final bid specs 09328.pdf - Freese and Nichols, Inc.

4. Maximum placement lifts measured in the loose condition are as follows:
a. 9-inches when heavy compaction equipment is used.
b. 4-inches when hand-directed compaction equipment is used.
5. Subgrade preparation for slab-on-grade
a. Provide a 3-inch layer of compacted FINE-GRADED GRANULAR MATERIAL.
B. MOISTURE CONTROL
1. GENERAL
The materials in each layer of the fill shall uniformly contain the amount of moisture within
the limits specified below necessary to obtain the maximum dry density for the soil.
Compact Class 1 and Class 2 Earth Fill with a moisture content of at or within five (5)
percentage points wet of optimum moisture content. Compact Class 3, Class 4, and
Class 5 Earth Fill with a moisture content within two (2) percentage points dry to five (5)
percentage points wet of optimum moisture content. The moisture content ranges
specified above for the various classes of earth fill represent maximum upper and lower
limits of the particular range. Determination of the maximum dry density-optimum
moisture shall be by one (1) or more of the following ASTM procedures: D-1556 or D-
6938. Completely cohesionless materials which are to be compacted to a specified
relative density shall be at a moisture content which will allow use of the specified
compaction equipment and consistent achievement of the specified density.
2. MOISTURE CONTROL DURING PLACEMENT
After spreading the soil, adjust the moisture content of the soil if necessary by either
aeration or the addition of water to bring the moisture content within the range specified.
Uniformly distribute the moisture content throughout the layer of soil to be compacted. In
order to accomplish this distribution, thoroughly mix the layer of soil by disking, harrowing,
or by the use of a power-driven pulverizer. Should the surface of a previously compacted
layer become dry due to exposure to the elements, appropriately wet surface of the
compacted layer prior to placing the succeeding layer of soil, and properly disk or harrow
the surface. Should a layer of soil be over wet, allow the layer to dry to a proper moisture
content prior to compacting. Should the surface of a layer become smooth and hard,
roughen the surface by scarifying, and wet the surface if necessary prior to placing the
next layer of soil. Reprocess any layer which becomes damaged by weather conditions to
meet the specification requirements. There shall be no additional payment made for such
reprocessing.
C. COMPACTION
1. Compaction shall be by power hand equipment or rubber tired equipment, provided the
rubber tired equipment does no damage. Compaction by power hand equipment or
rubber tired equipment shall be completed such that there will be a 24" overlap by roller
compaction.
2. Compact the Class 1 and Class 2 Earth Fill zones by a minimum of eight (8) passes with
a tamping roller. Compact the Class 3, Class 4, and Class 5 Earth Fill zones by a
minimum of eight (8) passes with a tamping roller or by a minimum of four (4) passes with
a tamping roller, followed by a minimum of four (4) passes with a pneumatic roller. A
vibratory roller shall be required if the material is sandy and if requested by the Engineer.
A pass shall consist of one (1) trip over the area being compacted. The front and rear
axle rollers on self propelled models shall only be considered as one (1) pass per trip.
The initial and final area to be rolled shall each have eight (8) passes. Stagger passes
between the initial and final area in order to establish overlapping with at least eight (8)
passes at all locations. Approve the exact method based upon the test section.
Dumping, spreading, sprinkling, and compacting may be performed at the same time at
different points along a section where there is sufficient area to permit these operations to
proceed simultaneously.
Structural Excavation and Backfill 31 23 10-4
DPR09328