Title:
Determination of the Curing Efficiency of Externally and Internally Cured Concrete Using Neutron Radiography
Author(s):
Mehdi Khanzadeh Moradllo, Lynda Bouchelil, Gwen Clark, W. Jason Weiss, Rita Maria Ghantous, Margaret N. Goodwin
Publication:
CRC
Volume:
Issue:
Appears on pages(s):
32
Keywords:
DOI:
Date:
12/1/2021
Abstract:
Curing is important to develop long-lasting durable concrete. Curing promotes hydration of the cement and reaction of the supplementary cementitious materials (SCMs) leading to improved strength and durability. Concrete specifications typically specify curing as a fixed duration of time (e.g., 14 days of curing using wet burlap). Currently, State Highway Agencies (SHA) are actively seeking ways in which they can reduce the time of construction to reduce the inconvenience to the traveling public and to improve safety for the construction workers in work zones. As such, it is often asked if the specified duration of curing can be reduced, especially by implementing new curing practices. However, relatively limited work has been performed to understand how the benefits of new curing practices (e.g., internal curing) can be achieved in the construction process. This study proposes a new methodology to quantify the effectiveness of external and internal curing with high spatial resolution over concrete depth. This research develops quantifiable equivalent durations of curing for concrete with conventional curing and internal curing, especially in SCM systems. It is shown that the use of internally cured concrete mixtures can reduce curing time, saving contractors both time and money during construction. For example, while a 14-day wet burlap may be specified on a bridge deck, it may be possible that 7 days of wet burlap with internal curing provides the same level of performance. This would reduce the construction schedule by one week.
The immediate findings of this study will provide tools to enable practitioners to implement internal curing for different applications due to its advantages in saving both time and money during construction. It also helps to evaluate the performance of different external curing methods by quantifying the depth of the curing-affected zone with high spatial resolution. In addition, the outcomes of this research can be directly incorporated into a new ACI guide to internal curing (ACI 308-213R).