Abstract：The primary issue for self-healing of concrete cracks by microbially induced mineralization is protection of the bacteria and the key to protecting the bacteria is the carrier material selection. This paper used calcium sulphoaluminate cement with 20% silica fume as a low-alkali binder type carrier material. An effective loading method was developed by regulating the binder pH and setting time through evaluations of the bacterial spore activity in this carrier. The concrete crack self-healing was successful up to a maximum crack width of about 322 μm that could be healed after 28 days. After the self-healing, the concrete compressive strength recovered up to 84% of the original strength with the water tightness completely restored.
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