Railway steel mold and bridge steel mold manufacturers teach you how to identify the quality of steel mold?

The reason for the problem of box girder steel formwork of bridge steel formwork manufacturers is that slurry leakage, uncompactness, holes, cold joints, water ripples and other phenomena occur at the junction of the bottom plate of box girder steel formwork and the web plate of box girder steel formwork. Mainly because the construction process is not perfect, aggregate gradation, particle size selection is unreasonable, coarse aggregate is too large. Prevention and control measures: the bottom plate, web plate, top plate full section oblique circulation progressive pouring process, basic synchronous pouring, vibrating web corrugated pipe below the concrete to strictly control the coarse aggregate particle size, slump during construction, if necessary, the coarse aggregate sieving.
Box girder wing plate bridge steel formwork manufacturers teach you how to prevent and control the quality of bridge steel formwork. Steel formwork is adopted for pier and abutment construction. In order to overcome the common quality defects of size deviation, uneven appearance and weak support of reinforced concrete structure and components in the production and installation of bridge steel formwork, the following preventive measures are adopted:
The steel formwork and support frame of the bridge shall have sufficient strength and rigidity. The vertical height shall be accurate when supporting the formwork, and the top of the formwork shall be pulled against each other. Bolts are used to tighten in the middle to bear the lateral pressure of concrete. The excavation of steel formwork foundation pit of bridge support shall strictly follow the principle of "layered excavation". The support erection shall be closely coordinated with the earthwork excavation. During excavation, the earthwork near the steel support shall be excavated by the central grooving method to prevent mechanical collision support, reduce unsupported exposure time.
The stability of steel formwork steel support of elevator protective door is one of the important factors to control the stability of the whole foundation pit. Prestress is applied strictly according to the design requirements, especially the stability of diagonal braces. During the diagonal bracing operation, every link of installation should be carefully operated. At the same time, the requirements of stability, strength and deformation of steel purlin should be ensured during the manufacturing and installation process. In addition, during the whole construction process from erection to demolition of steel support of foundation pit, steel supports shall be strictly monitored to ensure their stability.
When the steel support is installed, the axis deviation shall be ≤ 5cm, and the bearing capacity of the support joint shall meet the design requirements. When the steel support is connected, the bolts are symmetrically installed and fastened in sequence. At the same time, in order to prevent excessive deflection of the steel support when the axial force is applied, the deflection shall be corrected to the horizontal level before the axial force is applied. Before installing the steel support, check whether the processed support is vertical, and correct the non-vertical support; then install the steel support on the bracket and fasten it.
When the concrete is in plastic state, it is forbidden to beat hard on the outside of the template, so as not to cause the concrete to slide down and form root defects. The support is directly on the edge of the pit, and the lower surface is padded with wooden boards to expand the contact surface.
The joints of the formwork shall be tightly assembled, and the joints that are not tightly assembled shall be treated by filling, pasting and closing, welding and other methods to ensure that the formwork is flat and smooth. If you have any questions about Xinjiang hanging basket template, please come to our company, we will patiently answer any questions you have. And if you find anything that needs to be modified in the process of reading this article, please testify in time! For more relevant contents, please click for more information. The tensioning hole is not embedded with ring reinforcement and longitudinal stressed reinforcement in strict accordance with the construction drawings and specifications. The phenomenon of less reinforcement and wrong reinforcement often occurs. When pouring wet joints and tensioning hole concrete, the construction joints are not strictly handled. Prevention measures: ① Strengthen the inspection, the pre-buried reinforcement of the tensioning hole (especially the large tensioning hole) must not be buried less, and the beam shall be drilled out and straightened in time after prefabrication and molding; ② During the wet joint construction, the annular anchor bar of the roof shall be aligned and welded, and appropriate amount of micro-expansion agent shall be mixed into the concrete; ③ During the construction of closed tensioning holes and wet joints, special personnel shall be assigned to check the degree of chiseling, welding quality of steel bars and overlapping length. During concrete pouring, the construction joints shall be strictly treated and moistened by sprinkling water.
The anti-camber of prestressed box girder after tensioning affects the concrete bottom of the bottom plate at both ends of the box girder. Some longitudinal fine cracks appear at both ends of the concrete of the side plate of the beam after tensioning. Prevention and control measures: set up inclined planes at the bottom of the bottom plate concrete at both ends of the beam to avoid the quality defects of prefabricated small box girders caused by concrete squeezing and damage at this position; And set up reinforced spiral reinforcement and end reinforcement at the bottom of the two anchors of corrugated pipe, and strengthen the vibration of the end concrete, resulting in longitudinal fine cracks in the side plate concrete.