ST0501-CS120424 T H E G 1 T Y O F
COPPELL
q o
X n s
MEMORANDUM
TO: Tiseo Paving, Robert Caudill
FROM: Larry Davis, Construction Inspector for the City of Coppell
DATE: April 24, 2012
REF: Deforest Road — Spread Footing Retaining Wall — Vertical
During a site visit on 4- 24 -12, the contractor was observed performing the following: Concrete
truck from Redi -Mix arrived on job with approximately 5 CY with a 6" slump and was directed to
the staging lot within Windsor Estates; color was added to mix by wall contractor under observation
of representatives from Redi -Mix and materials testing firm Texas CMT; Redi -Mix truck was then
moved to the east end of the spread footing retaining wall, a slump test was performed and resulted
in 3" slump; under the wall contractor's initiative and observation by Redi -Mix employees, 10
gallons of water was added to the mix, slump was measured at 4 ", a total of 26 gallons (10 +16) was
added to the mix and the resulting slump was 7.5 ", during mid -pour another slump was taken and
measured at 7 ".
Questions:
1) Why would a contractor take it upon themselves to modify a material that had a
specified mix design which had been submitted for approval?
2) Was the supplier aware of the use of the material, i.e., color addition, add mixture?
When material arrives at the job it should already meet the specifications from its supplier and be
suitable for placement. The supplier has a responsibility to provide adequate materials for the job as
specified. Using the proper mix design, which includes added color, would be a far superior method
to ensure meeting the concrete specification requirement and achieving uniform color throughout
the wall.
Should the color vary throughout this job, the contractor may be required to remove and replace
said portion of wall poured on this date.