TM 5-822-7/AFM 88-6, Chap. 8
APPENDIX D
ROLLER-COMPACTED CONCRETE PAVEMENTS; DESIGN AND CONSTRUCTION
b. Coarse aggregate. The coarse aggregate may
D-1. Application. Procedures and criteria described
in this appendix are applicable to the design and
consist of crushed or uncrushed gravel, recycled
concrete, crushed stone, or a combination thereof.
construction of roller-compacted concrete (RCC)
The quality of coarse aggregate used by the Corps of
pavement (RCCP).
Engineers to date in RCCP has generally complied
D-2. General. Roller-compacted concrete pavement
with ASTM C 33, although satisfactory RCC maybe
employs a concrete paving technology that involves
possible with coarse aggregate not meeting these
laydown and compaction of a zero-slump concrete
requirements. Local state highway department
mixture using equipment similar to that used in
coarse aggregate grading limits, for example, should
placement and compaction of asphaltic concrete
generally be acceptable. A primary consideration
pavement. By using these construction techniques,
should be that, regardless of the grading limits
the potential exists to save one-third or more of the
imposed, the grading of the aggregate delivered to
cost of conventional concrete pavement. Although
the project site be relatively consistent throughout
the concept and technology behind RCCP is relatively
the production of RCC. This is an important factor in
new, RCCP has already proven itself cost-effective
maintaining control of the workability of the concrete
in several projects including log-sorting yards, port
mixture. The nominal maximum aggregate size
facilities, heavy equipment parking areas, tank
normally should not exceed 3/4 inch, particularly if
trails, and haul roads.
pavement surface texture is a consideration. When
D-3. Subgrade and base course preparation. The
aggregate larger than 3/4 inch is used, segregation
subgrade and base course should conform to the
and resulting rock pockets are likely to occur.
requirements outlined in TM 5-822-6/AFM 88-7,
c. Fine aggregate. The fine aggregate may consist
of natural sand, manufactured sand, or a combina-
chapter 3, or TM 5-824-3/AFM 88-6, chapter 3. The
freeze-thaw durability of RCCP is not fully
tion of the two, and should be composed of hard,
durable particles. The fine aggregate quality should
understood yet, but is presently being studied at the
US Army Engineer Waterways Experiment Station
generally be based on the limits given in ASTM C 33
(WES) and the Cold Regions Research Engineering
except that consideration should be given to
Laboratory (CRREL). Good performance has been
relaxing the maximum 5.0 percent limit of material
finer than the No. 200 sieve. The amount of material
observed in the field; however, marginal performance
passing the No. 200 sieve has been increased in
has been observed in the laboratory. For this reason,
Canada to 8 percent of the total weight of aggregates
in areas where the pavement or base course might be
with acceptable results. Sands with higher quan-
subjected to seasonal frost action, particular atten-
tities of nonplastic silt particles maybe beneficial as
tion should be given to providing a base course that
mineral filler and may allow some reduction in the
will adequately drain any water that infiltrates
through the pavement or subgrade. The base course
amount of cement required. However, mixtures made
with fine aggregates having an excessive amount of
should provide sufficient support to permit full
consolidation of the RCCP through its entire
clay may have a high water demand with attendant
shrinkage, cracking, and reduced strength. Deter-
thickness upon compaction.
mination of the specific gravity and absorption of
D-4. Selection of materials.
these sands with high quantities of fines should be
made according to Note 3 in ASTM C 128.
a. General. One of the most important factors in
determining the quality and economy of concrete is
d. Other aggregates. Recent experience with RCC
has shown that aggregate produced for uses other
the selection of a suitable aggregate source. This is
than portland cement concrete may also be success-
as true for RCC as for conventional concrete. Aggre-
gate for RCC should be evaluated for quality and
fully used as aggregate for RCC. Material produced
grading, and should comply with the provisions
for asphalt paving and base courses have both been
outlined in paragraph 4, with the exceptions noted in
used effectively as RCC aggregate. These materials
typically have a higher percentage of fines passing
the following discussion.
D-1
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