对于桥梁建设来说，桥梁造型与外观已经逐渐成为了其重 点考虑的问题。而桥梁防撞护栏作为桥梁外观工程中的重要工程，施工单位越来越重视桥梁防撞护栏质量的好坏与外观问题。所以，不断加强研究桥梁砼防撞护栏施工技术以及施工质量，对施工安 全有着很大的保障作用，并且能够有效地延长桥梁的使用寿命。
For bridge construction, bridge shape and appearance has gradually become the focus of its consideration. As an important part of the bridge appearance engineering, the construction units pay more and more attention to the quality and appearance of the bridge anti-collision barrier. Therefore, continuously strengthening the research on the construction technology and quality of the bridge concrete anti-collision guardrail has a great guarantee for the construction safety, and can effectively extend the service life of the bridge.
1. Analysis on construction technology of bridge concrete crash barrier
1. Precautions for fabrication and installation of reinforcement framework
When making the steel framework of bridge concrete anti-collision guardrail, the first step is to cut the material at the steel shed, and then clean the paint skin, scale rust and oil stains on the steel surface. In the actual construction process, the construction drawings should be strictly followed, and the construction should be carried out in strict accordance with the construction specifications. Secondly, the reinforcement should be bound according to different models and specifications, and the reinforcement should be bound on the bridge surface as far as possible. When colliding the anti-collision guardrail, it is usually colligated at the expansion joint of the bridge deck, but it must be colligated in strict accordance with the construction design drawings, and after the colligation work, it is necessary to strengthen the inspection to ensure that the colligated parts are in place, and at the same time, it must be colligated firmly, so as to avoid unnecessary trouble in the subsequent process.
2. Precautions for formwork installation
Generally speaking, when installing the formwork of bridge concrete anti-collision guardrail, the material used is steel formwork. Before the actual construction, the template should be positioned first, and then the fixed work should be completed by the crane. The staff should do a good job in the auxiliary work of template positioning on the construction platform. After the completion of the installation and fixing of the steel formwork on the side of the bridge, the formwork end sealing shall be installed and formed as soon as possible. In this process, as far as possible to choose hard and smooth surface of wood, to avoid warping problems. The processing of wood formwork can be carried out at the construction site, and the staff should set the formwork reasonably from the actual bridge angle. For the wooden formwork, it should be supported in a stable way to prevent the deformation of the formwork during concrete vibration.
3. Precautions for concrete pouring
For the pouring of concrete, the two aspects are mixing concrete and tamping concrete. Before mixing concrete, the staff should add water to the mixer and let it idle for a few minutes, and then pour out the accumulated water, so as to ensure that the whole mixing drum is wet. When the concrete is mixed formally, the loss of mortar and the dosage of concrete should be fully considered. The mix proportion of concrete should be adjusted ahead of schedule. In addition, a notice board should be hung next to the concrete mixing plant to ensure that other debugging equipment can enter. Because the entrance area of bridge concrete anti-collision guardrail is very narrow and the density of reinforcement is relatively high, when pouring concrete, it must be ensured that it falls evenly, and in the process of vibration, the performance of mechanical equipment should be fully considered. In addition, in the process of vibration, we should not only accurately grasp the time of concrete vibration, but also make the vibrator move appropriately to the spacing, and choose the appropriate position as far as possible, so as to prevent the occurrence of pockmarked surface.