Submit concrete mix designs, certified results of compressive strength
tests, certified field tests and copies of batch slips for all cast-in-place
inlets, catch basins or endwalls.
Inspection by the municipality will, at a minimum, be made of
materials upon delivery to the job site; of the subgrade, prior to
construction or placement; and of the completed structure, prior to
backfill.
Precast cement concrete products shall be subject to rejection
for failure to conform with these specifications or if any one of
the following conditions is noted:
Crushed stone subbase: AASHTO No. 57, Type C, Crushed Stone or Gravel
aggregate, Section 703.2, Publication 408 Specifications. Do not use
slag or cinders.
Modified boxes (PennDOT Type 1, 2 or 3, Modified Type I or Modified
Type II) shall have reinforced cover adjustment slabs in accordance
with details in Publication 72M.
Six-foot inlet grates shall be similar in all respects to standard
inlet grates except that the longitudinal dimension shall be increased
by 24 inches.
Precast cement concrete grade adjustment risers. Risers shall be
cast from 4,000 psi concrete (twenty-eight-day compressive strength),
shall be a maximum of two inches thick, and shall be reinforced in
accordance with ASTM A478.
Construct inlets and catch basins of either precast cement concrete
sections or of cast-in-place cement concrete, and of the type indicated
on the drawings.
Construct endwalls to the dimensions and design indicated on Standard
Drawing RC-31M, Publication 72M, and of the type shown on the drawings.
Construct endwalls of monolithically cast reinforced concrete.
Construct basin outlet structures with inverts, grates and openings
at the required elevations shown on the drawings. Connect to new or
existing outlet pipes, relaying or adding pipe as needed to meet the
structure.