High-toughness building material and its production process

Abstract

The application discloses a high-toughness building material and a production process thereof. The high-toughness building material comprises the following raw materials in parts by mass: cement 495.3-550.7 parts; sand 739.5-786.5 parts; aggregate 1132-1286 parts; water 170-202 parts; water reducing agent 0.18-0.22 parts; modified steel fiber 106.8-121.2 parts; the length of the modified steel fiber is 40±2 mm, the width is 1.5±0.5 mm, and the thickness is 0.5±0.1 mm; the surface of the modified steel fiber is solidified with fixed points of silica material, the size of the fixed points on the surface of the modified steel fiber is 0.12-0.18 mm, the distribution density is 1.25±0.25 pieces / mm2, and the surface bonding strength is 6.9-7.8 MPa; the application of the steel fiber in the concrete is convenient and uniform for reinforced mixing, and the stability of the high-toughness performance is good when the concrete is massively spread or cast in large volume.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of concrete, in particular to a high-toughness building material and a production process thereof. BACKGROUND

[0002] Concrete is the most widely used building material at present, and its main components include cement, admixture and aggregate, which are hardened after mixing with water, and have the advantages of simple process, fireproof performance, etc., but the concrete has low tensile strength, poor toughness and is easy to crack under strong impact.

[0003] To this end, the current application adds fiber materials to the concrete, such as steel fiber, polypropylene fiber and glass fiber, for example, the steel fiber high-strength concrete and its manufacturing method disclosed in CN1192987C applied on April 17, 2002, which discloses the application of steel fiber in high-strength concrete, and the concrete includes components in the following ranges (weight percentage): cement 18-20%, fly ash 2-4%, silica fume 3-5%, water 6-8%, steel fiber 2-4%, sand 20-30%, gravel 35-45%, and water reducing agent 0.2-0.5%, which uses steel fiber to prevent the expansion of cracks in concrete, thereby increasing the tensile strength and impact resistance of the concrete.

[0004] Due to the addition of steel fiber, the distribution and orientation of the mixed steel fiber also affect the expansion of the cracks - the steel fiber is randomly distributed in the concrete, which can limit the expansion of the cracks, but if the steel fiber is unevenly distributed in the concrete, the stress concentration caused by the aggregation of the steel fiber may occur, and when the concrete is subjected to external load, these stress concentrations will cause local stress concentration of the concrete, thereby increasing the brittleness of the concrete. This is a serious problem for large-volume concrete pouring or large-area concrete paving, such as road surface, and part of the road surface will quickly develop into a large area of road surface damage.

[0005] Therefore, the processing workers and preparation equipment have high requirements, and the uniformity of the mixed steel fiber is good, but the mechanical mixing alone cannot guarantee the mixing effect and is difficult to control, and the mixing for a long time is costly and easy to cause the concrete to be resolved. SUMMARY

[0006] In order to ensure the stability of the high-toughness performance of the concrete for large-area paving or large-volume pouring, a high-toughness building material and a production process thereof are provided.

[0007] The first invention of the present application is achieved by the following technical scheme:

[0008] A high-toughness building material, comprising the following raw materials by mass:

[0009] Cement 495.3-550.7 parts;

[0010] sand 739.5-786.5 parts;

[0011] aggregate 1132-1286 parts;

[0012] water 170-202 parts;

[0013] water reducing agent 0.18-0.22 parts;

[0014] modified steel fiber 106.8-121.2 parts;

[0015] The sand particle size is 0.6±0.2mm, the aggregate particle size grading is that the 5-8mm particle size aggregate accounts for 32±2wt%, the 12-15mm particle size aggregate accounts for 40±2wt%, the 30-35mm particle size aggregate accounts for 16±2wt%, and the rest is 40-50mm particle size aggregate;

[0016] The modified steel fiber length is 40±2mm, the width is 1.5±0.5mm, and the thickness is 0.5±0.1mm,

[0017] The modified steel fiber surface is solidified with fixed points, the fixed points are solidified convex points with a size of 0.12-0.18mm on the modified steel fiber surface, the fixed points are silica material, the fixed point distribution density is 1.25±0.25 / mm2, and the fixed point and modified steel fiber surface bonding strength is 6.9-7.8MPa.

[0018] By adopting the above technical scheme, a large number of fixed points are attached to the surface of the modified steel fiber, the fixed points are silica material, and have good affinity with the cement mortar;

[0019] The fixed points increase the friction between the steel fiber and the cement mortar during the raw material mixing process, so that the steel fiber is more easily dragged to each part of the concrete raw material mixture along with the flow of the cement mortar, and is more uniformly dispersed;

[0020] After the concrete is solidified, the fixed points strengthen the bonding strength and adhesion between the steel fiber and the cement mortar base material, so that when the concrete is impacted or stretched, the steel fiber is not easily pulled out by overcoming the adhesion of the base material, and the average effective tensile and bending strength of the concrete is further improved; when local and rare modified steel fibers are aggregated, the bonding strength between the steel fiber and the cement mortar base material is large, and the stress concentration problem can be overcome, and the cracking possibility at this place can be reduced.

