Study of self-healing properties in concrete with bacteria encapsulated in expanded clay

Abstract

Preparation process and life service solicitations can cause damage on concrete's internal structure, creating cracks that tend to propagate and increase with time. This poses a risk of failure as water penetrates, corroding the rebar reducing concrete's life span. Cement can exhibit up to a certain extent a natural ability to self-heal, consequence of the long-term hydration phenomenon. Some initial cracks can be spontaneously closed if the right conditions are met (humidity). However, it will not be enough to repair major cracks formed internally over a long period of use, so strategies need to be developed to achieve an efficient level of self-healing. This need lead to a new concept – self-healing. The biological approach is a suitable alternative to achieve healing in concrete. In this work, bacteria were immobilised in expanded clay and added to concrete by aggregate replacement.