Page 43 - CONCRETE MATERIALS AND MIXTURE
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1.3.3 Admixtures
• Is a material added to the batch of concrete mixture either
before or during its mixing to alter its properties such as
workability, curing temperature range, set time or colour.
• Reason for using admixture:
a. Increase slump and workability
b. Retard or accelerate initial setting
c. Reduce or prevent shrinkage
d. Modify the rate or capacity for bleeding
e. Reduce segregation
f. Retard or reduce heat evolution during early hardening
g. Increase strength
h. Increase durability or resistance to severe conditions of
exposure
i. Decrease permeability of concrete
