assistant professor of chemistry, are working with a group of students to create a geopolymer concrete, or GPC, made from a waste byproduct produced by coal fired power plants called “fly ash.”
The power plants typically store the ash, one of the most abundant industrial byproducts on earth, in massive lagoons and storage facilities. That method of storage puts aquifers and surface bodies of fresh water in danger if storage goes awry, and takes up thousands of acres. But GPC can help eliminate the need for that storage.
“It is important research for the U.S. because it’s environmentally friendly,” said Ivan Diaz, a PhD candidate who has been working on the research team for several years.
“We’re keeping the fly ash out of the landfills and we’re creating a valuable material.”
The researchers use another byproduct from the paper pulp industry, sodium hydroxide, to start the reaction that turns fly ash into GPC.
The goal is to market GPC as a substitute for Portland cement, the most widely produced man-made material on earth and one scientists have pegged as a major contributor to global warming.
An estimated 5 percent to 8 percent of all human-generated atmospheric carbon dioxide (CO2) worldwide comes from the concrete industry. More than 2.6 billion tons of Portland cement are produced per year, and production is growing 5 percent annually.
Compared to Portland cement, GPC produces 90 percent less CO2 during production.
According to Allouche, GPC offers several additional advantages compared to Portland cement.
GPC features greater resistance to corrosion, more fire resistance, greater strength and less shrinkage.
Companies have tried a mixture that used 85 percent Portland cement and 15 percent GPC, but “why use 15 percent we can use 100 percent?” Allouche asked.
So far, the Tech research team has produced a 5,000 pound block of GPC and constructed a 100-square foot gazebo made entirely of GPC.
The researchers are working with about 30 power plants to provide fly ash for the research, including Louisiana companies like Cleco Power of Pineville and Entergy.
Allouche said he foresees GPC being used for road and bridge construction, as well as for other civil-engineering products like sewer piping.
The researchers could reach that goal sooner rather than later, as Allouche said they are currently on the verge of marketing a sprayable geopolymer product.
“We’re not out to replace concrete, but we’d like to offer a complementary product,” he said.
Diaz said GPC is unlikely to replace Portland cement, but not because GPC isn’t a superior product.
“It’s not because it can’t do it, but because it’s really hard to change the minds of the civil-engineering community,” he said.
GPC currently costs about 15 percent more than Portland cement, “but that does not take into account savings (produced) by not having to store fly ash or ‘green’ tax credits,” Allouche said.
Allouche and Eklund, the other lead researcher, said the success of GPC will ultimately be determined by companies’ willingness to try something new.
“It’s up to the industry to accept it,” Allouche said.
By: Stephen Largen
Coal: Global Industry Guide is an essential resource for top-level data and analysis covering the Coal industry. It includes detailed data on market size and segmentation, textual analysis of the key trends and competitive landscape, and profiles of the leading companies. This incisive report provides expert analysis on a global, regional and country basis.
Scope of the Report
* Contains an executive summary and data on value, volume and segmentation
* Provides textual analysis of the industry’s prospects, competitive landscape and profiles of the leading companies
* Incorporates in-depth five forces competitive environment analysis and scorecards
* Covers the Global, European and Asia-Pacific markets as well as individual chapters on 5 major markets (France, Germany, Japan, the UK and the US).
* Includes a five-year forecast of the industry
Highlights
The global coal market grew by 20.7% in 2008 to reach a value of $338.6 billion.
In 2013, the global coal market is forecast to have a value of $610.2 billion, an increase of 80.2% since 2008.
The global coal market grew by 4.6% in 2008 to reach a volume of 6.6 billion short tons.
In 2013, the global coal market is forecast to have a volume of 8.8 billion short tons, an increase of 34.4% since 2008.
Power generation segment dominates the global coal market, accounting for 65.1% of the market’s value.
Asia-Pacific accounts for 64.7% of the global coal market’s value.
China Shenhua Energy Co., Ltd. generates 3.1% of the global coal market’s value.
Why you should buy this report
* Spot future trends and developments
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Market Definition
The coal market is defined as revenues due to the sale of coal for industry and power generation. Market volumes given within this profile are for both primary (anthracite, bituminous, and lignite) and secondary (anthracite, bituminous, and lignite briquets but excluding metallurgical coke) coal consumption. The market has been valued at annual average minemouth prices and does not include any transportation costs.
Apparently thicker is better — at least when it comes to paving roads — according to an MTO expert.
The critical thing is good design, Chris Raymond, acting head of the Ministry of Transportation Ontario bituminous section recently told an industry audience.
“If you can’t afford a good design, I tell agencies and municipalities, you can’t afford to waste your money on a poor design — you’ll just be throwing your money away,”
A strong advocate of the MTO’s Superpave standard, Raymond also said lift is important and urged opting for more thickness to ensure better roads and longevity.
“Unfortunately, costs drive agencies to go for minimum thickness,” he said, “Pavement wears from the top but falls apart from the bottom.”
With limited dollars and a growing number of kilometres to pave, owners cut back but will pay for it in the long run because those installations will fail long before they should and start to pothole and crack.
