TY - JOUR
T1 - Strength recovery of thermally damaged high-performance concrete subjected to post-fire carbonation curing
AU - Liu, Tiejun
AU - Wang, Haodong
AU - Zou, Dujian
AU - Long, Xu
AU - Miah, Md Jihad
AU - Li, Ye
N1 - Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/10
Y1 - 2023/10
N2 - This study investigates the efficacy of post-fire curing using carbonation with a 20% carbon dioxide concentration and a relative humidity cycle set between 40% and 90% for restoring the mechanical properties of thermally damaged high-performance concrete (HPC) specimens containing 0%–40% silica fume. The HPC specimens were exposed to temperatures of 600, 800, and 1000 °C for 1 h, and the compressive strength recovery was measured. The microstructure, porosity, pore size distribution, and chemical composition of the HPC specimens were analyzed to explore the strength recovery mechanism. After exposure to elevated temperatures, the average compressive strength of samples without silica fume decreased by 49.2 MPa. Subsequent carbonation recuring resulted in a significant recovery of 73.9 MPa in the average compressive strength. This recovery surpassed the original strength for the samples heated to 600 and 800 °C, attributable to the filling and coalescing effects of calcium carbonate polymorphs formed through the carbonation of residual cement particles and β-C2S. The samples containing 20% silica fume exhibited the second highest average strength recovery of 34.1 MPa. However, the strength recovery for the samples with 40% silica fume exposed to 800 and 1000 °C was negligible, as the microcracks exceeding 1 μm in width had barely been restored by the carbonation of the low-calcium calcium silicates with low reactivity. Overall, this study presents an exciting future prospect for the labor and cost-effective restoration of thermally damaged concrete structures through the use of carbonation curing.
AB - This study investigates the efficacy of post-fire curing using carbonation with a 20% carbon dioxide concentration and a relative humidity cycle set between 40% and 90% for restoring the mechanical properties of thermally damaged high-performance concrete (HPC) specimens containing 0%–40% silica fume. The HPC specimens were exposed to temperatures of 600, 800, and 1000 °C for 1 h, and the compressive strength recovery was measured. The microstructure, porosity, pore size distribution, and chemical composition of the HPC specimens were analyzed to explore the strength recovery mechanism. After exposure to elevated temperatures, the average compressive strength of samples without silica fume decreased by 49.2 MPa. Subsequent carbonation recuring resulted in a significant recovery of 73.9 MPa in the average compressive strength. This recovery surpassed the original strength for the samples heated to 600 and 800 °C, attributable to the filling and coalescing effects of calcium carbonate polymorphs formed through the carbonation of residual cement particles and β-C2S. The samples containing 20% silica fume exhibited the second highest average strength recovery of 34.1 MPa. However, the strength recovery for the samples with 40% silica fume exposed to 800 and 1000 °C was negligible, as the microcracks exceeding 1 μm in width had barely been restored by the carbonation of the low-calcium calcium silicates with low reactivity. Overall, this study presents an exciting future prospect for the labor and cost-effective restoration of thermally damaged concrete structures through the use of carbonation curing.
KW - Carbonation recuring
KW - Microstructure changes
KW - Silica fume content
KW - Thermally damaged concrete
UR - http://www.scopus.com/inward/record.url?scp=85171612187&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2023.105273
DO - 10.1016/j.cemconcomp.2023.105273
M3 - 文章
AN - SCOPUS:85171612187
SN - 0958-9465
VL - 143
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 105273
ER -