TY - JOUR
T1 - A new four stage model of capillary pressure in early age concrete
T2 - Insights from high capacity tensiometers
AU - Jamali, Armin
AU - Mendes, Joao
AU - Nagaratnam, Brabha
AU - Lim, Michael
N1 - Funding information: The financial contribution of the Northumbria University Faculty of Engineering and Environment and the Northumbria University Department of Mechanical and Construction Engineering MCE QR Steering Funds are greatly acknowledged. The technical support from Phil Donnelly (Senior Technician) for the manufacture of HCT components, saturation vessels and other experimental equipment necessary to conduct the experimental program.
PY - 2022/11/1
Y1 - 2022/11/1
N2 - Capillary pressure is frequently measured to evaluate the shrinkage performance of concrete but has been limited to pressures <100 kPa preventing a better understanding of the early age factors affecting concrete durability. In this study, high capacity tensiometers (HCTs) were employed for the first time to investigate the behavior of early age concrete. The evolution of capillary pressure in Self-Consolidating Concrete (SCC) with and without shrinkage reducing admixture was evaluated. The results demonstrate that HCTs are capable of measuring capillary pressure beyond 1500 kPa. This transformative new record of capillary pressure behavior has enabled the development of a model for the capillary pressure in early age concrete correlated to water evaporation, self-desiccation, setting time, temperature, and hydration processes. This ability to quantify real-time capillary pressure change in concrete generates important implications for optimizing the commercial durability of SCC and for understanding the link between early age concrete processes and resultant mechanical performance.
AB - Capillary pressure is frequently measured to evaluate the shrinkage performance of concrete but has been limited to pressures <100 kPa preventing a better understanding of the early age factors affecting concrete durability. In this study, high capacity tensiometers (HCTs) were employed for the first time to investigate the behavior of early age concrete. The evolution of capillary pressure in Self-Consolidating Concrete (SCC) with and without shrinkage reducing admixture was evaluated. The results demonstrate that HCTs are capable of measuring capillary pressure beyond 1500 kPa. This transformative new record of capillary pressure behavior has enabled the development of a model for the capillary pressure in early age concrete correlated to water evaporation, self-desiccation, setting time, temperature, and hydration processes. This ability to quantify real-time capillary pressure change in concrete generates important implications for optimizing the commercial durability of SCC and for understanding the link between early age concrete processes and resultant mechanical performance.
KW - Capillary pressure
KW - High capacity tensiometer
KW - Early age shrinkage
KW - Self-consolidating concrete
KW - Curing duration
KW - Shrinkage reducing admixture
U2 - 10.1016/j.cemconres.2022.106955
DO - 10.1016/j.cemconres.2022.106955
M3 - Article
SN - 0008-8846
VL - 161
JO - Cement and Concrete Research
JF - Cement and Concrete Research
M1 - 106955
ER -