What is the disappointment between the hollow slabs (uboot) and the ordinary hollow slabs?
A: The typical hollow slab that has been used for a long time in the building industry is composed of a number of orthogonal planes, with a concrete slab layer. This combination will create T-shaped beams to withstand the loads that will be incurred. In the hollow slabs of the yubot, in addition to the upper slab, a layer of reinforced concrete covers the lower part of the orthogonal arc and creates an I-shaped cross section. This change, in addition to increasing the rigidity of the slab, makes these slabs look like flat bottom.
What is the economic cost of a hollow slab (uboot) than conventional roof systems?
A: The use of dual-hollow slabs (Yuboot) technology to create benefits such as large openings, flat slabs, lower elevations, and more. If this is not an advantage for an architectural design, then this technology is not recommended. Therefore, economical considering the architecture and structure can be investigated and in some projects, the use of bulging slabs (uboot) technology is economical and in some cases increases the cost.
Is the implementation time of the hollow slab (uboot) different from the typical slabs?
Answer: If you remove the beams and create a slab and thus reduce the formatting and armoring, the speed of the roof with the hollow slab system (uboot) can be increased, but it should be noted that the length of time required to hold the shaping below the slab, such as the slab Concrete concrete and according to the ninth chapter of the national building regulations.
What is the largest covered crater with a hollow slab system (uboot)?
A: According to the studies and technical documents, the technology of bulkhead slabs (uboot) is able to cover spans of up to 18 meters. It should be noted that if combined with pre-tension technology, there is a possibility of increased span
How is the roof aperture rigged in the hollow slab system (uboot) compared to conventional roof systems?
Answer: Due to the fact that the thickness of the hollow slab (uboot) is higher than that of ordinary slabs, the rigidity of the ceiling with the system of hollow slabs (uboot) is higher than that of a solid slab with the same concrete consumption rate And has a better ability to transfer the load to the superstructure.
What are the norms used in Iran to design a hollow slab (uboot)?
Answer: According to the technical approval issued by the Research Center for Building and Housing, the ACI-Aba-2800 regulations and the Ninth Statute of the National Building Code can be used to design the structure and ceiling.
What is the performance of the hollow slab (uboot) in corrosive environments?
Answer: In order to protect the hollow slab (uboot) against corrosion, the issues mentioned in the Ninth Chapter of the National Building Regulations are adequate and adequate.
What is the type of mold used in the hollow slab (uboot)?
A: The molds used in the hollow bulkhead system (UBT) are either new or recycled polypropylene and in accordance with the British standard BBA.
Is it possible to combine the system of hollow slab (uboot) with pre-stress technology?
A: Yes, it’s possible to combine the system of hollow slab (uboot) with pre-tension technology.
What are the benefits of using a hollow slab (uboot)?
Answer: The use of hollow slab technology in buildings can have one or more of the following advantages: – Creating a larger span – Creating a slab and removing columns – Lowering the total building height – Increasing the useful floor space of the floors – Reducing the thin operation Work – Increase the run speed – Reduce the cost of construction.
Do you need special equipment or specialist equipment to run a hollow slab (uboot)?
A: Because these slabs are typically implemented as ordinary concrete slabs, they do not need more equipment, and contractors who are able to implement conventional concrete slabs can use the same equipment and manpower to run bulkhead slabs.
Do the materials used in these slabs have special characteristics?
A: Materials used in these slabs include concrete, rebar and yubut mold. The strength of concrete and fittings is determined by the structural designer, which is usually considered as other concrete structures of the structure.
What kind of software is used in the design of these types of roofs?
A: For designing these projects, commonly used software such as Etabs, Safe, Sap.
What are the dimensions of the uboot molds used in the bulkhead slab?
A: Yubut molds have a fixed width and width of 52 in 52 cm and their height is variable. For product specifications see the product section.
Is it possible to make uboot mold with other materials or new dimensions?
A: As mentioned, these templates have been investigated at the Building and Housing Research Center and its criteria have been determined. Therefore, it is not possible to change its dimensions and materials.
How much is the resistance of the ceiling of the dome (uboot) to the fire?
Answer: Since the Uboot molds are protected in concrete and at least 5 cm from the reinforced concrete tile against fire, according to the European standard (fire resistance behavior) these roofs have the ability to withstand fire at a temperature of 1000 ° C They have 3 hours in duration.
Is it possible to install the pendant before installing the chandeliers and fittings to install the false ceiling and duct of the air conditioning system?
Answer: 1- Use the plate before the concrete
In this method, steel plates (plate), which are welded U-shaped on their back, are used. These sheets are placed in pre-assembled areas prior to concreting on the floor molding, and after the molding and molding of the masonry under the roof, they are welded to the weld.
2. Use of plate after concrete
In this method, after opening the roof molds, the plates are fitted under the roof with special nails fired by special rifles and welded to the expected bars.
In the end, it should be noted that the passing of the waiting wedges from the molds to the bottom before the concrete is causing the gap between the molds, which causes the concrete to drop out of the molds, which in addition to creating the problem for the concrete, the surface under the ceiling is also difficult. .
Please explain how to model the structure with the Uboot roof system in the etabs software.
A: In designing structures with a ceiling of hollow slab (Yubut), like other buildings with a slab system (typical reinforced concrete slabs, slabs, etc.), Etabs and Sap are commonly used. The roof design also comes with Safe and Adapt software. In designing these structures, first, the UBT slab is modeled in a safe design and its thickness is determined. It should be noted that since the safe software is not able to model the slabs in a hollow manner, the slab is equal to a solid slab with similar difficulty. In this case, the weight of the concrete slab is considered zero, and according to the actual weight of the slab, the dead load is placed on the roof. After determining the equivalent thickness and the weight of the slab in safe software and control of deformations in this software, the design with a slab designed in etabs software is modeled to allow the actual weight of the roof to be considered in the analysis and design of the structure and foundation .