Poly(aspartic acid) superabsorbent polymers as biobased and biodegradable additives for self-sealing of cementitious mortar

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.