CN112521075A - Formula and preparation method of super-durable concrete - Google Patents

Abstract

The invention belongs to the technical field of concrete building materials, and particularly relates to a formula and a preparation method of super-durable concrete. The formula of the super-durable concrete comprises the following components in parts by weight: 300-360 parts of cement, 500-610 parts of quartz sand, 900-1100 parts of crushed stone, 30-60 parts of fly ash, 30-50 parts of mineral powder, 150-180 parts of water, 12-20 parts of asbestos-free mineral fiber, 12-15 parts of macroporous resin, 7-10 parts of film forming agent, 6-9 parts of water reducing agent and 2-5 parts of defoaming agent; wherein the film forming agent is a mixture of microcrystalline wax and stearic acid, and the mass ratio of the microcrystalline wax to the stearic acid is (2-5) to 1. The asbestos-free mineral fiber provided by the invention enables the concrete and the steel bar to have good associativity, is beneficial to forming a passive film on the surface of the steel bar by the film-forming agent, effectively prevents external water and air from entering and generating corrosion reaction, and simultaneously, the super-strong adsorption property of the macroporous resin is also beneficial to preventing external water from entering the interior to cause corrosion, so that the antirust property and durability of a PC component are improved.

Description

Formula and preparation method of super-durable concrete

Technical Field

The invention belongs to the technical field of concrete building materials, and particularly relates to a formula and a preparation method of super-durable concrete.

Background

The fabricated concrete (PC) member is widely applied to the fields of buildings, traffic, water conservancy and the like, and plays an important role in the construction of national infrastructure, such as prefabricated reinforced concrete column foundation foundations, prefabricated steel structure steel column foundations, street lamp billboard column reinforced concrete foundations, prefabricated floor slabs and the like. The production of the PC member generally relates to the steps of mold assembly, reinforcement cage installation, concrete pouring, construction, form removal and hoisting, member surface repair, member warehousing maintenance and the like.

The premixed concrete is usually formed by mixing cement, aggregate, an additive and water according to a certain proportion, but the prior concrete is easy to shrink and crack after being poured, has low tensile strength and the like, has poor fluidity and workability, is difficult to ensure the compactness of the concrete by depending on manual vibration under the condition of a steel bar structure, and can generate a porous structure due to a large amount of unremoved air bubbles inside a PC member. The structural defects further influence the durability of the PC components, so that the rust resistance and corrosion resistance of the building are greatly reduced, particularly in the south and coastal areas with damp and rainy days, buildings, roads, bridges and the like are easily corroded by rainwater under the influence of the quality of the PC components, even internal reinforcing steel bars are rusted, and the stability and durability of the building are seriously influenced.

Along with the multifunctionalization of concrete engineering, the complexity of construction and application environment and the optimization of resources and environment, people also put forward higher requirements on concrete materials. At present, in order to improve the durability of concrete or PC members, a water reducing agent or a compacting agent is often added to a ready-mixed concrete formula to improve the strength of PC members, such as a concrete formula disclosed in patent document CN111574153A, but there are few methods for enhancing the rust-proof and corrosion-proof functions of rust-proof PC members. The Chinese patent application with publication number CN111961361A provides a heat-insulating and antirust composition, which comprises antirust mortar and sealing paint, wherein the antirust mortar is required to be coated on the surface of a bound reinforcement cage bone by spraying, mixed-embroidery spraying is carried out, and then the waterproof sealing paint is sprayed on the outer surface of the maintained antirust mortar.

Disclosure of Invention

The invention aims to solve the technical problems and provides a formula of super-durable concrete and a preparation method thereof, and the water resistance, rust prevention and durability of a PC (polycarbonate) member are improved through a reasonable formula and a simple preparation method.

The above object of the present invention is achieved by the following technical solutions:

the formula of the super-durable concrete comprises the following components in parts by weight: 360 parts of cement, 500 parts of quartz sand, 610 parts of crushed stone, 900 parts of pulverized coal, 30-60 parts of fly ash, 30-50 parts of mineral powder, 180 parts of water, 12-20 parts of asbestos-free mineral fiber, 12-15 parts of macroporous resin, 7-10 parts of film forming agent, 6-9 parts of water reducing agent and 2-5 parts of defoaming agent.

