After reviewing the information submitted by' all commenters, EPA concludes that
GGBF slag currently is used primarily in Eastern states and states located just west of the
Mississippi River. The product also has been used in states more remote from the nation's
steel centers (e.g., Texas, Oklahoma, and Colorado), however. According to FHWA's data
base of state specifications, both Georgia and North Dakota permit the use of GGBF slag.
Since states generally do not specify a material unless it is available, the fact that these two
states permit the use of GGBF slag indicates that this item can be made available to states
more remote from steel mills.
As discussed in section VII.B.5 of this document, section 6002 of RCRA recognizes
that procuring agencies may not always be able to purchase a designated item. Section 6002
provides four exceptions to the requirement that procuring agencies must purchase items
designated by EPA. Two of these exceptions are when (1) the item is not reasonably
available within a reasonable period of time, and (2) the item is available only at an
unreasonable price. Thus, under RCRA, if GGBF slag is not available, a procuring agency
is not required to purchase it. The procuring agency must take the affirmative step of
inquiring whether the item will be made available, however.
EPA has concluded that availability is no longer a barrier to designating GGBF slag.
The item clearly is more widely available than in 1983, when EPA last considered
designating it. Commenters indicated that it can be made available in additional states. In
light of the Agency's' past experience with the positive effect of an item designation on
markets, EPA concludes that designation. of cement and concrete containing GGBF slag will
encourage additional states to consider the use of GGBF slag, thereby creating expanded
markets for this item.
(2) Performance. The comments contained both positive and negative information
about the performance of GGBF slag. Several states commented that they use GGBF slag
for its positive attributes. According to FHWA, GGBF slag reacts with some of the by-
products of the cement hydration reaction to form additional cementitious products. Both
FHWA and several state agencies commented that GGBF slag is known to contribute to a
reduction in alkali-silica reactivity. FHWA also commented `that GGBF slag can reduce the
permeability of the concrete and increase the concrete's resistance to sulfate attack, because
the concrete will contain less tricalcium aluminate, the component of Portland cement which
is susceptible to sulfate attack.
Commenters cited eight negative performance factors about the use of GGBF slag,
although conflicting information was provided about almost all of these factors. Based on the
information submitted by commenters, EPA concludes that there are instances when it is not
appropriate to use GGBF slag. However, in light of the fact that there are instances where
the use of GGBF slag can be beneficial, EPA believes that a designation of this item will
encourage procuring agencies to learn more about this product and increase the likelihood
that they will begin to purchase it where it is available.