[0021] In summary, the modified steel fiber is more uniformly distributed in the concrete, the possibility of aggregation of the modified steel fiber is reduced, the bonding strength of the steel fiber and the cement mortar after solidification in the concrete is increased, the toughness performance such as tensile strength and bending strength of the concrete is improved, and the possibility of cracking of the steel fiber and other raw materials in the concrete under stress concentration is reduced, so that the application of the steel fiber in the concrete is more convenient and uniform, and the high toughness performance of the concrete under large paving or large volume pouring is ensured.

[0022] Optionally, the fixed point surface has a hole.

[0023] By adopting the above technical solution, the fixed point surface has a hole, so that the fixed point can be better combined with the colloidal component in the concrete, the bonding strength of the modified steel fiber and the cement mortar in the concrete is further improved, the toughness performance of the concrete is improved, the possibility of cracking of the modified steel fiber and other raw materials under stress concentration at the bonding interface is reduced, and the high toughness performance of the concrete under large paving or large volume pouring is improved.

[0024] Optionally, the fixed point on the modified steel fiber is attached by the following method:

[0025] The steel fiber is first surface treated to form a protective layer, then point forming liquid is sprayed from both sides of the steel fiber, the spraying amount is 0.1-0.18 mL / (cm2·h) of the horizontal projection surface, the spraying pressure is 81.5±1.5 kPa, and the point forming liquid is a mixture of methyl silicate, ammonia, methanol and water in a mass ratio of 7.3:3.3:29.4:60, wherein the ammonia is added from ammonia water, and the water in the ammonia water is included in the water mass ratio.

[0026] By adopting the above technical solution, the effect of the modified steel fiber on the concrete in the application is based on the bonding strength of the fixed point and the surface of the modified steel fiber, if the bonding strength of the fixed point and the surface of the modified steel fiber is weaker than the tensile strength of the concrete itself, or the bonding strength of the fixed point and the surface of the modified steel fiber is weaker than the bonding strength of the concrete and the ordinary steel fiber, the toughening and performance stabilizing effect of the fixed point on the concrete will be minimal.

[0027] The bonding strength of the fixed point obtained by the above attachment method and the surface of the modified steel fiber can reach 7.5-7.8 MPa, which is higher than the tensile strength of general C50 concrete, so as to ensure the effect of the modified steel fiber in the application.

[0028] In addition, the spraying amount, the spraying pressure and the concentration of the point forming liquid in the method jointly determine the distribution density and size of the fixed point, and the porosity is mainly affected by the concentration of the point forming liquid.

[0029] Optionally, the protective layer formed by surface treatment of the steel fiber is modified by a hydrophilic silane coupling agent.

[0030] By adopting the technical scheme, the protective layer modified by the hydrophilic silane coupling agent can be consumed by abrasion, but its effect is far better than before the abrasion in the field of application;

[0031] The protective layer modified by the hydrophilic silane coupling agent can block the electrochemical corrosion of low-concentration ammonia in the point-making solution on the surface of the steel fiber, and can reduce the interfacial energy between the surface of the steel fiber and the silicate in the point-making solution and the produced silicon dioxide, and improve the bonding strength between the fixed points and the surface of the modified steel fiber.

[0032] Furthermore, the modified steel fibers rub against each other during transportation and feeding, and the bonding strength of the protective layer is far lower than that of the fixed points, but the surface of the modified steel fiber still has residual protective layer, which can reduce the interfacial energy between the surface of the modified steel fiber and other raw materials of the concrete, and improve the bonding strength between the surface of the modified steel fiber and other raw materials of the concrete, thereby further improving the toughness and stability of the concrete.

[0033] Optionally, the hydrophilic silane coupling agent is vinyltriacetoxysilane.

[0034] By adopting the technical scheme, among various hydrophilic silane coupling agents, the vinyltriacetoxysilane is selected, and the modification effect is better.

[0035] Optionally, the amount of the hydrophilic silane coupling agent is (hydrophilic silane coupling agent / steel fiber): 0.05-0.08 g / g.

[0036] By adopting the technical scheme, when the vinyltriacetoxysilane is selected as the hydrophilic silane coupling agent, the amount of the hydrophilic silane coupling agent is controlled to be (hydrophilic silane coupling agent / steel fiber): 0.05-0.08 g / g, and the toughness of the obtained concrete is better and more stable.

[0037] Optionally, the modified steel fiber is helically curved along the length direction, and the number of helical turns is 2-4.5 turns.

[0038] By adopting the technical scheme, the modified steel fiber is combined with the cement mortar in the preparation process of the concrete in the application, so that the modified steel fiber is more uniformly dispersed. Therefore, the modified steel fiber can be dispersed into the concrete in a helical curved shape, the combination stability of the modified steel fiber and the surrounding concrete curing components is improved by means of the physical structure, and the toughness of the concrete is improved.

[0039] If the steel fiber has no fixed points, the dispersion difficulty increases in a helical curved shape, and the steel fiber is more likely to gather, which leads to a decrease in the toughness of the concrete.

[0040] Optionally: the spiral turns of the modified steel fiber is 3.5 turns.

