A method to repair concrete leakage through cracks by synthesizing super-absorbent resin in situ

Concrete leakage through cracks is a key factor resulting in the deterioration of concrete structures. This work presented a method to repair concrete leakage through cracks by synthesizing super-absorbent resin (SAR) in situ. The procedures of this method are to inject the precursor solution of polymer(acrylic acid-co-acrylamide) with initiator and crosslinker into concrete cracks, then use infrared radiation to make the precursor copolymerize. The synthesized SAR can absorb water and swell, so that the cracks are filled and the leakage is prevented. The impermeability of concrete core with through-thickness cracks repaired by SAR was tested before and after being subjected to the attacks of acid, alkali, salts, dry–wet cycles and ultraviolet aging. Meantime, the absorbency of SAR was also evaluated by measuring the swelling ratio before and after the attacks of the same deteriorating factors. The experimental results show that the equilibrium swelling ratio of SAR sharply decreases after the attacks of acid and salts, and the impermeability of concrete cracks repaired with SAR is mainly governed by the swelling ratio of SAR and the width of cracks.