Basalt fiber anti-seepage and anti-crack mortar, and preparation method and construction method thereof

Abstract

The application discloses basalt fiber anti-seepage and anti-crack mortar, which is characterized by comprising the following components in parts by weight: cement 950 parts, silica fume 190 parts, fly ash microbead 50 parts, quartz sand 1000 parts, basalt alkali-resistant fiber 13.5 parts, water 200 parts and additive 23.8 parts. The application provides a high-density anti-seepage and anti-crack mortar, which is composed of a dense glue compound formed by high-strength cement with ultra-low water-cement ratio and active substances, has the characteristics of high strength and strong combination with concrete, changes the constraint condition of the bottom plate to the side wall, and solves the problem of side wall cracking from the root cause of crack.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of anti-seepage and anti-cracking mortar. More particularly, the present application relates to a basalt fiber anti-seepage and anti-cracking mortar, and a preparation method and application thereof. BACKGROUND

[0002] The cast-in-place box structure is one of the common structures in the engineering field, and is often used in underground pipe galleries, tunnels and civil air defense projects. Because it is often used in underground structures, there is often a certain water pressure head underground, so the anti-seepage performance of the structure is particularly important. The cast-in-place box structure is mainly composed of a bottom plate, side walls and a top plate, which are poured in sequence from bottom to top on the same section with a certain pouring time interval. The thickness of the bottom plate is usually 0.7-1.5m, the thickness of the side wall is usually 0.5-1.2m, and the thickness of the top plate is usually 0.5-1.1m. Moreover, the structure is narrow and long, and the side wall is constrained by the bottom plate, which is prone to cracking. According to incomplete statistics, 90% of the cracks in the cast-in-place box structure are caused by cracking of the side wall, and most of them are shrinkage through cracks caused by base constraints, which can easily cause leakage and cause durability and structural safety risks of the box.

[0003] Under normal circumstances, the concrete structure design must be designed according to mass concrete, and measures such as external addition of polypropylene fibers and expanding agents are often used to control concrete cracking. According to the actual effect, these measures can indeed play a certain role, but they cannot fundamentally eliminate the internal factors that cause cracking, and often cannot achieve the expected anti-cracking effect, and have certain side effects. SUMMARY

[0004] In order to achieve these objects and other advantages according to the present application, in one aspect, a preferred embodiment of the present application provides a basalt fiber anti-seepage and anti-cracking mortar, which comprises the following components by weight: cement 950 parts, silica fume 190 parts, fly ash microbeads 50 parts, quartz sand 1000 parts, basalt alkali-resistant fiber 13.5 parts, water 200 parts and admixture 23.8 parts.

[0005] In a preferred embodiment of the present application, the basalt alkali-resistant fiber has a fiber length of 16mm.

[0006] In a preferred embodiment of the present application, the admixture is prepared from montmorillonite powder and concrete waste liquid.

[0007] In a preferred embodiment of the present application, the admixture is prepared by the following steps:

[0008] Step 1), using a pulverizer to crush 180 parts by weight of montmorillonite to obtain montmorillonite powder with an average particle size of 500-600 mesh, and then taking 40 parts by weight of an acrylic-vinyl pyridine copolymer, mixing the acrylic-vinyl pyridine copolymer and the montmorillonite powder, and feeding them into a screw extruder for extrusion treatment at a screw speed of 60-70 r / min and a temperature of 125-135 DEG C, and then crushing to obtain modified montmorillonite powder;

[0009] Step 2), adding a fatty alcohol polyoxyethylene ether to the concrete waste liquid, wherein the amount of the fatty alcohol polyoxyethylene ether added is 3% of the mass of the concrete waste liquid, stirring and mixing uniformly, slowly adding hydrofluoric acid to the mixture, wherein the amount of the hydrofluoric acid added is 1% of the mass of the concrete waste liquid, ultrasonic stirring, and spray drying to obtain a powder;

[0010] Step 3), mixing the modified montmorillonite powder of step 1) and the powder of step 2) in a mass ratio of 1:3 to obtain the target product.

[0011] In another aspect, a preferred embodiment of the application is a preparation method of the basalt fiber anti-seepage and anti-cracking mortar, comprising the following steps:

[0012] Taking the above-mentioned parts by weight of cement, silica fume, fly ash microbeads, quartz sand, and basalt alkali-resistant fiber, dry mixing for 3 minutes, then adding half of the above-mentioned parts by weight of water, stirring until spherical objects appear, then adding the above-mentioned parts by weight of the additive and half of the above-mentioned parts by weight of water, stirring until a flowable slurry appears, which is the target product, the basalt fiber anti-seepage and anti-cracking mortar.

