Showing posts with label Penetration Grade Bitumen. Show all posts
Showing posts with label Penetration Grade Bitumen. Show all posts

October 10, 2016

TOT or Advance Selling of Human Traffic Loads ?

The National Highways Authority of India (NHAI) is preparing to start the process of monetizing toll-based operational road assets under the toll, operate and transfer (TOT) model, aimed to bring new investments to the highways sector.

“We have not as yet floated tenders to monetize road assets, but are preparing to do so. We expect to begin doing this in 2-3 months’ time under the TOT model,” NHAI chairman Raghav Chandra said in an email response to queries from Mint.

This will be India’s first exercise in auctioning NHAI’s operational projects after a cabinet clearance in August. The proceeds will fund new highway projects under various models.

NHAI is currently working on the guidelines for TOT, under which the investor will collect tolls and be responsible for operation and maintenance of the project. The TOT model will be essential to attract long-term foreign investment, financial investors and investment bankers told Mint.

NHAI can lease up to 75 national highway projects which are fetching tolls for at least two years to various entities on the TOT model. The overall annual toll collected from these projects is about Rs2,700 crore, against which NHAI can expect to raise Rs25,000-30,000 crore by granting 30-year concessions, said Ashish Agarwal, director (infrastructure) at investment bank Equirus Capital.

The TOT model is long overdue, said Gautam Bhandari, partner at I Squared Capital, a US-based investor in road projects. “We are hopeful that NHAI finally does launch its TOT programme so that it can serve as a model for other sectors as well. As a global investor, we believe that NHAI’s TOT model, if executed properly, could be a win-win for everyone. Proceeds from TOT auctions will free up valuable taxpayer capital that can then be recycled for much-needed new infrastructure projects,” he said.

I Squared is looking to invest as much as $1 billion in Indian infrastructure. It has invested more than Rs1,000 crore through its investment platform Cube Highways and Infrastructure Pte. Ltd in three road projects so far.

IDFC Alternatives, which has bought controlling stakes in operational road projects, is waiting to see the fine print. “The good part is that in the TOT model, there are far less variables and concerns to be addressed as compared to projects with embedded construction risks. The differences in the bids here would be more a function of how differently each investor views the traffic growth rates, maintenance costs, synergies with other projects in one’s portfolio, if any,” said Aditya Aggarwal, partner (infrastructure), IDFC Alternatives.

There is significant interest from international infrastructure funds in the Indian road sector, said Rahul Mody, managing director, Ambit Corporate Finance Pvt. Ltd. “The TOT model is an excellent idea. The model takes away two key risks in the road sector—delays or cost overruns and initial traffic discovery—as the assets that will be offered under this (model) will be operational with some tolling history; hence it should attract considerable interest from Indian companies as well as foreign investors,” Mody said.

“The model can be an avenue for NHAI to raise upfront capital to fund the EPC and HAM projects; opportunity to feed the increasing number of pension funds and infrastructure investors having access to low cost capital and further deepen the infrastructure market; and allowing players to choose better the nature of risk-reward play they want to play in the road sector,” Agarwal said.

Source- LiveMint

October 8, 2015

Nigeria Missed the Bus Again - This time Not Crude But Bitumen

Iriele is a small community situated in Ondo State and the indigenes have high demands for development. Over the years, they have dreamt of the day when bitumen would be exploited, creating job opportunities, infrastructure and economic prosperity. The people of this town consider bitumen as a God endowed heritage which should be harnessed immediately to create jobs, deliver infrastructure and reduce the hardship they face daily. 

Those dreams have not become reality up till now, denting their hopes and leaving them frustrated as the indigenes of these towns wait endlessly for the government to attract the needed investment.

In the light of the foregoing, is the wider debate about Nigeria’s rich mineral reserve and the failure of the government to properly utilise the wealth of the nation to the betterment of lives of the citizenry. This belief is voiced by majority of the ordinary people in this bitumen bearing community including border communities like Agbabu and Ilubirin.

Nigeria is the sixth largest bitumen deposit in the world with most of the reserve found in Ondo State. However, there’s a wider debate about Nigeria’s rich mineral reserves and the failure of the government to properly utilize the wealth of the nation to the betterment of lives of the citizenry.