“A higher lift, say going from 40 mm to 50 mm, isn’t a 25 per cent increase in cost because while you are using more asphalt cement and materials your equipment and labour costs are the same,” Sandy Brown, technical director of the Ontario Hot Mix Producers Association told a seminar during an association convention.
Brown said the optimum lift depends on the type of traffic the road faces and accordingly which aggregate has been specified. Thinner lifts stretch the asphalt and budget further, but add to later maintenance and rehabilitation costs.
“Most of the problems we find in forensic engineering analysis is that something simple was done wrong in the beginning of the process,” said Dale Decker, president of Dale S Decker LLC, a U.S. expert consultant who outlined five steps to better pavement.
In the end, it comes down to best practices, said Decker, whose recommended steps start with a design that addresses quality and function required of the road, specifications that clearly define the work, inspection to ensure proper construction according to the design, construction combing technology, workmanship and maintenance.
He said road designers must for consistently look to state-of-the-art design standards — not just what’s always been used before.
“Perpetual pavements, for example, have been used around the world for years and we’re just getting to use them in the U.S.”
Making sure the job is being done correctly is also critical.
“Who are the inspectors? Are they certified? We’re they working as a Wal-Mart greeter yesterday and working as a road inspector today?”
There’s a continuing shift by owners to an “end result contract” in which the contractor is given free reign to determine the construction of the road as long as it meets specifications.
But contractors must shoulder more responsibility and partner with owners to realize value engineering rather than take the old adversarial stance, he added.
He said the last step is the one which fails more often.
“Maintenance and rehabilitation is my major pet peeve,” he says. “We built one of the top 10 transportation systems in the world, but now three-quarters of our bridges are structurally unsound and our highways are in the same situation because we didn’t maintain the system.”
Vince Aurilo, manager of pavement engineering services at DBA Engineering, who also spoke on the specification and inspection process at the seminar, said partnerships between owner and contractors will be increasingly important.
Reducing variations from specification in aggregate mix, careful inspection and sampling, using the right equipment in the right way with trained, skilled workers is the surest way to meet the standards and get smooth, long-lasting pavement, he said.
“Stopping and starting the paver or bumping the screed because you are not using a shuttle buggy, for example, leads to bumps and affects the thickness. We’re going for smooth because smooth lasts longer.”
A case study of a pervious concrete quality assurance program
Mar, 12 2010
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Research and experience have shown that pervious concrete mixtures proportioned to have 15 to 25% air void contents should have sufficient infiltration rates to limit storm water surface runoff and adequate strength to avoid raveling.1 Until recently, however, there were no U.S. standards for the verification of air void content in fresh concrete or infiltration rates for in-place concrete. To help producers, contractors, and owners verify that their pavement projects will perform as needed, ASTM Committee C09.49, Pervious Concrete, has recently introduced Standard C1688, “Standard Test Method for Density and Void Content of Pervious Concrete”2 and Standard C1701, “Standard Test Method for Infiltration Rate of Pervious Concrete.”3 These standards were used as part of the quality assurance program for the construction of a parking lot at the Metropolitan Community College (MCC) in Omaha, NE. Using test placements to develop a compaction-density relationship, appropriate mixture properties could be defined without guesswork. Workability tests and unit weight tests per ASTM C1688 were used to screen loads to ensure that we placed only workable concrete that could be consolidated to achieve a target air void content.
UNIT WEIGHT AND AIR VOID CONTENT
Pervious concrete typically comprises a zero slump mixture with little to no fine aggregate and uniformly graded coarse aggregate. The workability of such mixtures can be highly sensitive to variations in moisture content and compaction effort, leading to large variations in the final void contents for a given pavement project. By mixing trial batches for the contractor to use in test placements of pavement, the producer can obtain unit weight data per ASTM C1688 and air void content Vair (in %) from cylindrical samples according to the procedure in Reference 4. Vair is given by
V^sub air^ = [1 - (W^sub D^ - W^sub S^)/(gamma^sub W^ . V^sub T^)] x 100 (1)
where WD is the weight of the oven-dried sample, WS is the submerged weight of the sample (after tapping to release trapped air), gW is the unit weight of water, and VT is the calculated volume of the sample using its measured diameter and length.
For the MCC project, six mixtures were prepared and samples were produced per ASTM C1688 during placement of the preliminary test panels (Fig. 1). Unit weight and air void content for each mixture were measured and plotted, and a linear regression analysis was used to determine the relationship between air void content and unit weight (Fig. 2). As one might expect, there is a linear relationship between void content and unit weight of pervious concrete mixtures, with a maximum unit weight (about 150 lb/ft3 [2400 kg/m3]) associated with zero air void content.
It must be noted that the ASTM C1688 procedure (filling a 0.25 ft3 [7 L] cylindrical container in two lifts, with each lift consolidated using 20 blows from a standard Proctor hammer) will not produce the same air void content as would be produced in pavement. Our preliminary field determination for cores removed from the test panels indicated that a mixture with an air void content of 12% and unit weight of 133.5 lb/ft3 (2140 kg/m3) when tested per ASTM C1688 would have an in-place air void content (found per Eq. (1) using core sample data) of 17.5%. This in-place value was specified for the project.
