Traditional Culture Encyclopedia - Traditional stories - The time for the concrete anti-collision wall of the bridge should be carried out when the concrete strength reaches.

The time for the concrete anti-collision wall of the bridge should be carried out when the concrete strength reaches.

Abstract: the bridge collision wall is an important part of ensuring traffic safety. This paper summarizes the main technical measures to ensure the appearance and internal quality of the collision wall, and puts forward a series of quality requirements from the aspects of formwork support, concrete mix design, pouring and vibrating, and maintenance. Keywords: brief introduction to the construction quality of bridge concrete collision wall, collision wall is a kind of safety protection facility of bridge. Because the anti-collision wall is located in the bridge deck system, it is the most intuitive position of the bridge, and it requires high quality indexes such as geometric size, surface smoothness and flatness. However, the hoof-shaped part at the lower part of the collision wall is in a special inverted arc shape, so the bubbles in the front side of the hoof-shaped part are extremely difficult to discharge during construction pouring, and dense bubbles often appear after formwork removal. At the same time, it is very difficult to cast-in-situ on the installed suspension board and erect the formwork. Surface defects such as honeycomb pits often appear at the joints and bottom of the formwork, resulting in slurry leakage, which has always plagued the construction and supervision personnel. Combined with engineering practice, the quality control of collision wall is briefly analyzed. 1, template The template used to install the crash wall should not use a small piece of composite steel template, but a large piece of steel template. This is because the smaller the template, the more joints, the worse the appearance, the uneven surface of joints, and easy to leak slurry. To control the thickness of the protective layer of steel bar, pebbles can be used to fill the steel bar, and concrete pads should not be used to avoid ugly spots on the wall after formwork removal. When the formwork is erected, horizontal belt screws made of channel steel are installed at the top and bottom of the side formwork of the collision wall for fixing. Then several steel support rods are evenly installed on the channel steel on both sides to fix the whole template. 2, concrete quality control Because the bottom of the collision wall is wide and narrow, and the internal steel bars are densely arranged, it is not conducive to the elimination of bubbles when pouring concrete, so there is a higher requirement for the workability of concrete. In construction, in order to make the workability of concrete better, it is necessary to carefully design and adjust aggregate gradation to achieve the best gradation curve, which can be handled by appropriately increasing cement dosage and sand ratio. In general, the sand ratio can be increased by 2% ~ 3%, but the sand ratio should not be too large. If the sand content is too large, it will make it difficult for bubbles in concrete to float and escape. When mixing concrete, attention should be paid to the proper mixing time. Mixing time is too long, which will reduce the workability of concrete; However, if the mixing time is too short, uniform concrete will not be obtained, and the strength of concrete will also be reduced. 3, concrete pouring and vibrating

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Quality assurance measures for bridge anti-collision wall construction

Keywords: construction quality of bridge concrete collision wall

introduce

Anti-collision wall is a kind of safety protection facility for bridges. Because it is located in the bridge deck system, it is the most intuitive position of the bridge, so it requires higher quality indicators such as geometric size, surface flatness and flatness. However, the hoof-shaped part at the lower part of the collision wall is in a special inverted arc shape, so the bubbles in the front side of the hoof-shaped part are extremely difficult to discharge during construction pouring, and dense bubbles often appear after formwork removal. At the same time, it is very difficult to cast-in-situ on the installed suspension board and erect the formwork. Surface defects such as honeycomb pits often appear at the joints and bottom of the formwork, resulting in slurry leakage, which has always plagued the construction and supervision personnel. Combined with engineering practice, the quality control of collision wall is briefly analyzed.