"Only the wisest ruler can use spies...There is nowhere that spies cannot be used...Therefore, enlightened rulers and good generals who are able to obtain intelligent agents as spies are certain for great achievements."
"Therefore, one who is skilled in warfare principles subdues the enemy without doing battle, takes the enemy's walled city without attacking, and overthrows the enemy quickly, without protracted warfare."
Sun Tzu, "The Art of War"
SABOTAGED STEEL
SMI and Foreign Scrap Steel
During my investigation I found that the rebar for the Carolina Bays Parkway was manufactured by SMI. This led me into an entirely different realm of conspiracy which will give you serious pause the next time you cross a new highway bridge in America. SMI has one of the largest rebar plants in the country, located in Columbia, S.C. According to their website, they melt scrap steel to produce rebar which is in compliance with the Buy America Act. Scrap steel is big business in the U.S., and much of it comes from foreign sources. At first I thought this was illegal since, according to the Buy America Act of 1982 signed by President Reagan, it was supposed to be illegal for foreign steel to be melted down and made into rebar or other end products for use in federally-funded infrastructure products. Well, not anymore. This regulation was changed by-you guessed it-Bill Clinton. In 1995 the FHWA, under Clinton's former corrupt campaign manager Rodney Slater (and corrupt USDOT Sec. Pena), issued an exemption allowing the use of foreign scrap steel or Direct Reduced Iron products in federal infrastructure projects. There have only been two exemptions ever issued by FHWA since the Act was passed in 1982; the other was some minor exemption which was of little consequence.
You will not believe how much potential damage this act of sabotage by Bill Clinton has conceivably done to our infrastructure system and economy. There are tremendous quantities of steel being imported from Third World countries such as China, Korea, Brazil, etc. For example, according to government statistics (which could easily be underestimates because of laundering of steel) Korea was #1 in rebar imports in 2000, having increased their imports by 3,303.8% since 1996. China increased their total steel products imports by 202.4% over this period; India increased theirs by 1,055.0%. Just imagine the wide range in quality in domestic scrap steel: dirty oil filters with the steel impregnated with petroleum contaminants (over 500 different chemical compounds have been isolated from crude oil), steel with various paint or other coverings, etc. Now complicate this with the fact that the steel is from a Third World source (which is possibly purposely importing bad steel), and the quantity of contaminants is mind-boggling.
According to a 1997 report, of 581,862 bridges in America, about 101,518 are classified as structurally deficient. While not all are in danger of immediate collapse, one of the main contributing factors is corrosion of rebar. It will cost a projected minimum of $78 billion to replace them.
As an aside, I should also mention that foreign-made steel, such as rebar, is not eligible for use under Buy America provisions, but could easily be laundered and used. The only identification on rebar is a simple brand that could easily be duplicated overseas, producing "gray market rebar."
Although I found nothing illegal, it is interesting to look momentarily into SMI's background to see who is really calling the shots. It turns out that SMI is part of a huge conglomerate, being owned by Commercial Metals Company (CMC), which does business worldwide. Their S.C. plant was just enlarged to ultimately double capacity. They terminated their only major pension plan and were involved in graphite-electrode anti-trust litigation. Interestingly, their 1998 stockholders report states:
"This past spring the U.S. Congress passed and the President signed the new $217 billion six-year transportation bill...[which] will help restore the nation's infrastructure and will substantially increase highway spending. Additionally, it includes especially large increases for the states of Texas and South Carolina. Consequently, your company should benefit considerably from this program."
CMC has agents in Thailand, India, Argentina, Egypt, Venezuela, Vietnam, Turkey, Indonesia, Taiwan, Philippines, Brazil, Poland, Belgium and Japan. They have offices worldwide ranging from New York, Australia, England, Singapore, Hong Kong, Switzerland, Moscow, Beijing all the way to tiny Hope, Arkansas (President Clinton's birthplace). Boy, it's a small world!