QUALITY ASSURANCE PROGRAM
The owner recognized pervious concrete as a new product and thus made it very clear that, regardless if the product was successful or not, “we need to know why.” The team was therefore expected to implement procedures within a set quality control program, including:
* Aggregate moisture tests conducted by the concrete producer before batching operations;
* Unit weight tests per ASTM C1688 conducted at the batch plant by the producer and at the job site on every load of concrete;
* Inverted slump cone tests (described in the following section) conducted at the job site by the owner’s testing agency;
* Estimated unit weight test (described in the following section) conducted on site by the owner’s testing agency;
* Unit weight tests (five total) using 4 in. (100 mm) diameter cores taken from the hardened pavement and tested using the procedure described in Reference 4 by the owner’s testing agency; and
* Permeability tests (six total) per ASTM C1701, taken at the core locations (prior to coring) by the owner’s testing agency (Fig. 3).
UNIQUE TEST PROCEDURES
Inverted slump cone test
The inverted slump cone test is qualitative, but it allows a rapid evaluation of workability. The procedure involves resting the small opening of a slump cone against a smooth, hard surface. The cone is then filled with fresh concrete in one lift, with no consolidation. Excess concrete is struck off, level with the large end of the cone, and the cone is then lifted. The fresh concrete is observed as it flows out of the cone. If the bulk of the concrete remains in the cone and can only be discharged by vigorous shaking of the cone, the mixture will be unworkable. Figure 4 shows two different mixtures after discharge. The concrete in Fig. 4(a) was discharged after tapping of the cone-the batch was remediated by increasing the water content. The concrete in Fig. 4(b) flowed freely from the cone and was approved for placement.
Estimated in-place unit weight
In this procedure, a 0.25 ft3 (7 L) cylindrical container is filled with fresh concrete in one lift, with no consolidation. Excess concrete is struck off, level with the top of the container. The net weight of the concrete is determined and the unit weight of the test sample is calculated. The resulting value is multiplied by a compaction factor, which is based on observations that typical consolidation methods lead to a 1 in. (25 mm) reduction in thickness relative to the initial placement depth. Thus, for the 6 in. (150 mm) thick pavement required on this project, the compaction factor was 7 in./6 in. = 1.17. Estimated unit weight values were correlated with specific regions of the in-place pavement.
APPLICATION
Placement
The pervious concrete pavement was placed by directly discharging the concrete from mixer trucks onto an aggregate base. Concrete was raked into place and consolidated and finished using a hydraulic roller-screed operating directly on top of side forms. As per ACI 522.1-08, the concrete was covered with a polyethylene sheet immediately after finishing.5
The 5650 ft2 (525 m2) paved area required 110 yd3 (84 m3) of concrete, which was delivered in 14 truckloads. Most of the placement was completed in 2 days, during which the average ambient temperature was 65[degrees]F (18.5[degrees]C) and the relative humidity was 70%.
Inverted slump testing showed that the first truck was not workable and additional water was added until the concrete had about 12% air void content as measured per ASTM C1688. The second truck had too much water added at the concrete plant and was held until the concrete had about 12% air void content per ASTM C1688. The water content for the third truck was acceptable, so concrete from this truck was placed while the second load was being held. Tests of subsequent loads indicated they also had acceptable water contents.
Pavement sections were installed with no reports of consolidation or finishing problems. Workers with previous experience with pervious concrete pavements reported, however, that the mixtures would have been considered too “wet” if evaluated by visual inspection only.
Fresh and hardened properties
ACI 522.1-08 Section 1.6.2.1 requires that the unit weight of fresh concrete is within +-5 lb/ft3 (+-80 kg/m3) of the specified fresh unit weight. ACI 522.1-08 Section 1.6.5.2.1.b requires that the unit weight of the hardened concrete is within +-5% of the approved hardened unit weight measured in test panels.
As indicated previously, the specified in-place air void content was 17.5%. Extending ACI 522.1-08 in-place density requirements to air void content, the allowable range would be from 12.5 to 22.5%. Air void contents measured using cores ranged from 13.4 to 21.6%- well within the allowable range. A comparison between estimated and in-place void contents is shown in Table 1. Even though the estimated in-place unit weight test is highly operator dependant, the mean of the test results was within 3% of the mean of the values measured using cores (Fig. 5).
Table 2 compares the air void contents of the fresh concrete (measured using ASTM C1688) and hardened concrete (measured using core samples). For all five cores, the void contents measured per ASTM C1688 were lower than the void contents found using the core samples.