[0013] In a preferred embodiment of the application, the flowable slurry has a slump flow time of 15-20 seconds.

[0014] In another aspect, a preferred embodiment of the application is a use method of the basalt fiber anti-seepage and anti-cracking mortar, comprising the following steps:

[0015] Step S1, after the side wall steel reinforcement engineering construction is completed, a sand mortar formwork with a height of 15 cm is supported between the bottom plate and the side wall pouring surface, the sand mortar formwork is closed around, and the prepared basalt fiber anti-seepage and anti-cracking mortar is introduced into the sand mortar formwork, wherein the thickness of the mortar is controlled to be 5-6 cm;

[0016] Step S2, after the mortar is initially set, a water stop belt is laid on the surface of the mortar along the length direction of the mortar formwork, and the water stop belt divides the mortar into two groove spaces.

[0017] Step S3, respectively in two grooving space along the direction perpendicular to the sealing tape in the mortar surface groove a plurality of, groove width is 3-6mm, groove depth 5-10mm, the horizontal distance between adjacent two grooves 5cm, then remove the mortar formwork, side wall formwork, within 24h after the completion of mortar laying, complete side wall concrete pouring.

[0018] The present application at least includes the following advantages: the present application provides a high density anti-seepage and anti-crack mortar, which is composed of dense glue of high-strength cement and active substance under ultra-low water-cement ratio, has the characteristics of high strength and strong bonding force with concrete, changes the constraint condition of the bottom plate to the side wall, and solves the problem of side wall cracking from the root of crack occurrence. Inorganic basalt fiber is used, which can improve the tensile strength of the mortar and is not prone to fiber aging, and has stronger durability. Moreover, the present application only needs to specially treat the 5-6cm part of the interface between the bottom plate and the side wall, and the side wall concrete does not need to use external fiber or expanding agent, which greatly reduces the material cost of the side wall concrete.

[0019] Other advantages, objects and features of the present application will be partly embodied in the following description, and partly understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structure schematic diagram of the basalt fiber anti-seepage and anti-crack mortar laying in the present application.

[0021] Figure 2 It is a schematic diagram of the mortar surface groove in the present application. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below with reference to the accompanying drawings, so that those skilled in the art can implement the present application according to the description.

[0023] The following description is used to disclose the present application so that those skilled in the art can implement the present application. The preferred embodiments in the following description are only as examples, and other obvious modifications can be thought by those skilled in the art. The basic principles of the present application defined in the following description can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present application.

[0024] It should be understood by those skilled in the art that in the disclosure of the present application, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation of the present application.

[0025] It can be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number.

[0026] In one aspect, a preferred embodiment of the present application provides a basalt fiber anti-seepage anti-crack mortar, comprising the following components by weight: cement 950 parts, silica fume 190 parts, fly ash microbeads 50 parts, quartz sand 1000 parts, basalt alkali-resistant fiber 13.5 parts, water 200 parts and admixture 23.8 parts. The fiber length of the basalt alkali-resistant fiber is 16 mm.

[0027] Considering that in the prior art, polypropylene fibers are often added externally to control concrete cracking, and polypropylene fibers are organic fibers, which can enhance the tensile strength of concrete when used in combination with concrete, thereby playing a certain anti-cracking role, on the one hand, the elastic modulus of the fiber is small, which cannot play a role under the micro-deformation of concrete, which is not conducive to the control of early cracking of concrete, on the other hand, the fiber is an organic substance, which cannot be tightly combined with the interface of concrete, and can easily form a tubular water seepage channel, thereby weakening the impermeability of concrete. Therefore, in the present application, alkali-resistant basalt fibers are used, which have an average diameter of less than 25 μm and a tensile strength of greater than 2000 MPa, which can improve the tensile strength of the composite, and the inorganic property and ultra-low diameter can effectively reduce the small channels formed by the fiber composite, thereby improving the water and ion permeability of the composite.

[0028] The mortar material of the present application is composed of a dense cementitious composite formed by high-strength cement with ultra-low water-cement ratio and active substances, and has the characteristics of high strength and strong bonding force with concrete.