[0041] By adopting the technical scheme, the improvement of the modified steel fiber performance by the spiral turns is based on the length of the modified steel fiber, the particle size grading of the aggregate, and the influence of the amount of other raw materials;

[0042] Under the length of the modified steel fiber, the particle size grading of the aggregate, and the amount of other raw materials in the application, when the spiral turns of the modified steel fiber is 3.5 turns, the performance of the obtained concrete is relatively optimal

[0043] The second application purpose of the application is achieved by the following technical scheme:

[0044] A production process of a high-toughness building material, each raw material is put into a mixing device according to a proportioning to be uniformly mixed.

[0045] By adopting the technical scheme, the production is convenient and simple, the modified steel fiber is uniformly mixed and dispersed, and the high-toughness performance of the obtained concrete is stable under a large amount of paving use or large-volume pouring use.

[0046] In summary, the application at least has the following beneficial effects:

[0047] By making the modified steel fiber surface adhere to the fixed point with high bonding strength and good affinity with the cement mortar, the modified steel fiber is more likely to move with the cement mortar during the preparation of the concrete, the modified steel fiber is more uniformly distributed in the concrete, the possibility of the aggregation of the modified steel fiber is reduced, the bonding strength between the steel fiber and the cement mortar after solidification is increased, the toughness performance such as tensile and bending resistance of the concrete is improved, and the possibility of the interface cracking between the steel fiber and other raw materials in the concrete under stress concentration is reduced, thereby making the application of the steel fiber in the concrete more convenient and uniform, and ensuring the stability of the high-toughness performance of the concrete under a large amount of paving use or large-volume pouring use. DETAILED DESCRIPTION

[0048] Raw materials:

[0049] The raw materials of the application include commercially available products and intermediate materials configured from commercially available products.

[0050] The commercially available products include the following:

[0051] The hydrophilic silane coupling agent includes vinyltriacetoxysilane, vinyltris(tert-butylperoxy)silane, and vinyltris(2-methoxyethoxy)silane.

[0052] The cement is commercially available 42.5-grade Portland cement.

[0053] The sand is natural sand with a particle size of 0.6±0.2 mm; the particle size of the aggregate is graded as follows: 32±2 wt% of 5-8 mm particle size aggregate, 40±2 wt% of 12-15 mm particle size aggregate, 16±2 wt% of 30-35 mm particle size aggregate, and the rest is 40-50 mm particle size aggregate; and the sand and aggregate are commercially available products.

[0054] The water reducing agent is sodium lignosulfonate, which is a commercially available product.

[0055] The methyl silicate, the methanol, and the ammonia are commercially available products; the ammonia is provided by diluting commercially available 25 wt% ammonia water.

[0056] The unmodified steel fibers and the steel sheet for testing are obtained by customizing the size from a commissioned steel fiber manufacturer.

[0057] The intermediate materials include the following:

[0058] Preparation Example 1

[0059] The modified steel fiber has a length of 40±2 mm, a width of 1.5±0.5 mm, and a thickness of 0.5±0.1 mm. The modified steel fiber is helically twisted along the length direction, and the number of helical turns is 3.5 turns.

[0060] Meanwhile, the surface of the modified steel fiber is also distributed with solidified fixed points, and the fixed points are silica material with pores.

[0061] The preparation method of the modified steel fiber is as follows:

[0062] The steel fiber with a length of 40±2 mm, a width of 1.5±0.5 mm, a thickness of 0.5±0.1 mm, and a number of helical turns of 3.5 turns is used as the initial steel fiber,

[0063] The initial steel fiber is soaked in a 5.6 wt% vinyltriacetoxysilane acetone solution, the initial steel fiber is in a ratio of 0.062 g / g with the amount of vinyltriacetoxysilane, ultrasonic treatment is performed at 22 kHz for 1 h, and the fiber with an attached protective layer is obtained by filtering and drying at room temperature;

[0064] The fiber with an attached protective layer is spread through a spraying area, a point-creating liquid is sprayed in the vertical spreading direction of the fiber with an attached protective layer in the spraying area, the spraying amount is 0.131 mL / (cm2·h) on the horizontal projection plane, the fiber with an attached protective layer passes through the spraying area for 5±0.1 s, the spraying pressure is 81.5±1.5 kPa, and the point-creating liquid is point-creating liquid 1, which is obtained by mixing methyl silicate, ammonia, methanol, and water in a mass ratio of 7.3:3.3:29.4:60, wherein the ammonia is added from 12 wt% ammonia water, and the water in the ammonia water is included in the water mass ratio;

[0065] After drying, the modified steel fiber is obtained by ventilation and refinement for 24 h at room temperature and in a dry environment.

[0066] Sampling and detecting the size and distribution density of fixed points on modified steel fibers:

[0067] The size of the fixed points is 0.12-0.18mm, and the distribution density of the fixed points is 1.25±0.25 / mm 2 .

[0068] The bonding strength of the fixed points on the steel fibers is also detected. Since the size of the fixed points is small, the area of the steel fibers is also small, and a steel sheet is used for magnification testing.

