Novel magnesium high-performance concrete expansion anti-cracking agent and preparation method thereof

Abstract

The invention discloses a novel magnesium high-performance concrete expansion anti-cracking agent and a preparation method, and relates to the field of preparation of concrete expansion anti-cracking agents, the novel magnesium high-performance concrete expansion anti-cracking agent and the preparation method comprise the following steps: S1, a raw material selection step: firstly selecting P.O42.5 cement, then performing field treatment, and then adding the P.O42.5 cement into the cement; the method comprises the following steps of: selecting medium-grade river sand, controlling the silt content of a sand raw material to be below 3 percent, and selecting coal ash, mineral powder, stones, an additive and an anti-cracking agent for later use; according to the anti-cracking agent, working raw materials are mainly developed from gully boulders and rocks around a site, the mixing amount of cement in concrete can be greatly reduced, the construction cost is highly saved, meanwhile, the anti-cracking agent is applied to construction, the green and environment-friendly construction characteristics can be further fused, and the anti-cracking agent is beneficial to being popularized in follow-up construction.

Description

Technical Field

[0001] The invention relates to the field of preparation of concrete expansion and anti-cracking agents, in particular to a novel magnesium high-performance concrete expansion and anti-cracking agent and a preparation method thereof. Background Art

[0002] Magnesium anti-cracking agent adopts rotary kiln calcination technology, calcining high-quality magnesite at different temperatures, and then preparing it with some functional adjustment materials. It is divided into two types: R type and S type. The activity index of light-burned magnesium oxide in R-type magnesium anti-cracking agent is 50-100 s, and the expansion rate is relatively fast under normal temperature conditions. It is mainly used in spring, autumn and winter; the activity index of light-burned magnesium oxide in S-type magnesium anti-cracking agent is 100-200 s, and the expansion rate is relatively slow, which is mainly used in summer.

[0003] Ordinary new magnesium high-performance concrete expansion and anti-cracking agents are unable to control the joint time during pouring, and are unable to control it during the initial setting stage, and are unable to achieve adequate vibration construction treatment. They cannot reduce the probability of concrete roughness and construction cold joints in subsequent construction, and cannot avoid the problem of gaps at the interface between the two layers of poured concrete caused by the differences in the pouring time settings, especially when the shrinkage rates are inconsistent. It is difficult to effectively avoid the occurrence of point seepage, and at the same time cannot be highly beneficial to saving construction costs, and cannot further integrate green and environmentally friendly construction characteristics, which is not conducive to promotion in subsequent construction.

[0004] Therefore, those skilled in the art provide a novel magnesium high performance concrete expansion anti-cracking agent and a preparation method to solve the problems raised in the above background technology. Summary of the invention

[0005] The purpose of the present invention is to provide a new type of magnesium high-performance concrete expansion anti-cracking agent and a preparation method to solve the problems that the ordinary new type of magnesium high-performance concrete expansion anti-cracking agent proposed in the above background technology cannot control the joint time during pouring, cannot be controlled in the initial setting stage, cannot achieve the vibration construction treatment in place, cannot reduce the probability of concrete roughness and construction cold joint problems in subsequent construction, cannot avoid the problem of gaps at the interface between the two layers of poured concrete due to the difference in pouring time, especially when the shrinkage rate is inconsistent, and cannot effectively avoid the occurrence of point seepage. At the same time, it is not highly beneficial to save construction costs, and cannot further integrate green and environmentally friendly construction characteristics, which is not conducive to promotion in subsequent construction.

