The present research has the following conclusion from a manufacture of a test material based on a recyclable aggregate mixture(30%, 60%)-based steel fiber reinforcement for using the same as a bigger aggregate instead concrete and a material and structural characteristic which affects the Reinforced concrete.
1. As a result of compressive strength test by age, it was found that specimen with non-mixture of steel fiber showed 3.1~18.3% decrease of compressive strength and specimen with mixture of steel fiber 1.7~20.1% decrease of compressive strength as replacement ratio of recycled aggregates increased.
In comparing reinforcement of steel fiber to non-reinforcement of steel fiber, specimen with the mixture of steel fiber showed 2.5~11.3% higher in compressive strength than specimen with non-mixture of steel fiber.
2. As a result of tensile strength test by age, it was found that specimen with non-mixture of steel fiber showed 1.6~19.5% of tensile strength and specimen with mixture of steel fiber showed 0.4~22.1% of tensile strength as replacement ratio of recycled aggregates increased.
In comparing reinforcement of steel fiber to non-reinforcement of steel fiber, specimen with the mixture of steel fiber showed 3.0~13.0% higher in tensile strength than specimen with non-mixture of steel fiber.
3. As a result of compressive strength test after fire resistance test, compressive strength of reinforced and non-reinforced specimens was lowered compared to normal concretes as mixture of recycled aggregates increased..
4. Yield strength and shear strength were reduced as replacement ratio of recycled aggregate increased regardless of mixture or non-mixture of steel fiber. Shear strength showed increase of 1.6% in WC0-S specimen, of 2.3% in WC30-S specimen and of 15.4% in WC60-S specimen by mixture of steel fiber.
In addition, ductile coefficient was decreased as replacement ratio of recycled aggregate increased, but ductile coefficient of specimens with the mixture of steel fiber was increased as 2.3% in WC0-S specimen, 14.5% in WC30-S specimen and 25.3% in WC60-S specimen.
5. To sum up the results of material and member tests, it was considered that mixture of steel fiber into recycled aggregate concrete produced effects of increasing compressive strength, tensile strength, shear strength and ductility.
It was also thought that specimen with 30% of recycled aggregate of mixed steel fiber had compressive strength, tensile strength and shear strength equivalent to or more than standard specimen and 30% of replacement ratio of recycled aggregate can be applicable to actual structure.