Workability, Factors influencing workability, Measurement of workability, Effect of time and temperature on workability

1. Concrete technology
Workability, Factors influencing workability,
Measurement of workability, Effect of time and temp.
on workability
A.Pavan Kumar
B.tech, Civil Engineering, SVEC,TPT,AP

2. What is workability ????????????
• The property of fresh concrete which is indicated by the amount of
useful internal work required to fully compact the concrete without
bleeding or segregation in the finished product.

3. Highly workable concrete Medium workability
generally workable

4. Factors Affecting Workability

5. ////Measurement of Workability

8. K-Slump Tester

9. Compaction Test
Concrete strength is proportional
to its relative density. A test to
determine the compaction factor
was developed in 1947. It involves
dropping a volume of concrete
from one hopper to another and
measuring the volume of concrete
in the final hopper to that of a fully
compacted volume. This test is
difficult to run in the field and is
not practical for large aggregates
(over 1 in.).

12. Flow Test
Measures a concretes ability to flow under
vibration and provides information on its
tendency to segregate. There are a number of
tests available but none are recognized by
ASTM. However, the flow table test described
for mortar flows is occasionally used.

15. Vee Bee
Consistometer
Apparatus

16. -------Effect of temperature-------
• When temperature increases, then in the same proportion
workability of fresh concrete decreases. The reason that stands
behind is “ when temperature increases then evaporation rate also
increases due to that hydration rate decreases and hence,
concrete will gain strength earlier “. Due to fast hydration of
concrete, a hardening comes in concrete and that decreases the
workability of fresh concrete. Therefore, In return manipulation of
concrete become very difficult.