CN114394788B - Special pervious concrete for pervious bricks and pervious bricks made of concrete - Google Patents

Abstract

The application relates to a special permeable concrete for permeable bricks and a permeable brick made of the concrete, belonging to the field of concrete. The raw materials comprise cement, water, broken stone, filling material, defoaming agent and cementing agent, wherein the cementing agent comprises the following raw materials: epoxy resin, polytrimethylene carbonate, diacetone acrylamide, hydroxypropyl acrylate. The preparation method comprises the following steps: 1) Uniformly mixing the broken stone, the cementing agent and the defoaming agent, and then mixing and stirring the cement, the filling material and the water; 2) Paving the mixture in a mold, and placing the mold in a pressing machine for vibration pressing processing to obtain a semi-finished product of the water permeable brick; 3) And (3) placing the semi-finished product of the water permeable brick in a curing chamber, standing and curing for 6-8 days, then removing the mold, and humidifying and curing for 21-28 days to obtain the water permeable brick. The water permeable brick has high mechanical strength, high water permeability and high durability.

Description

Special permeable concrete for permeable brick and permeable brick made of same

Technical Field

The invention relates to the field of concrete, in particular to permeable concrete special for permeable bricks and a permeable brick prepared from the permeable concrete.

Background

The water permeable brick is a prefabricated brick commonly used in pavement paving engineering, at present, most of the water permeable bricks are sintered by using argil, and the sintered bricks have the defects of high energy consumption, unstable quality and the like, so in recent years, the concrete water permeable brick is gradually applied and developed.

The concrete permeable brick is a prefabricated brick molded by adopting permeable concrete, the permeable concrete is porous concrete mixed by broken stones, cement and water, and the permeable concrete does not contain fine sand, and the broken stones are coated with a layer of thin cement slurry, so that the broken stones are mutually bonded to form a honeycomb structure with a plurality of pores inside, and the concrete permeable brick has the characteristic of water permeability similar to that of a sintered brick. However, since the broken stones of the concrete permeable brick are only bonded by the cement paste, the strength is poor, and the problems of brick cracking or broken stone loosening and collapsing are likely to occur, so that further improvement is needed.

Disclosure of Invention

In order to improve the mechanical strength of the brick that permeates water, this application provides a brick that permeates water that special concrete and utilize this concrete to make that permeates water of brick.

The application provides a pair of brick special use that permeates water and the brick that permeates water that utilizes this concrete to make adopts following technical scheme:

in a first aspect, the application provides a special pervious concrete for pervious bricks, which adopts the following technical scheme:

the special permeable concrete for the permeable brick comprises the following raw materials in parts by weight:

114-125 parts of cement;

58-63 parts of water;

367 to 384 parts of macadam;

42-52 parts of filler;

4-5 parts of a defoaming agent;

41.3-52 parts of cementing agent;

the cementing agent comprises the following raw materials in parts by weight:

20-30 parts of epoxy resin, 12-15 parts of polytrimethylene carbonate, 2.7-3.2 parts of diacetone acrylamide and 3-4 parts of hydroxypropyl acrylate.

The cement, the filler and the broken stone are well bonded by adopting the epoxy resin, the diacetone acrylamide, the hydroxypropyl acrylate and the polytrimethylene carbonate as the cementing agent, so that the point contact among internal materials is more continuous, the mechanical strength of the concrete is enhanced, in addition, the diacetone acrylamide and the hydroxypropyl acrylate can be copolymerized, the bonding strength among the concrete materials is enhanced, the compressive strength of the concrete is further enhanced, the acetone acrylamide-hydroxypropyl acrylate copolymer and the polytrimethylene carbonate are grafted on an epoxy resin chain segment in an alkaline environment of a concrete hydration reaction, the effect of the epoxy resin for flexibly coating the materials is enhanced, the hydrophilicity of the epoxy resin after film forming is also improved, rainwater can quickly permeate downwards when falling on the surface of the concrete, the moisture retained on the surface of the concrete is reduced, the film is formed at the gaps among the broken stone, the filler and the surfaces of cement particles in the concrete, the retention of the moisture in the concrete is reduced, the moisture removal is effectively accelerated, the harmful ion erosion of the concrete in the moisture is reduced, and the durability of the concrete is improved.

