The document discusses the critical issues surrounding building collapses, attributing them to poor designs, substandard materials, and inadequate workmanship. It highlights the importance of reinforcement bars in construction, detailing their required properties such as yield strength, rib configuration, and bendability to ensure safety and structural integrity. Additionally, it emphasizes the necessity of quality assurance measures and proper material standards in the construction industry.

1. STEEL

2. STEEL
 The state of collapsed buildings has become
a matter of concern for all stakeholders
 The reasons for collapses have been
attributed to:
 Poor designs
 Use of substandard materials
 Inadequate quantities of even good materials
 Poor workmanship

3. STEEL
 Reinforcement bars are major material
used in construction.
 Reinforcement bars are used to beef-up the
strength of concrete in construction.
 They assist concrete in load bearing
capacities.
 Good structural designs ensure that loads
are appropriately distributed as to ensure a
sturdy building.

4. STEEL
 The reinforcement bars used in the
construction are within the standards
used in the calculation of the
parameters of the design.
 Where the quality of bars is below the
standard applied, building collapse may
occur.
 As there are sub-standard drugs, there
are also substandard reinforcement bars
in the market.

5. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
 High Yield Strength
 The yield strength indicates the capacity of the bar
to carry load (vertical and horizontal) before
plastic deformation.
 The National Structural Code of the Philippines
(NSCP) stipulates a minimum of 420 MPa (Grade
60) for high tension bars.
 Grade 40 (275 MPa) is also available commercially
which is used as RSB
 For prestressing steel, a yield strength of as high
as 1860 Mpa is required.

6. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
 Rib Configuration
 The rib configuration of the bars refers essentially
to the height and types of the ribs.
 The ribs ensure concrete bonding and do not
contribute to the load bearing function of the
rebars.
 Very low rib height does not allow for adequate
concrete bonding while excessive ribs compromise
the weight bearing function of the bars.
 An average rib height of about 7 to 8% of the
rated diameter is just adequate.

7. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
 Standard Weight Per Meter
 There is a standard weight per meter for each
profile of rebar. (See Table 1)
 The heavier bar, of two pieces of rebar of same
length and profile will conform better to the
standard weight per meter for the profile in
question.
 Dimensional Specification
 This refers to the diameter and length of rebars.
 The diameter of rebars can be easily measured
by a vernier caliper and the length by a tape.

8. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
Imperial
Bar Size
"Soft"
Metric Size
Weight
(lb⁄ft)
Weight
(kg/m)
Nominal
Diameter
(in)
Nominal
Diameter
(mm)
Nominal
Area
(in²)
Nominal
Area
(mm²)
#3 #10 0.376 0.561 0.375 = 3⁄8 9.525 0.11 71
#4 #13 0.668 0.996 0.500 = 4⁄8 12.7 0.20 129
#5 #16 1.043 1.556 0.625 = 5⁄8 15.875 0.31 200
#6 #19 1.502 2.24 0.750 = 6⁄8 19.05 0.44 284
#7 #22 2.044 3.049 0.875 = 7⁄8 22.225 0.60 387
#8 #25 2.670 3.982 1.000 = 8⁄8 25.4 0.79 509
#9 #29 3.400 5.071 1.128 28.65 1.00 645
#10 #32 4.303 6.418 1.270 32.26 1.27 819
#11 #36 5.313 7.924 1.410 35.81 1.56 1006
#14 #43 7.650 11.41 1.693 43 2.25 1452
#18 #57 13.60 20.284 2.257 57.33 4.00 2581
REBAR SIZES AND GRADES
Imperial bar designations represent the bar diameter in fractions of
1/8”, i.e. #4 = 4/8 inch = 1/2 inch

9. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
 Bend-ability
 The rebar should be able to bend without
fracture to accommodate the design of the
building.
 Those that break on bending when the right
mandrel is used are substandard.
 Recommended mandrel diameters
Diameter of the bar
(mm)
Diameter of mandrel
(mm)
8 64
10 80
12 96
16 128
20 160
25 200
32 256

10. CHARACTERISTIC PROPERTIES/
FEATURES OF GOOD RSB
Features and other material properties Benefits
Perfect rib Excellent concrete bonding.
High strength ( YS between 420 and 480
N/mm2 )
Less steel volume per cubic meter of concrete
required for construction
Correct rib diameter and nominal
diameter
Excellent concrete bonding and more steel per
unit length for construction.
Better elongation Structure can sustain seismic vibration
Correct length (12 meter) More steel per length
Test certificates Company’s guarantee of quality
SON certified material Guarantee of quality product
Better bend ability (no fracture on
bending)
Structure can with stand vibration.
Standard weight per meter More steel available per unit length.
Oblique ribs (fins) Promotes concrete bonding & avoids lateral
movements.
ISO accredited firm Guarantee of quality product

11. QUALITY ASSURANCE
 It is generally better to patronize products
fro organizations that have adequate
quality assurance plans for their products.
 Quality checks are carried out right from
the raw materials consumed and at every
stage of production to ensure quality
conformity.
 Finished products are subjected to various
metallurgical tests to ensure conformity to
standard before dispatch to dealers and
end-users.

12. QUALITY ASSURANCE
 Until recent years, geomembranes were
used mostly as canal and pond liners.
 One of the largest current applications is
the containment of hazardous and
municipal wastes and their leachates.
 In many of these applications
geomembranes are employed with
geotextile or mesh