CN100532314C - A kind of high-strength low-water-absorption cement substrate material slurry and preparation method thereof - Google Patents

Abstract

The present invention belongs to the building material technology field, in particular to relate to a cement base plate material with high-intension and low water-absorbing capacity and the corresponding preparation method. The mortar material uses a technical process of a self-compact active powder concrete to be cast into a plate with the thickness from several mm to more than 10mm. The present invention is made of cement, silicon ash, quartz powder, sand, water reducer, crack-proof agent and water according to the weight ratio. The present invention uses the new type water reducer and the rational weight ratio to decrease the water consumption and to make the flow expanding degree for the prepared cast mortar up to 255mm (flow degree of the mortar desk, sectioned cone circular mould, not being vibrated); and then the present invention can cast the plate with the required thickness directly without needing vacuum dehydration and pressure. The prepared plate is compact, with the water-absorbing capacity less than 2 percent that is far lower than that of each fibre strengthened cement plate in the prior market (about 20 percent). The folding strength can be adjusted by changing the content of the strengthened fibre, which can be up to 15-25MPa. The materials used in the present invention all are common industrial materials; so the present invention can simplify the manufacturing process, decrease the manufacturing cost greatly and enhance the product quality. The present invention can be widely used.

Description

A kind of high-strength low-water-absorption cement substrate material slurry and preparation method thereof

technical field

The invention belongs to the technical field of building materials, and in particular relates to a high-strength and low-water-absorption cement substrate material slurry and a preparation method thereof.

Background technique

At present, the inorganic material boards on the market mainly include asbestos cement boards, GRC boards, fiber-reinforced silicon calcium boards, glass magnesium boards (glass fiber reinforced magnesium oxychloride cement boards), etc. The common problem of these boards is that the water content and water absorption rate are very high, which greatly limits their application in places such as outdoor and humid environments (such as basements, underground passages and tunnels). In order to make up for this shortcoming, the method of carrying out waterproof treatment to the above-mentioned boards is mostly adopted now, the process is complicated, the cost is very high, and the problem cannot be solved fundamentally. Because waterproof treatment is mostly carried out on the surface of the board in the factory, the section cut on site cannot be waterproofed, which still exposes a series of problems caused by the board's water absorption and subsequent dimensional changes.

On the other hand, the current production process of fiber-reinforced inorganic material boards (cement boards, calcium silicate boards, glass magnesium boards, etc.) is mostly the paper-making method, which requires vacuum dehydration and roller compaction processes.

Finally, high-density cement-based materials prepared with a low water-cement ratio are prone to the problem of self-drying shrinkage. When it comes to forming thinner plates, it is easy to cause warping, cracking and chipping of the plates.

Contents of the invention

The purpose of the present invention is to provide a high-strength and low water absorption cement substrate material slurry and a preparation method thereof.

The high-strength and low water absorption cement substrate material slurry proposed by the present invention is composed of cement, silica fume, quartz powder, quartz sand, water reducing agent, anti-cracking agent and water, and its composition ratio is as follows:

Components Parts by mass

Cement 100

Silica fume 20～30

Quartz powder 27～42

Sand 100～120

Based on 100 parts by mass of the total of cement and silica fume, the amount of the water reducing agent is 0.80-1.4 parts by mass, the amount of the anti-cracking agent is 0.5-2 parts by mass, and the amount of water is 22-27 parts by mass.

In the present invention, steel fibers can also be added, and the addition of steel fibers is added according to the requirements of the strength grade, and the added amount is 0% to 2.5% of the total volume of the slurry.

In the present invention, the cement is one of Portland cement or ordinary Portland.

In the present invention, the silica fume is non-agglomerated silica fume, the _SiO2 content exceeds 92%, and the preferred dosage is 25 parts by mass.

In the present invention, the fineness of the quartz powder is above 300 mesh, and the preferred dosage is 37 parts by mass.

In the present invention, the sand is any one of quartz sand or yellow sand, etc., and the fineness of the quartz sand is 30-70 mesh; ordinary yellow sand can pass through a 0.63mm sieve. The preferred amount is 110 parts by mass.

In the present invention, the water reducer is a polycarboxylate water reducer, and the amount of the water reducer is based on its solid content, preferably 1.0-1.2% of the total mass of cement and silica fume.

In the present invention, the anti-cracking agent is polyethylene glycol with a molecular weight of 1000-1600, preferably in an amount of 1% of the total mass of cement and silica fume.

In the present invention, the steel fibers are steel fibers for concrete conforming to the standard JG/T3064-1999, such as steel fibers with a section of 0.25×0.25mm and a length of 13mm.

The preparation method of the high strength and low water absorption cement substrate material slurry proposed by the present invention, its specific steps are as follows:

(5) Weigh each component as required, pour cement, sand, silica fume, quartz powder and anti-cracking agent into the mixing pot, and dry mix for 0.8-1.5min;

(6) Add water reducing agent and half of the water consumption to the mixture obtained in step (1), and stir for 2-4min;

(7) Add the remaining part of water to the mixture obtained in step (2), and stir for 2-4min;

(8) If steel fiber needs to be added, add half of the steel fiber amount to step (3), stir for 2-5 minutes, then add the remaining steel fiber, stir for 2-4 minutes to obtain the desired product.

The present invention has following advantage:

1. The slurry of the present invention is prepared with a low water-to-binder ratio, and has self-leveling and self-compacting properties, and does not require vacuum dehydration and roller compaction processes in the sheet forming process.

2. Since the anti-cracking agent is used in the slurry of the present invention, the problem of warping and cracking of the board caused by the inherent self-drying shrinkage of the cement-based material with a low water-to-cement ratio is avoided.

