Poly(aspartic acid) superabsorbent polymers as biobased and biodegradable additives for self-sealing of cementitious mortar
Lauren De Grave, José Roberto Tenório Filho, Didier Snoeck, Sofiya Vynnytska, Nele De Belie, Katrien V. Bernaerts, Sandra Van Vlierberghe
Abstract
Concrete is currently the most used man-made construction material. Unfortunately it is prone to defects, such as cracks. Crack repair is possible by incorporation of superabsorbent polymers (SAPs) which can fill a crack by swelling and promote formation of healing products. However, SAPs are usually acrylate-based and not biodegradable. Present work focuses on development of SAPs based on poly(aspartic acid) (PASP), which is a biobased and biodegradable alternative of acrylate-based polymers. The developed SAP was incorporated in mortar and the effect on the mortar properties was studied. When adding 1 m% SAP, a decrease in strength was observed, similar to commercially available acrylate-based SAPs. The SAPs showed an efficient and immediate sealing effect in cracked mortar, reflected by a reduction in water permeability over 50%. Hence, the developed biobased SAP shows good sealing properties and could be used as a sustainable alternative for acrylic SAPs in concrete repair.