QUOTE(Kevin Chan @ Apr 21 2014, 09:19 AM)
this powered after ageing is like saying steel structure get rusty after ageing. so you ban steel structure ?
you protect the structure from exposure. again i find the problem is people trying to used the product in "ingenious" manner, i call them "chikai" manner.
ACC is done by technically pumping air and creating air chamber [honey comb] in the material hence removing weight/density. the air structure provided "similar" structural strength. take completely solid rod versus a hollow rod. hollow rod is lighter but can also provide same strength as the solid rod ... IFF used correctly.
ACC is lousy at bearing static weight but provide similar impact integrity [you can hit it]. so for your situation, if weight is bare on to the ACC long term ... aka lousy structure, you are asking for trouble. but if the situation is sudden structure break, the ACC would have does it job of preventing total collapse fine.
YES those ACC does go powder. but if you does good wet work [water proof/ air proof] and paint job as you would protect steel structure. i don't really see much of a problem.
I would still chase after the ACC sales guy, what the heck he has promise you? the construction guy, does he know what is he doing with the product ?
I only used ACC for light weight and fire resistance. if its just a ground floor vault where floor loading can take ... i'll go for much cheaper, STANDARD fire brick !!
I have no opinion of those on site easy mix pour in version... never tried them before.
is ACC getting popular ? i still see sand brick trumping everyone in term of total cheapness , sand brick degrade even faster...
The crucial thing you may not know. The cement inside the 1m3 of AAC (600kg/m3) is about 20-25%, while FLY ASH is about 60%. Fly ash is a incomplete burnt coal waste containing heavy metals from power plant. It is to say AAC has very little cement bonding, too porous. The entire AAC is really good for fire resistance or insulation purpose. But why do we need this AAC being the wall.
In Malaysia, fine sand AAC is not yet the day. Fine sand AAC is still very similarly porous and fragile.
Fly ash AAC is about RM30-33/m2. Fine sand AAC is not known.
Cement sand brick is RM22-23/m2. Yet cement-sand work has more bonding cement than AAC.
The german people still dare to promote AAC and some people really buy the idea. In their case, AAC was 50% cheaper than their conventional blockwork cost. In Malaysia, unpromised performance AAC is more expensive than cement sand work.
I do not use AAC , I am smarter and would rather use cement sand masonry work if that is a low cost house.