[0069] The testing method is as follows:

[0070] Prepare a steel sheet with a size of 10cm*5cm*4mm, which is made of the same material as the initial steel fiber, and bend it 90° along the length direction to obtain a steel test piece;

[0071] Soak the steel test piece in a 5.6wt% vinyltriacetoxysilane acetone solution, and treat it with ultrasonic waves at 22kHz for 1h, filter and dry at room temperature to obtain a bonding strength test piece;

[0072] Place the bonding strength test piece in an inverted L shape into the spraying area, and spray from top to bottom in the spraying area. The spraying amount is 0.131mL / (cm 2 * h) on the horizontal projection surface, the passing time of the fiber in the spraying area is 225±0.1s, the spraying pressure is 81.5±1.5kPa, and the point-making liquid is point-making liquid 1 to obtain a fiber-containing test piece;

[0073] After the fiber-containing test piece is placed for 5min, place another steel test piece in an L shape with the horizontal plane as the symmetry plane on the fiber-containing test piece. The area of the bonding surface between the fiber-containing test piece and the steel test piece is 5cm*5cm. After being placed for 3 days, tear the two steel test pieces by clamping the two ends of the bonding surface with a tearing strength tester, detect the tearing strength, and divide the maximum tensile force obtained by the instrument by the area of the bonding surface to obtain the tearing strength as the bonding strength of the fixed points.

[0074] The bonding strength of the fixed points in Preparation Example 1 is 7.5MPa.

[0075] Preparation Example 2

[0076] A modified steel fiber, which is linear, has a length of 40±2mm, a width of 1.5±0.5mm, and a thickness of 0.5±0.1mm.

[0077] The preparation method of the modified steel fiber is as follows:

[0078] Use a steel fiber with a length of 40±2mm, a width of 1.5±0.5mm, a thickness of 0.5±0.1mm, and 3.5 turns as the initial steel fiber,

[0079] The initial steel fiber is soaked in a 5.6wt% vinyltriacetoxysilane acetone solution, treated with 22 kHz ultrasonic waves for 1 h, filtered, and dried at room temperature to obtain the modified steel fiber with a protective layer.

[0080] Preparation Example 3

[0081] A modified steel fiber has a length of 40±2 mm, a width of 1.5±0.5 mm, and a thickness of 0.5±0.1 mm. The modified steel fiber is helically twisted along the length direction, and has 3.5 turns.

[0082] The modified steel fiber is prepared as follows:

[0083] A modified steel fiber has a length of 40±2 mm, a width of 1.5±0.5 mm, and a thickness of 0.5±0.1 mm. The modified steel fiber is helically twisted along the length direction, and has 3.5 turns.

[0084] Preparation Example 4

[0085] A modified steel fiber is similar to that of Preparation Example 1, except that the initial fiber is a straight steel fiber having a length of 40±2 mm, a width of 1.5±0.5 mm, and a thickness of 0.5±0.1 mm. The modified steel fiber is straight, has a length of 40±2 mm, a width of 1.5±0.5 mm, and a thickness of 0.5±0.1 mm.

[0086] After testing, the binding strength of the fixed points is 7.5 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1.25±0.25 / mm 2 .

[0087] Preparation Example 5

[0088] A modified steel fiber is similar to that of Preparation Example 1, except that the time for the attached fiber to pass through the spraying area is 2±0.1 s.

[0089] After testing, the binding strength of the fixed points is 7.5 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 0.2-0.7 / mm 2 .

[0090] Preparation Example 6

[0091] A modified steel fiber is similar to that of Preparation Example 1, except that the time for the attached fiber to pass through the spraying area is 10±0.1 s.

[0092] The detection: the binding strength of fixed point is 7.5 MPa; the size of fixed point is 0.12-0.18 mm, and the distribution density of fixed point is 3-3.5 / mm 2 .

[0093] Preparation Example 7

[0094] A modified steel fiber, which is similar to Preparation Example 1, is different in that the point-making liquid used is point-making liquid 2, and the spraying pressure is 89 kPa. The point-making liquid 2 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 1.8:0.83:9.8:87.57.

[0095] The detection: the binding strength of fixed point is 7.49 MPa; the size of fixed point is 0.02-0.08 mm, and the distribution density of fixed point is 1-1.5 / mm 2 .

[0096] Preparation Example 8

[0097] A modified steel fiber, which is similar to Preparation Example 1, is different in that the point-making liquid used is point-making liquid 3, the spraying pressure is 42 kPa, and the spraying amount is 0.135 mL / (cm 2 ·h) in the horizontal projection plane, and the point-making liquid 3 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 13.14:5.94:35.28:45.64.

[0098] The detection: the binding strength of fixed point is 7.5 MPa; the size of fixed point is 0.3-0.36 mm, and the distribution density of fixed point is 1-1.5 / mm 2 .

[0099] Preparation Example 9

[0100] A modified steel fiber, which is similar to Preparation Example 1, is different in that the point-making liquid used is point-making liquid 4. The point-making liquid 4 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 7.3:1.6:26.7:64.4.

[0101] The detection: the binding strength of fixed point is 4.7 MPa; the size of fixed point is 0.12-0.18 mm, and the distribution density of fixed point is 1-1.5 / mm 2 .

[0102] Preparation Example 10

[0103] A modified steel fiber, which is similar to Preparation Example 1, is different in that the point-making liquid used is point-making liquid 5. The point-making liquid 5 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 7.3:2.2:28.1:62.4.

[0104] The detection shows that the binding strength of the fixed points is 5.6 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0105] Preparation Example 11

[0106] A modified steel fiber similar to that of Preparation Example 1, except that the point-making liquid used is point-making liquid 6.