Further, the formula of the super-durable concrete comprises the following components in parts by weight: 350 parts of cement 320-350 parts, 600 parts of quartz sand 550-1050 parts, 980 crushed stone 1050 parts, 35-45 parts of fly ash, 30-40 parts of mineral powder, 170 parts of water 160-170 parts, 15-19 parts of asbestos-free mineral fiber, 12-13 parts of macroporous resin, 6-7 parts of water reducing agent, 4-6 parts of antirust agent and 3-4 parts of defoaming agent.

According to the invention, the mineral powder and the fly ash can increase the compressive strength of the concrete, reduce the cracking problem of the concrete caused by poor early strength performance, improve the compactness, reduce the water addition amount under the action of the water reducing agent and improve the anti-seepage and anti-erosion capabilities. The addition of the asbestos-free mineral fibers can improve the toughness and the impact strength of concrete, meanwhile, the asbestos-free mineral fibers with various different cross sections can increase the interface cohesiveness of the asbestos-free mineral fibers and the concrete, the improvement of the dispersibility of various raw materials is facilitated, the asbestos-free mineral fibers can be adsorbed on the surface of a reinforcing steel bar to form a good and stable net structure inside the concrete, and the defoaming agent can reduce the formation of air cells in the vibrating process of the concrete.

When the PC member is made of concrete and steel bars, steam oxidation is usually needed, the film forming agent can further form a passive film on the surface of the steel bars by virtue of the permeation effect of asbestos-free mineral fibers and is filled in holes of the concrete, and the hydrophobic property of the passive film enables external moisture or other liquid to be difficult to soak into the concrete, so that the steel bars of the PC member are prevented from being corroded. Meanwhile, macroporous resin is added into the premixed concrete, and the ultrahigh adsorption performance of the macroporous resin is utilized to adsorb water or other pollutants entering from the outside, so that the water is prevented from entering the inside from the pores to corrode the reinforcing steel bars. The porous skeleton structure of the macroporous resin not only ensures that the interior of the macroporous resin has extremely high porosity and strong adsorbability in a dry state, but also has the advantages of high mechanical strength, good pollution resistance, thermal stability and the like, can further improve the strength of concrete, and avoids the influence of environmental factors on the quality of PC members.

Further, the film forming agent is a mixture of microcrystalline wax and stearic acid, wherein the mass ratio of the microcrystalline wax to the stearic acid is (2-5): 1.

Furthermore, the formula of the super-durable concrete also comprises 8-12 parts of antirust agent by weight.

Further preferably, the antirust agent comprises the following components in parts by weight: 3-5 parts of copper tetraammine sulfate, 2-4 parts of modified silica sol, 1-2 parts of acrylate emulsion and 0.5-2 parts of sodium fluosilicate.

The antirust agent component can be filled in concrete micropores by means of the strong permeability of the asbestos-free mineral fibers, and is combined with the asbestos-free mineral fibers to form a closed waterproof layer whole to prevent the corrosion of water or other liquid from the outside, and meanwhile, the antirust agent can act on the surface of the steel bar under the permeation and transmission effects of the asbestos-free mineral fibers, so that the protective effect on the steel bar is achieved. The copper tetraammine sulfate in the antirust agent can be adsorbed on asbestos-free mineral fibers, a layer of passive film is formed on the surface of the steel bar under the combined action of the acrylate emulsion, the modified silica sol and the film-forming additive, and the steel bar is prevented from being in contact with external gas or moisture to generate corrosion reaction, so that the antirust performance of the steel bar in the PC member is improved. The copper tetraammine sulfate and the asbestos-free mineral fibers can also play a role of a stabilizer, so that the stable dispersion of the antirust agent is ensured, the interference of other components on the stability of the antirust agent is avoided, and the overall stability and durability of the PC component are further enhanced.

Further, the modified silica sol is obtained by mixing and dispersing vinyl triethoxysilane, ethyl orthosilicate and silica sol in a mass ratio of 2:1 (3-6) for 30-50 min by ultrasound.