Preferably, the cementing agent also comprises the following raw materials in parts by weight: 2.5-3.5 parts of polyvinylpyrrolidone.

By adding polyvinylpyrrolidone and combining with a cementing agent formed by epoxy resin, diacetone acrylamide, hydroxypropyl acrylate and polytrimethylene carbonate, the cementing agent has higher cohesiveness and film-forming property, so that the point contact cohesive strength of the inner part of the concrete is better, and the inner pores of the concrete can form a more communicated water permeable channel, thereby improving the strength and water permeability of the concrete.

Preferably, the filler comprises the following raw materials in parts by weight: fumed silica, polyester fiber, diatomaceous earth.

By adopting the raw materials as the filling material of the concrete, the fumed silica can improve the hydration reaction degree of the concrete, fill small pores of concrete broken stones, further improve the compressive strength of the concrete, improve the cracking resistance of the concrete under the combined action of the polyester fiber and the cementing agent, reduce the water absorption of the concrete, contribute to better drainage, and the diatomite can improve the compressive strength and corrosion resistance of the concrete, and is favorable for enabling the concrete to be more durable.

Preferably, the defoamer is polydimethylsiloxane.

By adopting the polydimethylsiloxane as the defoaming agent, the polydimethylsiloxane has better compatibility with epoxy resin, diacetone acrylamide, hydroxypropyl acrylate and polytrimethylene carbonate, is beneficial to better ensuring that the cementing agent is dispersed in concrete to take effect, and the polydimethylsiloxane not only can reduce pores generated by bubbles in the concrete so as to reduce a water-permeable channel with low strength and without broken stone support, so that the water-permeable concrete has better compressive strength, but also can increase the viscosity of the cementing agent and improve the processability of the concrete.

Preferably, the particle size of the crushed stone is 4-7mm.

By adopting the concrete made of the crushed stones with the grain sizes of 4-7mm, the porosity among the inner crushed stones can be higher, and the compressive strength of the concrete can be maintained at a higher level.

In a second aspect, the application provides a water permeable brick, which adopts the following technical scheme:

a permeable brick is made of concrete special for the permeable brick.

The permeable brick made of the concrete has high internal porosity and good compressive strength, is particularly suitable for pavement paving, contributes to pavement drainage and has good application value.

Preferably, the preparation method of the water permeable brick comprises the following steps:

step 1) uniformly mixing the broken stone, the cementing agent and the defoaming agent according to a ratio to obtain a first mixture, then mixing the first mixture, the cement, the filler and the water according to a ratio and stirring for 5-10min to obtain a second mixture;

step 2) paving the second mixture in a mold, and placing the mold in a pressing machine for vibration pressing processing to obtain a semi-finished product of the water permeable brick;

and 3) placing the semi-finished product of the water permeable brick in a curing room for standing and curing for 6-8 days, then removing the mold, and carrying out water spraying humidification and curing on the water permeable brick for 21-28 days to obtain the water permeable brick.

By adopting the method, the broken stones are firstly mixed with the cementing agent and the defoaming agent, so that the surfaces of the broken stones are fully coated, the broken stones can be better and uniformly dispersed to serve as a supporting framework of concrete subsequently, then the broken stones are mixed with cement, filling materials and water to prepare pervious concrete, and the pervious concrete is compacted by vibration, so that the concrete is compact in interior, uniform in strength, complete in surface and good in compactness, and a supporting point of a pervious channel formed between the broken stones is more stable, so that the pervious brick has good compressive strength.

Preferably, in the step 2), during the vibration pressing, the pressure is set to be 23 +/-1 Mpa, the pressing time is 5-6s, and the vibration frequency is 60 +/-1 Hz.

