阅读说明：本技术 一种高效混凝土抗裂抗渗剂及其制备方法 (Efficient concrete anti-cracking and anti-permeability agent and preparation method thereof ) 是由 黄齐茂 龚慧敏 左芬 于 2021-06-30 设计创作，主要内容包括：本发明涉及一种高效混凝土抗裂抗渗剂及其制备方法,所述高效混凝土抗裂抗渗剂其原料组分及质量百分含量如下：四硼酸铵0.1～1％,铵明矾1～10％,麦饭石粉2～10％,硬脂酸1～5％,余量为水。本发明提供的高效混凝土抗裂抗渗剂使用方便,只需提前做好试配后随混凝土一并浇筑、振捣、养护即可,相比起工艺复杂的传统防水做法,质量可控性极强,不影响甚至能提高混凝土强度,并且用量少,掺量2％(按胶凝材料质量百分比计)的情况下抗渗等级即可达到P12。(The invention relates to a high-efficiency concrete anti-cracking and anti-permeability agent and a preparation method thereof, wherein the high-efficiency concrete anti-cracking and anti-permeability agent comprises the following raw material components in percentage by mass: 0.1-1% of ammonium tetraborate, 1-10% of ammonium alum, 2-10% of medical stone powder, 1-5% of stearic acid and the balance of water. The efficient concrete anti-cracking anti-permeability agent provided by the invention is convenient to use, and only needs to be prepared in advance and then poured, vibrated and maintained together with concrete, compared with the traditional waterproof method with a complex process, the efficient concrete anti-cracking anti-permeability agent has extremely strong quality controllability, can not influence or even improve the strength of the concrete, is low in dosage, and can reach the P12 anti-permeability grade under the condition that the dosage is 2% (by mass percentage of a cementing material).)

1. The efficient concrete anti-cracking and anti-permeability agent is characterized by comprising the following raw material components in percentage by mass: 0.1-1% of ammonium tetraborate, 1-10% of ammonium alum, 2-10% of medical stone powder, 1-5% of stearic acid and the balance of water.

2. The efficient concrete anti-cracking and anti-permeability agent according to claim 1, wherein the ammonium tetraborate, the ammonium alum and the medical stone powder are all nano-scale powder materials.

3. The preparation method of the high-efficiency concrete crack-resistant and anti-permeability agent according to claim 1 or 2 is characterized by comprising the following specific steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, stirring for 15-30 min after adding each component, adding the next component, and continuously stirring for 15-30 min after adding all the components to obtain the efficient concrete anti-cracking and anti-permeability agent.

4. The preparation method of the efficient concrete anti-cracking and anti-permeability agent according to claim 3, wherein the stirring speed is 50-65 r/min.

5. The use method of the high-efficiency concrete crack-resistant and anti-permeability agent according to claim 1 or 2, characterized by comprising the following steps: and (3) adding the efficient concrete anti-cracking and anti-permeability agent into concrete according to 2-8% of the mass of the cementing material, and pouring, vibrating and curing the concrete as anti-cracking and anti-permeability concrete to obtain a concrete product with anti-cracking and anti-permeability performance, or filling the concrete product into a concrete crack for repairing the crack.

Technical Field

The invention belongs to the technical field of concrete using inorganic materials as effective components, and relates to a high-efficiency concrete anti-cracking and anti-permeability agent and a preparation method thereof.

Background

In recent years, with the vigorous development of infrastructure construction, higher efficiency requirements have been made on concrete in construction works in various fields all over the world. In real life, various buildings have degradation and degeneration phenomena of different degrees along with the time, wherein the engineering quality is seriously affected by water leakage, cracking and other damage phenomena, and the concrete is an important problem to be solved urgently in the field of concrete.

At present, soft waterproof methods such as asphalt and rigid waterproof methods such as adding an expanding agent or polypropylene fibers are mainly used in the industry. Most of the soft waterproof materials of asphalt are made of broken stones to form a framework, asphalt mastic is used for filling pores in the framework, and asphalt mastic is formed together with the framework after being glued, so that the strength and the stability of asphalt concrete are improved. The mineral powder plays a role in filling the asphalt mixture and aims to reduce the gaps of the asphalt concrete, sometimes called as filler, the method has quick construction effect and good effect, but has poor corrosion resistance and seepage resistance, and the mineral powder is easy to leak in 5 to 7 years basically.

