SELF-HEALING TUNNEL LINING CONCRETE

摘要

The present invention relates to an improved concrete admixture, which generates a self-healing dehydrate by reacting with water and carbon dioxide in concrete and has improved drying shrinkage resistance and superior early strength properties, and a self-healing tunnel lining concrete using the same. The improved concrete admixture having the self-healing properties according to the present invention includes ettringite-based expansive inorganic minerals, a water-soluble inorganic gelling agent, alkaline sulfate, and sodium aluminate. Preferably, the concrete admixture includes 15-85 wt% of ettringite-based expansive inorganic minerals, 5-25 wt% of a water-soluble inorganic gelling agent, 5-45 wt% of alkaline sulfate, and 5-25 wt% of sodium aluminate. The self-healing tunnel lining concrete according to the present invention is mixed with a binding material consisting of cement, fly ash, and improved self-healing concrete admixture. The binding material preferably includes 70-91 wt% of cement, 5-25 wt% of fly ash, and 4-8 wt% of improved self-healing concrete admixture. Preferably, 0.5-2 wt% of polycarboxylic acid-based admixture is further added to the binding material.