Civil Engineering Reference
In-Depth Information
7
Superplasticizing
Admixtures
1.0
INTRODUCTION
The advantages derived from the use of superplasticizing admix-
tures include production of concrete having high workability and produc-
tion of high strength concrete having normal workability and lower water
content. Another possible application is the fabrication of concrete with
less cement, having normal strength and workability. Superplasticizers
have also been used with advantage in concretes containing fly ashes, silica
fume, rice husk ash, slags, etc.
A study of the hydration of cement and cement compounds in the
presence of superplasticizers is useful for theoretical and practical consid-
erations. Many types of thermal techniques including DTA, DSC, TG,
DTG, Conduction Calorimetry, and EGA have been used for such studies.
They have yielded important results that could be correlated with physical
and mechanical characteristics of cement systems. Investigations have
included the measurement of heat of hydration, the mechanism of reactions,
strength development, microstructure, permeability, durability aspects,
compatibility problems between cement and superplasticizers, the predic-
tion of some properties, material characterization and selection, math-
ematical modeling of hydration, development of test methods, and cement-
superplasticizer interactions.
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