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u-boot slabs technical points

1. The uboot molds should be arranged in accordance with the operational drawings on the roof. The distance between the first and last form of the uboot in each row and the column with the edge of the beam or beam shall be controlled to conform to the execution plans. It should be explained that sometimes due to inaccuracy in the implementation of the columns or the slab, this distance is different from the execution map, which should be coordinated with the project supervisor and, if necessary, be checked and approved by the ceiling.

2. The bundles on the side bands The uboot molds are adjusted to the required space specified in the operating plans, and tightened with plastic glue. It is worth noting that this gap is shown in the executive drawings in the section of the roof section and each of the settings on the strap is created for a specific distance.

3. Picking up and down the network reinforcements should be such that there is a reed on each of the two Uboot molds. For this purpose, it is recommended that the distance between the rails placed between the uboot be extracted from the drawings and arranged on the roof accordingly. Then, in between these bars, one or more other bars are added according to the drawings with the same distance.

4. In areas where there is no high corrosion risk, use should be made of spacers with a middle distance of the rebar to the bottom of the slab 2.5 to 3 centimeters.

5. During the implementation of the uboot roof (especially in the use of large U-bobs (H> 20 Cm)), it is recommended to close the bottom net of the reinforcement by closing the pipe to the pipe or profile below to prevent the Uboots from reaching the concrete.

6. Due to the fact that the uboot molds are designed to carry a massive load of about 80 kg, it is also possible to avoid loading more load or central load on the uboot, and after training the reinforcement of the network, the workers should be trained to Move on the bars.

7. In accordance with the operational plans, each jumbo must have a jumper armor in the corners. One of the tasks of these pins is to integrate the network up and down and keep the Uboots fixed between the two networks. Therefore, it is recommended to bend the 135 degrees of the pin in the bottom and bend 90 degrees in the top with a reinforcement wire so that during the installation of the high network separation from the bottom of the network and thus the rise of the Uboots can be prevented.

The strength of the concrete used in these slabs is determined in the design of the structure, which is stated in the first note of the executive drafts. The psychic of the concrete (slump) used should be about 11 to 13 centimeters so that concrete can easily move under the molds and fill the space below. It is strongly recommended to use an over-lubricant with the recommended amount in the manufacturer’s technical catalog to increase the slump of concrete and prevent its loss of resistance.
9. When it is better for the concrete to coat, first apply a layer of about 10 cm and then vibrate and then fill it. Of course, it should be noted that in no way the first layer does not reach its initial setting and the horizontal seam is not created.

10. After completing the main grid reinforcements, be sure to be controlled so that the additional bars required in the maps are executed. These bars include superimposed spindles in the middle of the span, on columns and shear walls, large openings, 45-degree reinforcement around openings and ….

11. If necessary, connect the non – instrument parts to the hollow slab of the Uboot, such as the facade, the elevator, etc., The plates are designed in place and tightened.

12. Creating a negative gap is allowed in the slab formatting.

13-For the uniformity of concrete thickness, it is recommended to prepare a suitable index before fitting.

14. If possible, it is advisable to use a pneumatic pump for concrete. The use of a ground pump in addition to impacting the ceiling during pumping can cause concrete tension in two layers and cause the rise of uboot molds.

15-Maintenance of concrete after concrete should be done exactly in accordance with the existing regulations.

16. Due to the fact that the weight of the slab above most of the time is greater than the design weight, it is strongly advisable to use a reciprocating jack under the two previous ceilings during the fitting of each roof. Otherwise, the weight of the ceiling in concrete will cause cracks and cracks in the bottom of the ceiling.

17. The opening time of the roof molds shall be determined according to the air temperature and in accordance with the existing regulations.

18-Resistance to power bars in the first note of the executive drafts. It should be noted that the conversion of the cross-section of the rebar to the ceiling is not allowed without the fitting of the ceiling.

19- In the case of blending hollow slab (uboot) with foam technology, in addition to the above, it should be noted:

The minimum resistance of concrete cylinders is 300 kilograms per centimeter square.

Do not open the following molds before performing the tensioning operations.

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