This belief is voiced by majority of the ordinary people in this bitumen bearing community including border communities like Agbabu and lIubirin. They have argued that since 

Nigeria’s crude might no longer generate sufficient revenue to run the nation’s economy, there should be an alternative to fall back on. In the perspective of these pro-bitumen agitators, bitumen is a guaranteed option as Nigeria re-defines its roadmap to economic recovery.

A lawmaker representing the Irele-Agbabu State Constituency in Ondo State House of Assembly, and one of the key proponents of bitumen Honourable Afolabi Iwalewa, thinks that the wobbly situation of Nigeria’s oil is a wakeup call for the exploitation of bitumen:

“ Any moment from now, crude oil will fade off. Look at what is happening now with the talk of oil theft. Every state is crying now, even the Federal Government is crying that it is not getting what it used to get from oil. What is the Federal Government doing, and why can’t we find another alternative? If crude oil is not going to fetch us what we project (in terms of revenue), why can’t we switch over to bitumen?”

Another standpoint of Honourable Iwalewa’s pro-bitumen advocacy is that the non-exploitation of the resource is causing people in these communities a lot of trouble because they have to cope with the reality of spill ravaging precious farmlands where bitumen is found so close to the surface that a simple shovel can excavate the glossy black substance.

Bitumen is found in tar sands, which is also a combination of clay, sand and water. A heavy black viscous substance, oil-rich bitumen is extracted from tar sands, which is then refined into oil. The bitumen in tar sands cannot be pumped from the ground in its natural state; instead tar sand deposits are mined, usually using strip mining or open pit techniques, or the oil is extracted by underground heating with additional upgrading.

In essence, it involves a complex process that will certainly disrupt their lives and livelihoods beyond what they can imagine. This is what the people of the bitumen bearing communities in Ondo State are calling for when they appeal for the exploitation of the resource in their soil.

Taking a closer look at the experience of Canada, the biggest producer of tar sands globally, shows that exploitation has actually resulted in serious damage to the local communities and the environment. The clearing of vast area which is a component of the mining process is responsible for the Canadian moon-landscape we see in Alberta, Canada, where large forest with pristine trees that sprawled across its landscape now looks more like a waste land ravaged by the exploration of bitumen.

In spite of all of the warnings pointing at the dangers of venturing into tar sands exploitation, especially the apparent impacts of livelihoods of ordinary people due to the far reaching implications for the environment, including the lands and water bodies, the people in the bitumen bearing communities have inclined to brush these opinions aside.

Olofun of lrele, Oba Olarenwajulebi, the octogenarian traditional ruler of the Irele community, for instance, criticizes talk of possible environmental hazards if bitumen were to be extracted in the area. He brags about of what his realm would look like if development were to prevail, using bitumen as the tool.

“If development were to succeed the way the people of this area want it, this town would have looked like Lagos. I say so because bitumen will provide a lot of employment for all the youths in this area, not in Irele alone, but all over the Southern senatorial district and even in the whole of Ondo State. The bitumen deposit here is a very huge one. It is the second largest in the world, according to the survey conducted by some experts,” he enthused.
And on the Canadian experience he explained: 

“In Canada, they do it in Calgary, and I have been there. They don’t drive away communities, and they replenish the soil. Where they mine the bitumen, they mix the soil with some chemicals, and restore it for the farmers to go back there and farm. And when those people were working here, I talked to them and they told me that even if they have to relocate some communities, they will have to build some fine buildings for them, and that the exploitation won’t affect much of their lands. It is something that they will dig from the ground; and it won’t affect us adversely.”

There’s no doubt that the allure of jobs, development and the improvement they envisage that bitumen development would give to their communities has strengthened their resolve to continue campaigning for the exploration of their God-given wealth. Any attempt to make the pro-bitumen agitators to consider the consequences is usually met with cold shoulders.

However, a geologist at the Federal University of Technology, Akure, Ondo State, Professor Peter Odeyemi offered a much more balanced picture of the realities on the ground. Odeyemi, who was a member of the defunct Federal Government’s Bitumen Implementation Committee (BIC) made a poignant observation when he noted that the mere presence of a resource does not necessarily translate into commercially viable deposits.


“The first thing is that how much is there? We don’t know! We need to carry out further work in that area in the first instance. Secondly, exploration can be carried out by an oil company because bitumen is a hydro-carbon but also there are difficulties (technical difficulties). If an oil company is going to carry out an exploration there, there is an interest, financial one. This company will calculate how much it’s going to get. It will also look at certain technical issues and the ease of exploitation. This is so because although both of them are hydro-carbon, one is easier to exploit than the other.