Figure 6 shows the general relationship between void contents, as determined per ASTM C1688, and permeability, as determined per ASTM C1701. Permeability tests were not performed directly on the cores, as that ASTM standard is under development. Because the same equipment and methods were used to consolidate all pavement sections, Fig. 6 implies that initial workability, which influences compaction, also influences hardened permeability. The largest infiltration rate measured per ASTM C1701 was 2016 in./hour (51,200 mm/hour) and the lowest was only 62 in./hour (1600 mm/hour). While our observation of an exponential increase in permeability with increased void content is consistent with observations made by others, the multi-operator reproducibility of the test method is under evaluation.1,6 INDICATIONS
Our work for the MCC pavement project (Fig. 7) indicates that:
* Air void and unit weight tests per ASTM C1688 can be used to predict in-place air void content;
* The inverted slump cone test is a good predictor of mixture workability and provides a rapid method for culling mixtures that will have unacceptably low unit weights; and
* A requirement that the in-place unit weight is within +-5% of the specified unit weight (as per ACI 522.1-08) is appropriate and achievable.
For workable mixtures that passed the inverted slump cone test, estimated in-place unit weights correlated well with measured in- place air void contents. Mixtures that met the specified unit weight of 133.5 lb/ft3 (2140 kg/m3) were very workable, although they might have been considered too “wet” if evaluated by visual inspection only.
Source: http://www.waterworld.com/index/display/news_display/142290922.html
SCHEDULE B
DESCRIPTION OF THE IDEA
Title : Industrialised Construction System for Road on Peat
Category : Others ( Specialised construction product )
Description
The idea is to pre-commercialise and value-add to a patented (MY-139642-A) precast lightweight composite wall and several award winning novel materials and method for road construction on problematic soft soil and peat. The business model is to supply production system, raw materials and chemicals to customers and resellers with technical and consultancy services.
The benefits of the system include cost reduction in construction and maintenance. Productivity and safety will be enhanced. The mobile system is designed for use in road construction on peat.
DESCRIPTION OF MENTOR
1. Description(s) of Mentor required:
A successful businessman in structural and geotechnical engineering
2. Details of the proposed mentor (if any):
Ir. Dr. Lam Kai Yang, MIEM, P.Eng.
Managing Director,
Reliacon Sdn Bhd
5A, Jalan Molek 2/4,
Taman Molek,
81100 Johor Bahru
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Construction technology is an interesting term that can mean anything that relates to the industry. In this instance it is being used to reference the growing application of electronics and wireless communication to the earthmoving world.
The application electronic technology goes back at least 40 years when the big controversy for equipment manufacturers was, “Do we use gauges or lights on the instrument panel?” On much of today’s equipment you can select what you want on the instrument cluster monitor and in the language of choice.
It was only a few years ago that GPS was first used to guide a dozer’s finishing touches on a project. Today a number of manufacturers have pre-wired their equipment so that machine controls and GPS systems can be added after the initial purchase.
“A term you will be hearing used more frequently is telemetrics. It’s not new. Telemetrics is a technology that involves the automatic measurement and transmission of data from remote sources. The process of measuring data at the source and transmitting them automatically is called telemetry. The two terms, telemetry and telemetrics, are often used interchangeably. In general, telemetrics works in the following way: Sensors at the source measure either electrical data (such as voltage or current) or physical data (such as temperature or pressure). These are converted to specific electrical voltages. A multiplexer combines the voltages, along with timing data, into a single data stream for transmission to the distant receiver. Upon reception, the data stream is separated into its original components and the data are displayed and processed according to user specifications.
“In 1912, the first telemetric application in Chicago used telephone lines to transmit operational data from a power plant to a central office. Because telemetry was originally used in projects like this, the first telemetry systems were called supervisory systems. In 1960, the interrogation-reply principle was developed, which allowed a more selective transmission of data upon request.
“Modern-day telemetrics frequently uses wireless communication. Telemetric applications include measuring and transmitting data from space flights, meteorological events, wildlife tracking, camera control robotics, and oceanography studies. Videoconferenceing and the Global Positioning System (GPS) are also considered to be telemetric technology.” (Source: Whatis.com)
Qualcomm has developed several telemetric products. The one most interesting to our industry is GlobalTRACS. GlobalTRACS is an equipment management system that automatically collects, wirelessly transmits and manages critical operational data — giving the contractor the ability to manage the equipment, not just track it.
The system tracks engine hours; GPS location; user-defined management and maintenance reports; multiple maintenance profiles and notifications; virtual fences and after-hours security alerts; driver directions and instructions; critical machine-health monitoring; easy back-office software integration; message delivery; and ruggedized construction.
Zonar Systems is another telemetric company but it specializes in over-the-road truck operations. Zonar Systems is in verified visual inspection technologies, helping companies capture, communicate and analyze information about the condition of their vehicles and other assets. Its products use radio frequency identification (RFID), wireless communication, web-based applications, and Global Positioning System (GPS) technology to enhance fleet utilization, safety, compliance, and employee satisfaction.
Zonar’s High-Definition GPS system (HD-GPS) captures data every time in four dimensions, instead of the traditional three, and at a sample rate of one second. This can be integrated with other company systems.
HCSS has launched an integrated GPS feature that significantly expands the capabilities of its resource management software, The Dispatcher ™. Managers can now make better decisions based on accurate information from the field, helping them utilize equipment more efficiently, lower fuel costs, reduce cycle times, minimize theft, and identify underused rentals.