By controlling the parameters of the vibration pressing in the above range, the broken stones and the fillers of the permeable brick are not damaged due to excessive pressing, so that the problems of reducing the water permeability and the compressive strength of concrete are not easily caused, and the permeable brick has good structural stability.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the epoxy resin, the polytrimethylene carbonate, the diacetone acrylamide and the hydroxypropyl acrylate are used as the cementing agent, so that the broken stone, the cement and the filler have good cohesive force, the interior of the concrete can have higher strength without being filled and bonded by fine sand, and the concrete only takes the broken stone as a framework, so that the communicated porosity in the concrete is high, and the concrete has good water permeability, and the cementing agent can improve the hydrophilicity of the concrete, so that the water can quickly wet the surface of the concrete and can be drained;

2. the permeable brick is prepared by prefabricating the permeable concrete, has high internal porosity, is particularly suitable for being laid on a road surface as a prefabricated brick, is beneficial to quickly draining rainwater on the road surface, reduces the problem of accumulated water on the road surface, has the compressive strength equivalent to that of the traditional baked brick, but is more energy-saving due to the adoption of the permeable brick prepared from the concrete, can be industrialized in batch and has good application value.

Detailed Description

The present application will be described in further detail with reference to examples.

Examples

Example 1

The raw materials of the special pervious concrete for the pervious brick comprise cement, water, broken stones, a filling material, a defoaming agent and a cementing agent, wherein the grain diameter of the broken stones is 4-7mm, the filling material is fumed silica, polyester fiber and diatomite, the defoaming agent is a SP-6103 polyether defoaming agent of the three-product science and technology, and the cementing agent is polytrimethylene carbonate, diacetone acrylamide and hydroxypropyl acrylate.

The specific adding amount of the raw materials is as follows:

118kg of cement, 60kg of water, 372kg of macadam, 23kg of fumed silica, 8kg of polyester fiber, 16kg of diatomite, 5kg of polyether defoamer, 25kg of epoxy resin, 12kg of polytrimethylene carbonate, 3kg of diacetone acrylamide and 3.5kg of hydroxypropyl acrylate.

Example 2

The special pervious concrete for the pervious brick is prepared from the following raw materials in percentage by weight in example 1:

120kg of cement, 60kg of water, 375kg of crushed stone, 22kg of fumed silica, 9kg of polyester fiber, 15kg of diatomite, 4kg of polydimethylsiloxane, 30kg of epoxy resin, 14kg of polytrimethylene carbonate, 2.8kg of diacetone acrylamide and 3.2kg of hydroxypropyl acrylate.

Example 3

The raw materials of the pervious concrete special for the pervious brick comprise cement, water, broken stones, a filling material, a defoaming agent and a cementing agent, wherein the grain diameter of the broken stones is 4-7mm, the filling material comprises fumed silica, polyester fiber and diatomite, the defoaming agent is a SI-2292 polydimethyl siloxane defoaming agent of Pasteur, and the cementing agent comprises polytrimethylene carbonate, diacetone acrylamide and hydroxypropyl acrylate.

The specific adding amount of the raw materials is as follows:

114kg of cement, 58kg of water, 367kg of broken stone, 20kg of fumed silica, 8kg of polyester fiber, 14kg of diatomite, 4kg of polydimethylsiloxane, 22kg of epoxy resin, 12kg of polytrimethylene carbonate, 2.7kg of diacetone acrylamide and 3kg of hydroxypropyl acrylate.

Example 4

The raw materials of the special pervious concrete for the pervious bricks comprise cement, water, broken stones, a filling material, a defoaming agent and a cementing agent, wherein the grain diameter of the broken stones is 4-7mm, the filling material is fumed silica, polyester fiber and diatomite, the defoaming agent is a SI-2292 polydimethyl siloxane defoaming agent of Pasteur, and the cementing agent is polytrimethylene carbonate, diacetone acrylamide, hydroxypropyl acrylate and polyvinylpyrrolidone.

