Plastic Shrinkage Cracking in Internally Cured Mixtures

Abstract

Depending on weather conditions between the time of placement and time of setting, concrete can be susceptible to plastic shrinkage cracks. In addition to being unsightly, these cracks are a problem because they can lead to ingress of corrosive substances/processes. Several studies have shown the beneficial effects of internal curing (IC) on autogenous shrinkage and shrinkage cracking in hardened concrete. It has also been noted that pavements with IC exhibit less plastic shrinkage cracking than equivalent conventional concretes. This article gives findings of a study that provides data on settlement and plastic shrinkage cracking in mortars and concretes with different volume replacements of prewetted lightweight aggregate (LWA). While the data indicate sufficient LWA can reduce or eliminate plastic shrinkage cracking, further research is needed to demonstrate the proper mixture proportions that should be used for a specific application.