HEAD DIAMETER
AMPLITUDE
APPLICATION
INCHES
VPM
INCHES
Thin walls, beams, etc. 1-1/4 - 2-1/2
9,000
- 13,500
0.020
-
0.04
General construction
2 - 3-1/2
8,000
- 12,000
0.025
-
0.05
Heavy sections
3-6
7,000
- 10,500
0.030
-
0.06
Mass concrete
5-7
5,500
- 8,500
0.040
-
0.08
The frequency and amplitude shall be within the range indicated in the
tabulation as determined in accordance with paragraph TESTS AND INSPECTIONS.
3.2.2
Embedded Items
Before placing concrete, care shall be taken to determine that all embedded
items are securely fastened in place as indicated in the drawings or
required. Embedded items shall be free of oil and other foreign matter
such as loose coatings of rust, paint, and scale. The embedding of wood in
concrete will be permitted only when specifically authorized or directed.
Any air or water lines or other materials embedded in structures as
authorized construction expedients shall conform to the above requirements
and upon completion of their use shall be backfilled with concrete or
mortar as directed. Welding will not be permitted on embedded or otherwise
exposed metals which are in contact with concrete surfaces. Tack welding
of or to embedded items will not be permitted.
3.2.3
Concrete on Earth Foundations
Earth foundations upon which concrete is to be placed shall be clean, damp,
and free from frost, ice, and standing or running water. Prior to
placement of concrete, the earth foundation shall have been satisfactorily
compacted in accordance with the provisions of Section [[_____]] [_____].
3.2.4
Concrete on Rock Foundations
Rock surfaces upon which concrete is to be placed shall be clean and free
from oil, standing or running water, ice, mud, drummy rock, coatings,
debris, and loose, semidetached, overhanging, or unsound fragments. Faults
or joints shall be cleaned to a satisfactory depth and to firm rock on the
sides as directed by the Contracting Officer. Immediately before concrete
is placed, all rock surfaces shall be cleaned thoroughly by the use of
air-water jet, high-pressure water jet, or sandblasting as described in
paragraph CONSTRUCTION JOINT TREATMENT. All rock surfaces shall be kept
continuously wet for at least 24 hours immediately prior to placing
concrete thereon. All approximately horizontal surfaces shall be covered
immediately before the concrete is placed with a 13 mm 1/2 inch layer of
mortar composed of the same sand and cementitious materials used in the
concrete. The sand-cementitious materials ratio and the water-cementitious
material ratio of the mortar shall be approximately the same as those used
in the concrete mixture. The mortar shall be covered with concrete before
the mortar has reached its initial time of setting.
3.2.5
Construction Joint Treatment
3.2.5.1
Concrete surfaces to which other concrete is to be bonded shall be prepared
for receiving the next lift or adjacent concrete by cleaning by
sandblasting, high-pressure water jet, or air-water cutting. Surface
SECTION 03700
Page 56
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