Also,how will you exploit without exposing the soil to direct rain fall impact, denudation, erosion and degradation. So they have generation of enlightened professors and everything. The place is highly enlightened and the environmental issues are potent here like in Europe. If you look at the Niger Delta, the people just welcomed oil companies with open hands not knowing that oil companies are devils. They are only interested in profits. They are not in any way interested in environmental sustainability, in flora, in fauna and even in the development of the people,” he said.

He continued: “Our problem is not bitumen; our problem is corruption. What do we do with the money we have been getting from oil? The one we are exploiting, what are we doing with it? The people are getting poorer; there is no electricity, water, healthcare, and education. This is despite the fact that we are making trillions of dollars. So, if we now exploit bitumen and add another trillion, we are just going to multiply the corruption,” Odeyemi concluded.

There is no doubt that the exploration of bitumen will have a heavy toll on the environment of Iriele, and neighboring Agbabu and IIlubirin Communities in Ondo State. Water will be polluted, farmlands destroyed, large expanse of forest will be brought down and communities destroyed. Is this kind if cost these communities are willing to pay or are their alternative development paths that communities can take that will have more sustainable economic impact? As the federal government plans to diversify the economy, and explore mining of solid minerals as an alternative, there’s no gainsaying that the environment must be protected even as the nation seeks improved economic fortune.


Inwerogu wrote from Lagos

September 23, 2015

Process and Save OilSands

Plans For Bitumen Refinery Ramp Up

Keynote speaker Frank McKenna at Bitumen Conference in Sarnia May, 2013Keynote speaker Frank McKenna at Bitumen Conference in Sarnia May, 2013
The Chairman of the Sarnia-based Bowman Centre is convinced that in 2016, possibly sooner, a commercial partner will be announced for the ambitious $10-billion SABER project.
The Sarnia-Lambton Advanced Bitumen Energy Refinery would process heavy crude from the Alberta Oil Sands and has been described as a potential game-changer for the economy.
The Bowman Centre, located at the Western Research Park, says 30 local organizations have recently committed over $100,000 to take the project to a new level.
Clem Bowman says a commerical proponent is needed to update marketing, logistics and margin analysis reflecting current crude oil prices.
He says with Prime Minister Harper’s indication of support in principle, they can proceed with or without the support of the provincial government.
Audio Player
A group of former Chemical Valley executives launched the project saying Canada is losing $2.5-billion a year by exporting, rather than processing oil sands bitumen at home.
They say there is an existing pipeline from Alberta to Sarnia, access to international markets and serviced industrial land available.
There is also a commitment to build a leading edge plant in terms of energy and greenhouse gas efficiency.
(With files from Josh Boyce)

August 29, 2015

Bitumen or the Environment ?


Aboriginal groups fear the consequences if bitumen from the Alberta oilsands were to spill into the sensitive ecosystem of Great Bear Rainforest. Part of the 2015 Atkinson Series on public policy.

