TY - JOUR
T1 - Characteristics of surface-treatment of nano-SiO2 on the transport properties of hardened cement pastes with different water-to-cement ratios
AU - Hou, Pengkun
AU - Cheng, Xin
AU - Qian, Jueshi
AU - Zhang, Rui
AU - Cao, Wei
AU - Shah, Surendra P.
N1 - Funding Information:
Supports from the Natural Science Foundation of China (Grant No. 51302105 ) and the Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province are gratefully acknowledged. In particular, the authors are in great debt to the editor for his kind, patient and professional help on the paper.
PY - 2015/1
Y1 - 2015/1
N2 - A reduced transport property of the superficial part of concrete structures is beneficial for enhancing their durability, due to the blocking of the migration of aggressive agents. In this study, influences of colloidal nano-SiO2 (CNS) with a mean particle size of 20 nm and its precursor, tetraethoxysilane (TEOS), on the transport properties of hardened cement pastes with water-to-cement ratios of 0.26, 0.38, 0.60 and 1.0 by mass were investigated by measuring the water absorption ratio and water vapor transmission coefficient, after the samples were first soaked in treatment agents for 1 h. Results showed that CNS and TEOS are capable of reducing the transport properties of hardened cement pastes by altering the pore structures. CNS reduces the threshold value and volume of the pores larger than about 0.1 μm, while TEOS reduces the threshold value and volume of the pores smaller than 0.1 μm, and TEOS also reduces the ratio of the 'ink-bottle' pore volume to the throat pore volume to a greater extent. A linear relationship between the volume of capillary pores smaller than 0.1/0.01 μm and the transport property was found, which can be ascribed to the reduction of transport properties of hardened cement pastes after surface-treatment with CNS or TEOS.
AB - A reduced transport property of the superficial part of concrete structures is beneficial for enhancing their durability, due to the blocking of the migration of aggressive agents. In this study, influences of colloidal nano-SiO2 (CNS) with a mean particle size of 20 nm and its precursor, tetraethoxysilane (TEOS), on the transport properties of hardened cement pastes with water-to-cement ratios of 0.26, 0.38, 0.60 and 1.0 by mass were investigated by measuring the water absorption ratio and water vapor transmission coefficient, after the samples were first soaked in treatment agents for 1 h. Results showed that CNS and TEOS are capable of reducing the transport properties of hardened cement pastes by altering the pore structures. CNS reduces the threshold value and volume of the pores larger than about 0.1 μm, while TEOS reduces the threshold value and volume of the pores smaller than 0.1 μm, and TEOS also reduces the ratio of the 'ink-bottle' pore volume to the throat pore volume to a greater extent. A linear relationship between the volume of capillary pores smaller than 0.1/0.01 μm and the transport property was found, which can be ascribed to the reduction of transport properties of hardened cement pastes after surface-treatment with CNS or TEOS.
KW - Cement paste
KW - Surface treatment
KW - Tetraethoxysilane (TEOS)
KW - Transport property
UR - http://www.scopus.com/inward/record.url?scp=84906539702&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84906539702&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2014.07.022
DO - 10.1016/j.cemconcomp.2014.07.022
M3 - Article
AN - SCOPUS:84906539702
VL - 55
SP - 26
EP - 33
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
SN - 0958-9465
ER -