A kind of high ductility brick post
Technical field
The invention belongs to technical field of civil engineering, be specially a kind of high ductility brick post.
Background technology
At present, brick masonry structure is widely used in industry and the covil construction field of China, but due to the brittleness of brick structures material, and its tension, shearing resistance and bending strength are all lower and deadweight is larger, and the utmost point is unfavorable for structural seismic.
Brick post is one of most important supporting member in brick masonry structure, bears the vertical load that superstructure and beam transmit, and also bears part or all of horizontal loading simultaneously, and its anti-seismic performance has considerable influence to the security of masonry structure.Set up defences and require to improve, use changing function and the reason such as structure erosion is impaired due to Antiseismic building, all may cause the bearing capacity of brick post not meet the demands.To sum up, existing common brick post have that fragility, intensity are low, the shortcoming of ductility and poor seismic behavior.
Summary of the invention
The high ductility brick post that provides a kind of difficult generation brittle rupture and ductility and anti-seismic performance good is provided one of object of the present invention.
For this reason, high ductility brick post provided by the invention comprises brick post, the masonry mortar of this brick post is high ductility mortar, the component of this high ductility mortar is cement, flyash, silicon ash, sand, PVA fiber and water, wherein, by mass percentage, cement: flyash: silicon ash: sand: water=1:0.9:0.1:0.76:0.58; Cumulative volume after mixing taking cement, flyash, silicon ash, Sha Heshui is as radix, and the volume volume of PVA fiber is 1.5%.
Preferably, above-mentioned cement is P.O.52.5R silicate cement; Flyash is I level flyash; The loss on ignition of silicon ash is less than 6%, dioxide-containing silica is greater than 85%, specific surface area is greater than 15000m
2/ kg; The maximum particle diameter of sand is 1.26mm; The length of PVA fiber is that 6 ~ 12mm, diameter are that 26 μ m are above, tensile strength is that 1200MPa is above, Young's modulus is more than 30GPa.
Preferably, in above-mentioned high ductility mortar, being added with water-reducing rate is more than 30% polycarboxylate water-reducer, and the addition of water reducer is 0.8% of flyash, silicon ash and cement total mass.
Preferably, the preparation method of above-mentioned high ductility mortar is: will after cement, silicon ash, flyash and sand dry mixing evenly, add the water of water reducer and 80% to stir; After adding again afterwards PVA fiber to stir, add residue 20% water to stir and obtain high ductility mortar.
The masonry mortar that the high ductility brick of the present invention post uses is that this mortar has the feature of high strength and high tenacity taking high ductility mortar as starting material, can improve intensity and the deformability of mortar, and then improves bearing capacity, ductility and the anti-seismic performance of brick post.
Compared with existing brick post, high ductility brick post of the present invention has following feature:
(1) more than the high ductility mortar ultimate compression strength that the present invention adopts can reach 60MPa, ultimate tensile strength can reach the more than 100 times of ordinary mortar, there is the plastic deformation ability of similar steel, and between brick structures, there is good adhesive property, it is a kind of ecological architectural material with high strength, high ductility, high-durability and high damnification resistant ability, can effectively improve intensity and the deformation performance of mortar, further improve bearing capacity, ductility and the anti-seismic performance of brick post.
(2) distortion and the energy dissipation capacity of high ductility brick post of the present invention are significantly increased, and have strengthened the bonding of blockhouse simultaneously, can increase substantially the anti-seismic performance of brick masonry structure, and manufacture craft are simple.
Brief description of the drawings
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Fig. 1 is the structural representation of the high ductility brick of the embodiment of the present invention 1 post;
The high ductility mortar of each coded representation: 1-, 2-solid brick in figure.
Embodiment
Embodiment 1:
As shown in Figure 1, in the present embodiment, the sectional dimension of the brick post in this example is 370mm × 370mm, the high 3.9m of post, and building block adopts solid brick, is of a size of 240mm × 115mm × 53mm.This brick post adopts high ductility mortar to build by laying bricks or stones, and mortar thickness is 7mm.
