Activated chemicals of cementitious capillary crystalline waterproofing materials and their self-healing behaviour

•Sodium carbonate, sodium silicate, sodium aluminate, tetrasodium EDTA and glycine proposed as activated chemicals of CCCW.•The optimal proportion of activated chemicals of CCCW was achieved through permeability and pre-pressure self-healing test.•White crystals with an average diameter of 0.2 mm were generated in the self-healing process of CCCW.•The self-healing mechanism of CCCW was proposed based on the self-healing experimental results. Activated chemicals play a key role in the waterproof performance of cementitious capillary crystalline waterproofing materials (CCCW). We proposed sodium carbonate, sodium silicate, sodium aluminate, tetrasodium EDTA and glycine as activated chemicals of CCCW. The proportion of activated chemicals of CCCW was optimized by two key parameters evaluation of the second permeability ratio and pre-pressure self-healing rate for their self-healing ability of CCCW. Results show that sodium silicate has the most significant impact on the self-healing ability of CCCW. In the self-healing progress of CCCW, the consumption of Ca(OH)2 (CH) and the production of Calcium Silicate Hydrate (CSH) gel, calcium carbonate and ettringite were observed through XRD and SEM analysis. The white crystals with an average diameter of 0.2 mm are produced on both sides of cracks, and consequently the cracks were healed by the accumulation of crystals. The self-healing mechanism of CCCW was proposed based on the self-healing experimental results.