Their 2001 annual report states:
"Given the strong impetus for globalization, we continue to open up emerging markets in the Near and Far East, as well as South America. In close cooperation with existing and new suppliers, we achieve organic [?] growth through constant market share gains and active product development. Accordingly...we facilitate producers and enable them to accelerate and deepen their market penetration of major U.S. economic sectors such as transportation, housing and capital goods."
Effects of Steel Contamination
Consideration of the above begs the question, what is the effect of these contaminants on the strength of the steel? But yet more importantly, what is the effect on the longevity of the steel? The steel may meet specs after manufacture, but what about after it has been in a bridge for ten years? The answer appears to be the dirty little secret of the steel industry. I conducted a computerized literature search on an engineering database, with records of every published engineering study from 1990 until 2002, and there was only one study which addressed contaminants in rebar, and it was from Pakistan. I only found a handful of studies which addressed the topic of steel contamination in general. Most of the research has been done overseas-very little has been conducted in America. This documents that foreigners know that the steel they are sending us is inferior. The studies I did find confirmed my worst fears. Some in the industry and research must know this, but their silence is deafening. Why is the truth being hidden from Americans?
I want to quote you from the one study I found, conducted by Dr. N. Shams at the University of Karachi in Pakistan [emphasis mine]:
"The presence of residuals [contaminants] affects both the microstructure and precipitation behavior of NB (C,N) and consequently, optimum mechanical properties are not achieved in rebar material...The effect of residuals on the processing and properties of steel has been a long-standing cause for concern for metallurgists. This concern is still valid because of the tremendous increase in scrap-intensive, electric furnace steelmaking and due to the recycling of ferrous fractions of municipal wastes. Carbon-manganese and low alloy steels are produced in very large tonnages and consume large quantities of scrap. Of these reinforcing bar steels have always been a favorite 'dumping ground' for off-chemistry heats, and 0.3 to 0.5 percent residual elements are usually accepted. Efforts toward quality control of this product have not been successful."
There it is, straight from the horse's mouth. In the entire world, this was the only study published in the last 12 years addressing contaminants in rebar, and it admitted that they are a known concern, and this study had to come from a foreign country. There was also a Russian study, which was in Russian except for the abstract, indicating that the Russians had discovered the problems of defective rebar manufacture and had figured out how to prevent it (Kustov et al., 1994). But beyond this, there is plenty more to be concerned about, and the average engineer is totally unaware of it. However, I should mention that I found one paper (Wilson, 1999) authored by a Bethlehem Steel manager, which contained the subdued statement: "Today the need for [high performance] steels is required not only for special situations, but also for everyday structural applications such as bridges and construction equipment."
Hydrogen Embrittlement
There is a little-known chemical reaction that occurs when steel remains in the prolonged presence of moisture, such as that caused by high humidity or rainfall. This effect is known as hydrogen embrittlement, and it consists of the hydrogen and oxygen in the water separating, whereupon the hydrogen causes the molecular structure in the steel to weaken. The process of the splitting of water can be simply described by the following chemical forumula:
2H2O = 2H2 + O2
Actually, it appears that at the molecular level, it is one atom of hydrogen that causes the embrittlement, as H2 is further split apart. What's worse, once this embrittlement starts, it attracts more hydrogen, thus the embrittlement accelerates in a vicious cycle. You will not likely learn of this process in any college engineering textbook nor from an engineer. It is through no fault of their own, but this is just another dirty little secret which has been kept from them. The fact of hydrogen embrittlement is an unavoidable physical process, and nothing can be done to stop it. However, there are many things in the manufacturing process that can be done to drastically slow it down.