3. Since the raw materials of the present invention are all mass-produced commercially available finished products, the raw materials are easy to obtain and are suitable for wide application.

The invention can directly cast plates with required thickness without vacuum dehydration and rolling compaction process, and adopts anti-cracking agent to prevent warping and cracking of cast plates. According to the different reinforcing fibers used, it can be directly mixed or sprinkled and embedded in the slurry, which simplifies the production process. The cast cement slurry used has a special formula, which has high compactness and low water absorption, and the obtained board can be used in outdoor and other humid places without waterproofing. The invention has a wide range of uses, for example, it can be used as the base material of various curtain walls, indoor and outdoor decorative panels and composite wall materials (such as composite thermal insulation walls).

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the examples. The material properties were determined on direct cast 8 mm thick plates.

Example 1: Slurry and board prepared using ordinary Portland cement. See Table 1 for raw materials and specifications, and Table 2 for material ratios and properties.

Table 1

Material Specification or grade source cement PO 42.5 ordinary Portland cement Shanghai Seal Cement Group Silica fume EM920U Elkem International Trading Shanghai Co., Ltd. Quartz powder 320 mesh Anhui Fengyang Fengcheng Powder Material Co., Ltd. Quartz sand 30～70 mesh Anhui Fengyang Fengcheng Powder Material Co., Ltd. steel fiber Section 0.25×0.25mm, length 13mm, conform to standard JG/T3064-1999. Produced by Shanghai Qingpu Shangta Metal Fiber Factory Superplasticizer PC new concrete high-efficiency water reducer; pH neutral; solid content 40%; viscosity (coated - 4 cups) 40s Shanghai Aoshen Architectural Chemical Technology Co., Ltd. Anti-cracking agent Polyethylene glycol, molecular weight 1000

Table 2 Slurry and boards prepared with ordinary Portland cement (parts by mass)

Example 2: Portland cement is used to prepare the prepared slurry and board. The specifications and manufacturers of the materials used are shown in Table 3, and the material ratio and properties are shown in Table 4.

table 3

Material Specification or grade source cement PII 52.5R Jiaxin Jingyang Cement Silica fume EM920U Elkem International Trading Shanghai Co., Ltd. Quartz powder 320 mesh Anhui Fengyang Fengcheng Powder Material Co., Ltd. yellow sand Pass 0.63mm sieve Ordinary yellow sand Superplasticizer GLENIUM SP-8CN Shanghai Master Building Materials Co., Ltd. Anti-cracking agent Polyethylene glycol, molecular weight 1600

Table 4 Slurries and panels prepared with Portland cement and their comparative examples

Embodiment 3: see Table 1 for raw material specifications, and see Table 5 for material proportions and properties.

Table 5 Slurries and panels prepared with ordinary Portland cement

Known from embodiment 1-embodiment 3, according to the slurry prepared by proportioning of the present invention and preparation process, its flow extension (utilize the truncated cone circular mold test of jumping table fluidity, but do not vibrate) surpasses 250mm, has automatic Compact performance, no need to vibrate when forming the product. The product is demoulded under normal temperature and humidity conditions for 1 day, then soaked in water at room temperature for 28 days, and the flexural strength of the sheet exceeds 15MPa; if it is cured with 90°C steam for 3 days, the flexural strength of the sheet exceeds 20MPa; it is a high-strength material that is easy to form. In addition, the obtained plate has a water absorption rate of less than 2%, and can be used in outdoor and other wet conditions without waterproofing.

Claims (5)

1, a kind of high-strength low-absorption cement base plate slurry is characterized in that being made up of cement, silicon ash, silica powder, quartz sand, water reducer, the agent of anti-cracking and water, and it is as follows that it forms proportioning:

Constituent mass part

Cement 100

Silicon ash 20～30

Quartzy 27～42

Sand 100～120

Summation according to cement and silicon ash is 100 mass parts meters, and water reducer is 0.80～1.4 mass parts, and the agent of anti-cracking is 0.5～2 mass parts, and water is 22～27 mass parts; Described anti-cracking agent is a polyoxyethylene glycol, and molecular weight is 1000～1600.

2, high-strength low-absorption cement base plate slurry according to claim 1 is characterized in that also adding steel fiber, and the add-on of steel fiber is 1%～2.5% of a slurry cumulative volume.

3, high-strength low-absorption cement base plate slurry according to claim 1 is characterized in that described cement is a kind of of silicate cement or normal silicate; Described silica powder fineness is more than 300 orders; Described sand be in quartz sand or the yellow ground any, the quartz sand fineness is 30～70 orders; Yellow ground is crossed the 0.63mm sieve and is got final product; Described water reducer is a polycarboxylate dehydragent.

4, high-strength low-absorption cement base plate slurry according to claim 2 is characterized in that described steel fiber is the concrete steel fiber of conformance with standard JG/T3064-1999.

5, a kind of preparation method of high-strength low-absorption cement base plate slurry as claimed in claim 2 is characterized in that concrete steps are as follows:

(1) each component of weighing is on request poured in the agitator kettle cement, sand, silicon ash, silica powder and the agent of anti-cracking into dry mixing 0.8-1.5min;

(2) in the compound of step (1) gained, add water reducer and half water consumption, stir 2-4min;

(3) in the mixture of step (2) gained, add remainder water, stir 2-4min;

(4) if need to add steel fiber, then in step (3), add half steel fiber consumption, stir 2-5min, then add remaining steel fiber again, stir 2-4min, promptly get desired product.