The rigid waterproof method adds an expanding agent into concrete to form an expandable crystalline hydrate, so that the concrete is moderately expanded in the early stage, the generated expansion energy is converted into prepressing capacity under the restraint of reinforcing steel bars and adjacent positions, the prepressing capacity can approximately offset the reaction capacity generated during dry shrinkage, a weak expansion potential is still kept in the middle and later stages of the concrete to compensate for cold shrinkage, meanwhile, the crystalline compound is continuously filled in gaps inside the concrete, the void structure of the concrete is improved, the compactness is improved, and the purposes of cracking resistance and seepage resistance are achieved. However, it is inconvenient to use, requires adjustment of the concrete mix ratio, and fails to achieve the desired shrinkage compensation effect when the expansion coefficients of the concrete and the expanding agent are not the same. The polypropylene fibers are uniformly distributed in the concrete in a larger quantity in unit volume, and form a uniform three-dimensional random network system in the concrete, so that the effect of supporting aggregate is achieved, the segregation tendency of the concrete is effectively prevented and inhibited, bleeding on the surface of the concrete is reduced, the tensile strength of the concrete is improved, and the generation of concrete plastic cracks is greatly reduced and inhibited. However, it has no swelling function, cannot continue the reaction, and can only restrict the crack from further expanding, and cannot prevent the generation of a new crack.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a high-efficiency concrete anti-cracking and anti-permeability agent and a preparation method thereof aiming at the defects in the prior art, the anti-cracking and anti-permeability agent is a new generation concrete anti-cracking and anti-permeability agent, the waterproof mechanism of the anti-cracking and anti-permeability agent is completely different from that of the current soft waterproof or rigid waterproof mechanism, the use is convenient, the mix proportion of concrete is not required to be adjusted, the strength of the concrete is not influenced or even improved, when the mix amount is 2%, the anti-permeability grade can reach P12, the expanding agent and the polypropylene fiber can be completely replaced, the engineering quality is good, and the manufacturing cost is low.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the high-efficiency concrete anti-cracking and anti-permeability agent is provided, and comprises the following raw material components in percentage by mass: 0.1-1% of ammonium tetraborate, 1-10% of ammonium alum, 2-10% of medical stone powder, 1-5% of stearic acid and the balance of water.

According to the scheme, the ammonium tetraborate, the ammonium alum and the medical stone powder are all nano-scale powder materials.

In the anti-cracking anti-permeability agent system, ammonium tetraborate reacts with silicon and calcium in cement to form fine mesh fillers to fill all corners of concrete, so that bubbles in the concrete are avoided; the ammonium alum can reduce the maximum hydration heat peak value in the early stage, relieve the temperature difference inside and outside the concrete structure, resist seepage and simultaneously play a role in corrosion resistance; the medical stone has double functions: on one hand, the concrete has good adsorption performance because the medical stone mainly contains silicate, and on the other hand, the medical stone contains more clay minerals such as kaolinite and the like, has a porous spongy special structure and has strong electrostatic attraction so as to increase the compactness and crack resistance of the concrete; stearic acid can introduce uniform micro-stable bubbles to increase elasticity and can avoid microorganisms from parasitizing on the concrete surface, thereby avoiding the reinforcing steel bars and the concrete from being corroded. The inorganic components of ammonium tetraborate, ammonium alum and medical stone powder are physically mixed to form an inorganic homogeneous system, a homogeneous framework system is constructed, and the uniform solidification of a colloid material is controlled, so that the concrete anti-permeability and anti-cracking mode is brand new.

The invention also comprises a preparation method of the high-efficiency concrete anti-cracking and anti-permeability agent, which comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, stirring for 15-30 min after adding each component, adding the next component, and continuously stirring for 15-30 min after adding all the components to obtain the efficient concrete anti-cracking and anti-permeability agent.

According to the scheme, the stirring speed is 50-65 r/min.

The invention also comprises a using method of the high-efficiency concrete anti-cracking and anti-permeability agent, which comprises the following steps: and (3) adding the efficient concrete anti-cracking and anti-permeability agent into concrete according to 2-8% of the mass of the cementing material, and pouring, vibrating and curing the concrete as anti-cracking and anti-permeability concrete to obtain a concrete product with anti-cracking and anti-permeability performance, or filling the concrete product into a concrete crack for repairing the crack.

