SB 66/ use of WOOD FORMS for support of concrete Flashcards Preview

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Flashcards in SB 66/ use of WOOD FORMS for support of concrete Deck (4)
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1

Method of forming poured concrete floors

-5/8" or 3/4" plywood hold in place by 4"x4" wood studs
-one shoring stud placed every 4 FEET on center extending from floor to underside of plywood form above

2

Heavy fire load.

storage of sheets of plywood and wood studs previously stripped from a CURED FLOOR
-lumber usually found stored on floor which is 2 LEVELS below the most RECENTLY POURED FLOOR and will serve as the forms for the next floor to be poured

-problems on this floor are not structural failure but HEAVY FIRE LOAD

3

Determine how STRUCTURALLY SOUND the most recently poured floor is ...

must be known WHEN CONCRETE was poured , how many HOURS CONCRETE HAS BEEN CURING
-obtaining this info difficult and not always accurate, unless there is a responsible person on the job site, CONSTRUCTION ENGINEER , BUILDING SUPERINTENDENT OR CONCRETE FOREPERSON AND THEY CAN STATE EXACTLY TIME IT WAS POURED, IF THEY CAN'T

ASSUME CONCRETE WAS POURED IN PRIOR 24 HOURS

4

STRUCTURAL STABILITY of the actual floor BELOW the recently poured floor should be considered SOUND

It is required that every floor that has been stripped of its supporting plywood forms and is inits curing stage be RESHORED
-this restoring of 4"x4" stud placed every 8 FEET will usually be found at least 8 Floors below the most recently poured floor

-if units observe studs placed approximately 8 FEET APART , as they proceed upward in the building, RESHORING IS INDICATED...IT SHOULD BE ASSUMED THESE FLOORS ARE IN ADVANCED CURING SATE AND SHOULD NOT PRESENT A PROBLEM IF EXPOSED DURING FIRE CONDITIONS

-KEY TO SAFE OPERATION IS KNOWLEDGE OF CURING TIME