A humpback whale breaches the surface near Hartley Bay along the Great Bear Rainforest in British Columbia. First Nations in the region are vehemently opposed to the Northern Gateway pipeline.
JONATHAN HAYWARD / THE CANADIAN PRESS FILE PHOTO
A humpback whale breaches the surface near Hartley Bay along the Great Bear Rainforest in British Columbia. First Nations in the region are vehemently opposed to the Northern Gateway pipeline.
Art Sterritt is the executive director of Coastal First Nations, an alliance of aboriginal groups in British Columbia. Though living about 1,200 kilometres west of the oilsands, Sterritt and other native leaders in the area have developed a keen interest in the production of thick black bitumen.
That’s because oilsands developers and Enbridge are proposing the $8-billion Northern Gateway pipeline be built between northern Alberta and the B.C. coast. It would move 525,000 barrels a day of diluted bitumen to Kitimat. There, it would be loaded onto tankers that would have to navigate chains of islands and narrow channels before reaching open sea en route to Asia.
The coastal First Nations in the area, known as the Great Bear Rainforest, make up the majority of the population, and they don’t want the pipeline. They particularly don’t want tankers full of diluted bitumen — which is much thicker than crude oil — in waters where salmon abound in a complex ecosystem that has supported their people for centuries.
“We are never going to allow pipelines as long as (the oil) can’t be cleaned up,” Sterritt told an audience in Calgary in June. “We know what happened just to the north of us with the Exxon Valdez.”
Haisla First Nation hereditary chiefs attend hearings on the proposed $8-billion Northern Gateway pipeline in B.C. in 2012. The pipeline was eventually approved, with 209 conditions.
DARRYL DYCK/THE CANADIAN PRESS
Haisla First Nation hereditary chiefs attend hearings on the proposed $8-billion Northern Gateway pipeline in B.C. in 2012. The pipeline was eventually approved, with 209 conditions.
In March 1989, the Exxon Valdez supertanker struck Bligh Reef and spilled 11 million gallons of crude oil into Alaska’s Prince William Sound. It was the worst American spill up to that point, damaging more than 2,000 kilometres of shoreline and killing hundreds of thousands of birds and marine animals and untold numbers of fish.
The Northern Gateway pipeline was the subject of extensive public hearings by the National Energy Board in 2012 and 2013, during which Sterritt’s group and others registered their fears. In the end, the National Energy Board approved it with 209 conditions that must be met before it proceeds. The Harper government seconded the motion when it gave its approval a few months later.
But many doubt the pipeline will ever be built because it is the subject of 18 court cases. Enbridge has confirmed that it won’t be in service by 2018, as previously predicted.
That’s fine with Sterritt, who asserts that it is incumbent on the oil companies to figure out how to clean up a spill should a tanker rupture or capsize.
“So far they haven’t done that,” he said. “There is no technology available to clean up oil spills. They just keep telling us that the chances of a spill are very low. But that’s not good enough.”
According to the final report of the Northern Gateway Joint Review Panel, there is significant disagreement among experts about whether the heavy diluted bitumen would sink to the sea bottom if a tanker ruptured, making it much more difficult to clean up than if it were floating on the surface. Enbridge says the diluted bitumen would float, but intervenors from Environment Canada and Fisheries and Oceans testified that their studies were inconclusive.
The joint review panel decided that a spill is “not likely to sink as a continuous layer that coats the seabed or riverbed.” But some of the conditions Enbridge must now meet deal with spill response and require further research on the likelihood that diluted bitumen would sink.
Meanwhile, bitumen is being transported by existing pipelines and trains. But as production at oilsands operations increases, there will be more pressure to build a pipeline such as the Northern Gateway.
Douglas Channel is the proposed end point of the Northern Gateway pipeline, which would carry 525,000 barrels a day of diluted bitumen from northern Alberta to the B.C. coast. Experts say more research is needed on the effects of an oil spill involving oilsands products.
DARRYL DYCK/THE CANADIAN PRESS
Douglas Channel is the proposed end point of the Northern Gateway pipeline, which would carry 525,000 barrels a day of diluted bitumen from northern Alberta to the B.C. coast. Experts say more research is needed on the effects of an oil spill involving oilsands products.
Source & Copytight -THE STAR

October 17, 2014

Return of the Bitumen Bubble

The Author discusses the Bitumen Bubble in waiting if the curdue oil price falls below USD 80.

Just when you think you're finding your way out of the woods, there's that damned Bitumen Bubble again.
This time, it's crude oil prices that are declining -- or, as they say in journalese, the official language of the Internet, "plummeting."

This is handy for conservatives once they're elected and want to cut the crap out of public services they promised to protect, but not so good in the lead-up to an election during the phase when conservative governments of all stripes go into a tax-and-spend-liberal-spree mode and shower dollars on electors.
The special problem facing newly selected Progressive Conservative Premier Jim Prentice out here on the western edge of the Great Aspen Parklands is that his principal opponent in the upcoming Oct. 27 mini-election, in which he hopes to get his own place in the Legislature and a couple more for his two unelected cabinet members, is another conservative party.

Before October 27 and certainly before the next general election, the Wildrose Party under would-be premier Danielle Smith will scream if the budget isn't balanced, and large numbers of cherry-picking voters will grow surly and disagreeable if it is, leastways if that means their particular enthusiasms aren't fully funded.
Imagine how much easier things would be for Prentice's PCs if the official Opposition party were the NDP!

Well, New Democrats will be working on that this weekend in Edmonton, but in the meantime the premier is just going to have to figure out a way to live with the cranky deficit scolds from the Wildrose opposition who don't have the disadvantage of having to actually run the place at the same time as they're trying to live down fired premier Alison Redford’s gruesome reputation.