Sulfide Stress Cracking
Hydrogen embrittlement is accelerated in the presence of certain contaminants, e.g. sulfur. There is a particular problem in the well drilling industry with high H2S concentrations. The following quote
(click here) reveals how subtle and undetectable this serious problem is [emphasis mine]:
"If H2S is present at all in drilling fluids, it's likely to be at much lower concentrations than would be required to produce severe pitting. In this event, the mechanism known as 'sulfide stress cracking,' or SSC, is cause for much more concern. Sulfide stress cracking occurs as the result of atomic hydrogen entering the metal. Atomic hydrogen, produced during aqueous corrosion, normally recombines to form molecular hydrogen. Molecular hydrogen, the result of the above reaction, is too large to enter the metal and thus is of little concern. However, H2S is thought to discourage this recombination reaction from atomic hydrogen into harmless molecular hydrogen, and hence can aid the entry of atomic hydrogen into the metal. Once inside, the atomic hydrogen will diffuse to 'trap' sites, where it can cause a local increase in stress or a decrease in strength of the metal lattice. For a material under load, there is evidence that the atomic hydrogen will concentrate near stress concentrators and may give rise to crack initiation at such points, leading to brittle fracture of the material. This type of cracking can occur rapidly and without warning. Because of its complexity, confirming SSC as the failure mechanism usually requires expert metallurgical analysis...A higher tensile stress state [such as that of rebar, nuts, bolts, etc. in a bridge-JS], higher H2S concentrations [more sulfur contamination in foreign scrap steel, or tidal muds in coastal areas-JS], lower pH [e.g. naturally acidic waterways-JS], higher pressure, higher chloride concentration [e.g. a coastal environment-JS], lower temperature [e.g. winter, esp. in northern latitudes-JS] and harder material all promote SSC attack...SSC is a Group 2 mechanism that can occur at stress levels well below material yield strength."
The above documents that sulfur combined with water will cause steel to become brittle, whereupon it will break. Steel made from melted scrap, whether foreign or domestic, will have contaminants such as sulfur. If it is foreign I believe it is likely to be worse. It is not economically possible to remove all the contaminants from scrap steel. I talked with someone high in the manufacturing operations of a major American steel company who told me that all his company does, in the manufacture of rebar, is melt the scrap down to a level where it will pass the tensile strength tests. They do not chemically analyze their steel for contaminants, except for phosphorus (along with carbon). This is the normal legal practice in the steel industry.
The following documents the extent to which this problem is ignored. The ASTI specs, which are the industry standard, only require one chemical analysis for rebar: it must not contain more than 0.06% phosphorus. There are no other chemical standards or analyses required. You could have severe sulfur contamination and no one would ever know.
The following gives an idea of how profit is a higher priority than fair dealing with some of the companies in the steel industry: there is an allowed 6% variation in the mass of rebar; in the above company, they always set their equipment to give 5% less than the specified diameter. In other words, if you as a customer paid for quarter-inch rebar, you will not get quarter-inch-you will get a quarter-inch minus 5%, as close as the company dares get without being illegal. So do you really think that they are going to care about contaminants in scrap steel? As a matter of fact, sulfur is sometimes added to steel to increase its machinability, which would increase profit margins.
So if contaminated steel is in a bridge in a reasonably wet area it has a chance of experiencing SSC. If the bridge is heavily traveled, the bridge is under more stress which accelerates the embrittlement process, and more traffic means that when it fails people will more likely be killed. And you certainly wouldn't want to be on such a structure during an earthquake, so earthquake-prone areas such as southern California should be particularly concerned with this problem.
I may sound like an alarmist, but the question of how extensive this problem is cannot be answered. There is no one or no agency in the country that can quantify the effect of steel contamination on our nation's infrastructure. And I will present more evidence later that indicates that Clinton allowed the importation of foreign, contaminated scrap purposely to sabotage our highway system and destroy our domestic steel industry.
Sinking of the RMS Titanic
But maybe you would like a good example of sulfide steel cracking involvement in catastrophic failure. The problem with this is that with a normal bridge failure, no one is going to be particularly looking for SSC, especially since so few engineers are familiar with the phenomenon. But there is one famous incident in which SSC was involved: the sinking of the RMS Titanic. In retrospect, the tragedy worsens when we see that the ship was doomed to sink. While SSC was probably not the cause of the sinking itself, it played a role in the event nonetheless. Some may reflect on that time period with contempt for their less-advanced technological methods, while sharing their arrogant attitude of invincibility concerning our modern structures. They should beware: history repeats itself.
