The foregoing specifications concerning terms,
materials, forms, subgrades, draining, subbase, mixing, placing, jointing
and curing shall govern the construction of curbs and gutters and
combined curbs and gutters, except as noted below.
The proportion shall be one part portland cement
to three parts sand and five parts coarse aggregate base, with a one
part portland cement and two parts sand top, or one part portland
cement, two and 1/2 parts sand and four parts coarse aggregate for
one-course construction.
The curbs, gutters and combined curbs and gutters
shall be cut into sections not larger than 20 feet and shall be provided
with one-half-inch expansion joints every 20 feet at the ends of all
curves.