It's always astonishing to me that conservative politicians -- who supposedly have the inside track on thinking like business people -- can’t figure out that commodity prices are cyclical. In other words, this week's oil-prices-are-too-low crisis can turn overnight in to an oil-prices-are-too-high crisis, and Prentice most certainly hopes it does.

Meanwhile, a new public opinion poll by ThinkHQ Public Affairs suggests Prentice's PCs are enjoying a bit of a honeymoon bounce -- although not necessarily where they need it the most for the four upcoming by-elections, three of which are in Calgary and one here in Edmonton.

ThinkHQ President Marc Henry's take Tuesday on these numbers was that "Tory fortunes have turned sharply positive" and, moreover, "the momentum shift is in the Tories' favour."

ThreeHundredEight.com author Eric Grenier's analysis of the same numbers yesterday, however, was that while the poll shows the Prentice PCs are closer to the Wildrose popularity numbers than they've been for a while, the Wildrose is doing well enough in Calgary it will be hard for the government to win all four seats.
So, from the PC perspective, this close to four crucial and highly symbolic by-elections was probably not the right moment for the media to start chanting gloom and doom about oil prices at the shocking thought of oil descending to a mere $82 per barrel.

Meanwhile, also yesterday, without any fanfare whatsoever, the government quietly issued a proclamation repealing the Redford Government's draconian Bill 46. That law -- technically known as the Public Service Salary Restraint Act -- would have enabled the government to order the Alberta Union of Provincial Employees back to work with a truly crappy contract had not the Alberta Court of Queen's Bench intervened last February and granted the union an injunction blocking the law's application.

The court's scathing ruling -- which excoriated the Redford government for bargaining in bad faith and other labour relations sins -- blew the government's entire strategy for dealing with its public service unions to smithereens.

In a way, the repeal of Bill 46 is meaningless -- a negotiated deal with AUPE after the injunction was issued having effectively rendered it moot.

Nevertheless, it can hardly have been unintended that one of the few remaining relics of Redford's bizarre anti-labour legislative agenda was tossed over the side the day before AUPE’s 38th annual convention was scheduled to start. That meeting will commence at 9:00 this morning with 800 or so AUPE members belting out Solidarity Forever.

Prentice's hope, it is said here, must have been that the symbolism of this will remind unionized public employees of the dangers of voting for an even more conservative party than the PCs.

However, still remaining on the law books, sort of, is the odious Bill 45 -- the Public Sector Services Continuation Act, which effectively banned free speech by all Albertans if they happened to feel like advocating a public service strike.

This bill was given Royal Assent on the same day as Bill 46 -- December 11, 2013, another December day that shall live in infamy -- but was never proclaimed by the chicken-hearted Redford Tories, presumably to make it harder for the courts to get their hands on its self-evidently unconstitutional restrictions on free expression.

With Bill 46 on the floor where it belongs, one hopes Prentice will soon drop his party's other remaining legislative shoe as well.

This post also appears on David Climenhaga's blog, Alberta Diary.

By David J. Climenhaga

djclimenhaga's picture 
David Climenhaga, author of the Alberta Diary blog, is a journalist, author, journalism teacher, poet and trade union communicator who has worked in senior writing and editing positions with the Toronto Globe and Mail and the Calgary Herald. His 1995 book, A Poke in the Public Eye, explores the relationships among Canadian journalists, public relations people and politicians. He left journalism after the strike at the Calgary Herald in 1999 and 2000 to work for the trade union movement. Alberta Diary focuses on Alberta politics and social issues.

December 24, 2013

Kazakhstan Launches Bitumen Plant


Kazakhstan has commissioned a new plant for production of road bitumen at Aktau Plastics Plant (Aktau bitumen plant) that was constructed by a group of companies KazMunaiGas.

The company reported that Governor of Mangistau region Alik Aidarbayev, Extraordinary and Plenipotentiary ambassador of China Le Yucheng, representatives of the Ministry of Oil and Gas of Kazakhstan and KazMunaiGas JSC, the management of CITIC Group company, Caspi Bitum JV LLP and other partner companies participated at the event.


"Our plant can almost completely cover the needs of the country in bitumen. This is a joint project of the KazMunaiGas National Company and the Chinese company CITIC Group," Chairman of the Kazakhstan Petrochemical Industries JSC Dauletkerey Ergaliev said.