The invention has the beneficial effects that: the efficient concrete anti-cracking anti-permeability agent provided by the invention is convenient to use, and only needs to be prepared in advance and then poured, vibrated and maintained together with concrete, compared with the traditional waterproof method with a complex process, the efficient concrete anti-cracking anti-permeability agent has extremely strong quality controllability, can not influence or even improve the strength of the concrete, is low in dosage, and can reach the P12 anti-permeability grade under the condition that the dosage is 2% (by mass percentage of a cementing material).

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention is further described in detail with reference to the following examples.

The ammonium tetraborate, the ammonium alum and the medical stone powder used in the embodiment of the invention are all nano-scale powder materials.

Example 1

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

Example 2

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

Example 3

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

Example 4

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

Example 5

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

Example 6

The efficient concrete anti-cracking and anti-permeability agent comprises the following raw material components in parts by weight:

the preparation method comprises the following steps: adding water into a reaction kettle, heating to 60-75 ℃, sequentially adding ammonium tetraborate, ammonium alum, medical stone powder and stearic acid, adding each component, stirring for 15-30 min, adding the next component, and continuously stirring for 15-30 min after all the components are added to obtain the efficient concrete crack-resistant and anti-permeability agent, wherein the stirring speed in the process is 50-65 r/min, and the temperature is 60-75 ℃.

The high-efficiency concrete crack-resistant anti-permeability agent prepared in the examples 1-6 is added into concrete according to 2% of the mass of the cementing material, and the mass ratio of each component in the concrete to water is as follows: 42.5R cement: sand (FM ═ 3.19-2.11): stone (5-20mm) ═ 0.41: 1: 1.03: 3.16, taking the concrete without the high-efficiency concrete anti-cracking and anti-permeability agent as a reference sample, testing the performances (shrinkage performance, 28d mechanical performance and impermeability) of each concrete according to the standards of GB 8076-.

TABLE 1 concrete shrinkage Performance test results of examples

Table 1 shows that after the high-efficiency concrete anti-cracking and anti-permeability agent is added, the shrinkage value is obviously reduced compared with the reference value, the shrinkage is more obvious in 3d, and the shrinkage can reach 82.5%; and the difference between the contraction value and the reference value is reduced along with the time, the most remarkable is realized at 90d, and the contraction value is at least 26.2%. The analysis shows that after the high-efficiency concrete anti-cracking and anti-permeability agent is added, the compactness of the concrete is enhanced, the amount of capillary pores causing shrinkage is effectively reduced, and a good anti-cracking effect is achieved.

Table 2 Experimental results of mechanical properties and deformation properties of concrete 28d in each example

Table 2 shows that, after the high-efficiency concrete anti-cracking and anti-permeability agent is added, the mechanical property and the deformation property of the concrete are obviously improved, the increase range is larger in the aspects of compressive strength, tensile strength and ultimate tensile value than the reference value, and the increase range is larger in the aspect of elastic modulus than the reference value, which indicates that the high-efficiency concrete anti-cracking and anti-permeability agent prepared by the embodiment of the invention can enhance the anti-cracking capability of the concrete.

TABLE 3 impermeability rating and electric flux test results for concrete 28d of each example

Sample (I)	Impervious label	Water penetration height (cm)	Electric flux (Coulomb)	Electric flux (%)
					Reference sample	P8	Permeable to water	1165	100
Example 1	P12	3.5	504	43.3
					Example 2	P12	3.6	518	44.5
Example 3	P12	4.0	576	49.4
					Example 4	P12	4.1	590	50.6
Example 5	P12	4.2	605	51.9
					Example 6	P12	4.4	634	54.4

Table 3 shows that after the high-efficiency concrete anti-cracking and anti-permeability agent is added, the water seepage height is lower than 4.5cm, so that the concrete has stronger anti-permeability capability and the permeability reducing performance is enhanced; under the condition that the impervious indexes are P & gt 12, the electric flux of the concrete is reduced by about 50 percent, which shows that the concrete has strong capability of resisting the inward permeation of media such as water, ions and the like.

Tables 1-3 show that the addition of the high-efficiency concrete anti-cracking and anti-permeability agent can enhance the anti-cracking and anti-permeability capability of the concrete, so that the concrete still has better working performance under the influences of climate influence, load influence, water permeation, acid radical ion permeation and the like.