The modified silica sol is added with the vinyltriethoxysilane as a modified material, and is grafted with the silica sol to improve the film forming property and enhance the compactness and the bonding force of the antirust agent after the antirust agent forms a film on the surface of the steel bar.

Further, the water reducing agent is a polycarboxylic acid water reducing agent with the water reducing rate of more than or equal to 28 percent.

Further, the defoaming agent is organic silicone oil and/or mineral oil amide polymer.

Furthermore, the particle size of the macroporous resin used in the invention is 0.2-0.8 nm.

Furthermore, the fineness modulus of the quartz sand is 1.8-2.5.

Furthermore, the particle size of the macadam is 3-5 mm.

Another object of the present invention is to provide a method for preparing super durable concrete, comprising the steps of:

weighing the raw materials in parts by weight;

firstly adding quartz sand, broken stone and mineral powder into a stirrer for mixing, then adding cement, fly ash, asbestos-free mineral fiber and a film-forming agent for stirring together, then uniformly mixing a water reducing agent, a defoaming agent and water, adding the mixture into the stirrer for mixing, and finally adding macroporous resin for continuously stirring uniformly to obtain concrete;

and placing the concrete into a curing room for curing, and testing the compressive strength of the concrete after the concrete reaches the specified age.

The concrete preparation method provided by the invention is simple to operate, and due to reasonable proportioning of the formula, the components can be rapidly dispersed and uniformly mixed, so that the production efficiency is ensured while the quality and stability of the concrete are improved.

Compared with the prior art, the invention has the following advantages:

1. the asbestos-free mineral fiber provided by the invention enables the concrete and the steel bar to have good associativity, is beneficial to forming a passive film on the surface of the steel bar by the film-forming agent, and can effectively prevent the corrosion reaction caused by the entrance of external water and air, thereby improving the antirust performance of a PC member;

2. the macroporous resin has super strong adsorption capacity on substances in different media, and can further prevent external moisture or gas from entering the concrete to cause corrosion, so that the rust resistance and durability of a PC (polycarbonate) member are improved;

3. the copper tetrammine sulfate and the asbestos-free mineral fibers are beneficial to improving the overall stability of concrete, and meanwhile, the modified silica sol in the antirust agent is beneficial to improving the film forming performance after being modified, and the compactness and the bonding force after film forming are increased;

4. the concrete of the invention has reasonable formula and simple preparation method, improves the strength and the water-resistant and corrosion-resistant capability of the concrete, is beneficial to improving the production efficiency of PC members and reducing the production cost.

Detailed Description

The technical solution of the present invention is further described and illustrated by the following specific examples. The raw materials used in the examples of the present invention are those commonly used in the art, and the methods used in the examples are those conventional in the art, unless otherwise specified. It should be understood that the specific embodiments described herein are merely to aid in the understanding of the invention and are not intended to limit the invention specifically.

Example 1

Embodiment 1 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 350 parts of cement, 560 parts of quartz sand, 1000 parts of broken stone, 50 parts of fly ash, 45 parts of mineral powder, 170 parts of water, 16 parts of asbestos-free mineral fiber, 12 parts of antirust agent, 12 parts of macroporous resin, 9 parts of film-forming agent, 7 parts of water reducing agent and 3 parts of defoaming agent; wherein the fineness modulus of the quartz sand is 2.2, the crushed stone has a particle size of 3-5mm, the particle size of the macroporous resin is 0.5-0.8 nm, and the film-forming agent is a mixture of microcrystalline wax and stearic acid (4.5:1, w/w); the water reducing agent is a polycarboxylic acid water reducing agent with the water reducing rate of more than or equal to 28 percent, and the defoaming agent is cyclohexyl diacetic acid monoamide;

the antirust agent of the embodiment comprises the following components in parts by weight: 4.5 parts of copper tetraammine sulfate, 3.5 parts of modified silica sol, 2 parts of acrylate emulsion and 2 parts of sodium fluosilicate; wherein the modified silica sol is obtained by mixing and dispersing vinyl triethoxysilane, ethyl orthosilicate and silica sol in a mass ratio of 2:1:4 for 40min by ultrasound.