In addition to cycle-time analysis, the integrated GPS feature shows where equipment is currently located, where it has been, how fast it’s been going, and meter readings of how long the equipment has been running. The meter readings, coupled with The Dispatcher’s maintenance scheduling ability, help improve preventive maintenance on equipment. It can integrate with other company software.
Gomaco and Lieca — Stringless curb and gutter paving have become a reality. Gomaco and Lieca use a 3-D machine control system to simplify concrete jobsite logistics, reduce costs and improve quality. The system puts the owner’s 3-D designs directly on the machine and controls height and steer, slope and draft of the paver automatically.
It allows operators to be self-directing and eliminates the need for layout and staking personnel. Using this approach, pre-production planning is kept to a minimum.
PaveSmart, as the system is called, uses Leica’s TPS and GPS; is compatible with data from a wide range of design and CAD systems; and is also compatible with major GPS base station systems.
Some of the obvious advantages are that the system makes sense of digital data, directly from the designer’s survey equipment. A definite big plus is that it eliminates staking out and stringline setup errors since no stakes and stringlines are required.
Truck site access is a lot easier since drivers don’t have to watch for the stakes. It allows for jobs in narrower work corridors and eliminates waiting for the surveyor to check grade and make certain stakes have been moved. The system is ideal for highway work as it improves safety.
The system is designed for curb and gutter, barrier, and monolithic and sidewalk paving projects.
Curb and Gutter: parking lots, residential subdivisions and commercial developments.
PaveSmart 3D takes the owner’s CAD plans directly onto the job site. Your operator simply sets up the position sensors, picks the required task, enters any working offsets if needed, and you’re ready to go to work. The system even brings the machine automatically onto line and grade, ready to start paving — a faster and smarter way to work.
Barrier: restricted access, “live” highway possessions, urban and narrow-corridor or zero-clearance projects.
Project logistics are made much simpler when you can throw away the stringlines. Get your concrete trucks in and out faster, with no risk of damaging the stringlines and stopping production. Site safety and setup time for stringlines are also big concerns for projects surrounded by live traffic.
Monolithic and Sidewalk: Pave any shape in any configuration.
The system is as flexible and reconfigurable as your machine. Simply attach your new mold, set the new machine information into Leica PaveSmart 3D and you’re ready to go back to work.
Some of the PaveSmart’s features include improved accuracy. According to Leica PaveSmart 3D delivers grade and steer accuracy to millimeters with All-Trac Steer and All-Trac Grade.
It uses a combination of slope sensors, total station and/or GPS data to continuously calculate the position, height, orientation, cross-slope, and draft of the mold as it is working. It automatically regulates all points of the mold relative to the 3-D design, and allows offsets to be adjusted “on the fly” by the operator.
The Gomaco GT3200 single-track-steer, the Gomaco GT3600 with front steer, the GT3600 all-track-steer, and the Commander III are all designed and progammed to use the PaveSmart system.
Caterpillar’s Accugrade — Most new models of excavating/dozing machines are being offered with an AccuGrade Ready Option (ARO). A machine equipped with ARO has all of the wiring and mounting brackets installed where they are protected and will perform reliably. The ARO fully integrates the automated blade control with the machine. Part of that integration enables a lockout system that keeps the blade from moving when the operator isn’t at the controls.
As part of that integration, new models of machines that often are assigned finish grading tasks are designed to perform precisely when controlled by AccuGrade. For example, the M-Series motor graders have electro-hydraulic blade control that enables the system to react quickly and precisely to automated control inputs. Similarly, the new D6K tractor has electro-hydraulic blade controls and electronically controlled hydrostatic drive.
Other machines, too, are now available with AROs. Many of the Cat tractors now have AROs, and the new Cat excavators and most of the backhoe loaders also have AROs.
The second major thrust that Caterpillar is taking to implement GPS-based machine control and guidance is training. Cat has identified the distribution of GPS-based systems and training of customers as a bottleneck in applying this productivity-enhancing technology. As a result, Cat has put a great deal of effort into training dealer personnel to sell and support machine guidance systems. In North America, Cat has trained 1,500 salespeople, 300 product support people and 120-plus technology specialists. More than 200 hours of curriculum have been developed for web-based training and instructor-led training.
John Deere and QUALCOMM announced an alliance to create an equipment and machine monitoring and information delivery system that will be sold across North America by certified John Deere construction and forestry dealers.
JDLink automatically collects, transmits and manages information about where and how construction and forestry equipment is being used, as well as critical machine health data for superior equipment utilization, improved productivity and increased revenue. The system leverages QUALCOMM’s GlobalTRACS® equipment management system to provide customers with vital information about equipment location, machine health and service status. Additionally, it issues special alerts to notify customers if equipment moves outside pre-set boundaries.
Four levels of service will be offered with JDLink. The Standard level will provide owners with machine location status, machine service hours and location monitoring capabilities. The Advanced levels of service provide customers with the Standard level, plus dash indicators and fuel and equipment utilization information via engine load monitoring. The Ultimate level of service expands upon these offerings by adding current and stored monitoring of component pressures and temperatures, and fuel consumption, as well as transmission gear selection and full-featured diagnostic information retrieval. The Direct level enables customers to download machine operating history and diagnostics directly to a laptop. The Advanced, Ultimate and Direct levels of service will be available in 2007 on select models of John Deere construction and forestry equipment.
