**Material Specification 524---Aggregates for Roller Compacted
Concrete**

1\. Scope

This specification covers the quality of aggregate for use in the
manufacture of roller compacted concrete (RCC).

2\. Quality

Aggregate shall conform to the quality requirements of ASTM
Specification C 33.

3\. Gradation

Aggregate gradation shall be within the limits provided below for the
total aggregate weight in a unit volume of RCC. For the sieve sizes
shown below that are larger than #4, no more than 20 percent of the
total aggregate shall be retained on an individual sieve. For sieve
sizes smaller than 3/8 inch, at least 3 percent of the total aggregate
shall be retained on each sieve.

> Sieve size Percent passing
>
> 2\" 100
>
> 1-1/2\" 85--100
>
> 1\" 70--100
>
> 3/4\" 60--84
>
> 1/2\" 50--70
>
> 3/8\" 40--60
>
> #4 32--50
>
> #8 26--42
>
> #16 20--35
>
> #30 14--28
>
> #50 8--22
>
> #100 4--15
>
> #200 0--7

Unless otherwise specified, the fines (material passing the #200 sieve)
shall have a plasticity index less than four.

***Particle shape***---The amount of flat and elongated particles with a
length-to-width or width-to-thickness ratio greater than 3:1, as
determined by ASTM D 4791, shall not exceed 25 percent on any individual
sieve size group nor a weighted average of 20 percent for all of the
sieve sizes in the total gradation.

4\. Reactivity with alkalies

The potential reactivity of aggregates with the alkalies in cement shall
be evaluated by petrographic examination and, where applicable, the
chemical method of test, ASTM C 289, or by the results of previous tests
or service records of RCC or concrete made from similar aggregates from
the same source. The standards for evaluating potential reactivity shall
be as described in ASTM C 33, appendix A1.

Aggregates indicated by any of the above to be potentially reactive
shall not be used except under one of the following conditions:

a\. Applicable test results of mortar bar tests made according to ASTM
Method C 227 are available and indicate an expansion of less than 0.10
percent at 6 months in mortar bars made with cement containing not less
than 0.8 percent alkalies expressed as sodium oxide; or

b\. RCC or concrete made from similar aggregates from the same source
has been demonstrated to be sound after 3 years or more of service under
conditions of exposure to moisture and weather similar to those
anticipated for the RCC under these specifications.

Aggregates indicated to be potentially reactive, but within acceptable
limits as determined by mortar bar test results or service records,
shall be used only with low alkali cement, containing less than 0.60
percent alkalies expressed as sodium oxide.

5\. Acceptance

Aggregates that fail to meet any requirement may be accepted only when
the specification for RCC expressly contains either:

a\. Special provisions for acceptance that can be proven before the
aggregates are used on the job and within a period such that no work
under the contract will be delayed by the requirements of such proof, or

b\. Special provisions for specific mix requirements to compensate for
the effects of the deficiencies.

6\. Storing and handling

Aggregates shall be stored in stockpiles at specified storage areas.
Separators, such as timbers, boards, or pre-cast concrete panels, shall
be used between adjacent stockpiles to prevent the contamination and
intermixing of dissimilar materials. The contractor shall be responsible
for providing a system that reliably and consistently stockpiles the
aggregates and allows the withdrawal of the aggregates from the
stockpiles without contamination or segregation. Segregated or
contaminated aggregates will not be allowed in production of RCC.