[0006] To achieve the above object, the present invention provides the following technical solutions: A novel magnesium high-performance concrete expansion and anti-cracking agent and a preparation method thereof, wherein the novel magnesium high-performance concrete expansion and anti-cracking agent and a preparation method thereof comprise the following steps: S1: Raw material selection step, first select cement with P·O42.5, then carry out on-site treatment to make it meet the indicators of engineering construction, select medium-grade river sand, the mud content of sand raw materials is controlled below 3%, and fly ash, mineral powder, gravel, admixtures and anti-cracking agents are selected for standby; S2: New magnesium high-performance concrete expansion anti-cracking agent ratio step, different ratios are used for concrete at different construction points, and then two groups are designed, namely the bottom plate group and the top plate group, where the bottom plate group and the top plate group both include water, cement, mineral powder, sand, admixtures, fly ash, gravel and anti-cracking agent; S3: Construction step, do a good job of pouring construction treatment for the bottom plate. In the design and construction of the bottom plate, the longest length of the bottom plate is controlled at 113m, and the one-time continuous pouring work is fully done. The pouring direction is according to Approaching the middle from the east and west sides, the pouring construction procedure of the expansion reinforced inner concrete was then carried out. In this construction process, two concretes with higher strength grades were selected, and the corresponding anti-cracking agent mixing amount was also increased accordingly. The amount used in this construction was increased by 5kg to prevent cold joints during construction. When dealing with ultra-long seamless construction, it is necessary to fully manage the self-waterproofing construction of the original concrete structure. During the on-site vibration construction, problems such as insufficient vibration and missed vibration must not occur, especially excessive vibration. It is necessary to focus on on-site management to prevent the concrete density from being too high.

[0007] As a preferred embodiment of the present invention: in the raw material selection step, the fineness modulus of the intermediate river sand is between 2.6 and 2.8, the stone can be ordinary crushed stone with a particle size range of 5-31.5 mm, the fly ash can be grade II fly ash, the mineral powder can be S95 grade ground slag powder, the admixture can be polycarboxylic acid high-performance water reducer, and the anti-cracking agent can be magnesium high-performance concrete anti-cracking agent.

[0008] As a preferred embodiment of the present invention: in the step of proportioning the new magnesium high-performance concrete expansion anti-cracking agent, 175 kg of water, 270 kg of cement, 58 kg of mineral powder, 780 kg of sand, 5.8 kg of admixture, 47 kg of fly ash, 1078 kg of gravel and 25 kg of anti-cracking agent can be selected from the base plate group.

[0009] As a preferred embodiment of the present invention: in the step of proportioning the new magnesium high-performance concrete expansion anti-cracking agent, 180 kg of water, 330 kg of cement, 55 kg of mineral powder, 723 kg of sand, 7.2 kg of admixture, 52 kg of fly ash, 1093 kg of gravel and 29 kg of anti-cracking agent can be selected from the top plate group.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a novel magnesium high-performance concrete expansion anti-cracking agent and a configuration method. During pouring, the joint time can be well controlled, the control can be performed in the initial setting stage, and the vibration construction treatment can be achieved in place, so the probability of concrete roughness and construction cold joint problems in subsequent construction can be reduced, and the problem of gaps at the interface between two layers of poured concrete caused by the difference in the pouring time can be avoided when the shrinkage rate is inconsistent, and the occurrence of point seepage can be effectively avoided. At the same time, the operating raw materials are mainly gully boulders and stone development around the site, which can greatly reduce the mixing amount of cement in the concrete, which is highly beneficial to saving construction costs. At the same time, the application of such anti-cracking agent in construction can further integrate the green and environmentally friendly construction characteristics, which is beneficial to promotion in subsequent construction. DETAILED DESCRIPTION

[0011] In an embodiment of the present invention, a novel magnesium high-performance concrete expansion and anti-cracking agent and a preparation method thereof are provided. The novel magnesium high-performance concrete expansion and anti-cracking agent and a preparation method thereof include the following steps: S1: Raw material selection step, first select cement with P·O42.5, then carry out on-site treatment to make it meet the indicators of engineering construction, select intermediate river sand, the mud content of sand raw materials is controlled below 3%, and fly ash, mineral powder, gravel, admixtures and anti-cracking agents are selected for standby; S2: New magnesium high-performance concrete expansion anti-cracking agent ratio step, different ratios are matched for concrete at different construction points, and then two groups are designed, namely the bottom plate group and the top plate group, where the bottom plate group and the top plate group both include water, cement, mineral powder, sand, admixtures, fly ash, gravel and anti-cracking agent; S3: Construction step, do a good job of pouring construction treatment for the bottom plate, during the design and construction of the bottom plate, The maximum length of the base plate is controlled at 113m, and full one-time continuous pouring work is done. The pouring direction is from the east and west sides to the middle, and then the pouring construction procedure of the expansion reinforced inner concrete is carried out. In this construction process, two concretes with higher strength grades are selected, and the corresponding anti-cracking agent mixing amount is also increased. The amount used in this construction is increased by 5kg to prevent cold joints during construction. When dealing with ultra-long seamless construction, it is necessary to fully manage the self-waterproofing construction of the original concrete structure. During the on-site vibration construction, problems such as insufficient vibration and missed vibration must not occur, especially excessive vibration. It is necessary to focus on on-site management to prevent the process from having too high concrete density.