Example 2

Embodiment 2 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 320 parts of cement, 600 parts of quartz sand, 1050 parts of broken stone, 40 parts of fly ash, 45 parts of mineral powder, 170 parts of water, 15 parts of asbestos-free mineral fiber, 12 parts of antirust agent, 12 parts of macroporous resin, 9 parts of film forming agent, 8 parts of water reducing agent and 3 parts of defoaming agent; wherein the quartz sand, the broken stone, the macroporous resin, the water reducing agent, the antirust agent, the film forming agent and the defoaming agent are the same as those in the embodiment 1.

Example 3

Embodiment 3 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 350 parts of cement, 580 parts of quartz sand, 950 parts of broken stone, 60 parts of fly ash, 50 parts of mineral powder, 180 parts of water, 12 parts of asbestos-free mineral fiber, 12 parts of antirust agent, 12 parts of macroporous resin, 9 parts of film-forming agent, 8 parts of water reducing agent and 3 parts of defoaming agent; wherein the quartz sand, the broken stone, the macroporous resin, the water reducing agent, the antirust agent, the film forming agent and the defoaming agent are the same as those in the embodiment 1.

Example 4

Embodiment 4 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 350 parts of cement, 550 parts of quartz sand, 1050 parts of broken stone, 55 parts of fly ash, 35 parts of mineral powder, 160 parts of water, 19 parts of asbestos-free mineral fiber, 12 parts of antirust agent, 12 parts of macroporous resin, 9 parts of film forming agent, 12 parts of water reducing agent and 3 parts of defoaming agent; wherein the quartz sand, the broken stone, the macroporous resin, the water reducing agent, the antirust agent, the film forming agent and the defoaming agent are the same as those in the embodiment 1.

Example 5

Embodiment 5 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 350 parts of cement, 560 parts of quartz sand, 1000 parts of broken stone, 50 parts of fly ash, 45 parts of mineral powder, 170 parts of water, 16 parts of asbestos-free mineral fiber, 13 parts of antirust agent, 12 parts of macroporous resin, 6 parts of film-forming agent, 7 parts of water reducing agent and 3 parts of defoaming agent; wherein the film forming agent is a mixture of microcrystalline wax and stearic acid (2:1, w/w); wherein the quartz sand, the broken stone, the macroporous resin, the water reducing agent, the antirust agent and the defoaming agent are the same as those in the embodiment 1.

Example 6

Embodiment 6 provides a waterproof and antirust material for PC members, comprising the following components in parts by weight: 350 parts of cement, 560 parts of quartz sand, 1000 parts of broken stone, 50 parts of fly ash, 45 parts of mineral powder, 170 parts of water, 16 parts of asbestos-free mineral fiber, 6 parts of antirust agent, 9 parts of macroporous resin, 7 parts of water reducer, 3 parts of defoaming agent and 3 parts of synergist; the antirust agent comprises the following components in parts by weight: 2.5 parts of copper tetraammine sulfate, 1.5 parts of modified silica sol, 1 part of acrylate emulsion, 0.5 part of sodium fluosilicate and 0.5 part of film-forming assistant; the quartz sand, crushed stone, macroporous resin, water reducing agent, film forming agent and defoaming agent used were the same as in example 1.

Example 7

Example 7 provides a waterproof and antirust material for PC members, which differs from example 1 only in that the film-forming agent is microcrystalline wax and the remaining components are the same as in example 1.

Example 8

Example 8 provides a waterproof and antirust material for PC members, which is different from example 1 only in that it does not contain a antirust agent, and the remaining components are the same as those in example 1.

Example 9

The concrete formulations in examples 1-8 were made into concrete test blocks, the specific method comprising the steps of:

weighing the raw material components in parts by weight;

firstly adding quartz sand, broken stone and mineral powder into a stirrer for mixing, then adding cement, fly ash, asbestos-free mineral fiber, a composite expanding agent and a synergist for stirring together, then adding a retarding and water reducing agent and water into the stirrer after uniformly mixing, and continuously stirring uniformly to obtain concrete;

and (2) putting the concrete into a curing chamber for curing, curing for 6 hours under the constant temperature condition of 85 ℃ under normal pressure, curing for 8 hours under high temperature and high pressure, wherein the constant pressure is 0.9-1.0 MPa, the constant temperature is 160 ℃, and cooling to normal temperature after curing.

