The ﬁrst product that the company succeeded in designing and mass production in 2013 is the frames of the hollow slab ceiling (Uboot) with polypropylene. The Uboot roof (hollow) is a structure system that is kind of double-sided hollow slab. In this structure system between the top and bottom strips mesh, polypropylene molds, called Uboot will replace the unconstrained concrete in the middle of the ceiling. In this method, the bottom of slab is completely ﬂat because the Uboot are buried between the slabs. The dimensions of the company’s Uboots are as follows:
Stages of implementing hollow slab with permanent frames:
• Molding and reinforcem ent mesh u n d e r block.
• Arranging block
• Reinforcin g m e s h u n d e r block
• Opening block.
Advantages of Uboot blocks of Gonbad Firoozeh Co. in comparison with similar products:
• Re d u c i n g t h e concrete volume and weight of the slab compared to the Cobiax slab and Modiﬁed Uboot.
• Increasing the thickness of the joists compared to the Cobiax slab and i n c r e a s i n g t h e shear and ﬂexural strength of the slab.
• Base production in diﬀerent sizes 67.5-9-10 cm which causes the rebar of bottom mesh not to stick to the mold surface and hallow slab separation due to the weight of the upper rebar mesh a n d e a s e o f movement of the executive assembly on the blocksthe blocks
• Providing the spacer for precisely putting rebar and non-displacement of blocks.
• Creating an intermediate cavity in the middle of the block greatly increased the strength of the block against the pressures such as impact, concrete pump, workers weight, thermal stress of the sun radiation.
• Removing the super lubricant due t o t h e f u l l penetration of concrete from the middle hole.
• Removing the concrete grains s e p a r a t i o n underlying ceiling problem due to an intermediate hole.
• Removing of capillary cracks underlying ceiling d u e t o n o n lubricating concrete.
• Transportation and loading economic blocks.
• Manufacturing high quality product.
• Equipped with a quality control unit and loading test device.
• Maintaining the distance between block joists and the eﬀective width of concrete beams.