(2) background technology
In engineering structures; The cast-in-place concrete hollow building roof technical application more and more widely; The kind of packing material is also rich and varied, like high-strength concrete class (being GRC) type light-wall pipe and thin-walled box, metal bellows, polyphenyl class filler rod and filling box, plastic pipe and plastic box.Packing material is equivalent to a kind of built-in template, though participation structure is not stressed for packing material itself, if the construction effect of packing material is bad, will have influence on reinforcing bar and mechanical properties of concrete.
Experimental study shows: in order to guarantee the bond stress of reinforcing bar, reinforcing bar needs certain thickness topping, and packing material must not be close to reinforcement placement, and the two should effectively be kept apart.Relevant rules regulation: the distance that 10mm should be arranged between packing material and the reinforcing bar at least.In order to reach the requirement of rules, way commonly used in the engineering is: add between steel bar stress at packing material and isolate reinforcing bar.The shortcoming of this way is: (1) steel using amount is big, and cost is higher; (2) effective to the bigger packing material of GRC class modulus of elasticity (being rigidity), for polyphenyl class and plastic filling material, the little then pressure of isolation reinforcing bar contact area is big, because material itself is softer, isolates reinforcing bar and is absorbed in easily in the packing material, does not reach isolation effect.
In engineering,, generally be between reinforcing bar and template, to lay cushion block for the outer thickness of concrete cover that makes steel bar stress satisfies code requirement.In the prior art; Cushion block of a great variety, as " a kind of reinforced concrete protective layer cushion block " (ZL99242261.2), " reinforcement cover cushion block " (ZL200620039122.2), " reinforced concrete protective layer cushion block " (ZL02220191.2), " comprehensive reinforced concrete protective layer cushion block " (ZL02263352.9), " reinforced concrete floor hassock piece " (ZL200420076201.1), " concrete cover plastic cushion " (ZL02268129.9), " worker China Democratic National Construction Association construction concrete cover cushion block " (ZL00237758.6), " reinforced concrete protective layer cushion block " (ZL01206326.6), " reinforced concrete protective layer approaches the abdominal pad piece " (ZL200720124513.9), " reinforcing bar is used the concrete cover cushion block " (ZL01239974.4), " reinforcement cover cushion block " (ZL200420090054.3), " reinforcement cover plastic cushion " (ZL02213898.6), " reinforcement cover cushion block " (ZL200420090054.3).Above cushion block mainly is between the reinforcing bar of using and template, and the rigidity of reinforcing bar and template is all bigger, reinforcing bar or template can not take place in the construction under the effect of cushion block, cracked phenomenon occurs.Therefore the common trait of these cushion blocks is: it is all more approaching with a side size of pressing close to template that a side of reinforcing bar is pressed close in (1); (2) even size is variant, press close to template a side maximum size usually all≤35mm.These cushion blocks are if be used to isolate reinforcing bar and packing material, when packing material rigidity less (like polyphenyl and plastics), be easy to the phenomenon that cushion block is absorbed in packing material takes place, so isolation effect are bad.
To polyphenyl class packing material; I also once invented " a kind of hollow building cover structure with heightening type cushion block " (ZL200520112552.8) myself; This kind heightening type cushion block is mainly used in the lower position of control packing material; The characteristics of this cushion block are that an end is close to packing material, and the other end is close to template, and are very effective for the location of packing material.But its defective is: (1) is not suitable for the upper position of control packing material; (2) the cushion block size is big, cost is higher.
To the shortcoming of prior art, develop a kind of new cushion block, be used for effectively isolating reinforcing bar and polyphenyl class packing material, be very favourable to promoting the cast-in-place concrete hollow building roof technology.
(3) summary of the invention
On the basis of existing technology, the technical scheme of the utility model employing is: a kind of cushion block of controlling the packing material position is provided, and cushion block is placed between slab muscle and the packing material; Be the packing material face with the packing material contact surface in the cushion block; With the reinforcing bar contact surface be the reinforcing bar face, the reinforcing bar face is provided with groove in the cushion block, the slab muscle is stuck in the groove; The area of packing material face is greater than the area of reinforcing bar face, and the horizontal maximum size b2 >=40mm of packing material face.This kind cushion block can be used to isolate packing material and plate lower rebar, can be used to isolate packing material and plate upper reinforcement again.
The utility model is characterised in that the height h>=15mm of cushion block, is provided with groove at least one on the reinforcing bar face of cushion block, depth of groove h1>=5mm, the horizontal maximum size b1>=20mm of reinforcing bar face, and b1≤35mm.
