RT info:eu-repo/semantics/article
T1 Influence of air-entraining agent and freeze-thaw action on pore structure in high-strength concrete by using CT-Scan technology
A1 González Cabrera, Dorys Carmen
A1 Mena Alonso, Álvaro
A1 Mínguez Algarra, Jesús
A1 Vicente Cabrera, Miguel Ángel
K1 Computed tomography
K1 Air-entraining agent
K1 Freeze-thaw cycles
K1 High-strength concrete
K1 Pore structure
K1 Pore distribution
K1 Ingeniería civil
K1 Civil engineering
K1 Materiales de construcción
K1 Building materials
AB In this work, the effects caused by both the amount of air-entraining agent (AEA) and freeze-thaw cycles on microstructure of high-strength concrete have been analyzed. For this purpose, five series of concrete specimens have been manufactured, each of them containing a different amount of AEA. Then, all series have been subjected to up to 300 freeze-thaw cycles. In addition, the specimens have been analyzed using a computed tomography (CT) scan device at pre-defined freeze-thaw cycles and all data have been processed with digital image processing (DIP) software.The results reveal, on the one hand, that the quantity of AEA has a greater influence on pore structure, and additionally the freeze-thaw action only slightly modifies the pore structure. As AEA increases, a progressive rise of the porosity and the number of pores is observed up to a maximum value. Next, a decrease is noticed. Moreover, there is not a linear relation between porosity and AEA. Furthermore, as AEA increases, a variation of its size and shape is observed. Alternatively, the effect of freeze-thaw cycles is more complex and does not show a monotonous tendency. The results reveal that the first 50 freeze-thaw cycles have the strongest influence on pore structure, observing a decrease in porosity. For the rest of the cycles, the porosity increases progressively resulting, after 300 freeze-thaw cycles, in a slightly lower porosity in almost all series than in those presented at the beginning. Hydration of unhydrated cement particles alongside with microcracking act as opposite performances during the freeze-thaw cycles. Therefore, this can suggest that, under these conditions, freeze-thaw action is not able to damage significantly the microstructure of concrete.The results show that the series with a lower AEA content show a better behavior under freeze-thaw cycles. In this case, the specimens exhibit a lower porosity and a higher level of small pores, and the pores evince a more elongated shape. All these features lead to a more impermeable concrete and, therefore, with a better performance under freeze-thaw cycles.
PB Elsevier
SN 0165-232X
YR 2021
FD 2021-09
LK http://hdl.handle.net/10259/10027
UL http://hdl.handle.net/10259/10027
LA eng
NO The authors are grateful for the financial support from the Ministerio de Economía y Competitividad, PID2019-110928RB-C32, Spain.
DS Repositorio Institucional de la Universidad de Burgos
RD 30-ene-2025