20211014 Ver 1_Riprap Size_20211018

Riprap Size

2.4.1 Rock
Only quarried stone shall be used. Rip rap shall be granite base
with a specific gravity between 2.5 - 2.75. A limestone rip rap
material shall not be allowed.
Individual rocks shall be blocky and angular, with sharp clean
edges and relatively flat faces. Individual rocks shall be as
close to equi-dimensional as possible. The long axis of the
individual stone is defined as "a". The intermediate axis, "b",
is the maximum width perpendicular to the long axis. The short
axis, "c", is the stone thickness perpendicular to the plane of
the "a" and "b" axes. The average ratio of the long axis, "a",
to the thickness, "c", shall be 2 or less.

Stone shall be well graded and shall conform to the gradation
limits below:
Size of Graded Rip Rap Stone (Measured at Intermediate Axis "b")
MAXIMUM AVERAGE MINIMUM
30 Inches 18 Inches 9 Inches

No more than 5.0% of the material furnished can be less than the
minimum size specified nor no more than 10.0% of the material
can exceed the maximum size specified.