Dowel bar with combined structure for cement concrete pavements and durable stitch contracting structure

Abstract

The invention provides a dowel bar with a combined structure for cement concrete pavements. The dowel bar consists of a steel dowel bar, a glass steel sleeve tube and polyethylene films, wherein the inner wall of the glass steel sleeve tube is smooth, the outer surface consists of two parts, rib-shaped threads are formed in one side and firmly connected with the edge of a cement concrete plate, and the outer surface of the other side is smooth, so that the dowel bar can freely extend in adjacent grooves of the cement concrete plate. Threads are formed in one end of the steel dowel bar, one end of the steel dowel bar is tightly connected with the edge of the cement concrete plate, the outer surfaces of the other parts are smooth, the surfaces are painted and wrapped with the polyethylene films, and the bar end extends into the grooves in the edge of the cement concrete plate and can freely extend in the grooves of the cement concrete plate. The dowel bar with the combined structure has the advantages of good shearing resisting property and good corrosion resistance; besides, the stress of the contact surface with the cement concrete is uniform, the failure of the dowel bar caused by the breaking because of the cracking of the edge of the cement concrete plate is avoided, and prolonging the service life of the cement concrete pavements is benefited.

Description

technical field [0001] The invention belongs to the field of cement concrete pavement design and relates to a cement concrete pavement composite structure dowel bar. Background technique [0002] Highway cement concrete pavement is one of the main pavement forms of high-grade highways in my country. Because of its advantages of high strength, high rigidity, good durability, and small daily maintenance workload, it is widely used in mining areas and rural roads. The "Code for Design of Highway Cement Concrete Pavement" promulgated by my country points out that the design service life of cement concrete pavement is not less than 20 years. However, the service life of my country's existing cement concrete pavement is far below the design period, which indicates that the investment benefit of the road will be greatly reduced. [0003] A large number of cement concrete pavement road condition investigations found that the FWD (Falling Weight Deflectometer) and drill core sampl...

AI Technical Summary

Problems solved by technology

Corrosion of steel dowel bars results in a loss of effective cross-section and a decrease in the shear strength of the dowel bar, thereby impairing its ability to transmit loads and resist changes in vertical displacement; the dowel bar transfers the load from a plate through the free end The generation of rust will hinder the smooth contraction of the free end of the dowel bar, restricting it from staying in place, resulting in the loss of the shrinkage joint of the cement concrete pavement.

[0005] Therefore, an excellent cement concrete pavement dowel structure should have the following three characteristics: first, the dowel structure itself has good shear resistance, and can not be sheared under repeated wheel loads; The dowel structure should have good corrosion resistance and not rust under complex environmental conditions; third, the force state between the dowel structure and the cement concrete material should be more uniform and reasonable, so as not to crack the surrounding cement concrete Cause the loosening of the rods, and eventually make the overall loss of the load transmission capacity of the dowel bar

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