Construction process of U-shaped aqueduct for small concrete prefabricated components
1. The small aqueduct of the U-shaped aqueduct is the main connecting building in the farmland water conservancy supporting facilities. It has various forms. According to the diameter of the aqueduct, there are five types of D40cm, D60cm, D80cm, D100cm and D120cm; the span is 4m. Four types of 6m, 8m, and 10m, the size of which depends on the number of irrigation acres, the flow rate, and the width of the ditch and canal. At first, there were two main ways in the construction process: one was made with the inner membrane of the cow, and the other was made of the adobe. The cow is made of intima, which is characterized by the use of soil in the aqueduct inner membrane to make the soil, the outer membrane and the plug for wood processing template, and the steel mesh is inverted on the cattle. It is mainly used in areas where the diameter is small, the construction site is relatively wide, and it is convenient for manual installation. During the construction process, the aqueduct network is first tied according to the drawings and the outer membrane is made. According to the diameter and span of the aqueduct, the processed wood is used as the plug of D40cm, D60cm, D80cm, etc.; 4m, 6m, 8m, 10m, etc. The upright sideform, on the plug, also draws the shape and cross-sectional dimensions of the aqueduct. Then level the site, with a 6m diameter D60cm aqueduct as the column, first use the loess according to the diameter and length of the aqueduct, layer by layer, to a certain height. Then, the hanging line is initially cut out of the aqueduct pattern, and the two ends of the cow are fixed with the plugs prepared in advance, and the line is cut and cut into the shape of the aqueduct, and then the mud is leveled on the soil cow, and then a layer of sand ash or It is directly laid on the film, the reinforced mesh is fastened on the top, the vertical mold is fixed, and the aqueduct is poured with concrete. After the concrete of the aqueduct is condensed, the plug is manually removed, and the cattle are slowly removed from the aqueduct. Allow it to dry quickly and reach the condensation period. The adobe is made of outer film. The difference is that the aqueduct inner membrane and the plug are made of wood processing template, the outer film is made of adobe, and the steel mesh is placed in the cow. It is mainly used for aqueducts with larger spans and larger diameters, such as D120cm (also available in D40cm, D60cm, etc.). It is not easy to install and has relatively poor construction conditions. It is made of ready-made adobe and mud. The aqueduct shape, then leveling with mud, smearing, then sanding or directly laying the film is basically the same as the former. The two methods are generally the same, and the manufacturing process is simple, original, rough, unsightly, and of low quality. The artificial vibrating of the concrete is not dense, and there are honeycomb, pockmark, and leakage ribs, and it is difficult to eliminate many drawbacks.
Second, the U-shaped aqueduct is nowadays
1. The composition of U-shaped aqueduct steel mold is composed of U-shaped aqueduct steel mold. The type of U-shaped aqueduct is 6m, 8m, 10m according to the span. There are four kinds of diameters: D60cm, D80cm, D100cm and D120cm. It has a span of 8m and diameter. The D80cm aqueduct is described: the U-shaped aqueduct steel mold consists of the inner membrane, the outer membrane, the plug, the lateral plug and the accessory parts. The inner membrane consists of a side mold and a middle mold. The two ends of the aqueduct are two sets of side molds (abbreviated as side molds). Each set consists of two 100×20cm rectangles and five ring-shaped steel rings with a certain angle. In order to be durable, high-precision and non-deformable, each steel mold is reinforced with 5cm wide slats around the back and in the middle, similar to a plurality of square grids. The surrounding slats have many perforations along the long and short sides. Easy to connect to the template. There are 3 sets of aqueduct middle steel molds (referred to as medium molds), each set is 2 pieces of 200×20cm rectangles and 5 pieces of ring-shaped steel molds with a certain angle. The back side is similar to the side molds. The connection method is side mold (1m). + inner membrane (2m) + inner membrane (2m) + inner membrane (2m) + side mold (1m). The outer membrane is also composed of a side mold and a middle mold. There are 2 sets of outer membranes at both ends of the aqueduct, each set consisting of 2 pieces, separated along the center line of the aqueduct water flow, 1 piece on each side (4 pieces in diameter D120cm); 3 sets in the middle mold Each set is also 2 pieces, the separated position and the corresponding connection method are the same as the inner film. The back side is reinforced with many 8cm slats, and the holes are reserved for screw connection. The side molds of the side mold and the inner film are different in shape, and it is connected with the aqueduct. The molds of the two ends are welded together. There are 2 sets of steel molds, each of which has 2 pieces. It is welded with the outer film of the buttress and is disconnected at the center line of the aqueduct flow. Lateral plug, there are 4 steel molds, two at each end of the aqueduct. Its size is 99×18cm rectangular steel mold, which is an independent steel formwork. It is connected with the plug and the outer mold of the aqueduct. Auxiliary accessories, mainly screws, steel cards, support frames, fixed frames and other accessories for connecting steel molds. The support and fixed frame are designed by prefabricated manufacturers according to their own experience. It is essential in the prefabrication of aqueducts. Explain.