The specific adding amount of the raw materials is as follows:

125kg of cement, 63kg of water, 384kg of broken stones, 25kg of fumed silica, 10kg of polyester fibers, 17kg of diatomite, 5kg of polydimethylsiloxane, 28kg of epoxy resin, 15kg of polytrimethylene carbonate, 3.2kg of diacetone acrylamide, 4kg of hydroxypropyl acrylate and 1.8kg of polyvinylpyrrolidone.

Example 5

The special pervious concrete for the pervious brick has the raw materials consistent with those in example 4, and the specific adding amount of the raw materials is as follows:

122kg of cement, 62kg of water, 379kg of broken stone, 23kg of fumed silica, 9kg of polyester fiber, 15kg of diatomite, 4kg of polydimethylsiloxane, 20kg of epoxy resin, 13kg of polytrimethylene carbonate, 2.8kg of diacetone acrylamide, 4kg of hydroxypropyl acrylate and 1.5kg of polyvinylpyrrolidone.

Example 6

A water permeable brick is prepared by the following steps:

step 1) according to the mixture ratio of the embodiment 1, uniformly mixing the broken stone, the cementing agent and the defoaming agent according to the mixture ratio to obtain a first mixture, and then mixing and stirring the first mixture, the cement, the filler and the water for 5min to obtain a second mixture;

step 2) paving the second mixture in a mold, placing the mold in a pressing machine, and performing vibration pressing processing for 5s under the pressure of 23 +/-1 Mpa and the vibration frequency of 60 +/-1 Hz to obtain a semi-finished product of the water permeable brick;

and 3) placing the semi-finished product of the water permeable brick in a curing room for standing and curing for 7 days, then removing the mold, and carrying out water spraying humidification and curing on the water permeable brick for 21 days to obtain the water permeable brick.

In other embodiments, the concrete for preparing the water permeable brick is made of the concrete of one of embodiments 2 to 5, and the standing curing time can be 6 to 8 days, and the humidifying curing time can be 21 to 28 days.

Comparative example

Comparative example 1: the difference from example 1 is that the polytrimethylene carbonate in comparative example 1 was replaced with an equal mass of epoxy resin.

Comparative example 2: the difference from example 1 is that diacetone acrylamide in comparative example 1 is added instead of using an equal mass of epoxy resin.

Comparative example 3: the difference from example 1 is that hydroxypropyl acrylate in comparative example 1 was replaced with equal mass of epoxy resin.

Comparative example 4: the difference from example 1 is that the polytrimethylene carbonate, diacetone acrylamide and hydroxypropyl acrylate in comparative example 1 were replaced with equal mass of epoxy resin.

Performance test

1. Test sample

The concrete of examples 1 to 5 and comparative examples 1 to 4 were processed into 240X 115X 53mm square water permeable bricks by the method of example 6, and the water permeable bricks made of the concrete of examples 1 to 5 were set as test group samples 1 to 5, respectively, and the water permeable bricks made of the concrete of comparative examples 1 to 4 were set as control group samples 1 to 4, respectively.

2. Detection item and detection basis

2.1. Coefficient of water permeability

The water permeability coefficient (mm/s) of the test specimen was measured according to the method prescribed in the standard GB/T25993-2010 permeable pavement bricks and panels.

2.2. Flexural strength

The flexural strength (Mpa) of the test specimen was measured according to the method specified in the standard GB/T25993-2010 "water permeable pavement bricks and panels".

2.3. Compressive strength

The compression strength (Mpa) of the sample is detected according to the method specified in the standard GB/T50081-2002 standard for testing the mechanical properties of common concrete.

2.4. Water absorption

Water absorption (%) of the alkali test specimen according to the method specified in standard G/T4111-2013 "test methods for concrete blocks and bricks").

2.5. Freezing resistance

According to a method specified in GB/T25993-2010 permeable pavement bricks and permeable pavement slabs, a test sample is subjected to freeze-thaw cycling for 15 times at-15 ℃, and the compressive strength loss rate (%) of the test sample is detected.

