A kind of novel steel-concrete combination beam
The utility model relates to the steel-concrete combined structure being applied to construction work, is specifically related to a kind of framework steel-concrete composite beam.
In existing steel-concrete combined structure design, framework steel-concrete composite beam, due to its design feature, also exists a kind of irrational phenomenon:
In practical structures process, when girder steel end exists constraint and constraint is stronger (as frame column, shear wall etc.), girder steel end there is hogging moment and this moment of flexure is greater than mid span moment; And due to the characteristic of combining structure, for girder steel end, because concrete floor is in tensile region, cross section, so floor cracking deactivates pair cross-section bearing capacity without contribution, girder steel end hogging moment is born by girder steel completely; And in the middle part of girder steel, concrete floor is in pressure zone, cross section and assume responsibility for the whole or most pressure in pressure zone, cross section, so its section bearing capacity is just much larger than girder steel end bearing power.That is, can form compound section in the middle part of girder steel, girder steel end can not form compound section.Which forms so a kind of state: the section bearing capacity that moment of flexure is large is little, the section bearing capacity that moment of flexure is little is large.Along with girder steel span increases, this contradiction is more outstanding, and in order to reach structural safety, the normal following methods that adopts of design solves:
1. get cross section by girder steel end bearing power, this will increase substantially steel using amount.
2. girder steel height is constant, configures upper and lower Ji Yuan respectively by moment of flexure in girder steel end and beam, but the method can make Ji, girder steel end listrium than much thick in the middle part of girder steel, can increase steel using amount and manufacture difficulty like this.
3. adopt differing heights in beam-ends and beam, can reduce building like this and use clear height, affect attractive in appearance, architectural discipline is difficult to accept.
Meanwhile, all there is certain potential safety hazard in above method girder steel end cross-sectional stability.
Summary of the invention
The purpose of this utility model is to solve the shortcoming existed in current engineering design, provides a kind of novel steel-concrete combination beam.
The technical scheme that the utility model adopts is: a kind of novel steel-concrete combination beam, is characterized in that, comprises the girder steel be made up of top flange, web and bottom flange, and is located at the concrete floor above girder steel top flange; In the girder steel end contacted with frame column or shear wall, the casing being provided with opening or remaining silent, poured concrete in case; Casing opposite side is connected with frame column or shear wall.
Described casing can be the end at girder steel, is divided into the top flange of dividing plate and girder steel, web, bottom flange and frame column (or shear wall) side; Also can be that both sides are connected with girder steel, frame column (or shear wall) respectively as an independently casing.
For improving the bearing capacity of girder steel end further, in the concrete floor above girder steel end, the longitudinal tensile reinforcing bar being parallel to girder steel direction can be set.
Structure of the present utility model improves the bearing capacity of girder steel end, rigidity and monolithic stability, can carry out pre-assembled, easy construction, effectively can reduce depth of beam in component manufacturer, saves steel using amount.Specifically:
1, adopt the utility model structure, can, under employing identical Ji edge and deck-molding situation, make girder steel end and spaning middle section bearing capacity meet force request, thus overcome the shortcoming of conventional design compound beam existence, reduce steel using amount and improve building headroom;
2, by arranging tensile reinforcement above girder steel end, increase tensile region, girder steel end resistance to tension, make girder steel top flange in the constant situation of maintenance thickness, girder steel end cross-sectional reaches design bearing capacity requirement, reduces whole beam steel using amount;
3, girder steel end is placing of concrete in box and case, strengthens underbeam end section stability.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model (sectional drawing).
Fig. 2 is the A-A sectional view of Fig. 1.
Detailed description of the invention
Below in conjunction with accompanying drawing, structural principle of the present utility model is described further.
Reference numeral: 1---top flange; 2---web; 3---bottom flange; 4---floor; 5---frame column; 6---the concrete in casing; 7---tensile reinforcement; 8---frame column side; 9---dividing plate.
As shown in Fig. 1 ~ 2, steel-concrete composite beam of the present utility model, is characterized in that, comprises the girder steel be made up of top flange, web and bottom flange, and is located at the concrete floor above girder steel top flange; The girder steel end contacted with frame column, is provided with the box of remaining silent, poured concrete in case, and described box is made up of top flange, web, bottom flange and frame column side, dividing plate; The longitudinal tensile reinforcing bar being parallel to girder steel direction is set in the concrete floor above girder steel end.