To standardize the construction of anti-collision guardrail, we must strictly follow the construction technology and quality control points from the early construction preparation, steel bar production and installation, formwork erection, concrete pouring to the later concrete maintenance and other construction links, so as to ensure the completion of bridge anti-collision guardrail construction with high quality.
1、 Construction control points:
1. The survey control points shall be set every 5m to lay a good foundation for the control of elevation and alignment, and then the concrete within the anti-collision barrier shall be roughened and cleaned.
2. The processing size of reinforcement shall be accurate, and the positioning frame method shall be adopted for installation. According to the position, angle and size of No.2 and No.3 steel bars in the design drawing, the positioning frame is made respectively, and the positioning frame is used to cooperate with the control point, so that the elevation and linear of the steel bar of the crash barrier are effectively guaranteed, and the qualified rate of the steel bar protective layer can be maintained above 90%.
2、 The application of No.2 steel bar positioning frame in the construction of bridge crash barrier. The positioning frame is erected on the measuring control point and leveled with a level ruler. The angle between the front cross bar and the vertical bar is processed according to the angle in the design drawing, and the length of the cross bar is also reserved according to the size in the design drawing. The No. 2 reinforcement adjusted in position shall be firmly welded with the No. 4 reinforcement embedded in the flange.
3、 The application of No.3 steel bar positioning frame in bridge crash barrier construction. After the position is adjusted, the No. 3 steel bar is welded firmly with the No. 4 steel bar embedded in the beam flange plate and the No. 2 steel bar installed before by arc welding. And so on, form a standard section every 5 meters, and then hang the line to install the middle section reinforcement.
4、 The installation, reinforcement and removal of the formwork shall be carried out by the special trolley for the anti-collision barrier formwork.
5、 The fixed steel formwork is adopted for the bridge crash barrier, and the single piece length is 1.5m. The reinforcement method is inner tie rod with outer support. The end formwork is also made of shaped steel plate and fixed by high-strength bolts. At the same time, the broken joint of the crash barrier is also made of shaped steel plate, and the broken joint after formwork removal is 62.5px wide, which fully ensures that the concrete of the crash barrier does not crack and the appearance quality is good.