TY - JOUR
T1 - Effect of curing condition on mechanical properties and durability of alkali-activated slag mortar
AU - Liu, Chen
AU - Wu, Haoming
AU - Li, Zhenming
AU - Shi, Hu
AU - Ye, Guang
PY - 2024
Y1 - 2024
N2 - While alkali-activated slag (AAS) has emerged as a promising alternative binder in construction engineering, a consensus on the optimal curing condition for this material has not been reached yet. It is well known that AAS can harden at ambient temperatures, but the influence of humidity on its properties remains poorly understood. Herein, we considered five curing conditions with different relative humidities (RH), including ambient/dry condition (RH=55 %), sealed condition (RH=80–95 %), fog condition (RH>95 %), water immersion condition (RH=100 %), and saturated limewater immersion condition (RH=100 %). Various properties have been examined, including flexural and compressive strengths, elastic modulus, shrinkage, pore structure, carbonation resistance, and freeze-thaw resistance of AAS mortars (AASM). Two types of activators, sodium hydroxide and sodium silicate (modulus at 1) solutions were used. The experimental results indicate that drying at early ages is detrimental to almost all the properties investigated. Sealed curing can deliver desirable mechanical properties and durability, but considerable shrinkage. Fog and water curings are highly effective at mitigating early shrinkage in AASM, but the problem of leaching adversely affects its long-term properties. Generally, limewater curing offers limited benefits compared to other high-humidity curing methods.
AB - While alkali-activated slag (AAS) has emerged as a promising alternative binder in construction engineering, a consensus on the optimal curing condition for this material has not been reached yet. It is well known that AAS can harden at ambient temperatures, but the influence of humidity on its properties remains poorly understood. Herein, we considered five curing conditions with different relative humidities (RH), including ambient/dry condition (RH=55 %), sealed condition (RH=80–95 %), fog condition (RH>95 %), water immersion condition (RH=100 %), and saturated limewater immersion condition (RH=100 %). Various properties have been examined, including flexural and compressive strengths, elastic modulus, shrinkage, pore structure, carbonation resistance, and freeze-thaw resistance of AAS mortars (AASM). Two types of activators, sodium hydroxide and sodium silicate (modulus at 1) solutions were used. The experimental results indicate that drying at early ages is detrimental to almost all the properties investigated. Sealed curing can deliver desirable mechanical properties and durability, but considerable shrinkage. Fog and water curings are highly effective at mitigating early shrinkage in AASM, but the problem of leaching adversely affects its long-term properties. Generally, limewater curing offers limited benefits compared to other high-humidity curing methods.
KW - Alkali-activated slag
KW - Carbonation
KW - Curing
KW - Elastic modulus
KW - Freeze and thaw
KW - Shrinkage
UR - http://www.scopus.com/inward/record.url?scp=85198011219&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2024.137376
DO - 10.1016/j.conbuildmat.2024.137376
M3 - Article
AN - SCOPUS:85198011219
SN - 0950-0618
VL - 439
JO - Construction and Building Materials
JF - Construction and Building Materials
M1 - 137376
ER -