Design and testing of anionic superabsorbent polymers for use in durable con- crete structures

Author(s): Laurence De Meyst, Els Mannekens, Maria Araújo, Didier Snoeck, Kim Van Tittelboom, Sandra Van Vlierberghe, Geert Deroover, Nele De Belie
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials, Systems and Structures (SMSS2019) New Generation of Construction Materials
Editor(s): Marijana Serdar, Nina Štirmer, John Provis
ISBN: 978-2-35158-217-6,
Vol 1. ISBN: 978-2-35158-223-7
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 638-646
Total Pages: 9
Language : English

Abstract: Superabsorbent polymers (SAPs) can be added to a concrete mixture to provide internal curing and reduce the risk for early-age shrinkage cracking. Hence, they help to increase the overall durability of concrete structures. The type, swelling characteristics, kinetics of water release, amount and particle size of the SAPs will dictate their effectiveness for this purpose. An anionic SAP was synthesized with varying amounts of cross-linker and ground to particle sizes with d50 varying between 10 and 100 μm. The swelling capacity in demineralised water of 40 μm particles increased with a decreasing degree of cross-linker from 87 g/g SAP to 270 g/g SAP, and was about 3 to 4 times larger than the swelling capacity in cement filtrate. The SAPs were tested for their effect on mortar workability, cement hydration kinetics and mechanical properties of the hardened mortar. With proper compensation for the absorbed water by the SAPs, the mortar workability was not negatively affected and a reduction in flow over the first two hours remained limited. The SAPs with the lowest swelling capacity, resulting in the least macro pore formation, showed the smallest negative effect on mortar compressive strength and a negligible effect on cement hydration. The difference in strength with the reference decreased as a function of mortar age. Different SAP particle sizes in the range of 10 – 100 μm had no significant effect on mortar properties.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00