Innovative SuperAbsorbent Polymers (iSAPs) to construct crack-free reinforced concrete walls: An in-field large-scale testing campaign

Although a lot of research has been performed with the use of Superabsorbent polymers (SAPs) in cementitious materials, there is still a lack of studies describing the use of SAPs in large-scale concrete structures under realistic conditions. This paper presents results of an in-field testing campaign where SAPs were used in a large-scale demonstrator. Commercial SAPs and in-house-developed SAPs (constituted of an alkali-stable and alkali-unstable crosslinker, for a tailored swelling behavior) were used. Five reinforced-concrete walls (14 m x 2.75 m x 0.80 m) were built and monitored with regards to shrinkage-cracking with demountable strain gauges and optical-fiber sensors. A laboratory campaign was performed simultaneously to characterize the concrete mixtures. The addition of SAPs promoted a reduction of up to 75% of shrinkage strains in the first 7 days. No cracks have developed in the SAP walls up to 5 months, while the reference wall cracked 5 days after casting.