EXPERIMENTAL RESEARCH ON COASTAL REINFORCED CONCRETE DURABILITY BASED ON THE ELIMINATION OF CHLORINE INFILTRATION CHANNEL

The electrochemical reaction for steel bars caused by chloride ions is the direct reason for coastal reinforced concrete durability damage. The chloride ions will immerse coastal reinforced concrete by long-term physical and chemical processes when the structure has pores and fractures in the inner of concrete. It is the efficient method for solving coastal concrete erosion problems to prevent the Infiltration Channels of chloride ions. It is showed that salting-out phenomena is easily happened for the coastal concrete which is in the splash and water level variation zones. Owning to alternation of drying and wetting, the concentration of seawater is high in the internal structure of the concrete. So the concrete will be cracked by the crystallization stress and the stresses caused by the secondary ettringite. With increasing of concrete cracks, the chloride ions will continuously migrate the inner of the structures. For the consideration of the elimination of the seepage channel, the following researches have been done in this paper on the basis of the experimental study. The concrete density is ensured by admixtures substituting some cement. The concrete surface voids are blocked by spraying polymer cement slurry. The compact concrete protection layer is obtained by spraying slight expansion cement mortar. The hydrophobic coating is formed by painting silicone in the concrete surface. It is difficult for the salting-out and the secondary ettringite to form when the above measures are applied. Because the present concrete is protected, the concrete durability is efficiently improved.