The plant will produce about 400,000 tons of oxidized and 120,000 tons of modified road bitumen, as well as 15,000 tons of gasoline fraction and 230,000 tons of kerosene and diesel fraction, 220,000 tons of vacuum gas oil.

To avoid the loss of quality of bitumen while transporting it to the asphalt paving place, Aktau bitumen plant provides innovative technology for packing bitumen into a disposable shipping container of two types - Big Bag (1000 kilograms) and plastic bags (40 kilograms).

The use of packed cold bitumen will not only keep the original physicochemical characteristics of the material, but also get savings in asphalt plants by reducing the costs of keeping the molten bitumen in large bitumen storages.
Source- AZERNews

March 12, 2013

Self Healing Roads

Self-healing roads may one day become a reality, after a university engineering professor invented an asphalt that can last twice as long as the traditional porous variety.
 
Delft University of Technology professor Erik Schlangen said the key is to add steel wool fibers to close the cracks that may form in porous asphalt.
 
"We add a very small amount of steel wool fibers, less than one percent of the volume, and then apply an induction plate to heat up the steel wool. When the wool heats up it melts the bitumen around it and closes the micro cracks,” he said, according to a report on HumansInvent.
 
HumansInvent noted a porous asphalt road will last about eight years before the top layer will replacement.
 
Schlangen said that while porous asphalt has very good properties, it has "durability problems."
 
With many pores, he said oxidation is faster than with usual asphalt, and the bitumen becomes very brittle due to this oxidation and cracks easily.
 
"You get these small micro cracks in the bitumen and so, when a car drives over the road, the stones at the surface come off," he said.
 
Such small cracks may grow until they become large potholes that can damage vehicles and eventually cause accidents, HumansInvent said.
 
Schlangen said they have tested the steel-infused asphalt on a 400-meter section of road in the Netherlands, and the initial results appear encouraging.
 
“We’ve tested a 400 meter section of road in the southern Netherlands that we laid down two years ago. There we applied induction heat and it works perfectly. We took a lot of samples from the road and aged them in the lab by putting them in the oven and spraying them with water etc and then applied induction heat and the tests have proved that we can double the surface life of asphalt, maybe even more,” he said.
 
Induction heating
 
Under Schlangen's solution, when cracks start to appear every couple of years, induction heat can be applied to the roads and they would heal themselves.
 
“You have to do that before they turn into potholes. You go on the road with an induction machine, it can be on a truck say and you drive over it, it heats up the wool and melts the bitumen and then the stones are fixed again,” Schlangen said.
 
High cost
 
HumansInvent said that while the steel-infused asphalt costs more, it may bring savings in the long run.
 
“The cost of material is increased somewhat because you have to add steel fibres but that’s not more than a 25-percent increase of the cost of the material and then there is the induction machine – you need some investment to build that and you have to drive over the roads with it. However, if you have double the surface life of your road, and no maintenance in between except driving over it with an induction machine, that saves a lot of money – the government will be able to make new savings this way,” Schlangen said.
 
Source - TJD, GMA News

October 2, 2012

Concrete or Asphalt - Besides the Economy




One of the questions you’ll hear drivers and crew chiefs asked a lot this weekend at Dover is how the concrete track affects the racing.  Here’s how:
 
 Concrete and asphalt are father and son.  They have in common what you and would call it “rocks”, but professionals call it “aggregate”.  Aggregate comes in a huge variety of types, depending on the materials from which the rocks are made, the quality of the material, the size of the rocks and the distribution of sizes of the rocks.

  Asphalt vs. Concrete

Concrete is an technically any mixture of rocks aggregate stuck together with a binder.  The type of binder determines the properties of the concrete and even the color.

Concrete is the oldest engineered construction material, dating back to the Roman Empire.   The reason only parts of the Roman Colosseum and the Pantheon are missing have more to do with humans than the failure of the materials.  Today’s concrete is more than ten times stronger than the version the Romans developed.
The most common binder in the concrete used in roads, parking lots and sidewalks is Portland cement.  Portland cement (and its close relatives) are mixtures of  limestone and clay, which are crushed to a powder and heated to over 2700 degrees Fahrenheit.  This is the form you buy it in.  To use is, you reconstitute the dry powder with water, and the individual grains form calcium-silicate-hydrate (C-S-H) bonds that make a very strong glue.

