Chapter 5 Flashcards
(27 cards)
the determination of the
relative weight proportions of cement, fine aggregate, coarse
aggregate and water by absolute volume as outlined in the
American Concrete Institute (ACI) Standard 211.1,
“Recommended Practice for Selecting Proportions for Normal
and Heavy Weight Concrete.”
design of concrete mixture
The design of concrete mixture is the determination of the
relative weight proportions of cement, fine aggregate, coarse
aggregate and water by absolute volume as outlined in the
________________________
“Recommended Practice for Selecting Proportions for Normal
and Heavy Weight Concrete.”
American Concrete Institute (ACI) Standard 211.1,
The design of concrete mixture is the determination of the
relative weight proportions of cement, fine aggregate, coarse
aggregate and water by absolute volume as outlined in the
American Concrete Institute (ACI) Standard 211.1,
___________________________________
“Recommended Practice for Selecting Proportions for Normal
and Heavy Weight Concrete.”
The purpose of concrete mixture is designed to give the _________________________
most economical
and most practical combination of the materials
The concrete mixture is designed to give the most economical
and most practical combination of the materials which will
produce the desired
workability, strength and durability.
Some the materials used in producing concrete should
be tested as to quality ahead of the start of concreting
work,
False, All
Cement Factor Specification
9.10 bags/cu.m.
Flexural Strength at 14 days
3.8 MPa (550 Psi) Third-Point Loading
4.5 MPa (650 Psi) Mid-Point Loading
Compressive Strength
85% of 3500 Psi
Slump Specification
40-75mm (1.5”-3”)
The mix shall either be designed or approved
by the Engineer.
True
A change in the source of materials during the
progress of work must necessitate a new mix design.
False (may)
Other
methods of proportioning may be employed in the mix design with prior
approval of the Owner.
False (Engineer)
All superstructures and heavily reinforced substructures.
Class A
The important parts of the structures included are slabs, beams, girders,
columns, arch ribs, box culverts, reinforced abutments, retaining walls and
reinforced footings and large diameter cast-in-place reinforced concrete
piles (bored piles).
Class A
Footings, pedestals, massive pier shafts, pipe bedding, and gravity
walls, unreinforced or with a small amount of reinforcement.
Class B
Thin reinforced sections, railings, precast R.C. piles and cribbing and for filler in steel grid floors.
Class c
Pre-stressed concrete structures and members.
Class P
Concrete deposited in water.
Seal
It will be necessary for the Project Engineer to determine in
advance of construction by means of trial mixes, the exact
proportions by weight for each class of concrete. If the trial mix or
batch is made in the laboratory, representative samples of the
concrete materials which will be used in the work should be
furnished.
True
The second trial mix is selected on the basis of established relationships
such as those given in Table V.
False
This Table, which has been developed
from experience and data from several research agencies, indicates
the __________________ required per cubic meter of concrete and the
________________ (of total aggregate by absolute volume) required for
good workability
amount of water, perfect sand
The values in Table V are based on a mix having a water-cement
ratio of ____ by weight of ____ kg. per bag of cement, ____
mm slump and natural sand having a fineness modulus of
_____
0.57, 22.80, 75.0, 2.75
Each _____ increase or decrease in water-cement ratio
0.05
