Expansion and degradation of cement paste in sodium sulfate solutions

External sulfate attack is a progressive degradation process that may cause expansion, cracking, loss of binder cohesion and increased permeability in cementitious materials. Crystallization pressure theory has often been referred to as the most likely mechanism. However, thus far the stress causing the expansion has not been quantified. In...

Self-sealing cementitious materials by using water-swelling rubber particles

Water ingress into cracked concrete structures is a serious problem, as it can cause leakage and reinforcement corrosion and thus reduce functionality and safety of the structures. In this study, the application of water-swelling rubber particles for providing the cracked concrete a self-sealing function was developed. The feasibility of...

Micromechanical properties of a new polymeric microcapsule for self-healing cementitious materials

Self-healing cementitious materials containing a microencapsulated healing agent are appealing due to their great application potential in improving the serviceability and durability of concrete structures. In this study, poly(phenol-formaldehyde) (PF) microcapsules that aim to provide a self-healing function for cementitious materials were...

A novel capsule-based selfrecovery system with a chloride ion trigger

Steel is prone to corrosion induced by chloride ions, which is a serious threat to reinforced concrete structures, especially in marine environments. In this work, we report a novel capsule-based selfrecovery system that utilizes chloride ions as a trigger. These capsules, which are functionalized via a smart response to chloride ions, are...