Topcon’s new 3-D steep slope add-on kit gives control on more job sites. The new 3-D steep slope add-on kits for motorgraders from Topcon Positioning Systems (TPS) gives contractors a wide-range sensor that allows 3-D use of these machines even in steep applications.
The slope sensor allows for precise measurement of up to 100-percent cross slope whenever needed by a Topcon System Five 2-D or 3-D application.
“We’ve found that this type of technology is needed as more and more contractors are using 3D-GPS+ motograders in applications with steeper slopes,” said Jason Killpack, Topcon senior product marketing manager. “Topcon created the new kits, which have a wider range slope sensor than the standard add-on kits, to provide superior accuracy and response on more job sites and applications.”
The new kit is compatible with all System Four, System Five and 9168 control boxes and features a temperature-compensated sensing element to enhance its use in any weather condition.
Interesting application
Grant Garrett with Garrett Excavation, Inc., of Hot Springs, Ark., bought a Topcon 3D-GPS+ system to put on a single bulldozer six years ago. Today the company has a full complement of 3-D and 2-D machine control systems, GPS rovers and base stations, total stations, and all types of laser instruments. He firmly believes that “Without GPS capabilities, we wouldn’t even be in business. Satellite technology provides us the competitive edge we need to continue to grow out business every year.”
Since last fall, a 15- to 20-man Garrett crew has been “attacking” a 122.5-acre plat in West Little Rock, moving massive amounts of dirt for a multipurpose development. The largest and hardest part of the job was a 50-acre section in the middle of the development dedicated to a 200,000-square-foot church.
Garrett’s crews relied on two CAT D-11 dozers and a D-9 to do the major earthmoving chores. “We slapped GPS+ on the D-9 and one of the D-11s and got to work.”
The initial church pad portion of the job was located on a former dairy farm. The hilly site presented its own special problems: Some areas required more than 30-foot cuts; others needed fills of more than 25 feet.
Garrett solved the problem of moving more than 170,000 yards of dirt in a short time span. The crew finished the work in less than 30 days. (The total job will entail moving more than 800,000 yards of dirt.) In the rough grading phase, crew members ran the three bulldozers side by side using the two Topcon-equipped GPS-controlled dozers to set the angle and depth of the cuts; the third dozer shadowed the movement of the other two with amazing results.
The result was a 57-foot-wide, 9-foot-high “wall of dirt” moving across the pad site. “I’ve been around dirt work all my life,” Garrett said, “and that even impressed me.”
Due to the contour of the site, the “shadow” dozer operator “eye-balled” the blade position in relationship to the position of the other blades of the GPS+-equipped dozers. When the machines were close to final grade, the two GPS+ dozers were used and “we were within 0.10-foot consistently,” Garrett said.
The church pad was finished three days early. “Without using GPS technology, the 30-day limit to finish the pad would have been impossible,” he said. “But using satellite positioning, ingenuity and the right people on the crew gave us a big productivity edge.”
Komatsu’s KOMTRAX provides not only location and hour meter updates, but additional invaluable information regarding machine health and productivity.
The system was designed to give owners the information they need to make strategic business decisions regarding machines and their operations.
KOMTRAX relays basic and critical performance data from a machine to the owners’ computer as well as to the local distributor. Owners receive detailed information in easy-to-read daily, monthly and annual reports about both basic and more advanced aspects of machine performance.
Lists and charts are great, but they don’t mean much unless owners can easily adapt that information to more efficiently use their equipment. Because one key way to lower costs is to reduce machine idle time, the KOMTRAX system has a feature that differentiates between idle hours and actual working hours.
KOMTRAX has been standard on most Tier 3-compliant Komatsu machines since early 2006 which have provided revealing analysis of machine idle time statistics for thousands of machines. According to those data, 20 percent of 20-ton class excavators idle more than 50 percent of their service meter hours, and the average idle time for this machine class is 36 percent of the time. But some operators idle far less. By using the data provided from the remote monitoring system, 20 percent of the operators have reduced idle time to fewer than 20 percent of operating hours.
Over a machine’s life, idle time typically accounts for nearly 20 percent of the machine’s total fuel burn. By eliminating 50 percent of non-productive idle time, fuel costs can be reduced by 10 percent. And, in today’s environment of rising fuel costs and increased concern about global warming and diesel engine emissions, this kind of reduction is significant.
Reducing idle time saves on fuel costs, but one of the main hidden costs of excessive idle time is reduced residual value of a machine. For example, if two machines actually work 600 hours per year doing identical work, but one idles 40 percent of the time and the other idles 20 percent of the time, these machines will accumulate service meter hours at a different rate. After five years the machine that idles 40 percent of the time will register 5,000 hours, while the one idling 20 percent will have less than 4,000 hours. All other things being equal, the machine with fewer hours is obviously worth more. In addition, the lower hour machine likely will have avoided two maintenance intervals, translating into less downtime for maintenance and more time to move dirt.
