Concrete structure strengthened using grid reinforcement material and non-shrink grout and method of strengthening the same

A method of strengthening a concrete structure using a grid reinforcement material and a non-shrink grout, the method comprising:

• a) cleaning a surface of a structure to be strengthened that is damaged or deteriorated;
• b) fixing a grid fixing device including a first retainer, a spacer, and an anchor pin to the structure to be strengthened;
• c) mounting a grid reinforcement material on the first retainer of the grid fixing device;
• d) fastening a second retainer of the grid fixing device so that the anchor pin passes therethrough to fix the grid reinforcement material;
• e) installing an air vent and a slab side end portion formwork on each side end portion of the structure to be strengthened;
• f) installing a slab lower portion formwork on the slab side end portion formwork and installing at least one or more grout injection holes in the slab lower portion formwork;
• g) injecting and filling non-shrink grout through the grout injection hole and allowing the non-shrink grout to cure;
• and
• h) when curing of the non-shrink grout is completed, removing the slab lower portion formwork and the slab side end portion formwork to finish strengthening of the structure to be strengthened,
• wherein a crack in the structure to be strengthened is automatically filled with the non-shrink grout to strengthen the structure to be strengthened, and
• wherein the grid fixing device includes:
• the first retainer which has a first through-hole formed in a central portion and which comes in direct contact with the lattice-type grid reinforcement material so that the grid reinforcement material is fixed;
• the cylindrical spacer which has a second through-hole corresponding to the first through-hole formed therein and which is integrally formed with a lower surface of the first retainer so that the first retainer maintains a predetermined distance from the structure to be strengthened;
• the anchor pin which is tacked using a tacker or tacking device and which passes through the first through-hole and the second through-hole to be tacked into the structure to be strengthened;
• and
• the second retainer which is formed to be stacked on the first retainer, has a through-hole formed in a central portion, and comes in direct contact with the grid reinforcement material.

A method of strengthening a concrete structure using a grid reinforcement material and a non-shrink grout, the method comprising:

• a) cleaning a surface of a structure to be strengthened that is damaged or deteriorated;
• b) mounting a grid fixing device including a first retainer and a spacing pin on a side surface of a wall body, which is the structure to be strengthened;
• c) mounting a grid reinforcement material on a side surface of the first retainer of the grid fixing device;
• d) fastening a second retainer of the grid fixing device so that the spacing pin passes therethrough to fix the grid reinforcement material;
• e) installing an air vent on an upper end portion of the structure to be strengthened and installing a wall body end portion formwork on each of an upper end portion and a lower end portion of the structure to be strengthened;
• f) installing a wall body side surface formwork on a side surface of the wall body end portion formwork and installing at least one or more grout injection holes in the wall body side surface formwork;
• g) injecting and filling non-shrink grout through the grout injection hole and allowing the non-shrink grout to cure;
• and
• h) when curing of the non-shrink grout is completed, removing the wall body side surface formwork and the wall body end portion formwork to finish strengthening of the structure to be strengthened,
• wherein a crack in the structure to be strengthened is automatically filled with the non-shrink grout to strengthen the structure to be strengthened, and
• wherein the non-shrink grout is formed by mixing 100 parts by weight of cement, 25 to 35 parts by weight of fine blast-furnace slag powder, 2 to 3 parts by weight of silica fume, 140 to 150 parts by weight of fine aggregate, 40 to 50 parts by weight of water, 1.5 to 2.5 parts by weight of a high-performance water reducing agent, and 1.2 to 2 parts by weight of a polymer expansion material.