Follow technical scheme of the present invention, the component of the high ductility mortar of this embodiment is cement, flyash, silicon ash, sand, PVA fiber and water, wherein, by mass percentage, cement: flyash: silicon ash: sand: water=1:0.9:0.1:0.76:0.58; Cumulative volume after mixing taking cement, flyash, silicon ash, Sha Heshui is as radix, and the volume volume of PVA fiber (polyvinyl alcohol fiber) is 1.5%; Cement used is P.O.52.5R silicate cement, and flyash is I level flyash, and the loss on ignition of silicon ash is 5%, dioxide-containing silica is 88%, specific surface area is 18000m
2/ kg, the maximum particle diameter of sand is 1.26mm; PVA fiber is the PA600 fiber that Shanghai Luo Yang Science and Technology Ltd. produces, and length is that 8mm, diameter are that 26 μ m, tensile strength are that 1200MPa, Young's modulus are 30GPa, is added with Jiangsu Botexin Materials Co., Ltd in the high ductility mortar of this embodiment
-I high performance water reducing agent of polyocarboxy acid, the addition of water reducer is 0.8% of flyash, cement and silicon ash gross weight.
The preparation method of the high ductility mortar of this embodiment is: first cement, silicon ash, flyash and sand are poured in forced mixer into dry mixing 2 ~ 3 minutes; Add again the water of water reducer and 80%, stir 1 ~ 2 minute; Then add PVA fiber to stir again the water that adds residue 20% after 2 minutes, stir 1 ~ 2 minute.
Below mechanical property test and the result thereof of the high ductility mortar about the present embodiment that provides of contriver.
(1) adopt the standard die trial of 70.7mm × 70.7mm × 70.7mm to make test cube, by normal curing method maintenance 60 days, carry out cubic compressive strength test.Test-results shows: high ductility mortar specimen ultimate compression strength mean value is 65MPa, and test block reaches after peak load and unloads and load for the second time, and Residual Compressive Strength can reach 80% of peak load, and test block destructive process has obvious resistance to compression toughness.
(2) adopt the standard die trial of 40mm × 40mm × 160mm to make prism bending resistance test specimen, by normal curing method maintenance 60 days, carry out experiment on flexural behavior.Test-results shows: the first crack strength of high ductility mortar specimen is 4.8MPa, after test specimen cracking, bearing capacity continues to improve, ultimate strength is 10.1MPa, reach peak load after depression of bearing force slow, calculate its bend ductility of bend ductility coefficient I of gained according to ASTM C1018 method
5, I
10, I
20, I
30be respectively 6.2,14.5,33.0,50.6, show to have very high bend ductility.
(3) adopt the die trial of 50mm × 15mm × 350mm to make stretching test block, by normal curing method maintenance 60 days, carry out direct tensile test.Result shows: high ductility mortar specimen uniaxial tension test mean value is 3.6MPa, and ultimate tensile strength can reach 1.2%, and after test specimen cracking, bearing capacity remains unchanged substantially, has good tensile toughness, occurs more than 10 cracks in destructive process.
More than test shows, the ultimate tensile strength of high ductility mortar is far above the ultimate tensile strength of ordinary mortar in " Code for design of masonry strucres " GB50003, high ductility mortar pressurized, tension, all have higher toughness while being subject to curved destruction, its destructive characteristics has obviously different from ordinary mortar generation brittle rupture.
The above-mentioned mechanical characteristic of the high ductility mortar of this embodiment shows, the mortar strength that adopts high ductility mortar to make is high, deformability good, is difficult for occurring brittle rupture.Build brick post by laying bricks or stones with it, can significantly improve bearing capacity, ductility and the anti-seismic performance of brick post.
High ductility brick post of the present invention can be used for classroom building of elementary and middle schools brick post, single-storey factory building heavy-load bearing brick post, classroom building of elementary and middle schools forming column etc.