"What would happen if we pour concrete into this?"
Because of asking this stupid question (and take photo in the same time in front of the site superviser), the stupid photographer has earned a 5 minute-long-dirty-words-bombing.
Why the photographer being scolded?
1) Because he is not the supervisor's boss, or paymaster. The supervisor need not to reply in nice way.
2) The supervisor pointed that the reinforcement is not yet done the final part - inserting lapping bars. The act of taking photo of half done work seems "cari pasal" (inviting trouble).
3) Because the photographer was not used to the site language, he interpreted the supervisor's way of communication as "scolding".
From this event, the photographer realized that:
1) The site people knew that the connection is unsafe without additional bars across the main beam.
2) The site people like to do "double lapping" (which consume more steel).
3) Don't comment to the supervisor if you are not his paymaster. And, don't let the supervisor know that you are the one who tell his boss about his fault.
I've been inspired by this event. Since the digital camera or video cam are so popular nowaday, we can fully utilize it in the site monitoring. Before concreting, just ask the engineer to shoot every details and record his comment, like this: "Today is 25 August 09, 3pm. BLC is reporting. Now I am standing near the column at Grid 8/A. You can see the lift core is 2 columns away from here. Now I'm inspecting the beam top bars across this this column. It supposed to be 3T32 at top and 2T25 below, let's see. Oh yes, it is! Lets check the cover, measure from the marking on the formwork... mmm, 30mm... not too bad, still accpetable. This part is ok, let's proceed to the next joint....". Another video camera may be set on the tower crane to make sure that all bars checked by the engineer are there untill the concrete poured are set.
Check every details, record how you check and what did you check. The extra cost is a little bit more disc space which any project management can afford. Then, anyone can check again later on.
Just a wild idea based on limited knowledge. Some other countries have already implementing the similar concept in more efficient way. Anyway, I believe that no matter how advance is it, no system is unbreakable in bolehland.
Yeah, back to the photographer story, someone from the project management told me that the supervisor has put in enough steel bar to lap with this "independent" cage. This joint is ok.
Great photo!
ReplyDeletenothing would actually happen. it's a job done by boleh-lang. (the boleh human)
ReplyDeleteHmmm...
ReplyDeleteSay, what will happen next?
Will it reduce the reinforcement forces?
when the concrete poured into and set, the beam won't perform as a beam as the rebar on top for the compression zone was not there therefore cannot transfer the load so the beam will fail. and the bottom bar for tension zone i think is not sufficient depend on the formwork size. who did this? bolehland? damn...
ReplyDeleteAt support area, compression bar will be at bottom and tension bar will be at top. So in this case, there was no tension bar. This beam can crack since concrete is weak in tension.
ReplyDeleteI showed this photo to a hands on contractor. Without knowing much details, he pointed out that:
ReplyDelete1) Contractor may choose to form the cage elsewhere and put it directly into the formwork to save time. Those top bars and bottom bars to link to the main beam will be inserted later on. These extra steels are the price paid for buying time.
2) It is a long haul big job.
Bingo! A great contractor.
So, I learned a lesson. There's no regret to ask the stupid question: "what if we pour concrete into this?"
Interesting piece about construction
ReplyDeletehttp://mt.m2day.org/2008/content/view/27499/84/