According to Dr. Tim Foecke of the National Institute of Standards and Technology, the rivets on the Titanic contained high amounts of slag which may have contributed to their failure when the ship struck an iceberg. But the ship's steel was extremely brittle and this may have accelerated the break-up of the ship. Testing of the ship's metal indicates there was a rather high sulfur content of approximately 0.065 to 0.069%. The manganese content was too low (0.47 to 0.52), as manganese will help bind sulfur. This contributed to the brittle nature of the ship.
Just how brittle was the Titanic? It was brittle enough that it should never have left port. There is a point known as the transition temperature, which is the temperature at which steel transitions from a ductile (flexible) state to a brittle state. A ship made with ductile steel will flex upon collision, whereas brittle steel will break apart like a dropped flower pot. The transition temperature for the Titanic steel was 40o C or greater. The ocean temperature was -2o C. In other words, the ship was more than 40o below its ductile temperature, and it was like sailing across the North Atlantic in an eggshell. It cannot be emphasized enough: just like our modern steel highway construction materials, the RMS Titanic was built within the metallurgical specifications of the time period and was touted as unsinkable. Think about this the next time you drive across a bridge built since Bill Clinton lowered the quality of steel.
Pollution and Other Contaminants
Sulfur and phosphorus are not the only contaminants that can cause problems. Arsenic, selenium, tellurium, antimony and tin can also exert either an individual or synergistic effect upon hydrogen embrittlement (Matocha et al., 1990; Hendrix, 1997). These can be present either in the steel initially or in the atmosphere. Carbon and niobium content, which are not atmospheric but can be controlled during manufacturing, have also been implicated in premature aging of steel (Campillo et al., 1993). Coastal areas and/or locations near high concentrations of atmospheric pollutants have experienced the majority of failures high-tension bolts (Shimomura et al., 1991). This means that areas like southern California should be using particularly high-quality steel in their infrastructure projects because of its air pollution, and especially in areas like San Francisco, with its ocean fog. The frequency of earthquakes in this region further demands that only top-quality steel should be used here.
Use of Direct Reduced Iron (DRI)
Another potential problem is the increased use of DRI, which is cheaper than scrap. As previously mentioned, this is how Lakshmi Mittal of LNM Group and Inspat International has edged out competitors. Traditional production of steel requires first converting iron ore to pig iron by heating ore with coke (carbon) and lime (CaCO3). The purpose of the lime is to remove contaminants by forming a slag that floats to the top and is disposed of. This leaves reduced pig iron with a relatively high carbon content (5%), which is later further refined to remove more carbon. Carbon adds strength, but when present in too large amounts (>1.7%) it causes brittle conditions. Then controlled, minute amounts of carbon can be added to the pure iron to produce steel. The amount added depends upon the desired grade of steel.
Production using DRI avoids the more expensive above procedure of reducing iron with lime and coke. DRI involves heating the iron ore with natural gas. Hydrogen, carbon monoxide and methane in the natural gas reduce the iron. Thus, the older process of creating slag with lime removes dangerous contaminants, while the cheaper DRI method does not. This is an extremely important point to remember. For example, the phosphorous content can be five to ten times too high in DRI (USDOE, 2001). As previously discussed, this can lead to embrittlement. Also, the DRI process is incomplete and there are potential problems such as having a higher carbon content. This is not always recognized by steel makers (Midrex, 2000), and if not further refined will make the steel too brittle.
Concrete Construction and Permeability Effects on Rebar
The primary cause of the loss of flexural strength in concrete beams with rebar is the loss of the reinforcement bond between the concrete and steel (Mangat and Elgarf, 1999). This means that the degree of surface corrosion, not the depth of corrosion, is the significant factor in determining failure. Beyond 5% corrosion, the flexural load decreases significantly.
