To explore the bridge made of polystyrene hollow mold application technology

With the continuous development of the national economy, and the role of road transport in the national economy is more and more significant as the highway traffic hub - the bridge has also been a great development. In the upper part of the small multi-span bridge prestressed and non-prestressed hollow plate girder assembly structure, in the form of hollow plate girder structure is simple compared to other forms of T-shaped and box girder beams, etc., with a low building height, Prefabricated convenient, simple process, timber economy, easy to factory and standardization of production, transportation and hoisting easy to adapt to a wide range of features, it has been widely used in our roads and bridges, which greatly limits to meet the needs of production and construction. 1, hollow plate girder design change traditional use of prestressed hollow plate girder structure, plate width 99cm, double internal model or a single round hole-shaped oval, with the increase in road traffic and load, the traditional hollow panel has not suited to the development of modern highways, according to a new design theory, in order to improve the overall stiffness and stability of the bridge, highway 16 ~ 20m prestressed hollow beam generally by bottom width 132.3cm ~ 150cm, 75 ~ 90cm high beam design internal structure corresponding chamfered inner mold into a rectangular, similar to a small box girder, due to internal small size (53X93cm), if the use of steel in the mold, form removal and can not be artificially assembled, change the dimensions of will inevitably lead to the construction process should produce a corresponding breakthrough. Traditional hollow plate girder production process ills conventional prestressed hollow gas-filled capsule for the mold, there is construction is simple, fast, and low cost, but as in recent years, increasing highway traffic, overloaded vehicles increase, and because its drawbacks hollow, there will be a variety of defects. Such as inadequate bearing capacity, Veneer Force, deck cracks, deflection is too large, it will affect the use of the bridge in serious condition. In recent years through disease survey found that bridge, hollow plate girder most typical common problem is susceptible to longitudinal cracks, mainly due to: Most of the current, hollow beams of inflatable capsule mold, the casting process, because the air-filled capsule mandrel light weight, easy to deform, resulting in uneven webs and roof thickness. Mandrel construction will produce partial or total float and deviation, the construction process is difficult to control, resulting in a low roof and uneven thickness, the thinnest at less than 1/3 the thickness of the design, and the inner side of the roof forming waves shaped convex surface, side protective layer thickness is insufficient, inadequate bearing capacity of the bridge of a security risk. If early form removal is also easy to make hollow cracks, affect the durability of the bridge. The main analysis for three reasons: First, the rubber mandrel is flexible, there is a big surface tension after inflation, the top side will be under pressure sunken part bulging, top unpressurized parts of the contrary, the performance on the convex side of the recess; two Removal of floating positioning reinforced by pads and mandrel capsule contact area is small, it strengthened bump effect mandrel capsule; three, pouring concrete to form a secondary bump effect the order, the first part of the first pressurized pouring depressed first so that the internal parts of the capsule after pouring the gas flow and the formation of bulge here. It is not difficult to see uneven thickness resulting hollow mandrel is uneven effect capsule, resulting in uneven effect mandrel capsules are mainly small anti-floating pads and mandrel capsule contact area, there is no surface contact. To solve the problem of uneven thickness hollow plate must try to expand the contact area between the preform and the mold core and improve the overall stiffness of the core parting. So hollow girder construction, the roof thickness control is the focus of construction is difficult. 2, the construction characteristics of new technology for the prevention of defects hollow beam, improve construction quality concrete hollow slab bridge, two aspects of the hollow beams improved; the one hand, hollow structural changes to improve the overall mechanical behavior of hollow plate beam ends of the secondary cast from the original (pre) capped to once a subject-cast concrete, thereby greatly enhancing the overall force of the hollow plate. The other is the inner mold fermentation instead of polystyrene foam, use foam as a filling the mold can not only save a lot of manual and mechanical use, and its light weight, easy operation, without increasing the weight of the beam, After pouring concrete can remain in the structure does not have to take out, into mechanical and artificial numbers are small, but also to ensure the quality of construction. The construction of the first foam is made within the appropriate mode size by 3 ~ 4m each good backup, first pouring of concrete when pouring the floor, after pouring into the mold to carry out immediate lashing steel roof and the upper template to pull Tighten bolts of solid, concrete due to higher grade (typically 50 to 60) in order to prevent the pouring of the first concrete produce coagulation time to try to shorten this process, should be controlled in about 20 minutes, and finally pouring concrete roof plates . 3. Examples of our construction project tenders, Highway 23 Green Pro underlying hollow precast prestressed hollow beam 16m and 10m non-prestressed hollow beam total 540. I bid hollow beams used in all polystyrene foam as an internal mold fermentation filler, foam density 12.5kg / m3 (if the density is too light will produce foam floating phenomenon), it has been calculated to increase approximately every meter beam weight 6kg, to Use of the bridge has no effect. And the construction is simple, easy to control quality, from a dug hollow molded polystyrene foam inside the inner wall beams, the inner wall is smooth, hollow plate girder top and side thickness can meet the design requirements, because polystyrene light weight molded within the foam does not have to take out, the construction of precast hollow plate end and plate Shaft pouring molding, change the previous time that a pneumatic capsule capped a quadratic phenomenon, to the construction of a great convenience, coring effect through the roof beams of each piece, the design thickness of 12cm coring results for 11.5 ~ 12.5cm, the passing rate of 95 percent or more, to fully meet the design requirements. Using polystyrene foam as an internal mold, which is to ensure the construction quality, and simplifies the construction process, with the development of highways, its adaptability more and more people's attention. Address: Xinxiang City, Henan Province shop Industrial Park Company Contact: Manager Zhao Tel: 13937394068 18703735315 Company Website: www.wsjxcg.com