Asphalt is a type of concrete, that uses bitumen — tarry black stuff — to hold it all together.   A typical composition for asphalt is 80% aggregate, 15% binder and 5% air voids.  Bitumen comes from the heaviest components of crude oil, and has the consistency of molasses (which is why it has to be heated before being used).   Because bitumen derives from oil, the price of asphalt changes with the price of oil.



But Which is Better?

As with most “which is better”, the answer depends on what you what to use it for.  The primary difference between asphalt and concrete is the rigidity of the two materials and how they distribute the load over the base on which they are laid.   The more rigid the pavement, the more the load is distributed over the surface when something like a car move over it.

Asphalt, which is more flexible (relative to concrete), transmits higher, more concentrated loads to the base, as shown below.  I’ve drawn the stress distributions in red.  The concrete spreads out the stress over a larger area, while the asphalt transmits stress to a narrows area.  The narrower area and the same load means that the stress is more concentrated.

Because concrete is stronger, asphalt has to be thicker to get the same rigidity.  Asphalt does have an advantage, however, in that its flexibility allows it to expand and contract with temperature changes with less cracking.  Even so, concrete lasts 10-15 years longer than asphalt.

Asphalt is the traditional material for paved racing surfaces.  Only three Sprint Cup tracks feature concrete:  Dover, Martinsville and Bristol.  They have in common that they are all tracks of one mile or less with significant banking.  (OK – you may not view the 12 degree banking at Martinsville as ‘significant’, but those 12 degrees are the reason the corners are concrete while the rest of the track is asphalt.  The stress on the pavement in the corners necessitated replacing the original asphalt with concrete.)

Dover is one mile with 24-degree banking and Bristol is a little more than a half mile with 24-28 degree banking.  The steep banking and the tight curves make keeping asphalt in good racing condition a challenge.  Having concrete also gives a track a unique character – as well as the opportunity to have a really cool monster statue outside.

How Concrete Changes Racing

 Grip Level
The grip level can be very different between asphalt and concrete, depending on a lot of factors.   Concrete is inherently more grainy, and its surface can be patterned to create more grip.  Drivers talk about bumps in asphalt as being large and wavy, while bumps in concrete they describe as  more vibrational.  Concrete usually has to be laid down in sections, which means you can have those bumps like you find between slabs on a sidewalk.  The picture at left shows the Google Earth view of Dover’s surface and you can see the individual slabs.

The grip on an asphalt  track depends  on the type of aggregate used, the degree of wear and the character of the bitumen.

For example, Atlanta has a very rough surface because its bitumen wears faster than the aggregate, as I’ve shown at right.   When an asphalt track is first laid down, the surface is very level.  As the bitumen wears away, the tops of the uppermost layer of aggregate are exposed.  The sharp edges of the aggregate are worn down by the tires rubbing against the rocks, but the aggregate sticking out provides a lot of grip.  Eventually, enough bitumen wears away that the aggregate starts coming out, which weakens how well the track holds together and necessitates a re-pave.

Concrete doesn’t wear as fast as asphalt and thus the grip level doesn’t change as much over long periods of time.

Light and Heat

Would you believe that the color of the track makes a big difference in how the track races?
Light comes in a range of wavelengths from smaller than billionths of a meter to larger than billions of meters long.  Our eyes detect a very, very small fraction of that electromagnetic radiation in the nanometer (billionth of a meter) range.  From red to violet, the wavelength ranges from about 800 nanometers to 400 nanometers.  The light from the Sun contains a wide range of wavelengths, including ultraviolet light (UV) (which is smaller wavelength than visibile light), all the colors of the rainbow, and lots of infrared  (IR) radiation.

Our eyes don’t detect the UV or IR light – we see the mixture of all the different colors of light together, which makes white.  Artificial light (like fluorescent) generates a different mixture of wavelengths, which is why it looks different than sunlight.

You see the colors of objects because all materials absorb some wavelengths (colors) of light and reflect others.  When light hits a red object, as I’ve shown at left, all colors except red are absorbed and what comes to your eyes is just the red light.

White surfaces reflect a wide spectrum of wavelengths and absorb very little of the spectrum.  The light that is incident on a white surface is reflected back to our eyes and the broad spectrum of wavelengths we see as ‘white’.  Black is the opposite:  black absorbs a lot of different wavelengths, so very little reflects back to our eyes and we get black.


