Was SteelAsia ‘s substandard QT steel rebar used in the buildings that were severely damaged or collapsed in the Mindanao Quake ?
The recent quakes in Mindanao are only beginning to reveal our country’s precarious situation in dealing with The Big One — which can be a magnitude 7 earthquake emanating from any of the Philippine’s five major faults.
The National Disaster Risk Reduction and Management Council (NDRRMC) reported that six people were killed by Thursday’s quake and 10 from the 6.6-magnitude temblor two days earlier.
In all, 21 people have been killed by the three major quakes centered near Tulunan, Cotabato. The NDRRMC said 403 people had been injured in the last two quakes.
The damage and death toll reports the Porac Quake, Batanes Quake, and the Polillo Quake this year, all seem to portend the coming of a calamity.
In Luzon, The Big One could come from the movement of the East Valley Fault. Scientists claim that the 100-km fault last moved in 1658, moves every 400 years or so.
Structural engineers who’ve been warning about substandard steel reinforcement bars being used in medium and high rise buildings in the Philippines. They estimate that that the death toll arising from the collapse of structures as well as landslides could reach tens of thousands or several times higher than the death toll arising from the Sichuan Quake in 2008.
I hate to sound alarmist, but I can’t help but be alarmed by a petition on ChangeDotOrg that has been making the rounds on Facebook this week.
And you should be too!
Moreover, YOU SHOULD SIGN THE PETITION to compel the administration to conduct an investigation and implement measures to avoid the death of thousands!
On the surface, the petition titled “Stop SteelAsia’s GREED before it kills you and your loved ones!” (source) appears like a blaring siren.
Having previously read about substandard steel rebar having flooded the market and written about on GR Post, the implications could be catastrophic.
It can make the 1991 Killer Quake appear insignificant if even a handful of high rise buildings in Metro Manila collapse.
The petition reads:
The next big earthquake that will hit the Philippines is bound to kill you and your loved ones!
Especially if the building you are in and the elevated roads you drive on were built using SteelAsia’s substandard steel rebar.
SteelAsia has been deceiving thousands of developers and builders for over a decade by selling them grade 40 steel rebar made to appear as grade 60 rebar.
SteelAsia makes its steel rebar by quench tempering (QT) low grade steel to make it appear like higher grade steel.
This results in AMPAW steel rebar with a weak core which will be warped and snapped by the fluctuating stresses and strains of a strong earthquake.
QT steel rebar has been banned in earthquake prone countries in the Pacific Rim, most notably in China. The ban on quench tempered steel rebar in China was triggered by the 2008 Sichuan earthquake which killed more than 69,000 people and injured 374,176.
If the Philippines is hit by an earthquake as strong as the Sichuan quake, buildings and elevated roads in the Philippines will collapse because of SteelAsia’s substandard steel.
What is Quench and Tempered Steel Rebar and Why Has China Banned Its Use?
According to a common definition of the Quenching and Tempering process found here.
Quenching and tempering are processes that strengthen and harden materials like steel and other iron-based alloys. The process of quenching or quench hardening involves heating the material and then rapidly cooling it to set the components into place as quickly as possible. The process is tightly controlled, with the heating temperature, cooling method, cooling substance and cooling speed all dependent upon the type of material being quenched and the desired hardness.
Depending on the type of steel alloy, this can produce various grades of steel rebar (reinforcement bar) that are designed for specific uses in the structural engineering of buildings.
According to one scribd document on rebar grades and their uses found here, steel rebars with grade 33 are used for low rise buildings, grade 40 is used for medium rise buildings, and grade 60 is used for both medium as well as high rise buildings.
In a number of articles found in Philippine newspapers, the allegation against SteelAsia is that it has been Quench and Tempering steel alloy intended for the production of grade 40 rebar to make it appear as if it were grade 60 rebar.
Structural engineers quoted in some articles say this could result in the collapse of buildings, as what happened in Sichuan China in 2008.
In an archived story from Globe and Mail, a worker that was employed in the construction of one of several buildings that collapsed in the Sichuan quake seems to prove what the Philippine structural engineers are saying:
One man, gazing at the corpse of his nine-year-old cousin, said he had disturbing evidence that could explain the collapse of the five-storey Juyuan school building, along with eight other schools in the region.
The man, who gave his surname as Ren, is a 32-year-old steel worker who has worked for a decade in the local construction industry. He said he always knew that the Juyuan school was a disaster in waiting. Local officials, he said, had pocketed money that was budgeted for the school, while a private construction company had saved money by cutting corners on the project.
After the temblor, when he picked up a chunk of concrete from the flattened school, he was appalled by the evidence of shoddy construction. “It crumbled very easily,” he said.
To boost its profits, the company used iron instead of steel in many parts of the construction of the building, Mr. Ren said. It cut back on the size and number of steel braces in the cement foundation slabs. And it used cheap materials to make the concrete walls, weakening the entire structure.
“The supervising agencies did not check to see if it met the national standards,” he said.
Many other survivors were convinced that corruption had played a role in determining which buildings collapsed and which were unscathed. One man pointed to a new building whose first floor had collapsed, even as older buildings around it were intact. “They used fewer bricks in the new building, so they could earn more money,” he said.
The shoddily constructed buildings are commonly called “tofu buildings” because of their weak structural condition.
In November 2018, China began enforcing a policy against the use of Quench and Tempered rebar and upgraded its standards for steel rebar used in the construction of buildings (source):
The new rebar policy, effective November 1, 2018, requires Chinese steel mills to eliminate the original 335 megapascals (MPa)-tensile strength rebar and start producing 600MPa-tensile strength rebar, which has better earthquake resistance.
In doing so, the policy encourages domestic Chinese mills to utilize greater volumes of alloys to meet the revised strength requirements.
The policy also seeks to restrict the production of rebar via the water-quenching process, which produces rebar that has lower durability because it rusts easily and therefore poses a risk to building safety.
Moreover, according to Philippine structural engineers as well as articles from various experts online, Quench and Tempered steel rebar fails at a higher rate during cyclic loading tests when compared to micro alloyed steel rebar.
The suspicious thing is that Philippine’s Department of Trade and Industry Bureau of Product Standards, although not equipped with cyclic loading facilities to test Quench and Tempered rebar, has issued statements saying that Quench and Tempered steel rebar is SAFE. (source)
In a typical side step to avoid culpability if people survive The Big One, in essence the DTI Bureau of standards says that cyclic load tests are unnecessary and gives the impression that QT steel rebar doesn’t play as major factor in the capability of a building to withstand strong earthquakes:
Even odder is that, in an interview with Veronica Files, an official of the DTI Bureau of Standards says several QT rebars were sent to cyclic loading test facilities abroad but REFUSES to disclose the results of the test.
What bothers me is the seeming callousness of refusing to release vital information that could very well lead to the DEATH OF THOUSANDS!
The only way to defeat this callousness which may result in the death of thousands is to pressure the administration to investigate SteelAsia and figure out how many buildings are at risk of collapsing because of its substandard steel.
Again, I urge you to sign this PETITION TO INVESTIGATE AND PROSECUTE STEELASIA for flooding the market with sub standard steel rebar.
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