Prefabricated floor element, structure comprising prefabricated floor elements and installation for obtaining the prefabricated floor element

Abstract

Prefabricated floor element (1) having an elongated shape wherein a longitudinal direction (X), a transversal direction (Y), a height direction (Z), two end faces (11) which delimitate the element (1)in the longitudinal direction (X), two lateral faces (12) which delimitate the element (1) in the transversal direction (Y), a lower face (13) and an upper planar face (14) that delimitate the element (1) in the height direction (Z) are defined, which comprises transversal continuous upper grooves (15) on the upper planar face (14) or lateral grooves (26) on the lateral faces (24), the lateral grooves (26) extending from the lower tab (TS) to the upper planar face (24). The invention also relates to a structure comprising such prefabricated floor element (1)and further comprising a linear supporting element (LS) which supports one end of the prefabricated floor element (1)such that in the linear supporting element (LS) a supporting surface (S1) is defined and a moment resisting system (MS) arranged on the linear supporting element (LS) and facing an end face (11) of the prefabricated floor element (1)and an upper concrete layer (LC) poured on top of the element (1) or in the shear key(SK) defined between two adjacent floor elements. The invention also relates to an installation for manufacturing the floor elements (1, 2).

Description

technical field [0001] The present disclosure generally relates to an improved construction system for structural floors and a method of erecting the same. Structural floors are made of modified structural precast concrete elongated elements and placed in operation reinforced concrete capable of working properly with the precast elements due to proper bonding and such precast floor elements due to improved industrial device is manufactured. Background technique [0002] A number of floor systems based on precast concrete elongated floor elements and reinforced concrete placed in operation are known in the art. For the sake of clarity, from here on all term "elongated floor elements" will be used exclusively to refer to a specific family of floor elements: the two ends of which are supported exclusively in the main structural members such as main beams, girders or walls Those floor elements that span directly from one end to the other. Also included are those elements that...

AI Technical Summary

Problems solved by technology

A disadvantage that must be mentioned is that cast-in-place roofs usually have considerable shrinkage due to their shallowness and large surface exposed to the air (small theoretical dimensions)

Finally, such floors have the same problems at the ends of the prefabricated elements as those that only fill the lateral joints with concrete: wide and deep cracks appear parallel to the linear support elements

This solution is not common in practice, even if it is accepted in some national standards, due to the following four main disadvantages: 1) Making the upper part of the honeycomb of the plate open requires additional work during the pre-casting process, which requires human labor and results in wasted concrete being removed, or requiring investment in specific machinery capable of opening and reclaiming the removed concrete

2) Openings are usually not made along the full length of the hollow, but usually along 2 / 3 of the length of each plate, which complicates pre-casting and makes it difficult to resolve issues that occur on the plates during the casting phase. Higher cost of local defects (because larger lengths of prefabricated elements have to be scrapped and wasted when compared to the very short scrapped parts required when the cross section is perfectly uniform)

3) Eliminating part of the upper flange of the slab (to make the honeycomb open) considerably reduces the moment of inertia of the slab and makes it more flexible and less efficient during the erection process, often resulting in the need for supports during erection

However, it has one major disadvantage: while there is usually some bond in the first weeks, months or years after the structural floor is completed, this bond usually breaks completely over time, appearing shrinks unevenly, and the structure must withstand cyclic loading and unloading due to normal use of any structure

2) Since isolated protrusions will generally have more edges, it may be more difficult to release from the mold

3) No reinforcements at all

Those precast slabs that are solid but thick are expensive because precast concrete is usually rich in cement and additives

Those prefabricated panels with voided sections are usually expensive due to the expensive embedded permanent form and often require bracing during the job

All most common precast panels include protruding stiffeners which makes them all expensive

Some recent Chinese patents (like the ones mentioned above) for precast panels do not cover such expensive stiffeners but instead include complex geometries which may not be so cheap for precast either as special models or complex demoulding procedures

Hollow core slabs with honeycombs with large openings will generally require support during operation and are expensive to pre-cast due to their specific geometry

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