Some may be thinking, "Well, concrete is waterproof and we don't have to worry because water can't get reach the rebar, and thus no hydrogen embrittlement can occur." That is not true. Some engineers used to think that concrete is waterproof, but it is not. This can cause a particular problem in areas where deicing salts are used, as the salt is carried by water into the concrete and rebar. This leads us to another potential problem particularly associated with the design/build method of highway construction: that of improper pouring of concrete, which leads to premature cracking. Because of the accelerated timescales under which highways are constructed with the design/build method, concrete may not be mixed or poured correctly. This will then allow moisture to quickly seep into contact with rebar. With the design/build concept, the contractor's main incentive is profit, naturally, and time = money. He is going to save money when he saves time, and that includes mixing and pouring concrete. He is in charge of his own quality control so there is no one to prevent him from cutting corners.
The following is quoted from Issa (1999, emphasis mine):
"Hydration of cement in concrete starts at the moment water is added to the concrete mixture. About 50% of the cement hydrates in the first 3 days (Type I portland cement). Nevertheless, the process of hydration may continue for months, if not years. However, the most critical period is during early strength development. A specific amount of water is needed to completely hydrate the cement...Use of high slump concrete must be avoided...[and] any load that may be imposed on the structure must be carefully examined...Inaccurately estimated deflections may lead to insufficient deck thickness and insufficient steel cover that may present danger not to the concrete as a material but to a structure as a whole...
"Higher heat of hydration or solar radiation may be desired during winter concreting, and may have disastrous consequences during the summer. The temperature influences a concrete deck in two ways-it affects properties of fresh and hardened concrete, and it affects deformation of the structure...
"Various factors influence the cracking of concrete bridge decks to a more significant degree. Although it is difficult to separate one factor from the other, it seems that in most cases cracking of concrete may be attributed to the following (in descending order of importance):
"1. High evaporation rate, and thus high magnitude of shrinkage, as a result of inadequate concrete curing procedures during hot weather conditions, especially at very early concrete ages. This effect is attributed to lack of concrete protection, inadequate uniform coverage with a curing compound, and delay of concrete protection application.
"2. Use of high slump concrete.
"3. Excessive amount of water in the concrete as a result of inadequate mixture proportions and retempering of concrete.
"4. Insufficient top reinforcement cover due to inadequate reinforcing detail plans, improper placement of reinforcement, and insufficient deck depth due to deflections during construction.
"5. Insufficient vibration of the concrete.
"6. Inadequate reinforcing details of the joint between the new and old deck.
"7. Sequence of pour.
"8. Weight and vibration of machinery.
"9. Weight of the forms.
"10. Deflection of forms."
I apologize for the above extended excerpt, but it scientifically documents in engineering language how easy and common it is for concrete to be improperly poured, which can not only disrupt the integrity of the concrete but the entire structure itself. I should also add another problem: adding too much/inferior calcium chloride, which speeds up the drying time, but can assist in corroding the rebar, as in the above Lowes Speedway bridge collapse. In plain terms, if the contractor is in a hurry, particularly as in design/build contracts and those with time incentives (i.e. he receives a reward for finishing early), he will be tempted to cut corners. Suppose it was too hot but he poured the concrete anyway, or didn't add enough water. Or maybe he added too much calcium chloride to make it dry quicker, or let heavy equipment drive over the concrete before curing. Or perhaps he sloppily placed the rebar too high in the bridge deck without enough cover.
When you combine defective concrete with contaminated steel, you have a recipe for disaster.
T.Y. Lin Mentions Bad Steel in Concrete
In the Berkeley interview of Lin (2001) the following interesting exchange took place (unfortunately the interviewer cut Lin off):
Q: I worry about cracks too because I don't understand. Have you been down to the new library?
Lin: Not recently.
Q: There are circular stairs that go down--
Lin: Oh, they're bound to crack.
Q: Every stair, every step is cracked.
