Civil Engineering Reference
In-Depth Information
G
=
C-S-H
H
1
and H
2
=
first and second peaks for C
4
AH
13
and C
2
AH
8
H
3
=C
3
AH
6
CH
=
Ca(OH)
2
CC
=
CaCO
3
Figure 8.
Influence of sodium carbonate (NLS) and sodium lignosulfonate + sodium
carbonate (NC) on the paste hydration of C
3
S (80%)-C
3
A (20%).
2.7
Cement-Lignosulfonate-Water System
Thermal investigations have shown that the rate of hydration of
C
3
A and the inter-conversion of ettringite to the low monosulfoaluminate
in the C
3
A-CaSO
4
•2H
2
O-CLS-H
2
O system, and hydration of individual
cement phases C
4
AF, C
3
S, and C
2
S are all retarded by lignosulfonates.
Thus, it is expected that the rate of hydration of cement should also be
retarded by the addition of lignosulfonates.
