Will SteelAsia ‘s Substandard QT Rebar Cause Buildings to Collapse in The Big One?

250 Shares

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.


(Source)

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.

print

5 Comments on “Will SteelAsia ‘s Substandard QT Rebar Cause Buildings to Collapse in The Big One?”

  1. If the steel reinforcement is already inside the concrete structure; there is no way to test the safety of the structure. It is during the construction , that serious testings must be done on both, the concrete and the steel reinforcement materials.

    It is not only the materials; but the soundness of the designs of the building structures; the load factors; the strength factors; we have to take into consideration the location of the building structures. If it is earthquake prone, or it is located in a fault line. The geological structure of the soil foundation; and others, must also be taken into consideration.

    The Bureau of Standards do not have any Quality Control Department, and experienced Quality Engineers, to go after construction companies, that build these buildings. They may not have also experienced Structural Engineers, to look and see the soundness of the designs. How about the testing equipment ? Are they obsolete or up to date ? There are many factors to look to, that ensure the safety of the design and the construction. They should do the Failure Mode Analysis on any design, before, the Structural Engineer approves the design. This will save lives…

    Do we produce good Structural Engineers in the Philippines ?

    1. Regarding Structural Engineers, yes, we do have good structural engineers both locally and abroad.

      For those that collapsed, it would be worth it to simply look at the history of the structure itself (or the age). If it was before the latest structural code of the philippines, then I think those did not stipulate the requirement for designs to pass Magnitude 7 Earthquake (moment forces) as the current NSCP does.

      For the construction side, the contractor is required to submit test reports of both concrete and steel as part of their submittals for Occupancy Permit. Now, did the structures in question obtain their Occupancy Permits (meaning all their papers are in order)? Without occupancy permit, the structure should not have been used by the building owner/tenants.

      The reports above would be supporting documents to be compared to the construction plans. If it appears to match, then you also check for multistoreys what their soil test report said and who prepared it. This Soil Test Report used to only be required for 4 storeys or large sprawling developments (warehouse, malls etc). Nowadays, it is required to start from 3 storeys or more (sprawling still applies).

      If you did not have an accurate or proper soil test report for multistoreys, then the starting point of the structural design would be “questionable” as it basically works on “assumptions/estimated bearing capacities and forces”.

      So there should be a “traceback” that can be done from the documentary standpoint.

      All the above are not discounting the fact that Quenched Steel (QT Steel) should not be used in multistoreys.

      But I recall rebar material testing indicates whether or not it is QT Steel or not as it compares the “design/required strength of material” vs actual strength of material.

  2. The problem with the word “substandard” is that it makes the implicit assumption that standards exist, and that they are generally upheld.

    I do a bit of building work occasionally, and IMO the building materials on sale in the Philippines don’t even merit the word “substandard”. It’s almost impossible to guess what you’ll have delivered, even if you’re clear about the specification; this is partly due to lying, thieving Filipinos who imagine that scamming a potential repeat customer is a clever idea, but mainly due to the fact that nobody knows any different. Crap materials is completely normal.

    My long-term experience is that anything made in the Philippines is as bad as, or worse than, the equivalent made in China. My favorite examples are Filipino-standard “marine grade” plywood, which you wouldn’t even make packing cases out of in proper countries, and “stainless steel”, which rusts.

    If standards exist at all, they are either low standards, or they are not being enforced.

    As @17Sphynx17 said, there ARE good structural engineers in the Philippines. But they are heavily constrained in what they can achieve by the puede na yan culture.

    1. Re Stainless Steel, if it is Grade 304, then it shouldn’t rust. However, there are retailers that sell stainless steel of grade 2## which will rust.

      If you are exposing these Stainless Steel to Corrossive chemicals or fumes, you should actually be using Grade 316 and not 304, which is more expensive.

      The problem lies as well with “non disclosure” by an unscrupulous seller who will tell you that it is Stainless but not inform you of the Grade of Stainless. If they don’t tell you outright or are unsure, walk away. I have work done with Proper Grade 304 Gutters sourced here in Manila and they haven’t rusted one bit.

      For material testing of concrete and rebar, even with mill/supplier “guarantees/certification”, it is still adviced to go with random sampling and cylinder sampling for each batch of deliveries for both those materials. Problem is some do not do that “extra step” when provided with the “certificates” which is quite lazy all for lowering their cost by a few thousand pesos, and I mean a few thousands only because they don’t cost that much.

      For proper gauge of metals, roofing, sheet metal, I’ve bought myself a digital caliper for some “peace of mind” before and I have rejected and accepted deliveries that met the specs.

      These are just somethings you can have done or do yourself as part of due diligence if your guidance from whoever is the project manager/construction manager is “lacking”.

      Hope that helps, at least.

      Just an FYI, for testing of concrete and steel, there are a lot of third party laborities all over the philippines but if you doubt private companies, UP has material testing as well. You just have to line up.

      They even test water quality if you really need to go that extreme if you want to test out your filtering system or water source (if from stream or spring). But the sample needs to be at the lab within 24 hours which might be an issue for farther locations

      1. The thing is this, though: why should I have to have my materials independently tested? Is it really too much to ask that, when a product is made from “stainless steel”, it performs the function that would be expected of it? If I order engineered materials almost anywhere else on the planet (outside of, say, Nigeria or Bangladesh) I can be 99% certain that I’ll be given what I’ve paid for. Why is this not so in the Philippines?

        I’m aware that there are many, many different types of steel (stainless or otherwise), but I’m referring here to water tanks, and I think it’s reasonable to expect a water tank to use a grade of steel that does not rust in the presence of water.

        Same with Philippines “marine” plywood, which delaminates if you wipe it breathe on it. I wouldn’t like to find out what happens to it when you put it in seawater.

        And on a similar theme: if I order 10mm plywood, is it really too much to ask that I get material delivered that measures 10mm instead of 6.5mm, along with some ridiculous story about “that’s the standard thickness of 10mm plywood in the Philippines”?

        I think “nondisclosure” is really not the right word. Can’t we just call it what it is? It’s dishonesty and ignorance.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.