[0029] In a preferred embodiment of the present application, the admixture is prepared by the following steps:

[0030] Step 1), using a pulverizer to crush 180 parts by weight of montmorillonite to obtain montmorillonite powder with an average particle size of 500-600 mesh, and then taking 40 parts by weight of acrylic-vinyl pyridine copolymer, mixing the acrylic-vinyl pyridine copolymer and the montmorillonite powder, and feeding them into a screw extruder for extrusion treatment at a screw speed of 60-70 r / min and a temperature of 125-135 DEG C, and then crushing to obtain modified montmorillonite powder;

[0031] Step 2), adding fatty alcohol polyoxyethylene ether to the concrete waste liquid, wherein the amount of the fatty alcohol polyoxyethylene ether is 3% of the mass of the concrete waste liquid, stirring and mixing uniformly, slowly adding hydrofluoric acid to the mixture, wherein the amount of the hydrofluoric acid is 1% of the mass of the concrete waste liquid, ultrasonic stirring, and spray drying to obtain a powder;

[0032] Step 3), mixing the modified montmorillonite powder of step 1) and the powder of step 2) at a mass ratio of 1:3 to obtain the target product admixture.

[0033] The present application allows the acrylic-vinyl pyridine copolymer to enter the interlayer structure of the montmorillonite powder in a high-pressure expansion environment of a screw extruder, so that the surface of the montmorillonite powder is ionized, thereby improving the adsorption and dispersion capacity of the montmorillonite powder for the powder.

[0034] In another aspect, a preferred embodiment of the present application is a preparation method of the basalt fiber anti-seepage and anti-cracking mortar, which comprises the following steps:

[0035] The cement, silica fume, fly ash microbeads, quartz sand, and basalt alkali-resistant fiber are dry-mixed for 3 minutes, then half of the above-mentioned water is added and stirred until spherical objects appear, and then the above-mentioned admixture and the other half of the water are added and stirred until a flowable slurry appears, and the flowable slurry has a slump flow time of 15-20 seconds, which is the target product, the basalt fiber anti-seepage and anti-cracking mortar.

[0036] Table 1 below shows the performance parameters of the mortar prepared in the above-mentioned examples.

[0037] Table 1 shows the material test parameters.

[0038] Indicators 24h compressive strength 3d compressive strength 3d splitting tensile strength 28d coefficient of chloride ion permeability Measured values 58.3 MPa 98.2 Mpa 10.3 MPa 0.9*10-12㎡ / s

[0039] As shown in the above table, the mortar of the present application has strong compressive strength, high splitting tensile strength, and strong resistance to chloride ion penetration.

[0040] In another aspect, a preferred embodiment of the present application is a use method of the basalt fiber anti-seepage and anti-cracking mortar, which comprises the following steps:

[0041] Step S1, after the side wall 100 reinforcement engineering construction is completed, the sand mortar formwork with a height of 15 cm is supported between the bottom plate 200 and the side wall pouring surface, the sand mortar formwork 600 is closed around, the prepared sand mortar 300 is introduced into the sand mortar formwork 600, wherein the thickness of the sand mortar is controlled to be 5-6 cm;

[0042] Step S2, after the sand mortar is initially cured, a water stop tape 400 is laid on the sand mortar surface along the length direction of the sand mortar formwork, the water stop tape divides the sand mortar into two groove spaces;

[0043] Step S3, a plurality of grooves 500 are engraved on the sand mortar surface in the two groove spaces respectively along the direction perpendicular to the water stop tape, the groove width is 3-6 mm, the groove depth is 5-10 mm, the horizontal distance between the adjacent two grooves is 5 cm, then the sand mortar formwork is removed, the side wall formwork is spliced, and the side wall concrete pouring is completed within 24 h after the sand mortar laying is completed.

[0044] The construction method of the present application changes the constraint condition of the bottom plate to the side wall, and solves the problem of side wall cracking from the root cause of the crack. Only the special treatment of the 5-6 cm part of the interface between the bottom plate and the side wall is needed, and the side wall concrete does not need to use measures such as external addition of fibers or expanding agent, which greatly reduces the cost of side wall concrete materials.

[0045] The basalt fiber anti-seepage and anti-cracking sand mortar with a pouring thickness of 5-6 cm within 24 h before the side wall pouring has high anti-cracking performance, the splitting tensile strength is greater than 10 Mpa, and can fully resist the tensile stress generated by the constraint of the bottom plate concrete. At the same time, since the pouring time of the material and the side wall concrete is only within 24 h, the shrinkage difference caused by the age is small, so that the side wall is not cracked due to the constraint shrinkage stress caused by the age difference.

