F. K. Kong MA, MSc, PhD, CEng, FICE, FIStructE, R. H. Evans CBE, DSc, D ès Sc, DTech, PhD, CEng, FICE, FIMechE, FIStructE (auth.)-Reinforced and Prestressed Concrete-Springer US (1987)

36 Properties of structural concrete
Gravel
Basalt
Limestone
0 o 100 200 300 400 soo
Duration of exposure (days)
Fig. 2.5-6 Effect of type of aggregate on shrinkage [15]
inversely with the ratio of the volume to the surface area of the member.
For the purposes of structural design, it may be assumed that, for a given
volume/surface ratio, shrinkage is independent of the shape of the
member. Figure 2.5-7 provides guidance on the effect of the volume/
surface ratio on concrete shrinkage.
The length of the moist-curing period has no effect on the magnitude of
the total long-term shrinkage, provided this period is not shorter than 2 or
3 days. However, a sufficiently long period of moist curing before drying
enables the concrete to develop higher tensile strength before shrinkage
takes place and hence reduces the incidence of cracking.
10 ......
~
~
"'-.....
~
.........
' ...............
20 40 60 80 100 120 140
Volume/surface ratio Cmm)
Fig. 2.5-7 Effect of volume/surface ratio on shrinkage [16]