Lin: Then I should study it. They must have buried steel in there to take care of it. That's what we called reinforced concrete, whose steel acts only when the concrete cracks.
Q: I hope so.
Lin: If it's proper steel, it's no problem. If not--
Q: But it's a brand new building...
Calcium Chloride in Grout Causes Steel Corrosion in Speedway Bridge Collapse
On Saturday May 20, 2000 a pedestrian bridge over U.S. 29 outside of Lowes Motor Speedway in Charlotte, N.C. collapsed, injuring 107 people. Miraculously no one was killed. The bridge was only five years old. Eventually the cause of the collapse was determined to be grout containing calcium chloride, which caused corrosion in the steel reinforcing cables in the concrete (Silicon Valley/San Jose Business Journal, 8/21/00). All eleven of the cables were found to be corroded. Other concurrent renovations made at the speedway were then found to be similarly defective, requiring $650,000 for a bracing system. In spite of the fact that the bridge crossed a U.S. highway route, the State of N.C. never inspected the bridge (CNN, 5/21/00). This incident illustrates how important the prevention of corrosion is in steel reinforcement in concrete bridges.
Safety Hazards of Post-tensioned Bridges
I previously discussed how SCDOT awarded a contract for $368 million to Fluor Daniel to build the Conway Bypass with post-tensioned bridges. According to their own engineers, this was the first major use of this design in S.C., and probably with good reason. In South Wales in 1985, the 32-year old Ynys-y-Gwas bridge, of post-tensioned construction, collapsed without warning. Even while Fluor Daniel was constructing the post-tensioned bridges on the Conway Bypass, in 1998 Britain had a moratorium on post-tensioned bridge construction, and engineers were questioning the safety of post-tensioned bridges (Henriksen et al., 1998).
Post-tensioned bridges consist of concrete beams with internal cables stretched between each end and tightened after the concrete beam is formed, instead of normal steel reinforcement methods. An investigation of the Ynys-y-Gwas bridge collapse (Woodward and Wilson, 1991) led to several interesting conclusions. One is that it is impossible to predict the failure of post-tensioned bridges. The failure of the bridge in question was caused by the intrusion of water and chlorides at the joints which corroded the internal cables. The bridge gives no visible warning signs of cracking, etc. and there is no way to inspect the internal cables. Intrusion of contaminants can also occur due to faulty grout (as with Lowes Speedway). The corrosion of cables in one beam can lead to the catastrophic failure of the entire structure. It was also found that the lack of continuity of reinforcement across the joints is a design flaw that causes a concentration of cracking at the joints.
An analysis of a bridge in Slovenia (Vehovar et al., 1998) was conducted when rust products from the steel cable were observed leaking out of cracks. The investigation revealed that chloride ions, in the presence of water, can seep deep into the bridge and corrode the steel cable. Hydrogen embrittlement causes the formation of microcracks in the cable under stress, which then coalesce into major cracks. Some of the strands were corroded to the point of test failure.
During construction of the post-tensioned bridge, if the steel cable is exposed to any of type of corrosion this can lead to failure at a very early age (Henriksen et al. 1998). The high-strength steel used in cable is very sensitive to hydrogen embrittlement, and when combined with the tremendous stress of the taut cable, this can lead to premature catastrophic failure. The cables and its metallic duct are often in contact with reinforcement and this can result in a very large cathode and an accelerated corrosion rate.
Hydrogen Embrittlement in Steel Cable Bridges
California has a number of cable bridges such as the Golden Gate bridge. A natural question might be, if protected rebar can be subject to hydrogen embrittlement, what about the exposed steel cable in bridges? The following quote is from Barton et al. (2000, emphasis mine):
"Suspension bridge cable inspections have revealed severely corroded and broken wires in some main cables. Accelerated cyclic corrosion studies were conducted to assess the relative effect of general corrosion, corrosion cracking, and hydrogen embrittlement on the deterioration in material properties of high-strength steel bridge wire. Galvanized and ungalvanized wire samples were corroded in a cabinet that cyclically applied an acidic salt spray, dry conditions, and 100% relative humidity at elevated temperatures...Elongation measurements indicate a significant embrittlement of the wires, a result supported by fracture surface morphology. Ultimate load was found to degrade at a rate in excess of that attributable to material loss by general corrosion. The hydrogen content of corroded wire was found to be greater than that of uncorroded wire, particularly for galvanized wire."
