(A) Trench excavations. Trench excavation shall be classified as either common excavation or rock excavation as classified below.
COMMON EXCAVATION. Removal of all materials, which is not classified as rock excavation.
ROCK EXCAVATION. Removal of all materials which, by actual demonstration, cannot be the Town Engineer’s or Superintendent’s opinion, be reasonably excavated with a backhoe equipped with a general duty dipper and rock points, or similar approved equipment and which is in fact, systematically drilled or blasted. The Town Engineer or Superintendent reserves the right to waive the demonstration of the material encountered as well defined rock. The term ROCK EXCAVATION shall be understood to indicate a method of removal and not geological material. In addition, ROCK EXCAVATION may include removal of a well-defined rock by the method of systematic drilling and mechanical splitting.
(B) Trench backfill. Placement of native backfill material for Class A and C backfill shall include the working of material to achieve suitable moisture content and compaction to the specified density. In lieu of using native material excavated from the trench for Class A and C backfill, the contractor at his or her option may place and compact to specified density and approved imported backfill material. Imported material must be approved by the Town Engineer or Superintendent prior to placement. Material shall be earth, gravel, rock, or combinations thereof, free of humus, organic matter, vegetative matter, frozen material, clods, sticks, and debris and containing no stones having a dimension greater then four inches. Sand or pea gravel will not be an approved backfill material.
(1) Foundation stabilization. Gravel for trench foundation stabilization shall be clean pit-ran gravel, crushed rock or gravel, having reasonably even gradation from coarse to fine. The maximum size shall be four inches.
(2) Crushed gravel pipe base. Material for pipe base and pipe zone shall be three- fourth inch minus crushed gravel, having reasonably even gradation from coarse to fine.
(3) Gravel for trench, backfill. Gravel for trench backfill shall be clean pit run gravel, crushed rock, or gravel having a reasonable even gradation from coarse to fine. The maximum size shall be four inches.
(4) Bituminous cements. Bituminous cement for use in tacking the edges of existing asphaltic concrete pavement shall be RC-1 asphaltic road materials conforming to the applicable specifications of the Asphalt Institute, or shall be an asphalt emulsion.
(5) Asphaltic concrete. Asphaltic concrete shall not be hot plant mix, Class C material.
(6) Crushed gravel. Material shall be one and one-half inch minus or three-fourths inch minus crushed gravel or rock, reasonably even graded from coarse to fine.
(7) Controlled density fill. Controlled density fill (CDF) shall be a mixture of cement, fly ash, aggregates, water and admixtures proportioned to provide a non-segregating, self-consolidating, free-flowing, and excavatable material that will result in a hardened, dense, non-settling fill. CDF is approved as an alternative for “gravel for trench backfill” and as an alternative to “crushed gravel” and must be used at any location on the project at the option of the contractor for foundation stabilization material, pipe base material, pipe zone material, trench backfill material and pavement base material.
(Ord. passed - -)