Page 64 - Urban Construction Project Management

Testing and Quality Control 39
a factory-made component. Thus, great care must be taken to ensure that proper test-
ing is performed so that a failure will not occur. The erection of a concrete structure
is an excellent example where the use of a mixed type material must have adequate
testing. Concrete is a very viable construction material if placed according to the
standards established by the organizations. However, due to the complexity of mix-
ing the ingredients at the plant and transporting it to the site, placing the concrete at
the site requires numerous controls to obtain an excellent final product. The testing
of concrete should include:
1. A trial concrete mix approved by the owner’s engineer
2. Proper mixing procedures at the concrete plant
3. Timing for the transportation of the concrete mix
4. Designed and properly installed form work and shoring so that they will not col-
lapse or deflect
5. Temperature monitoring of the concrete at the site (to make sure that flash setting
will not occur)
6. Ambient temperature monitoring (too hot for flash setting and too cold for freezing)
7. Slump test to confirm water/cement ratio of the concrete
8. Supervision for concrete vibration and dropping height for the actual placement of
the concrete
9. Monitoring the thickness of a concrete slab
10. Assurance that all the concrete encapsulates the reinforcing bars, especially when
pouring columns
11. Placement of a sample of the concrete into concrete cylinders to determine the
compressive strength of the concrete at 7, 14, and 28 days (via testing in the labo-
ratory). This will be accomplished for design strength conformance and to know
when the forms can be stripped
12. Checking the number and location of the reinforcing bars required for the pour
13. Proper curing of the concrete
14. Assurance that reinforcing bars are properly lapped
15. Assurance that all exterior exposed concrete is covered by 3 inches of concrete
(2 inches for interior concrete) over the reinforcing steel

Even though steel sections are fabricated in a controlled environment at a plant, the steel
members must be connected in the field by iron workers with bolts and/or welding.
Thus, stringent testing is also required for a steel structure. Some of the tests that would
have to be considered when erecting steel are the following:

1. Proper bolts are being utilized.
2. Required tightening (torque) of the bolts needs to be accomplished by code
standards.
3. Steel sections as indicated on the approved shop drawings are in fact being
installed.
4. Welds have to be checked for proper thickness and continuity.