Quoting further in the paper:
"Water has been shown to penetrate into the cable, with water pH as low as four. Zinc galvanization has been shown to decay to the point where significant steel corrosion occurs. Broken wires are found that demonstrate significant loss of ductility and fatigue strength in laboratory tests...It is likely that these broken wires are the result of embrittlement phenomena...
"In cold-worked steels, absorbed hydrogen is thought to collect at dislocations, grain boundaries, and voids...Absorbed hydrogen tends to reduce the ductility of hardened steel, leading to lower strain at fracture, a phenomenon known as hydrogen embrittlement. In materials undergoing subyield applied stress, hydrogen tends to increase the rate of propagation of microcracks, leading to so-called hydrogen-stress cracking (HSC). HSC can lead to failure under subyield loads if unfavorable conditions persist over long time periods. In corroding conditions, HSC can augment other crack propagating mechanisms such as stress corrosion cracking."
One of the amazing results of this study is that bare wire is actually more corrosion-resistant than galvanized wire, which is contrary to popular belief. The reason for this is because "the presence of the zinc-iron couple increases the rate of cathodic hydrogen evolution on the relatively small exposed steel surface." This also illustrates the complex electrical interactions that take place when various elements are present in steel, such as may occur when contaminants are present.
The authors conclude with:
"The results presented above indicate that corrosion degradation of high-strength bridge wire exceeds mere loss of load-bearing material. Ultimate load was found to decay with exposure time faster than that predicted by reduction in a cross-sectional area, suggesting that cracking or pitting effects may be present, whether induced by corrosion of by hydrogen interaction, or both...Measurements of wires aged at high temperatures do not indicate that the embrittlement process can be reversed. Thus, it appears that permanent microstructural damage has been caused by the corrosion process."
In the results section of the paper itself, a very interesting observation was made. The authors tested the ultimate load-bearing capacity of various wires, galvanized, ungalvanized, etc. There was an extremely wide variation in this number given the same amount of exposure to corrosion. This illustrated that regardless of the initial specs of the construction material, it is not possible to accurately ensure that no failure will occur. In other words, as the materials experience hydrogen embrittlement over time, one cannot be confident in predicting when and where a failure will occur. One of their galvanized test samples experienced a 9.2% decrease in strength over a representative 5.2 years. One non-galvanized sample experienced a 21.5% decrease after a representative 7.3 years exposure. This was similarly observed in the Hoan Bridge collapse (see below). I should point out that the authors' objective was to demonstrate the chemical mechanisms of HSC, not to simulate a particular region's environment, so these times may not be realistic predictions of strength loss over time. There is only one study (Eiselstein and Caligiuri, 1988) that has attempted to replicate regional environmental conditions (acid rain in NY City).
In light of the above discussion, the problems with cable suspension bridges should be obvious. These would be compounded in coastal areas and those with acid rain. Even acknowledging the problems of hydrogen embrittlement, for bridge maintenance, how would one go about identifying the weak spots in miles and miles of stranded cable, with an infinite number of cracks and crevices? Take a magnifying glass and crawl over every foot of cable?
Sabotaged Steel in World Trade Center?
There was a very disturbing anomaly concerning the steel in the WTC catastrophe which is as yet unexplained. When the interior of the WTC debris pile finally began to be cleaned up, after many days of smoldering heat, some of the steel was found to have holes like swiss cheese. A one-inch column was reduced to a half-inch thickness, with edges curled and paper thin. There were melted pools of steel in the basement. Investigators were perplexed as to what could have caused this.
