ST9905-CS071113
Nov 13 2007 5:20PM
Johnson Count~ PiFe
8177836002
F. 1
JOHNSON COUNTY PIPE, INC.
An AnMlfc8,. 0wMd C4lm,.nJl
November 13,2007
Mr. Robert Tichenor
MUlTaY Construction Company, [nc
515 N. Kealy Ave
Lewisville, TX 75057
RE: City of Coppell
Mr. Tichenor:
I have viewed the video provided of the various pipe installed on your job. I have also
seen the comments and concerns listed by the inspector. It is dear from the video that the
concrete pipe installed on the job has been subjected to a certain aDlO1.mt of stress, as can
be seen from the cracking. I think the fact that the pipe had been jetted moments before
the video was made has accentuated the cracking by showing the contrast between wet
and dry concrete.
Without going into too much detail, let me say that concrete pipe is designed to crack,
like all reinforced concrete stroctures. This cracking is indicative of the stresses being
transferred from the concrete surface to the reinforcing steel inside the pipe. We know
that the transfer of stress is going to occur, giving credence to the need for steel
reinforcement. In cases where hairline cracking is visible, it is shown to have no effect
on the structum1 or long term perfonnance of the pipe. In cases where large cracks have
formed, the most common practice is to seal the cracks to prevent the possibility of
oxygen in the water from reaching the steel and corroding.
I hope this infonnation is helpful.
P.O. Box 1588. Alvarado, Texas 78009 · (B17) 783.3444 . Fax (B17) 783-El002