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Re: DRY PACK SPECIFICATION

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     Yangsoo,
     
     Your strength requirements do seem rather high.  Typical dry pack 
     strength is around 2000 psi at 7 days and 3500 psi at 28 days although 
     I do not know if you will find a definitive number in an ASTM or ACI.
     
     Test samples can be taken per ASTM C387 and tested in accordance with 
     ASTM C39 or ASTM C109.
     
     Dry pack, for your application, should only be used for very minor 
     "sacking" (smoothing out surface imperfections just after form 
     removal).  For filling up holes, cracks, and damaged concrete I would 
     recommend you use a proprietary non-shrink grout.  Contact your local 
     Master Builders, Sika, or W.R. Grace representative for the 
     appropriate product.
     
     Thomas Hunt, S.E.
     Fluor Daniel


______________________________ Reply Separator _________________________________
Subject: DRY PACK SPECIFICATION
Author:  "" <kimslove(--nospam--at)ns.kopec.co.kr> at fdinet
Date:    2/23/99 4:58 PM


Dear all
     
I'm looking for dry pack specification and field strength test results. 
In our project (Nuclear Power Plant Construction In Korea), dry pack 
used for repair of concrete such as holes left by the removal of 
fasteners
from the ends of form tie rods, narrow slots cut for repair of creaks, 
and
drilled hole for anchor bolts but not used.
     
In a construction specification states as follows;
     
 1. Mixing : Drypack mortar shall be mixed as stiff as practical using
not
    more than  1 part cement to 2-1/2 parts of sand by damp loose
volume.
    The sand shall be graded so that 100 percent will pass the No. 16
sieve.
    Sufficient water shall be used to produce a mortar, which will stick
together
    when molded into a ball by squeezing gently in the hands and will
not exude
    water but will leave the hands damp.
     
2. Minimum Compressive Strength : 5,000 psi at 28 days
     
3. Expansion : No Expansion
     
4. Shrinkage : Not more than 1%
     
5. Bleeding : No visible bleeding
     
The field test results of drypack strength that mixed as shown on above 
was about
3,500psi, so didn't meet strength requirement. Contractor complains that 
they could
not make drypack grout which meet the above strength requirement. 
I'd like to ask for following question;
     
1. Standard specification for drypack ?
     
2. Min, strength of drypack?
     
3. Anyone who has a experience of drypack strength test ?
   Test results?
     
4. Can I use drypack for above described purpose (crack repair, 
remaining anchor
    bolts hole)?  (Structure design concrete strength is 4,500 to
5000psi.)
     
     
Regards,
Yangsoo KIM, PE
KOREA POWER ENGINERING COMPSNY, INC.