Jinyi Railway Beam Yard, China Railway Shanghai Engineering Group Co., Ltd.

Background

Jinyi Railway Beam Yard, China Railway Shanghai Engineering Group Co., Ltd is located in Lujia Village, Changshan Township, Wucheng District, Jinhua City, on the left side of the line between mileage DK41+150 and DK41+800. The yard covers a total area of approximately 104.2 mu, of which 50.32 mu fall within the red-line area of Changshan Station and 53.88 mu are newly added temporary land. It is equipped with 24 beam-casting beds, comprising 18 for 32 m beams and 6 for 24 m beams, enabling a maximum daily output of 6–8 beams. A total of 156 storage beds and one static-load test bed are provided. Among these, 129 are double-deck 32 m storage beds and 26 are double-deck 24 m storage beds, giving the yard a maximum storage capacity of 312 beams (excluding casting beds). The casting area is divided into two production lines, served by four 42 m-span, 100 t gantry cranes for hoisting T-beams and loading them for transport. The on-site batching plant is equipped with one HZS120×2 unit for producing beam concrete, which is placed using a portal crane in conjunction with 2.5 m³ hoppers.

Project Challenge

Precast hopper-delivered C55T girders demand concrete that is free of visible blowholes and exhibits a uniform color. To suit site operations, a one-hour slump-retention is required. The main challenge is the inefficient escape of air voids in summer under conditions of high paste content and a low water-binder ratio. Rapid bubble release during vibration is essential, placing extremely stringent demands on the balance between defoaming and air-entraining agents.

Solution from ARIT

ART-DF (E) can effectively eliminate small bubbles, while ART-DF (D) can accelerate the discharge of bubbles. The combination of the two completely meets the requirements of construction and appearance.

Fig. 1 On-site mold removal picture

Product from ARIT

• ART-DF (E) 

• ART-DF (D) 

For detailed remixing formula, feel free to contact technicians of ARIT.