[0107] Point-making liquid 5 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 7.3:3:30.1:59.6.

[0108] The detection shows that the binding strength of the fixed points is 7.2 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0109] Preparation Example 12

[0110] A modified steel fiber similar to that of Preparation Example 1, except that the point-making liquid used is point-making liquid 7.

[0111] Point-making liquid 7 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 7.45:3.67:32.8:56.08.

[0112] The detection shows that the binding strength of the fixed points is 7.7 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0113] Preparation Example 13

[0114] A modified steel fiber similar to that of Preparation Example 1, except that the point-making liquid used is point-making liquid 8.

[0115] Point-making liquid 8 is obtained by mixing methyl silicate, ammonia, methanol and water in a mass ratio of 7.5:4.02:33.5:54.8.

[0116] The detection shows that the binding strength of the fixed points is 7.8 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0117] Preparation Example 14

[0118] A modified steel fiber similar to that of Preparation Example 1, except that the initial steel fiber is directly introduced into the spraying area to receive spraying.

[0119] The test results show that the binding strength of the fixed points is 6.9 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0120] Preparation Example 15

[0121] A modified steel fiber similar to that of Preparation Example 1, except that the silane coupling agent used for modifying the initial steel fiber is vinyl tri(2-methoxyethoxy) silane.

[0122] The test results show that the binding strength of the fixed points is 7.42 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0123] Preparation Example 16

[0124] A modified steel fiber similar to that of Preparation Example 1, except that the silane coupling agent used for modifying the initial steel fiber is vinyl tri(2-methoxyethoxy) silane.

[0125] The test results show that the binding strength of the fixed points is 7.45 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0126] Preparation Example 17

[0127] A modified steel fiber similar to that of Preparation Example 1, except that the amount of the silane coupling agent used for modifying the initial steel fiber is 0.02 g / g.

[0128] The test results show that the binding strength of the fixed points is 7.28 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0129] Preparation Example 18

[0130] A modified steel fiber similar to that of Preparation Example 1, except that the amount of the silane coupling agent used for modifying the initial steel fiber is 0.05 g / g.

[0131] The test results show that the binding strength of the fixed points is 7.36 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0132] Preparation Example 19

[0133] A modified steel fiber similar to that of Preparation Example 1, except that the amount of the silane coupling agent used for modifying the initial steel fiber is 0.08 g / g.

[0134] The test results show that the binding strength of the fixed points is 7.45 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0135] Preparation Example 20

[0136] A modified steel fiber similar to that of Preparation Example 1, except that the amount of silane coupling agent used for modifying the initial steel fiber is 0.1 g / g.

[0137] The test results show that the binding strength of the fixed points is 7.52 MPa, the size of the fixed points is 0.12-0.18 mm, and the distribution density of the fixed points is 1-1.5 per mm 2 .

[0138] Preparation Example 21

[0139] A modified steel fiber similar to that of Preparation Example 1, except that the number of spiral turns of the initial steel fiber and the modified steel fiber is 2.5.

[0140] Preparation Example 22

[0141] A modified steel fiber similar to that of Preparation Example 1, except that the number of spiral turns of the initial steel fiber and the modified steel fiber is 4.5.

[0142] Example 1

[0143] A high-toughness building material is obtained by curing a mixture of the following raw materials in a uniform manner:

[0144] Cement 495.3 parts, sand 739.5 parts, aggregate 1132 parts, water 170 parts, water-reducing agent 0.18 parts, and modified steel fiber 106.8 parts. The modified steel fiber is prepared according to Preparation Example 1.

[0145] Example 2

[0146] A high-toughness building material is obtained by curing a mixture of the following raw materials in a uniform manner:

[0147] Cement 523.1 parts, sand 754.5 parts, aggregate 1214 parts, water 194 parts, water-reducing agent 0.21 parts, and modified steel fiber 114.3 parts. The modified steel fiber is prepared according to Preparation Example 1.

[0148] Example 3

[0149] A high-toughness building material is obtained by curing a mixture of the following raw materials in a uniform manner:

[0150] Cement 550.7 parts, sand 786.5 parts, aggregate 1286 parts, water 202 parts, water-reducing agent 0.22 parts, and modified steel fiber 121.3 parts. The modified steel fiber is prepared according to Preparation Example 1.

[0151] Comparative Example 1

[0152] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0153] Cement 550.7 parts, sand 786.5 parts, aggregate 1286 parts, water 202 parts, water reducing agent 0.22 parts; modified steel fiber 121.3 parts. The modified steel fiber was prepared in Preparation Example 2.

[0154] Comparative Example 2

[0155] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0156] Cement 523.1 parts, sand 754.5 parts, aggregate 1214 parts, water 194 parts, water reducing agent 0.21 parts; modified steel fiber 114.3 parts. The modified steel fiber was prepared in Preparation Example 2.

[0157] Comparative Example 3

[0158] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0159] Cement 550.7 parts, sand 786.5 parts, aggregate 1286 parts, water 202 parts, water reducing agent 0.22 parts; modified steel fiber 121.3 parts. The modified steel fiber was prepared in Preparation Example 2.

