UNIT 5.2 Flashcards
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 ____________ is designed to give the most economical
and most practical combination of the materials which will
produce the desired workability, strength and durability.
concrete mixture
All the materials used in producing concrete should
be tested as to ______ ahead of the start of concreting
work, taking into consideration the duration of testing and
curing period of trial mix for strength test specimens.
quality
S P E C I F I C A T I O N :
a. Pavement
1. Cement Factor –__________
2. Strength at 14 days
a. Flexural –________ Third-Point Loading
b. Flexural –________Mid-Point Loading
c. Compressive(Core Sample) –_______
3. Slump: ___________
9.10 bags/cu.m.
]3.8 MPa (550 Psi)
4.5 MPa (650 Psi)
85% of 3,500 Psi
40 –75 mm (11⁄2” –3”)
All superstructures and heavily reinforced substructures.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 __________to determine in
advance of construction by means of _____, the exact
proportions by weight for each class of concrete. If the____ or
batch is made in the laboratory, representative samples of the
concrete materials which will be used in the work should be
furnished.
Project Engineer , trial mixes, trial mixe
This Table, which has been developed
from experience and data from several research agencies, indicates
the amount of water required per cubic meter of concrete and the
percent of sand (of total aggregate by absolute volume) required for
good workability
Table V
The _________ is selected on the basis of established relationships
such as those given in Table V.
first trial mix
The values in Table V are based on a mix having a water-cement
ratio of 0.57 by weight of 22.80 kg. per bag of cement, 75.0
mm slump and natural sand having a fineness modulus of
2.75. T or F
True
