Crack Control Technology of Steel Fiber Reinforced Concrete Floor

Steel fiber is a kind of steel fiber, which can be used as reinforcing material in concrete after forming into a specified length. Steel fiber reinforced concrete (SFRC) is a new building material with excellent properties. It can significantly improve the properties of concrete, such as tensile, shear, flexural strength, seismic, explosive, crack, impact, fatigue and crack delay. Polypropylene fiber

The research shows that the application of steel fiber reinforced concrete in ground engineering can give full play to its high flexural and tensile strength, crack resistance, fatigue resistance, wear resistance and impact resistance. It can replace steel bars, reduce pavement thickness, increase shrinkage joint spacing, shorten construction period, improve engineering quality, reduce engineering maintenance costs and prolong engineering service life. Steel fiber reinforced concrete has good material properties. Compared with ordinary concrete, its compressive strength increases by 5%~20%, flexural strength increases by 20%~50%, tensile strength increases by 20%~40%, and wear resistance increases by 40%. Under the condition of artificial rapid test, when steel fiber content is 30kg/m3, the total shrinkage cracks are 40%~50% of the reference specimens. Under the impact load, steel fiber reinforced concrete has good mechanical properties. The crack resistance of concrete is 3 to 4 times that of ordinary concrete. When the number of fatigue is 1 million times, its flexural strength is 1.62 to 2.5 times that of ordinary concrete.

1 General situation of Engineering

An international logistics park project consists of a single-storey warehouse and a management and equipment room. The total building area is 35218 m2. The foundation is an independent concrete foundation and the main body is a steel structure. The warehouse floor of this project is made of steel fibers with a thickness of 180 mm, steel fibers with RC80/60BN of Jiamike silk, the design content is 15kg/m3, and the strength grade of concrete is C30

From January to February 2012, technicians investigated, collected and sorted out five similar engineering qualities of steel fiber reinforced concrete floors provided by steel fiber manufacturers, and counted the cracks caused by different reasons of steel fiber reinforced concrete floors.

Feasibility and Cause Analysis

2.1 Feasibility Analysi

At present, the company has mastered the construction technology of large area concrete ground warehouse, ground grinding technology, maintenance technology, and has successful experience, and has the corresponding construction methods to guide the construction.

Although the company lacks understanding of the performance of steel fiber reinforced concrete, it has been cooperating with universities such as Qingdao University of Science and Technology for many years. It can grasp the shrinkage performance of steel fiber reinforced concrete quickly through certain experimental research, and take corresponding measures to eliminate the cracks in the construction stage.

Surface air-drying cracks are inevitable, belong to micro cracks, non-structural cracks, as long as the maintenance can be eliminated in time.

According to the above analysis, it is feasible to eliminate the visual crack-free of steel fiber reinforced concrete in construction stage.

Steel fiber is a kind of steel fiber, which can be used as reinforcing material in concrete after forming into a specified length. Steel fiber reinforced concrete (SFRC) is a new building material with excellent properties. It can significantly improve the properties of concrete, such as tensile, shear, flexural strength, seismic, explosive, crack, impact, fatigue and crack delay.

The research shows that the application of steel fiber reinforced concrete in ground engineering can give full play to its high flexural and tensile strength, crack resistance, fatigue resistance, wear resistance and impact resistance. It can replace steel bars, reduce pavement thickness, increase shrinkage joint spacing, shorten construction period, improve engineering quality, reduce engineering maintenance costs and prolong engineering service life. Steel fiber reinforced concrete has good material properties. Compared with ordinary concrete, its compressive strength increases by 5%~20%, flexural strength increases by 20%~50%, tensile strength increases by 20%~40%, and wear resistance increases by 40%. Under the condition of artificial rapid test, when steel fiber content is 30kg/m3, the total shrinkage cracks are 40%~50% of the reference specimens. Under the impact load, steel fiber reinforced concrete has good mechanical properties. The crack resistance of concrete is 3 to 4 times that of ordinary concrete. When the number of fatigue is 1 million times, its flexural strength is 1.62 to 2.5 times that of ordinary concrete.

1 General situation of Engineering

An international logistics park project consists of a single-storey warehouse and a management and equipment room. The total building area is 35218 m2. The foundation is an independent concrete foundation and the main body is a steel structure. The warehouse floor of this project is made of steel fibers with a thickness of 180 mm, steel fibers with RC80/60BN of Jiamike silk, the design content is 15kg/m3, and the strength grade of concrete is C30.

From January to February 2012, technicians investigated, collected and sorted out five similar engineering qualities of steel fiber reinforced concrete floors provided by steel fiber manufacturers, and counted the cracks caused by different reasons of steel fiber reinforced concrete floors.

Feasibility and Cause Analysis

2.1 Feasibility Analysis

At present, the company has mastered the construction technology of large area concrete ground warehouse, ground grinding technology, maintenance technology, and has successful experience, and has the corresponding construction methods to guide the construction.

Although the company lacks understanding of the performance of steel fiber reinforced concrete, it has been cooperating with universities such as Qingdao University of Science and Technology for many years. It can grasp the shrinkage performance of steel fiber reinforced concrete quickly through certain experimental research, and take corresponding measures to eliminate the cracks in the construction stage.

Surface air-drying cracks are inevitable, belong to micro cracks, non-structural cracks, as long as the maintenance can be eliminated in time.

According to the above analysis, it is feasible to eliminate the visual crack-free of steel fiber reinforced concrete in construction stage.