[0160] Comparative Example 4

[0161] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0162] Cement 550.7 parts, sand 786.5 parts, aggregate 1286 parts, water 202 parts, water reducing agent 0.22 parts; modified steel fiber 121.3 parts. The modified steel fiber was prepared in Preparation Example 3.

[0163] Comparative Example 5

[0164] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0165] Cement 523.1 parts, sand 754.5 parts, aggregate 1214 parts, water 194 parts, water reducing agent 0.21 parts; modified steel fiber 114.3 parts. The modified steel fiber was prepared in Preparation Example 3.

[0166] Comparative Example 6

[0167] A building material was obtained by curing a mixture of the following raw materials in uniform quality:

[0168] Cement 550.7 parts, sand 786.5 parts, aggregate 1286 parts, water 202 parts, water reducing agent 0.22 parts; modified steel fiber 121.3 parts. The modified steel fiber is prepared according to Preparation Example 3.

[0169] Example 4

[0170] A high-toughness building material is obtained by curing a mixture of the following ingredients:

[0171] Cement 523.1 parts, sand 754.5 parts, aggregate 1214 parts, water 194 parts, water reducing agent 0.21 parts; modified steel fiber 114.3 parts. The modified steel fiber is prepared according to Preparation Example 4.

[0172] Comparative Examples 7-12

[0173] A building material similar to Example 2, except that the modified steel fiber used is as follows:

[0174] Source of modified steel fibers Comparative Example 7 Preparation Example 5 Comparative Example 8 Preparation Example 6 Comparative Example 9 Preparation Example 7 Comparative Example 10 Preparation Example 8 Comparative Example 11 Preparation Example 9 Comparative Example 12 Preparation Example 10

[0175] Examples 5-16

[0176] A high-toughness building material similar to Example 2, except that the modified steel fiber used is as follows:

[0177] Source of modified steel fibers Example 5 Preparation Example 11 Example 6 Preparation Example 12 Example 7 Preparation Example 13 Example 8 Preparation Example 14 Example 9 Preparation Example 15 Example 10 Preparation Example 16 Example 11 Preparation Example 17 Example 12 Preparation Example 18 Example 13 Preparation Example 19 Example 14 Preparation Example 20 Example 15 Preparation Example 21 Example 16 Preparation Example 22

[0178] The flexural strength of the concrete of Examples 1-16 and Comparative Examples 1-12 was tested after 28 days of curing, and 100 groups of samples were prepared for each example. The test results are shown as the average value.

[0179] The relative average deviation of the flexural strength of the 100 groups was also recorded to reflect the influence of the mixing and dispersion of the modified steel fiber or steel fiber on the flexural strength of the concrete. If the mixing and dispersion are not good, the flexural strength of the concrete will deviate greatly, and the relative average deviation will be large. The test results are shown in the following table.

[0180] Table 3. Flexural test results of the concrete of Examples 1-16 and Comparative Examples 1-12

[0181] Flexural strength / MPa Relative average deviation / % Example 1 7.5 2.4 Example 2 8.1 1.9 Example 3 7.9 2.1 Comparative Example 1 6.1 6.7 Comparative Example 2 6.5 7.2 Comparative Example 3 6.4 6.9 Comparative Example 4 6.4 8.6 Comparative Example 5 6.8 9.8 Comparative Example 6 6.7 9.5 Example 4 7.5 1.7 Comparative Example 7 7.1 9.2 Comparative Example 8 6.7 10.4 Comparative Example 9 6.8 9.7 Comparative Example 10 6.9 10.1 Comparative Example 11 7 9.5 Comparative Example 12 7.1 9.6 Example 5 7.9 2.1 Example 6 8.3 1.9 Example 7 8.4 1.9 Example 8 7.6 2.4 Example 9 8 2.1 Example 10 8.1 2 Example 11 7.6 2.5 Example 12 7.9 2.1 Example 13 8 2.1 Example 14 8.2 2 Example 15 7.7 2.3 Example 16 7.9 2.5

[0182] As can be seen from Examples 1-3 and Comparative Examples 1-6,

[0183] The application adds the modified steel fiber with high bonding strength fixing point in the examples 1-3, the fixing point is silica material, which has good affinity with cement mortar. The fixing point increases the friction between the steel fiber and the cement mortar during the raw material mixing process, so that the steel fiber is more easily dragged to each part of the concrete raw material mixture with the flow of the cement mortar, and is more evenly dispersed. After the concrete solidifies, the fixing point strengthens the bonding strength and adhesion between the steel fiber and the cement mortar base material. When the concrete is impacted or stretched, the steel fiber is not easily pulled out by overcoming the adhesion of the base material, which further improves the average effective tensile and bending strength of the concrete. When local and rare modified steel fiber aggregation occurs, the bonding strength between the steel fiber and the cement mortar base material is large, which can overcome the stress concentration problem and reduce the possibility of cracking at this point.

[0184] The modified steel fiber selected in Comparative Examples 1-3 is a straight modified steel fiber without a fixing point, and the modified steel fiber selected in Comparative Examples 4-6 is a spiral modified steel fiber without a fixing point. The bending strength of Examples 1-3 is significantly improved compared to Comparative Examples 1-6, and the relative average deviation of the bending strength of Examples 1-3 is significantly lower than that of Comparative Examples 1-6. This is because the modified steel fiber with a high bonding strength fixing point is more evenly dispersed during the preparation of the concrete, which overcomes the shortcomings of the steel fiber in the application of large volume or large area paving concrete, and ensures the stability of the high toughness performance of the concrete under large area paving or large volume pouring.