Reduced idle time translates into greater operator productivity. Measuring idle time, observing operator behavior, goal setting, and regular operator feedback are keys to reducing excessive idle time. Because KOMTRAX measures idle time, users with multiple machines doing similar work can compare machine-to-machine idle times for insight into how much improvement is possible. Observations of operator behavior and noting when machines are idled are critical pieces of information to set meaningful idle reduction goals. A monitoring system that provides monthly idle time reports can be an effective way to reinforce and reward good operator behavior as well as identify training opportunities for those operators who are slower to change excessive idle habits.
Glacier Computer, a designer, developer and supplier of rugged industrial PC-compatible devices, introduces its Magnum series of computers. Specifically designed for use in the construction industry, the Magnum can be mounted in a variety of work environments and applications. Engineered to withstand shock, vibration, dust, and moisture, the Magnum can be mounted into cranes, dump trucks, backhoes, graders, and onboard forklifts. Additionally, the Magnum can be mounted outside in a fixed location and used as a time clock at a temporary work location.
The Magnum is an Intel-based PC traditionally configured with either XP Pro or XP Embedded. An array of standard I/O allows for attaching numerous peripherals, including portable printers for producing work orders and employee ID card readers. Wide area network cards and GPS accessories provide easy data transfer from the work site and constant vehicle mapping and location data.
Unlike traditional laptop solutions, the Glacier Magnum is a sealed unit with no fans or vents. The unit can operate in the most intense environments, including extremes of temperature, shock, vibration, and moisture. Each unit has a touchscreen and high-bright display for ease of use with even a gloved hand. All units accept and easily run traditional Windows software applications. There are a variety of processor, DRAM, and both rotating and solid-state hard drive options.
Glacier’s Magnum series of computers are HALT tested, have passed thermal and reliability testing, and have an MTBF of nearly 40,000 hours. Built to Mil-Spec standards, these computers have an IP 64 environmental rating.
Trimble’s The Eagle Eye Obstacle Detection System alerts drivers to objects hidden in vehicle blind spots up to 20 feet away. The system features a series of sensors mounted around the truck and an alert module that provides visual and audible warnings of hidden obstacles.
The DriveSafe system automatically records speed on turns, starts and stops in relation to vehicle’s status. In addition, GPS positioning monitors average road speeds, and scores are assigned for each maneuver so driver behavior can be compared to the fleet average. As a result, early adopters such as Maricopa (see Trucking for Construction Special Section) aren’t just working to prevent accidents, they are taking steps to actually improve the quality of their driver’s decisions.
By Greg Sitek — Associated Construction Publications
Some suggest concrete may be cheaper than asphalt for roadwork
(Florida) — Asphalt often wins out over concrete when transportation authorities select materials to build roads. But experts debate whether that might change, as funding for road construction goes down and the price of asphalt, which is petroleum-based, goes up.
Motorists won’t see much of a switch of asphalt roads being replaced with concrete, said Bob Burleson, president of Florida Transportation Builders Association.
But, “in some new construction, there might be an opportunity to look at concrete,” he said.
Asphalt is becoming scarce, as U.S. refiners overhaul their equipment to maximize output of highly profitable fuels, such as diesel and gasoline, using inexpensive — and hard-to- process — crude oil.
The dearth of asphalt compounds the challenges states, counties and cities already face in fixing bridges, highways, local streets and other critical infrastructure at a time when budgets are squeezed by falling income, sales tax revenues and real estate tax revenues. There also are higher costs for fuel, steel and other raw materials.
While it hasn’t experienced the shortages like other states and communities across the country, Florida has seen a spike in the price of liquid asphalt, Florida Department of Transportation spokesman Dick Kane said.
Liquid asphalt makes up only about 6 percent of the asphalt mixture, but adds 40 percent to the cost, he said.
The shift in refinery technology that led to the decline in asphalt production was spurred by increased oil prices earlier this year.
Oil refineries around the country are installing billion-dollar machines called “cokers” that are able to refine the chunkiest, low-grade and least expensive crude oil into highly profitable fuels, such as gasoline and diesel.
Asphalt is cheaper than concrete upfront, but concrete lasts longer before it needs repairs.
When deciding between the two materials, the Florida Department of Transportation compares the life of the road with the cost of using both materials, said Roger Schmitt, materials and research engineer for DOT District 5, which includes Brevard County.
That amount includes not just the initial construction costs and the price of maintaining it, but the costs to drivers in terms of their time spent delayed in construction traffic and the cost of running their cars.
An analysis for a section of Interstate 95 being widened from State Road 528 to Fiske Boulevard pointed to concrete as the more cost-effective option.
Generally, road project analyses have to show the project done with concrete will last three times longer than if it’s done with asphalt before the transportation agency picks concrete, Schmitt said.
But that could shift somewhat as asphalt prices rise.
“If asphalt increases more, concrete will become more and more viable,” he said.
Building roads with asphalt can end up costing more when upkeep costs are considered, said Jamshid Armaghani, director of concrete paving with the Florida Concrete & Products Association.
“The reason this cost is becoming a drain on the counties and cities is because asphalt more often needs repair and resurfacing,” he said.