Comparative example 1

Comparative example 1 provides a concrete which was prepared in the same manner as in example 9 except that the macroporous resin was not added to the raw material composition of example 1 and the remaining composition was the same as that of example 1.

Comparative example 2

Comparative example 2 provides a concrete which was prepared in the same manner as in example 9 except that the composition of the raw material was changed from that of example 1 without adding asbestos-free mineral fibers and the composition was the same as that of example 1.

The concrete prepared in examples 1 to 8 and comparative examples 1 to 2 was subjected to a water permeation pressure resistance ratio test with reference to the DBJ01-54-2001 interfacial permeation type waterproof paint quality test evaluation criteria, and the waterproof property thereof was examined with reference to the test method of JC/T1018-2006 aqueous permeation type inorganic waterproof agent, and the results are shown in the following table.

TABLE 1 results of Performance test of examples 1-8 and comparative examples 1-2

The above embodiments are not exhaustive of the range of parameters of the claimed technical solutions of the present invention and the new technical solutions formed by equivalent replacement of single or multiple technical features in the technical solutions of the embodiments are also within the scope of the claimed technical solutions of the present invention, and if no specific description is given for all the parameters involved in the technical solutions of the present invention, there is no unique combination of the parameters with each other that is not replaceable.

The specific embodiments described herein are merely illustrative of the spirit of the invention and do not limit the scope of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims (8)

1. The formula of the super-durable concrete is characterized by comprising the following components in parts by weight: 360 parts of cement, 500 parts of quartz sand, 610 parts of crushed stone, 900 parts of pulverized coal, 30-60 parts of fly ash, 30-50 parts of mineral powder, 180 parts of water, 12-20 parts of asbestos-free mineral fiber, 12-15 parts of macroporous resin, 7-10 parts of film forming agent, 6-9 parts of water reducing agent and 2-5 parts of defoaming agent.

2. The super-durable concrete formulation according to claim 1, comprising the following components in parts by weight: 350 parts of cement 320-350 parts, 600 parts of quartz sand 550-1050 parts, 980 crushed stone 1050 parts, 35-45 parts of fly ash, 30-40 parts of mineral powder, 170 parts of water 160-170 parts, 15-19 parts of asbestos-free mineral fiber, 12-13 parts of macroporous resin, 6-7 parts of water reducing agent, 4-6 parts of antirust agent and 3-4 parts of defoaming agent.

3. The super-durable concrete formulation according to claim 1, wherein the film forming agent is a mixture of microcrystalline wax and stearic acid, wherein the mass ratio of microcrystalline wax to stearic acid is (2-5): 1.

4. The super durable concrete formulation according to claim 1, further comprising 8-12 parts by weight of a rust inhibitor.

5. The super-durable concrete formulation according to claim 4, wherein the rust inhibitor comprises the following components in parts by weight: 3-5 parts of copper tetraammine sulfate, 2-4 parts of modified silica sol, 1-2 parts of acrylate emulsion and 0.5-2 parts of sodium fluosilicate.

6. The formula of the super-durable concrete according to claim 5, wherein the modified silica sol is obtained by mixing and dispersing vinyl triethoxysilane, tetraethoxysilane and silica sol in a mass ratio of 2:1 (3-6) for 30-50 min by ultrasound.

7. The super-durable concrete formulation according to claim 1, wherein the particle size of the macroporous resin is 0.2-0.8 nm. .

8. The preparation method of the ultra-durable concrete formula is characterized by comprising the following steps of:

weighing the concrete formula raw material as defined in any one of claims 1 to 7 in parts by weight;

firstly adding quartz sand, broken stone and mineral powder into a stirrer for mixing, then adding cement, fly ash, asbestos-free mineral fiber and a film-forming agent for stirring together, then uniformly mixing a water reducing agent, a defoaming agent and water, adding the mixture into the stirrer for mixing, and finally adding macroporous resin for continuously stirring uniformly to obtain concrete;

and (5) placing the concrete into a curing room for curing until the concrete reaches the specified age.