[0185] In addition, as can be seen from Example 4, the difference between Example 4 and Example 2 is that the modified steel fiber of Example 4 is changed from the original high bonding strength spiral modified steel fiber to the high bonding strength straight modified steel fiber. The bending strength of Example 2 is significantly improved compared to Example 4, and the relative average deviation only increases slightly. In contrast, the modified steel fiber of Comparative Examples 4-6 is changed from a straight modified steel fiber to a spiral modified steel fiber compared to Comparative Examples 1-3. Although the bending strength is increased, the increase is significantly less than the increase in Example 2 compared to Example 4. Moreover, the relative average deviation in Comparative Examples 4-6 increases significantly, which is because the steel fiber without a fixing point is more likely to gather due to the increased difficulty of dispersion in the spiral curved shape, which leads to a decrease in the toughness performance of the concrete. The modified steel fiber with a fixing point in Example 2 is more evenly dispersed during the preparation of the concrete by combining with the cement mortar, so that the modified steel fiber can still be dispersed in the concrete in a spiral curved shape, thereby improving the bonding stability of the modified steel fiber and the surrounding concrete solidification components by means of the physical structure, and improving the toughness performance of the concrete.

[0186] Comparative Example 2 and Comparative Examples 7-8 can be seen, Comparative Examples 7-8 change the distribution density of the fixed points on the surface of the modified steel fiber by the residence time of the steel fiber in the spraying area. The distribution density in Comparative Example 7 is 0.2-0.7 / mm2, and the distribution density in Comparative Example 8 is 3-3.5 / mm2.

[0187] But the flexural strength of Comparative Example 7 is lower than that of Example 2, and the relative average deviation is higher than that of Example 2; the flexural strength of Comparative Example 8 is lower than that of Example 2, and the relative average deviation is higher than that of Example 2, and the performance of Comparative Example 8 is also weaker than that of Comparative Example 5.

[0188] Comparative Example 7 is due to the too low distribution density, the adhesion between the surface of the modified steel fiber and the cement mortar during the preparation of the concrete is not enough to effectively drag the cement mortar, and the migration auxiliary dispersion effect of the modified steel fiber is not strong;

[0189] The cement mortar has a minimum particle size under the influence of the surface tension of water during the preparation of the concrete, and Comparative Example 8 is due to the too large distribution density, the interval between the fixed points is too small, which hinders the contact between the cement mortar and the surface of the modified steel fiber, resulting in a decrease in the flexural strength and an increase in the relative average deviation.

[0190] Therefore, the modified steel fiber in the present application plays a role, and the distribution density of the fixed points thereon is 1.25±0.25 / mm2. 2 。

[0191] Comparing Comparative Examples 9-10 with Example 2 can be seen that Comparative Examples 9-10 obtain modified steel fibers by changing the components of the point-making liquid, the spraying time, and the spraying amount, and the size of the fixed points of the modified steel fibers is different from that of the modified steel fiber used in Example 2.

[0192] But the flexural strength of Comparative Examples 9-10 is not as good as that of Example 2, and the relative average deviation is also higher than that of Example 2;

[0193] Among them, Comparative Example 9 is due to the too small particle size of the fixed points, which leads to the too small bonding force between the modified steel fiber and the cement mortar;

[0194] And Comparative Example 10 is due to the too large particle size, which leads to the easy scratching of the sand with a particle size of 0.6±0.2mm in the cement mortar, and then the sand is clamped and locked by the aggregate, which is difficult to be driven by the cement mortar to migrate and disperse uniformly in the whole concrete.

[0195] Therefore, the modified steel fiber in the present application plays a role, and the size of the fixed points thereon is 0.12-0.18mm.

[0196] Meanwhile, the bonding strength between the fixing point and the surface of the modified steel fiber is also one of the key points for the modified steel fiber to play its role, because if the bonding strength between the fixing point and the surface of the modified steel fiber is weaker than the tensile strength of the concrete material itself, or the bonding strength between the fixing point and the surface of the modified steel fiber is weaker than the bonding strength between the concrete and the ordinary steel fiber, the toughening and performance stabilizing effect of the fixing point on the modified steel fiber to the concrete will be minimal.

[0197] The fixing point bonding strength distribution of the modified steel fiber used in Comparative Example 11 and Comparative Example 12 is 4.7 MPa and 5.6 MPa, and from the test structure, it can be known that the uniformity of the modified steel fiber mixed in the concrete is increased, but the effect of enhancing the flexural strength of the concrete does not take effect, and the problem of increasing the brittleness of the concrete at the aggregation of the modified steel fiber is not overcome, and the relative average deviation is slightly improved, but compared with Example 2, it is obviously far from enough.

