TY - CHAP
T1 - Internal Curing Using Superabsorbent Polymers for Alkali Activated Slag-Fly Ash Mixtures
AU - Wang, Ying
AU - Montanari, Luca
AU - Jason Weiss, W.
AU - Suraneni, Prannoy
N1 - Publisher Copyright:
© RILEM 2020.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2020
Y1 - 2020
N2 - Increased shrinkage is often noted as a concern for alkali activated materials. In this study, two slag-fly ash paste and mortar mixtures with slag:fly ash ratios of 30:70 and 50:50 activated using 4M sodium hydroxide are formulated. The effects of two dosages of a commercial superabsorbent polymer (SAP) on the reaction heat, strength gain, autogenous shrinkage, drying shrinkage, and mass loss behavior are presented here. The SAP increases the heat of reaction of the alkali activated pastes, however, this increase is less than 5% at 7 days. The SAP slightly decreases the compressive strength of the alkali activated mortars, and this decrease is generally less than 10% at 1, 7, and 28 days. The SAP significantly reduces the ultimate autogenous shrinkage (by more than 50%) and reduces the drying shrinkage (by 15–30%) of the mortars. Mixtures with SAP have autogenous shrinkage between 50–300 με and drying shrinkage between 600–700 με. When SAP is used, the mass loss in the mortars increases, however, the slope of the mass loss-drying shrinkage curve decreases. Shrinkage mitigation in the studied mixtures increases as the SAP dosage increases. Further studies on this system, and on other binders, activator combinations, and SAP types are currently ongoing.
AB - Increased shrinkage is often noted as a concern for alkali activated materials. In this study, two slag-fly ash paste and mortar mixtures with slag:fly ash ratios of 30:70 and 50:50 activated using 4M sodium hydroxide are formulated. The effects of two dosages of a commercial superabsorbent polymer (SAP) on the reaction heat, strength gain, autogenous shrinkage, drying shrinkage, and mass loss behavior are presented here. The SAP increases the heat of reaction of the alkali activated pastes, however, this increase is less than 5% at 7 days. The SAP slightly decreases the compressive strength of the alkali activated mortars, and this decrease is generally less than 10% at 1, 7, and 28 days. The SAP significantly reduces the ultimate autogenous shrinkage (by more than 50%) and reduces the drying shrinkage (by 15–30%) of the mortars. Mixtures with SAP have autogenous shrinkage between 50–300 με and drying shrinkage between 600–700 με. When SAP is used, the mass loss in the mortars increases, however, the slope of the mass loss-drying shrinkage curve decreases. Shrinkage mitigation in the studied mixtures increases as the SAP dosage increases. Further studies on this system, and on other binders, activator combinations, and SAP types are currently ongoing.
KW - Alkali activated materials
KW - Fly ash
KW - Slag
KW - Superabsorbent polymers
UR - http://www.scopus.com/inward/record.url?scp=85075885770&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85075885770&partnerID=8YFLogxK
U2 - 10.1007/978-3-030-33342-3_26
DO - 10.1007/978-3-030-33342-3_26
M3 - Chapter
AN - SCOPUS:85075885770
T3 - RILEM Bookseries
SP - 239
EP - 247
BT - RILEM Bookseries
PB - Springer
ER -