Next: Experimental procedures Proper curing of concrete is
paramount for obtaining optimum performance from a given set of
mixture proportions. For high-performance concretes, curing
becomes even more important, due to the typically lower water-
to-cement (w/c) ratios and the increased propensity for early
age cracking due to thermal and self-desiccation stresses .
Besides the water which is removed due to exposure to an ambient
environment, additional empty capillary porosity is created
within the cement paste component of the concrete due to the
chemical shrinkage that accompanies the cement hydration
reactions, quantified many years ago by Powers , but also the
subject of much recent research [3,4,5]. The creation of empty
capillary pore space has two major effects on the evolving
cement paste system. First, the resultant capillary pressures
induce shrinkage stresses within the cement paste
microstructure, causing a measurable external physical shrinkage
[3,5]. The magnitude of these stresses (at relative h