The utility model is characterised in that the reinforcing bar face is provided with the mutually perpendicular groove of twice in the cushion block, and the degree of depth of twice groove is different.If the purpose of twice groove has two, the one, there is different isolation distances in the crosspoint of blocking the both direction reinforcing bar but can make between reinforcing bar and packing material.
The utility model is characterised in that the flat shape of packing material face and reinforcing bar face is polygon, circle, oval or camber line and straight line composite figure in the cushion block; Packing material face and reinforcing bar face both can be consistent in the cushion block, also can adopt the different plane shape.
The utility model is characterised in that in the sectional drawing of cushion block, and the packing material face is with being to take oblique line, stepped line, camber line or assemble line to connect between the reinforcing bar face.
The utility model is characterised in that the side of cushion block is provided with stiffening rib, and the purpose that stiffening rib is set is exactly under the prerequisite that satisfies the cushion block stress performance, reduces the consumption of material as far as possible.
The utility model is characterised in that the material of producing cushion block is rigid plastics, cement products, the clay of firing or pottery.
The utility model cost is low, makes with easy for installation, has excellent economy and applicability, and the development of Building technology is played a driving role.
Below in conjunction with accompanying drawing the utility model is further specified.
Fig. 1 is the sketch map that the utility model cushion block is used in the cast-in-place concrete hollow building.
Fig. 2 is the sectional drawing of cushion block.
Fig. 3 is the plan view of cushion block.
Fig. 4 A, Fig. 4 B are the sectional drawings of cushion block both direction.
Fig. 5 A-Fig. 5 D is several kinds of floor map of cushion block.
Fig. 6 A-Fig. 6 F is several kinds of floor map of packing material face and reinforcing bar face in the cushion block.
Fig. 7 A-Fig. 7 F be in the cushion block packing material face with connected mode sketch map between the reinforcing bar face.
Fig. 8 is the sectional drawing that the side of cushion block is provided with stiffening rib.
Fig. 9 is the plan view that the side of cushion block is provided with stiffening rib.
Among the figure: 1. cushion block, 2. slab muscle, 3. packing material, 4. packing material face; 5. reinforcing bar face, 6. groove, 7. concrete, 8. polygon (containing square 8A and rectangle 8B); 9. circular, 10. ellipse, 11. camber lines and straight line composite figure, 12. oblique lines; 13. stepped line, 14. camber lines, 15. assemble lines, 16. stiffening ribs.
The utility model is to realize in such a way:
In the embodiment shown in fig. 1, cushion block (1) is placed between slab muscle (2) and the packing material (3), and the three is embedded in the concrete (4), forms cast-in-place concrete hollow building roof.
Fig. 2, embodiment illustrated in fig. 3 in; Be packing material face (4) with the packing material contact surface in the cushion block; With the reinforcing bar contact surface be reinforcing bar face (5), reinforcing bar face (5) is provided with groove (6) in the cushion block (1), slab muscle (2) is stuck in the groove (6); The area of packing material face (4) is greater than the area of reinforcing bar face (5), and the horizontal maximum size b2 >=40mm of packing material face (4).Height h>=the 15mm of cushion block (1) is provided with one groove (6) on the reinforcing bar face (5) of cushion block at least, depth of groove h1>=5mm, the horizontal maximum size b1>=20mm of reinforcing bar face (5), and b1≤35mm.
In the embodiment shown in fig. 4, reinforcing bar face (5) is provided with the mutually perpendicular groove of twice (6) in the cushion block (1), and the degree of depth of twice groove is different.
In the embodiment shown in fig. 5, perhaps twice groove (6) can be set together on the reinforcing bar face (5) of cushion block (1).
In the embodiment shown in fig. 6, the flat shape of packing material face (4) and reinforcing bar face (5) is polygon (8) (containing square 8A and rectangle 8B), circular (9), oval (10), camber line and straight line composite figure (11) in the cushion block (1).
In the sectional drawing of cushion block embodiment illustrated in fig. 7 (1), packing material face (4) is with being to take oblique line (12), stepped line (13), camber line (14) or assemble line (15) to connect between the reinforcing bar face (5).
Fig. 8, embodiment illustrated in fig. 9 in, the side of cushion block (1) is provided with stiffening rib (16).
[0034] in Fig. 1-embodiment illustrated in fig. 9, the material of producing cushion block (1) is rigid plastics, cement products, the clay of firing or pottery.