3. Detecting data and analyzing

The measured data of the permeability coefficient, the breaking strength, the compressive strength, the freezing resistance and the water absorption of the experimental group samples 1 to 5 and the control group samples 1 to 4 are shown in the table below.

TABLE 1 test data

According to the detection data, the water permeability coefficient, the breaking strength and the compressive strength of the water permeable bricks of the experimental group samples 1-5 are high and can reach the quality requirement level of the water permeable pavement bricks, and the water permeable bricks made of the concrete with the formula have high porosity, are compact and stable in internal structure and have excellent mechanical properties. In addition, the water absorption rates of the experimental group samples 1-5 are all below 5%, and the strength loss at the later stage of the freeze-thaw test is lower than 10%, which shows that although the porosity of the experimental group samples 1-5 is high, the connectivity of pores is good, the drainage effect is good, and water is not easy to permeate and remain in gaps inside concrete, so that the water permeable brick has good frost resistance and is more durable when being applied to pavements.

The test results of the samples 1-4 in the control group show that the water permeable brick of the present application shows better level in both water permeability and mechanical strength, and the water permeable brick is mainly improved by using epoxy resin, diacetone acrylamide, hydroxypropyl acrylate and polytrimethylene carbonate as the cementing agent. The macadam in the concrete obtains a good bonding effect by utilizing the interaction of the reaction among diacetone acrylamide, hydroxypropyl acrylate and polytrimethylene carbonate, and even if the porosity among the macadams is high, the point contact support of the macadam is more continuous, so that the concrete has good water permeability and good mechanical property.

In addition, the comparison of the detection results of the experimental group samples 1 to 3 and the experimental group samples 4 to 5 shows that the addition of polyvinylpyrrolidone as a cementing agent to concrete can further improve the bonding strength of the broken stones in the concrete and the film forming property of the broken stone interface, so that the water permeability, water absorbability and frost resistance of the water permeable brick are further improved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims (7)

1. The special pervious concrete for the pervious bricks is characterized by comprising the following raw materials in parts by weight:

114-125 parts of cement;

58-63 parts of water;

367-384 parts of rubble;

42-52 parts of filler;

4-5 parts of a defoaming agent;

41.3-52 parts of cementing agent;

the cementing agent comprises the following raw materials in parts by weight:

20-30 parts of epoxy resin, 12-15 parts of polytrimethylene carbonate, 2.7-3.2 parts of diacetone acrylamide, 3-4 parts of hydroxypropyl acrylate and 1.5-1.8 parts of polyvinylpyrrolidone.

2. The special pervious concrete for pervious bricks according to claim 1, wherein the filler comprises the following raw materials in parts by weight: 20-25 parts of fumed silica, 8-10 parts of polyester fiber and 14-17 parts of diatomite.

3. The special pervious concrete for pervious bricks in claim 1, wherein the defoaming agent is polydimethylsiloxane.

4. The special pervious concrete for pervious bricks in claim 1, wherein the particle size of the broken stone is 4-7mm.

5. A water permeable brick characterized in that it is made of the concrete for water permeable bricks claimed in any one of claims 1 to 4.

6. The water permeable brick according to claim 5, wherein the preparation method of the water permeable brick is as follows:

step 1) uniformly mixing the broken stone, the cementing agent and the defoaming agent according to a ratio to obtain a first mixed material, and then mixing the first mixed material, the cement, the filler and the water according to a ratio and stirring for 5-10min to obtain a second mixed material;

step 2) paving the second mixture in a mold, and placing the mold in a press for vibration pressing processing to obtain a semi-finished product of the water permeable brick;

and 3) placing the semi-finished product of the water permeable brick in a curing room for standing and curing for 6-8 days, then removing the mold, and carrying out water spraying humidification and curing on the water permeable brick for 21-28 days to obtain the water permeable brick.

7. The water permeable brick according to claim 6, wherein in the step 2) of vibration pressing, the pressure is set to 23 ± 1Mpa, the pressing time is 5-6s, and the vibration frequency is 60 ± 1Hz.