Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1456171 | Cement and Concrete Research | 2015 | 13 Pages |
Water sorption of two superabsorbent polymers in cement-based pastes has been characterized by neutron radiography. Cement pastes with W/C of 0.25 and 0.50 and one additionally containing silica fume (W/C = 0.42) were investigated. The SAPs differed in their inherent sorption kinetics in extracted cement pore solution (SAP 1: self-releasing; SAP 2: retentive).Desorption from SAP 1 started very early after paste preparation. Hence, its individual non-retentiveness governs its behavior only.SAP 2 released water into all matrices, but its kinetics were different. In the paste with the highest W/C, some moderate water release was recorded from the beginning. In the other two pastes, SAP 2 retained its stored liquid during the dormant period, i.e., up to the percolation threshold. Intense desorption then set in and continued throughout the acceleration period.These findings explain the pronouncedly higher efficiency of SAP 2 as internal curing admixture as compared to SAP 1.