Meanwhile, concrete pavement should last for 40 years before it needs maintenance, he said.
State Road A1A, which he said was built with concrete, has been in place for 60 to 70 years.
“It’s like buying a car that’s going to cost you a little bit more, but doesn’t require maintenance over the long time,” he said.
Asphalt advocates, however, dispute that.
Asphalt is easier to repair than concrete, said Margaret Cervarich, vice president for marketing and public affairs with the National Asphalt Pavement Association.
To rehab asphalt roads, crews only have to mill off the top inch or two, and replace it with a new overlay, Cervarich said. In some cases, that milled material can be reused at the site.
“Regardless of the initial cost, the life cycle of asphalt is always going to be lower,” she said.
BY SUSANNE CERVENKA
there has been much discussion regarding the carbon footprint of different pavement types, namely concrete vs. asphalt. Judging by the various opinions expressed, it appears that there are strongly opposing views.
As such, it was refreshing to hear Dr Helen Murphy, director, Environmental Services for VicRoads, present her paper – “The Carbon Footprint of Road Construction,” at the 2008 Roading New Zealand Conference held in Wellington recently.
Dr Murphy stressed that the main reason for the dissimilar carbon footprint estimates cited by the concrete and asphalt industries, stems from the different methods of calculation each adopts to present its case.
The asphalt industry has traditionally restricted its method of carbon footprint calculation to the embodied energy approach, while the concrete industry has taken a more comprehensive life cycle assessment approach.
In discussing potential future actions for greenhouse gas abatement, Dr Murphy examined vehicle and fuel technologies, travel behaviour and urban planning, as well as road design and construction. She emphasised that to gain an understanding of a roading project’s true carbon footprint, it is essential to perform a life cycle assessment.
Nicholas Stern, in his groundbreaking report – “The Economics of Climate Change: The Stern Review,” also chose to follow the life cycle assessment path, and it has become standard for many government departments here in New Zealand.
The term ‘life cycle’ refers to the notion that a fair, holistic assessment requires the consideration of raw material production, manufacture, distribution, use and disposal (or reuse/recycling), including all intervening transportation steps necessary or caused by the product’s existence. The sum of all those steps – or phases – is the life cycle of the product. The procedures of life cycle assessment are part of the ISO 14000 environmental management standards: in ISO 14040:2006 and 14044:2006.
As the appropriate means to investigate and value the environmental impacts of a product, caused or necessitated by its existence, a life cycle assessment fully accounts for the durability, low maintenance, and reduced fuel consumption benefits of concrete roads. This approach has recently been adopted by the Athena Institute, a non-profit organisation specialising in the science of life cycle assessment, who were commissioned by the Cement Association of Canada to produce a comprehensive report comparing the carbon footprint of concrete and asphalt roads.
The report – “A Life Cycle Perspective on Concrete and Asphalt Roadways: Embodied Primary Energy and Global Warming Potential,” is available at http://www.cement.ca/index.php/en/Life_Cycle_Perspective_.html
The report presents estimates of embodied primary energy usage and global warming potential over a 50-year life cycle for the construction and maintenance of a range of comparable rigid concrete and flexible asphalt pavements for highly trafficked roads.
In all cases, the embodied primary energy use is lower for the rigid concrete pavement. The report also demonstrates that if concrete shoulders and concrete restoration with no overlay are implemented as part of the maintenance and rehabilitation schedule, the primary embodied energy requirements will be 5.6 times higher for the asphalt option.
In order to measure direct global warming potential, the report also converts all greenhouse gas emission estimates (CO2, CH4 and N2O), using the well-accepted CO2 equivalence method developed by the International Panel on Climate Change. The results vary depending on pavement structure, but in some instances are up to 11 per cent higher for the asphalt design compared to the concrete alternative.
As illustrated by the Canadian report, if the true carbon footprint of a pavement type is to be calculated, then the inclusive methodology of life cycle assessment must be adopted. This requires that a service life of at least 50-years (not a mere 30-years) be the norm, and that all resources consumed in relation to maintenance and fuel consumption during the service life, be considered.
The ability to accurately gauge the superior long-term maintenance and user benefits of concrete roads through life cycle assessment methodology, must inevitably lead to their uptake for highly trafficked roads in New Zealand. This requirement is more pressing if the New Zealand Transport Agency is to contribute to an affordable, integrated, safe, responsive and sustainable transport system, and even more so if the Prime Minister’s vision for New Zealand becoming the world’s first carbon neutral country is to be realised.
By Patrick McGuire, Cement & Concrete Association of New Zealand (CCANZ)
SINGAPORE’S building industry is taking steps to green itself, with the opening on Wednesday of a new plant which will recycle used copper slag to make concrete.
The plant by Geocycle Singapore can process 360,000 tonnes of collected copper slag from local shipyards, which will be a substitute for sand in making ready-mixed concrete.
The Sungei Kadut facility will also function as a research and development centre for alternative and eco-friendly building materials.
It is a joint venture firm by cement maker Holcim Singapore and local recycling firm ecoWise, which have equal stakes.
By Jessica Cheam