TY - JOUR
T1 - Long-term salt freeze-thaw resistance of polyvinyl alcohol (PVA) modified mortar
T2 - The role of molecular structure
AU - Deng, Qian
AU - Zhang, Xuzhe
AU - Li, Shaohua
AU - Yu, Qingliang
N1 - Publisher Copyright:
© 2025 The Authors
PY - 2025/9
Y1 - 2025/9
N2 - Polyvinyl alcohol (PVA) has shown potential in developing cost-effective anti-freezing technologies for concrete. However, its effectiveness in reducing scaling and performance stability under combined salt freeze-thaw conditions and the involved mechanism remains unclear. This investigation systematically evaluates the salt freeze-thaw resistance of cementitious systems modified with PVA variants possessing different hydrolysis degrees (DH) and molecular weights (Mw). Experimental results demonstrate that while PVA adsorption on C3S/C3A surfaces inhibits cement hydration and degrades mechanical properties and pore structure, these effects appear very limited at ≤0.04 % low dosages. Fully hydrolyzed PVA with an Mw of 75000 g/mol achieves an 18.8 % reduction in mass loss compared to the unmodified group and maintains a stable microstructure after 25 freeze-thaw cycles. The enhancement is primarily attributed to improved ice nucleation inhibition capacity, which positively correlates with DH and Mw. However, cryogenic gelation of PVA compromises its ice inhibition effectiveness, especially PVA with lower DH and Mw showing exacerbated performance degradation due to short-chain aggregation and acetate group steric effects. High-Mw PVA maintains its functionality through 3D network formation that preserves ice-binding sites. These findings provide crucial theoretical foundations for optimizing PVA-modified concrete formulations in cold-region engineering applications.
AB - Polyvinyl alcohol (PVA) has shown potential in developing cost-effective anti-freezing technologies for concrete. However, its effectiveness in reducing scaling and performance stability under combined salt freeze-thaw conditions and the involved mechanism remains unclear. This investigation systematically evaluates the salt freeze-thaw resistance of cementitious systems modified with PVA variants possessing different hydrolysis degrees (DH) and molecular weights (Mw). Experimental results demonstrate that while PVA adsorption on C3S/C3A surfaces inhibits cement hydration and degrades mechanical properties and pore structure, these effects appear very limited at ≤0.04 % low dosages. Fully hydrolyzed PVA with an Mw of 75000 g/mol achieves an 18.8 % reduction in mass loss compared to the unmodified group and maintains a stable microstructure after 25 freeze-thaw cycles. The enhancement is primarily attributed to improved ice nucleation inhibition capacity, which positively correlates with DH and Mw. However, cryogenic gelation of PVA compromises its ice inhibition effectiveness, especially PVA with lower DH and Mw showing exacerbated performance degradation due to short-chain aggregation and acetate group steric effects. High-Mw PVA maintains its functionality through 3D network formation that preserves ice-binding sites. These findings provide crucial theoretical foundations for optimizing PVA-modified concrete formulations in cold-region engineering applications.
KW - Concrete
KW - Ice recrystallization inhibition
KW - Molecular structure
KW - Polyvinyl alcohol
KW - Salt freeze-thaw cycles
UR - http://www.scopus.com/inward/record.url?scp=105007058743&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2025.106159
DO - 10.1016/j.cemconcomp.2025.106159
M3 - Article
AN - SCOPUS:105007058743
SN - 0958-9465
VL - 162
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 106159
ER -