15 September 1999
(3) Slump at placement should not be greater than the design mix slump. If contractor
elects to pump mix, pumping aids will be allowed, provided shrinkage potential does not
(4) High range water reducers (HRWR) will be allowed, if it is shown that concrete
produced with HRWR is not subject to increased shrinkage, segregation, and retarding/flash
setting. Testing will be performed on concrete with the proposed HRWR to determine shrinkage
(5) Guidelines for the use of shrinking-compensating cements, as outlined in ACI 223,
should be provided if they are to be used in the construction of RRMS.
(6) The mix design must incorporate a 25 to 38 mm (1.0 to 1.5 inches) coarse
aggregate maximum size with appropriate gradation specification. Follow ACI guidance for use
of well- graded aggregates.
(7) Cold and hot weather concrete placement guidelines must be provided. Place at a
lower initial concrete temperature.
(8) Require reduction of cement content by using fly ash. The volume of fly ash when
combined with Portland cement should be 20% plus or minus 5% of the volume of Portland
cement plus fly ash.
(9) Require 7-day, wet mat, moist curing unless the project is in an area of restricted
8. THREE-PHASE CONTROL PROCESS. There are certain items listed in the specifications
and shown on the drawings that require close scrutiny during the construction of RRMS. The
districts and operating divisions must inform Area/Resident Engineer Offices of these items.
The Area/Resident Engineer must assure that they are addressed by the Quality Assurance
Staff during the Three Phase Control Process; the following is a list of items that must be
a. Mix proportions for RRMS will be Government approved (GA) to ensure suitability of the
b. Area/Resident Engineers will perform the following quality assurance checks to verify
the Contractor's QC Inspector's compliance with the drawings and specifications: