Cracked Floor Repair

The building is a residential construction project with cast-in-place reinforced concrete shear wall structure. Building 31#, 38#, 39#, 40# has 11 floors above ground, frame shear wall structure, 35# building, 41# building is six-story brick-concrete structure. Due to the partial cracks in the roof of the project, the cracks in the beams are non-stress cracks, but the occurrence of cracks in the floor affects the integrity and durability of the structure. For this reason, the cracked floor is reinforced with carbon fiber.

Material selection 

1. The carbon fiber sheet material adopts: 300g/㎡ carbon fiber cloth, and the matching glue should meet the physical and mechanical properties of "Technical Specification for Carbon Fiber Sheet Reinforced Concrete Structure".

(1) Standard value of tensile strength≥3400MPa;

(2) Tensile modulus of elasticity≥2.4×105MPa;

(3) Elongation rate≥1.7%;

(4) Bending strength ≥700MPa;

(5) Interlayer shear strength≥45MPa;

(6) The positive tensile bond strength of fiber composite material and concrete under the condition of upward sticking is ≥2.5MPa, and the concrete is cohesive failure;

(7) The mass per unit area is less than or equal to 300g/㎡.

2. Requirements for crack injection glue

(1) Tensile strength ≥40MPa;

(2) Tensile elastic modulus ≥2500MPa;

(3) Elongation rate≥1.5%;

(4) The bending strength is ≥50MPa, and it must not be brittle (fractured) damage;

(5) Compressive strength ≥70MPa;

(6) The standard value of steel-steel tensile and shear strength ≥14MPa;

(7) Steel-steel uneven pull-off strength ≥20KN/m;

(8) The positive tensile bond strength with concrete is ≥2.5MPa, and it is a cohesive failure of concrete

(9) Non-volatile content (solid content ≥99%).