2. The U-shaped aqueduct of the U-shaped aqueduct steel mold and the concrete pouring production focus on how to make the aqueduct inner membrane, outer membrane, plug, lateral plug and accessory parts include fixed skeleton, support frame, screw, bolt, etc. connected. During the construction of the prefabricated U-shaped aqueduct, the outer membrane, the plug, the lateral plug and the support frame are assembled first. The side molds with plugs, lateral plugs and outer membranes on both ends of the aqueduct are placed directly on the prefabricated platform. Four support frames are distributed in the bottom of the outer membrane. At the junction of the outer and outer molds, 10 cm away from the junction. The lower part of the outer middle mold, the other several support frames are also the same. The intersection of the die and the mold is arranged in the bottom of the aqueduct in turn. The support frame is made of round steel plate base, 48mm steel pipe and upper and lower movable flat iron. Its characteristics It is a supporting aqueduct and a balanced aqueduct. The position of the support column must be separated from the side mold and the middle mold or the middle mold and the middle mold according to the force of the abutment. The support order between them is the buttress-1#support-2#support-3#support-4# Support - buttress. After the steel outer membrane, plug, lateral plug and support frame are assembled, apply the release agent, then put the bundled groove mesh into the mold, and then put the main abutment and distribution ribs of the good aqueduct. The mold is ligated, which is integrated with the grooved steel mesh, and the steel mesh is supported by a 12 mm steel bar. The inner membrane is reassembled, and the inner membrane is assembled in parallel with the concrete pouring of the aqueduct. The concrete is poured while assembling, and the concrete is assembled and poured four times. Before assembling the inner membrane, the inner membrane fixed skeleton is installed, and the outer membrane of the aqueduct is corrected, and the function of the fixed skeleton is to fix the outer membrane and the inner membrane, and correct the outer membrane. The fixed skeleton has 4 sets in the 8m diameter D80cm aqueduct. It is fixed on the upper edge of the outer membrane of the aqueduct (10cm away from the joint between the side mold and the middle mold). It has steel pipe, flat iron and rebar welded. to make. Then install the innermost layer of the inner membrane, an inner membrane at the center line of the aqueduct, and then start pouring the concrete for the first time. After the pouring, remove the ash from both sides of the template; then place the inner membrane on both sides of the center line of the symmetric aqueduct, and The former inner membrane is connected by a screw, and then the concrete is poured twice; and the concrete is poured three times in sequence; before the concrete is poured four times, the steel bars of the abutment beam are firstly cut and spliced from the middle to the main rib of the aqueduct. Leave it for construction, install the intimal section of the intimal aqueduct and pour the concrete, then smear the concrete along the concrete, thus completing the concrete pouring of the aqueduct shell and the abutment buttress.
3. Production of U-shaped aqueduct beam The beam of the U-shaped aqueduct is the last process of producing the finished aqueduct. It can be smoothly carried out after the aqueduct shell and the pier concrete are poured, condensed and demoulded. It is subject to temperature, time, The limit of the initial setting period of the concrete needs to be fixed for a certain period of time. Usually, in June, when the temperature in the daytime reaches 28 degrees, the outer film is 30 hours, and the inner film is removed after 20 hours. Before the prefabricated aqueduct draws the beam, the inner membrane is removed first, and the concrete is chiseled at the position where the beam is reserved, the reserved ribs are separated and then tied, and then the beam mold 80×10×12cm is embedded in the tank shell. Concrete pouring