[0012] During pouring, the joint time can be well controlled, it can be controlled in the initial setting stage, and the vibration construction treatment can be in place, which can reduce the probability of concrete roughness and construction cold joints in subsequent construction, and can avoid the difference in the setting of pouring time. In the case of inconsistent shrinkage rates, it can reduce the problem of gaps at the interface between the two layers of poured concrete, and effectively avoid the occurrence of point seepage. In the raw material selection step, the fineness modulus of intermediate river sand is between 2.6-2.8, ordinary crushed stone can be used as stone, and the particle size range is between 5-31.5mm, fly ash can be used as Class II fly ash, mineral powder can be used as S95 grade ground slag powder, admixture can be used as polycarboxylic acid high-performance water reducer, and anti-cracking agent can be used as magnesium high-performance concrete anti-cracking agent. In the proportioning process of the new magnesium high-performance concrete expansion and anti-cracking agent, 175kg of water, 270kg of cement, 58kg of mineral powder, 780kg of sand, 5.8kg of admixture, 47kg of fly ash, 1078kg of stone and 25kg of anti-cracking agent can be used in the bottom plate group. In the proportioning process of the new magnesium high-performance concrete expansion and anti-cracking agent, 180kg of water, 330kg of cement, 55kg of mineral powder, 723kg of sand, 7.2kg of admixture, 52kg of fly ash, 1093kg of stone and 29kg of anti-cracking agent can be used in the top plate group.

[0013] At the same time, the operating raw materials are mainly gully boulders and stone development around the site, which can greatly reduce the amount of cement mixed in the concrete, which is highly beneficial to saving construction costs. At the same time, the application of such anti-cracking agents in construction can further integrate the characteristics of green and environmentally friendly construction, which is conducive to promotion in subsequent construction.

[0014] The working principle of the present invention is: a novel magnesium high performance concrete expansion anti-cracking agent and a preparation method thereof comprises the following steps: S1: the step of selecting raw materials, firstly select cement with P·O42.5, then carry out on-site treatment to make it meet the indicators of engineering construction, select intermediate river sand, the mud content of sand raw materials is controlled below 3%, and fly ash, mineral powder, gravel, admixture and anti-cracking agent are selected for standby; in the step of selecting raw materials, the fineness modulus of intermediate river sand is between 2.6 and 2.8, ordinary crushed stone can be selected as gravel, and the particle size range is between 5 and 31.5 mm, fly ash can be selected from Grade II fly ash, mineral powder can be selected from S95 grade ground slag powder, polycarboxylic acid high-performance water reducing agent can be selected as admixture, and magnesium high-performance concrete anti-cracking agent can be selected as anti-cracking agent. S2: The proportioning steps of the new magnesium high-performance concrete expansion and anti-cracking agent, according to different proportions of concrete for different construction points, and then two groups are designed, namely the bottom plate group and the top plate group, wherein the bottom plate group and the top plate group both include water, cement, mineral powder, sand, admixture, fly ash, gravel and anti-cracking agent; in the proportioning steps of the new magnesium high-performance concrete expansion and anti-cracking agent, 175kg of water, 270kg of cement, 58kg of mineral powder, 780kg of sand, 5.8kg of admixture, 47kg of fly ash, 1078kg of gravel and 25kg of anti-cracking agent can be selected in the bottom plate group. In the mixing steps of the new magnesium high-performance concrete expansion and anti-cracking agent, 180kg of water, 330kg of cement, 55kg of mineral powder, 723kg of sand, 7.2kg of admixture, 52kg of fly ash, 1093kg of gravel and 29kg of anti-cracking agent can be used in the top plate group. S3: Construction steps, the pouring construction work of the base plate is carried out well. During the design and construction of the base plate, the maximum length of the base plate is controlled at 113m, and the one-time continuous pouring work is fully done. The pouring direction is from the east and west sides to the middle, and then the pouring construction procedure of the expansion reinforced inner concrete is carried out. In this construction process, two concretes with higher strength grades are selected, and the corresponding anti-cracking agent mixing amount is also increased. The amount used in this construction is increased by 5kg to prevent cold joints during construction; when processing ultra-long seamless construction, it is necessary to fully manage the self-waterproofing construction of the original concrete structure. During the on-site vibration construction, problems such as insufficient vibration and missed vibration should not occur, especially excessive vibration. It is necessary to focus on on-site management to prevent the process from having too high concrete density.