[0046] The stress device is arranged at the bottom axis center and the quarter of the side wall concrete respectively using the process of the present application and the traditional process (the side wall and the bottom plate control the concrete cracking by external addition of polypropylene fiber, expanding agent, etc.), the side wall concrete is C50, and the same mixing ratio is adopted, and the test side wall concrete tensile stress values after pouring for 3 d, 7 d and 14 d are as follows:

[0047]

[0048] From the data in the above table, it can be known that the tensile stress generated by the constraint of the side wall base can be effectively reduced after the construction of the present application.

[0049] While embodiments of the application have been disclosed in connection with the above specification and drawings this description is not intended to limit the scope of the application and many modifications, enhancements, alternatives, and variations will become apparent to those skilled in the art from this disclosure. Accordingly, it is intended that the application not be limited to the described embodiments, but that it include all variations falling within the scope of the claims, and their equivalents.

Claims

1. A construction method of a basalt fiber impermeable anti-crack mortar, characterized in that, The basalt fiber anti-seepage and anti-cracking mortar uses the following raw materials by weight: Cement 950 parts, silica fume 190 parts, fly ash microbeads 50 parts, quartz sand 1000 parts, basalt alkali-resistant fiber 13.5 parts, water 200 parts, and additive 23.8 parts; The method comprises the following steps: Step S1, after the side wall steel reinforcement engineering construction is completed, a sand mortar formwork with a support height of 15 cm is arranged between the bottom plate and the side wall pouring surface, the sand mortar formwork is closed around, and the prepared basalt fiber anti-seepage and anti-cracking mortar is introduced into the sand mortar formwork; Step S2, after the sand mortar is initially cured, a water stop belt is laid on the surface of the sand mortar along the length direction of the sand mortar formwork, and the water stop belt divides the sand mortar into two groove spaces; Step S3, a plurality of grooves are engraved on the surface of the sand mortar in the two groove spaces along a direction perpendicular to the water stop belt, the groove width is 3-6 mm, the groove depth is 5-10 mm, and the horizontal distance between adjacent two grooves is 5 cm, then the sand mortar formwork is removed, the side wall formwork is assembled, and the side wall concrete pouring is completed within 24 hours after the sand mortar laying is completed; The additive is prepared by the following steps: Step 1), 180 parts by weight of montmorillonite powder is crushed and sieved by using a crusher to obtain montmorillonite powder with an average particle size of 500-600 mesh, and 40 parts by weight of acrylic-vinyl pyridine copolymer is taken, and the acrylic-vinyl pyridine copolymer and the montmorillonite powder are mixed and put into a screw extruder for extrusion treatment, the screw rotation speed is 60-70 r / min, the temperature is 125-135 ℃, and the montmorillonite powder is crushed to obtain modified montmorillonite powder; Step 2), fatty alcohol polyoxyethylene ether is added to the concrete waste liquid, the input amount of the fatty alcohol polyoxyethylene ether is 3% of the mass of the concrete waste liquid, the mixture is stirred and mixed uniformly, then hydrofluoric acid is slowly added dropwise, the input amount of the hydrofluoric acid is 1% of the mass of the concrete waste liquid, ultrasonic stirring is performed, and spray drying is performed to obtain a powder; Step 3), the modified montmorillonite powder of step 1) and the powder of step 2) are mixed in a mass ratio of 1:3 to obtain the target product additive.

2. The construction method of the basalt fiber impervious anti-crack mortar according to claim 1, characterized in that, In the step S1, the thickness of the sand mortar is controlled to be 5-6 cm.

3. The basalt fiber anti-seepage and anti-cracking mortar construction method according to any one of claims 1-2, comprising the following steps: The cement, silica fume, fly ash microbeads, quartz sand, and basalt alkali-resistant fiber are taken by weight, dry-mixed for 3 minutes, then half of the water by weight is added, stirred, until spherical objects appear, then the additive by weight and half of the water by weight are added, stirred, until a flowable slurry appears, and the target product basalt fiber anti-seepage and anti-cracking mortar is obtained.

4. The construction method of the basalt fiber impermeable anti-crack mortar according to claim 3, characterized in that, The flowable slurry has a slump flow time of 15-20 seconds.

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