[0198] The required bonding strength of the fixing point on the modified steel fiber is studied, and Examples 5-7 use modified steel fibers with different fixing point bonding strengths, and the bonding strength is 7.2 MPa, 7.7 MPa, and 7.8 MPa. According to the test results, when the bonding strength reaches 7.2 MPa, the flexural strength of the concrete is significantly improved compared with Comparative Example 5, and the relative average deviation is significantly reduced. When the bonding strength reaches 7.7 MPa, the improvement trend is gentle. The bonding strength of the fixing point is 7.2-7.8 MPa, which can play its role in the modified steel fiber of the present application.

[0199] Example 8 of the present application has a slightly weaker bonding strength of 6.9 MPa than Examples 5-7 without preforming a protective layer on the surface of the steel fiber during the treatment of the modified steel fiber. The flexural strength of the concrete is significantly improved compared with Comparative Example 5, and the relative average deviation is significantly reduced, so the modified steel fiber of the present application can play its role, and the bonding strength of the fixing point needs to be above 6.9 MPa.

[0200] On the other hand, as can be known from Example 8 and Example 2, preforming a protective layer on the surface of the steel fiber with a silane coupling agent during the treatment of the modified steel fiber can not only reduce the electrochemical corrosion of the modified steel fiber by ammonia water, but also further improve the bonding strength of the fixing point, thereby enhancing the toughness and performance strength of the concrete.

[0201] As can be known from Examples 9-10, in addition to the vinyltriacetoxysilane used in Preparation Example 1, the silane coupling agent can also be selected from vinyltris(tert-butylperoxy)silane and vinyltris(2-methoxyethoxy)silane.

[0202] In combination with Embodiments 11-14, the amount of silane coupling agent used to form the protective layer in the modified steel fibers is different, and the distribution is 0.02 g / g, 0.05 g / g, 0.08 g / g and 0.1 g / g, the binding strength of the fixed points on the modified steel fibers obtained is increased in turn, but is lower than 7.8 MPa, and when the amount is greater than 0.08 g / g, the increase in the binding strength of the fixed points is gentle, and in combination with the detection of the performance of the concrete, the amount of silane coupling agent used to form the protective layer is selected to be 0.05-0.08 g / g.

[0203] In combination with Embodiments 2, 15 and 16, the difference among them is that the number of spiral turns of the modified steel fibers used is different under the condition of the same length, the more the number of spiral turns, the more the binding stress direction of the modified steel fibers and the cement mortar, but the more the possibility of the aggregation of the modified steel fibers, and the more the possibility of the brittleness of the concrete.

[0204] According to the test results, the number of spiral turns of Embodiments 2, 15 and 16 is 3.5, 2.5 and 4.5, respectively, among which the flexural strength of Embodiment 2 is optimal and the relative average deviation is the smallest, so the number of spiral turns of the steel fiber in the present application is 3.5.

[0205] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and the person skilled in the art can make a modification of the present embodiments without creative contribution according to the need after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high-ductility construction material, characterized by, The raw materials include the following quality parts: cement 495.3-550.7 parts; sand 739.5-786.5 parts; aggregate 1132-1286 parts; water 170-202 parts; water reducing agent 0.18-0.22 parts; modified steel fiber 106.8-121.2 parts; the sand particle size is 0.6±0.2mm, the aggregate particle size distribution is that the 5-8mm particle size aggregate accounts for 32±2wt%, the 12-15mm particle size aggregate accounts for 40±2wt%, the 30-35mm particle size aggregate accounts for 16±2wt%, and the rest is 40-50mm particle size aggregate; the modified steel fiber length is 40±2mm, the width is 1.5±0.5mm, and the thickness is 0.5±0.1mm, the modified steel fiber surface is solidified with fixed points, the fixed points are solidified convex points with a size of 0.12-0.18mm on the surface of the modified steel fiber, the fixed points are silica material, the fixed point distribution density is 1.25±0.25 / mm2, and the fixed point and modified steel fiber surface bonding strength is 6.9-7.8MPa; the fixed point adhesion method on the modified steel fiber is as follows: The steel fiber is first surface treated to form a protective layer, and then a point forming liquid is sprayed from both sides of the steel fiber, the spraying amount is 0.1-0.18 mL / (cm 2 2) of the horizontal projection surface, the residence time is 5±0.1 s, the spraying pressure is 81.5±1.5 kPa, and the point forming liquid is a mixture of methyl silicate, ammonia, methanol and water in a mass ratio of 7.3:3.3:29.4:60, wherein the ammonia is added by ammonia water, and the water in the ammonia water is included in the water mass ratio.

2. A high toughness building material as claimed in claim 1, wherein the steel fiber surface treatment forms a protective layer modified by a hydrophilic silane coupling agent.

3. A high toughness building material according to claim 2, wherein the hydrophilic silane coupling agent is vinyltriacetoxysilane.

4. A high toughness building material as claimed in claim 3, wherein the hydrophilic silane coupling agent dosage is hydrophilic silane coupling agent / steel fiber: 0.05-0.08g / g.

5. A high toughness building material as claimed in claim 1, wherein the modified steel fiber is helically curved along the length direction.

6. A high toughness building material according to claim 5, wherein the modified steel fiber helical turns are 3.5 turns.

7. The process for producing a high-ductility construction material according to any one of claims 1 to 6, characterized in that each raw material is put into a mixing device according to the proportion and mixed uniformly to obtain.