In addition to the visible light, the spectrum from the sun includes the aforementioned ultraviolet  and infrared waves.  Infrared radiation has longer wavelengths than red light.  We don’t see it – we sense it as heat.  You’ll notice that the lamps they use to keep food warm always have a red glow:  they output some visible light, but they mostly output heat .  You will never see food being kept warm by blue light.
How is all this relevant to a racecar?

Put a piece of black paper and a piece of white paper in the Sun and feel their surfaces after a few hours.   The black paper absorbs a lot of the radiation from the Sun and gets very warm.  The white paper doesn’t absorb as much of the Sun’s energy (although it does absorb some), so it stays relatively cooler.  If you measure the temperature of a track over the course of a race, it can change by tens of degrees depending on the weather.

One effect of the changing temperature is how hot the tires get.  If the track is 60 degrees vs. 120 degrees Fahrenheit, that generates a very noticeable level of change in the grip.  But even more importantly, bitumen (the binder in asphalt) is a petroleum product.  As the temperature rises, oils in the bitumen get warmer and make the track more slippery.   Portland cement is crushed-up rocks which (when dry) are not slippery at all.

The end result is that, a concrete track doesn’t change over the course of a race nearly as much as an asphalt track.  Crew chiefs say that the track at Dover is easier to ‘keep up with’ because changes in temperature over the course of the race don’t change the racing surface as much with concrete as they do with asphalt tracks.

The Nature of Friction

There are two types of friction .  The first, called abrasive friction, is the one you learned about in school.  This is the type of friction between sandpaper on a wood block.  The second kind (which I never know about until I wrote The Physics of NASCAR) is adhesive friction, which is the molecular-level stickiness of the track combining with the molecular-level stickiness of the tires.  The heat generated by the tires makes the topmost layer of the track gooey.  The outermost layer of the tire also becomes gooey, resulting in an effect very much like chewing gum stuck on your shoe on a hot sidewalk.  The gooeyness of the track  bonds with the gooeyness of the tires for microseconds and resists forward motion.  That’s grip.
The nature of adhesive friction on asphalt is very different than on concrete because the two materials are so very different.  Concrete has much less adhesive friction.  This doesn’t change the grip level so much (because the abrasive frictions are different) – however, it does make a big difference in what happens when you lose grip. Think about sticking a weight to a piece of wood with gum.  The asphalt surface would be really sticky gum and the concrete surface would be dried up, not-very-sticky gum.  If you turn the wood so that the surface is vertical, the stickier gum is going to hold better.
In terms of a racecar, Mark Martin pointed out:
“… when you lose grip on a concrete surface, you feel like you just got cut loose from a rope. It’s amazing. It’s like losing half of your grip, rather than about 20 or 30 percent that you lose on asphalt.”
All the drivers’ intuitions that are developed on asphalt – which comprise the vast majority of NASCAR tracks – are thus challenged when they drive on concrete.

So there you have it – not necessarily better or worse, just different.

Source 

DLP Picture

To learn more about me (including upcoming speaking engagements), please check out my personal website:  www.drdiandra.com

 

June 23, 2012

Re Application of Novel Oil Sands Project


E-T Energy Ltd., Calgary, indicated it will refile an application for commercial-scale production of bitumen in Alberta based on a proprietary electrical heating system.

The provincial Energy Resources Conservation Board returned an application filed in July 2009 saying the company hadn’t demonstrated that the system, ET-DSP (for electrothermal dynamic stripping process), can obtain or sustain commercial bitumen production rates. The ERCB cited a lack of production data.
E-T said the application didn’t include results of a crucial field test that remains in progress. It said the test, which it calls Step 3, won’t establish the recovery factor and energy-oil ratio required to produce bitumen until later this year or early next year.

The returned application was for a 10,000 b/d project. “In light of the recent decision by the ERCB, the timing of the Step 3 results, and weak capital markets, management will be considering other alternatives, including a smaller project building upon the existing Step 3 field test surface assets,” E-T said in a statement.
The company holds acreage in the Athabasca oil sands region adjacent to Fort McMurray. The ET-DSP system, based on a grid of production and electrode wells, has been used by the environmental industry for remediation of contaminated sites.

E-T wants to apply the technology to recovery of bitumen from Lower Cretaceous McMurray formation zones too deep to be mined, more than about 75 m, and too shallow to be produced by steam-assisted gravity drainage, less than about 150 m.

 By OGJ editors