Study on Mechanism of Pore Modification by Polymer Particles

Abstract

In recent years, deterioration of concrete structures has become a problem, and requires maintenance and repair. The cross-sectional repair method is frequently used to repair deteriorated structures. The material used in this method must have good adhesion to concrete and durability against the deterioration factors such as carbonation, chloride penetration and water permeability. In ordinary polymer cement mortars, the polymer particles bond together and make a polymer film, which improves the mass transfer resistance. Therefore, it is often used as a cross-sectional repair material. On the other hand, new developed core-shell polymer particles have dispersibility and two-layer structure of core and shell. In some cases, the addition of this polymer has been shown to have very high mass transfer resistance to water. However, the mechanism of the performance improvement has not been understood yet. The improvement in mass transfer resistance is thought to be due to the modification of the pore, which is a mass transfer pathway. In this study, we measured the porosity and conducted mass transfer resistance, and compared core-shell polymers with various materials which densifies the pores. For example, ordinary polymers that has films and silica fume which has a pore-filling effect with fine particles. In addition, by comparing several tests and expressing the state inside the pores, we investigated the mechanism of improving mass transfer resistance when core-shell polymer is added.