Global Knowledge Management and Economy - Nik Zafri

The Star Global Malaysians Forum

preferred-anonymous student by e-mail wrote:
Dear Encik Nik, I like to know in general of the common methods of building insulation and the insulators that is no longer used and why?

Dear student, thank you for your query. Please be be more specific in your question as building insulation methods depend on so many factors e.g. type of building/structure, calculations and types of insulation e.g. blankets, radiant barrier, batts, (even loose fills), cellulose, foams, rigid panels, fiberglass, SIP etc. Please help me to understand.

The insulators you've mentioned - I think - not only no longer be used but have been banned in the market as well eg. asbestos & urea formaldehyede foam.
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Posted: 26 July 2007 at 1:36pm

sam by email wrote:
Mr. Nik, I am joining a newly-operational factory having interest in precast concrete. I did not have much experience in this line - except the basics. Since I'm expected to do some presentations to contractors, I would like to get any useful tips from you on how precast concrete works.


Thanks Sam for the question. I'm glad that I do have a little bit of experience in precast technology. If I may comment, you didn't specifically mentioned what type of precast products that your company are dealing with. The standard ones are beams (upright, rectangular, T-inverted), drains (inlet/trench/cast-in)/manholes/culverts, railings, fences, railway ties/sleepers, core slab (hollow),planks, retaining walls etc.

The other type is the 'customized' precast products using special moulds/forms that can be reused again and again. This type is usually well-oiled and undergo two or more types of curing - i.e. 1. in the form itself, and 2. in the yard : prior to delivery to site.

These types are useful for special constructions like bridges, tunnels, buildings etc. e.g. Tunnel segments (RAPID/PUTRA LRT Tunnel from Ampang Park to Masjid Jamek), precast facade, load bearing walls,columns (single/double tier with corbels-> e.g. highways)
etc.

Precast (especially the modern/special types) is a wonderful discovery indeed - one of my ex-MD used to call it 'Lego Technology' (e.g. Teachers Quarters in Gombak) It's a bit pricy but worth investing - it's fire & sound proof, can stand extreme weather (durability also guaranteed), longer shelf-life, very time saving - imagine this, while you're placing foundations at site, your walls are being manufactured (or cast at a different place) at the same time etc.)

(wow..I'm talking like a salesman)
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Posted: 10 February 2007 at 2:33pm

emailquery wrote:
Our consultants have issued NCRs regarding accurate positioning of piles. We have argued with the consultants that positioning of piles depends on the type of work that is being done but failed to convince the C & S consultant (working for the client). As an experienced QA/QC man cum a Consultant, what do you think, Encik Nik?"


First of all, you are almost correct (theoretically speaking as I'm not there at the project site..so it's hard to assume or say) in terms of 'depending on type of work' and piling positioning (it doesn't have to be too accurate) - unless you're talking about bridges (spaced footing clusters), THEN the consultants are right!

I assume you're talking about building and that you've reached the pile driving stage. For example in in a large mat foundation supported on piles at relatively wide centers- of course it is impossible for you to get an exact measurement. Strong templates may also be applied to ensure proper centering if close tolerances apply.

Handle pile with proper care - set plumbs in the lead. Attention is required for precast piles lifting e.g. use of rigging, to avoid cracking the piles. Installed but misaligned/crooked piles cannot be repaired anymore..remember..

The rest are hammering and driving like the weight of hammer vs pile being drived and the use of jetting to facilitate pile-driving.

Anyway, you should honour the clients/consultants NCR as what they really want is the BEST measurement you can come out with. After all they are professional engineers.