One possibility is that the steel, manufactured in Japan, was of poor quality and loaded with contaminants. Steel produced in Japan at that time was not of good quality. The steel may possibly have been made with DRI, which was first available in 1957 from the company Hylsa, inventor of the process.
There is a dangerous but uncommon problem associated with DRI. During transportation, the pellets can "catch on fire." They are relatively porous which allows air, i.e. oxygen, to enter into the interstitial spaces which provides more exposed surface area. If the shipment gets damp, particularly with salty air typical of the maritime environment, the oxygen can recombine with the iron in DRI. This chemical reaction is exothermic, i.e. heat-producing. However, burning DRI looks like hot charcoal, with no fire. Another problem can then occur if someone tries to put out the "fire" with water. The water molecules can then be split into hydrogen and oxygen, resulting in a flame and further increasing combustion. Magnesium has this effect upon water, which is why water should never be put on a magnesium fire, because it only accelerates the combustion.
Of course, quality steel should never burn like DRI because it has been processed and is denser than DRI pellets, with consequently less exposed surface area. However, there may have been a unique combination of circumstances at the WTC which allowed such deterioration to occur. First, the Japanese may have purposely supplied cheap steel which was not the normal density of steel and would have contributed to oxygenation. Second, contaminants like sulfur lower the melting point of iron and could greatly accelerate the process. Interestingly, the propensity of DRI to burn has to been found to vary with the source of the iron ore, which suggests that contaminants play an unknown role in burning.
Also, water on the burning mass of WTC debris may have only accelerated the burning. Furthermore, available video of the basement of the WTC after cleanup shows that the retaining wall was cracked and saline water from the nearby Hudson River was leaking into the basement. Only 60 liters of seawater in a ship's hold can cause ignition of DRI. Electrolytes in the seawater would have substantially accelerated the rapid oxidation of the steel. Additionally, the process is accelerated by increased temperature, which would have been the case with the smoldering debris of the WTC. The autooxidation temperature of DRI has been reported as low as 150o C.
In another report (click here) I documented how the WTC could have been built with explosives mixed in the concrete for future detonation. In light of this, it is also possible that the Japanese purposely sabotaged the WTC steel during the manufacturing process. Aluminum will burn in a thermite reaction, when aluminum is combined with iron or another metal oxide and the oxygen is transferred from the metal oxide to the aluminum. It is a difficult reaction to initiate but is highly exothermic. Magnesium also burns, and it may be possible that the Japanese discovered a way to create a special alloy which would burn under certain circumstances. The WTC steel was hurriedly rushed off for recycling, which may have been to prevent sufficient examination. Regardless of the explanation, the unique observations of the highly deteriorated WTC steel suggests that it was of inferior quality.
BIBLIOGRAPHY
Barton, S.C., G.W. Vermaas, Duby, P.F., West, A.C. and R. Betti. Accelerated Corrosion and Embrittlement of High-strength Bridge Wire. 2000. Journal of Materials in Civil Engineering 12(1):33-38.
Campillo, B., Perez, R. and L. Martinez. Aging Embrittlement of Microalloyed Reinforcing Bars. 1993. First International Conference on Microstructures and Mechanical Properties of Aging Materials, Nov. 2-5, 1992, Chicago, Ill. pp 71-74.
Eiselstein, L.E., and R.D. Caligiuri. Atmospheric Corrosion of the Suspension Cables on the Williamsburg Bridge. 1988. Degradation of Metals in the Atmosphere, Spec. Tech. Publ. 965, S.W. Dean and T.S. Lee, eds., ASTM, Philadelphia, pp 78-95.
Foecke, T. Metallurgy of the RMS Titanic. ND. NIST-IR 6118. U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology, Materials Science and Engineering Laboratory, Gaithersburg, MD 20899-001.
Giguere, L. Carbon in DRI-Friend or Foe? Midrex. 2000.
Hendrix, D.E. Hydrogen Embrittlement of High-strength Fasteners in Atmospheric Service. Materials Performance 36:54-56.
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