a. Any rock that is capable of furnishing cement when properly treated.
Fay
b. Scot. Argillaceous limestone-magnesian.
See also:hydraulic limestone
Silver precipitated from solution, usually by copper. Fay
A pourable or pumpable mixture of water, cement, and fine sand-- having
the consistency of a thick liquidlike heavy cream. Long
The addition of cement to a soil, which acts as a binding agent and
produces a weak form of concrete called soil cement. The quantity of
cement to be added depends upon the type of soil. Cement can be used with
most types of soil, providing the clay fraction is reasonably small and
other specified impurities are not present. A small percentage of lime is
usually added. With very poor soils, cement stabilization may be
uneconomical or impracticable. See also:soil stabilization
Nelson
A ball, flapper, or clack-type valve placed at the bottom of a string of
casing, through which cement is pumped. When pumping ceases, the valve
closes and prevents return of cement into the casing. Long
An era of geologic time, from the beginning of the Tertiary period to the
present. (Some authors do not include the Quaternary, considering it a
separate era.) The Cenozoic is considered to have begun about 65 million
years ago. Also spelled: Cainozoic; Kainozoic. AGI
A temporary timber framework upon which the masonry of an arch of
reinforced masonry lintel is supported until it becomes self-supporting.
See also:centers
In surveying, a system that allows accurate final centering of the
theodolite above (or below) its station by sliding the whole instrument on
its stand (tribrach). Important with short sights where small centering
errors could introduce serious inaccuracy. Pryor, 3
A special, hollow, refractory shape used at the base of the guide tubes in
the bottom pouring of molten steel. The center brick has a hole in its
upper face, and this is connected via the hollow center of the brick to
holes in the faces (often six in number). The center brick distributes
molten steel from the trumpet assembly to the lines of runner bricks. It
is also sometimes known as a crown brick or spider. Dodd
In air velocity determination, the ratio of the mean velocity to the
velocity measured at the center. This ratio is found to be dependent upon
the Reynolds number. See also:Reynolds number
A method of tunneling whereby the center is left to the last for
excavation. Sandstrom
Aust. The rock between the limbs of a saddle reef.
Drilling a conical hole (pit) in one end of a workpiece. ASM, 1
The fixing of the center spot of a proposed shaft at the site selected and
the maintenance of the shaft sinking along this plumb line during its
entire depth. See also:plumbing
center-latch elevator and links
See:elevator
a. A line marked on the roof of a mine roadway, or a plumbline, for
controlling the direction in which the roadway is driven.
b. In U.S. public land surveys, the line connecting opposite
quarter-section or sixteenth-section corners. AGI
In anthracite and bituminous coal mining, one who locates the centerline
of underground openings in a mine, such as entries, rooms, and
haulageways, so that the miners can drive the openings in a straight line
without calling the mine surveyor. DOT
a. The center of mass of a cut or a fill. Nichols, 1
b. That point in a body or system of bodies through which the resultant
attraction of gravity acts when the body or system is in any position;
that point from which the body can be suspended or poised in equilibrium
in any position. AGI
a. The point that represents the mean position of the matter in a body.
Webster 3rd
b. The point in a body through which acts the resultant resisting force
due to the body's inertia when it is accelerated. Coincident with the
center of gravity. CTD
c. In a cut or a fill, a cross section line that divides its bulk into
halves. Nichols, 1
d. Also called center of inertia.
See:torsional center