[0015] During pouring, the joint time can be well controlled, it can be controlled in the initial setting stage, and the vibration construction treatment can be completed, which can reduce the probability of concrete roughness and cold joints in subsequent construction, and can avoid the difference in the setting of pouring time. In the case of inconsistent shrinkage rates, it can reduce the problem of gaps at the interface between the two layers of poured concrete, and effectively avoid the occurrence of point seepage. At the same time, the operating raw materials are mainly gully boulders and stone development around the site, which can greatly reduce the amount of cement mixed in concrete, which is highly beneficial to saving construction costs. At the same time, the application of such anti-cracking agents in construction can further integrate the characteristics of green and environmentally friendly construction, which is conducive to promotion in subsequent construction.

[0016] What has been described above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A novel magnesium high performance concrete expansion anti-cracking agent and a preparation method, characterized in that: The novel magnesium high performance concrete expansion anti-cracking agent and preparation method thereof comprise the following steps: S1: Raw material selection step, first select cement with P·O42.5, then carry out on-site treatment to make it meet the indicators of engineering construction, select intermediate river sand, the mud content of sand raw materials is controlled below 3%, and fly ash, mineral powder, gravel, admixtures and anti-cracking agents are selected for standby; S2: New magnesium high-performance concrete expansion anti-cracking agent ratio step, different ratios are matched for concrete at different construction points, and then two groups are designed, namely the bottom plate group and the top plate group, where the bottom plate group and the top plate group both include water, cement, mineral powder, sand, admixtures, fly ash, gravel and anti-cracking agent; S3: Construction step, do a good job of pouring construction treatment for the bottom plate, during the design and construction of the bottom plate, The maximum length of the base plate is controlled at 113m, and full one-time continuous pouring work is done. The pouring direction is from the east and west sides to the middle, and then the pouring construction procedure of the expansion reinforced inner concrete is carried out. In this construction process, two concretes with higher strength grades are selected, and the corresponding anti-cracking agent mixing amount is also increased. The amount used in this construction is increased by 5kg to prevent cold joints during construction. When dealing with ultra-long seamless construction, it is necessary to fully manage the self-waterproofing construction of the original concrete structure. During the on-site vibration construction, problems such as insufficient vibration and missed vibration must not occur, especially excessive vibration. It is necessary to focus on on-site management to prevent the process from having too high concrete density.

2. A novel magnesium high performance concrete expansion anti-cracking agent and preparation method according to claim 1, characterized in that: In the step of selecting the raw materials, the fineness modulus of the intermediate river sand is between 2.6 and 2.8, the stone can be ordinary crushed stone with a particle size range of 5-31.5 mm, the fly ash can be grade II fly ash, the mineral powder can be S95 grade ground slag powder, the admixture can be polycarboxylic acid high-performance water reducing agent, and the anti-cracking agent can be magnesium high-performance concrete anti-cracking agent.

3. A novel magnesium high performance concrete expansion anti-cracking agent and preparation method according to claim 1, characterized in that: In the proportioning step of the novel magnesium high-performance concrete expansion anti-cracking agent, 175 kg of water, 270 kg of cement, 58 kg of mineral powder, 780 kg of sand, 5.8 kg of admixture, 47 kg of fly ash, 1078 kg of gravel and 25 kg of anti-cracking agent can be selected from the base plate group.

4. A novel magnesium high performance concrete expansion anti-cracking agent and preparation method according to claim 1, characterized in that: In the proportioning step of the novel magnesium high-performance concrete expansion anti-cracking agent, 180 kg of water, 330 kg of cement, 55 kg of mineral powder, 723 kg of sand, 7.2 kg of admixture, 52 kg of fly ash, 1093 kg of gravel and 29 kg of anti-cracking agent can be selected from the top plate group.