CN110041036A - A kind of alkali-activated carbonatite concrete material being specially adapted for underwater casting - Google Patents

Abstract

An alkali-excited concrete material specially suitable for underwater pouring belongs to a preparation method applied to alkali-excited concrete. In the method, slag and slaked lime are used as cementitious materials, medium and coarse sand and crushed stone are respectively used as fine and coarse aggregates, NaOH and liquid sodium silicate are used as activators, and polyacrylamide is added as underwater non-dispersible agent to prepare a It is an alkali-excited concrete material that can be directly poured underwater. The material is non-dispersible underwater and can be directly poured underwater. At the same time, the alkali-excited concrete of underwater pouring is not easy to produce the phenomenon of dispersion and segregation, which reduces the pollution caused to the construction water area and significantly improves the pouring quality of underwater concrete. Therefore, the invention of underwater pouring alkali-activated concrete material can significantly speed up the construction progress, significantly reduce the difficulty and cost of underwater construction, and have significant environmental and social benefits.

Description

A kind of alkali excited concrete material specially suitable for underwater pouring

technical field

A kind of alkali excited concrete material specially suitable for underwater pouring

Background technique

In order to further expand the living space and develop and utilize underwater resources, people build various projects in different waters. Due to the influence of natural conditions such as terrain, geology, hydrology, and meteorology, underwater engineering construction has the characteristics of high strength, complex technology and difficulty. Therefore, the materials for underwater engineering construction must have excellent performance. At present, the material used in underwater engineering construction in my country is mainly cement concrete. However, there are problems such as easy separation of aggregates and cementitious materials, bleeding, etc., which seriously affect the pouring quality of cement concrete, hinder the development of concrete strength, and cause serious environmental pollution to the construction waters. Therefore, people urgently seek a new type of concrete material specially suitable for underwater pouring to solve many problems caused by underwater pouring of cement concrete.

Alkali-excited materials are a new type of inorganic non-metallic materials newly developed in recent years. Most of these materials use natural aluminosilicate minerals or industrial solid waste as the main raw materials, mixed with other mineral admixtures and an appropriate amount of alkali silicate solution. Mixed, cured and formed under natural conditions, it is a kind of cementitious material bonded by aluminosilicate cementitious components. Compared with cement cementitious materials, alkali-activated materials have the advantages of high strength, short setting time, less pollution, good cohesion and strong water retention, and are more suitable for underwater pouring. Therefore, if the alkali-excited material can be further modified to make it non-dispersible underwater, then the alkali-excited material will be possible to replace cement and serve as a special building material suitable for underwater pouring. The application of alkali-excited materials and promotion is of great significance.

This patent uses industrial solid waste (slag) as the cementitious material for preparing alkali-excited concrete, medium-coarse sand and crushed stone as fine and coarse aggregates for preparing alkali-excited concrete, and supplemented with an appropriate amount of liquid sodium silicate and hydrogen. Sodium oxide is used as an activator, and an appropriate amount of polyacrylamide is added as an underwater non-dispersible agent to prepare an alkali-activated concrete material specially suitable for underwater pouring. Underwater pouring alkali-activated concrete material has the characteristics of underwater non-dispersibility, which can be directly poured under water, which can obviously alleviate the phenomenon of aggregate separation and bleeding, and will not cause pollution to the water body. At the same time, alkali-activated concrete uses industrial solid waste as the main raw material, which can not only eliminate the environmental pollution problem caused by the accumulation of industrial solid waste, but also alleviate the excessive dependence on cement and reduce the excessive consumption of non-renewable resources. A country with a shortage of energy and serious environmental pollution is of great significance.

SUMMARY OF THE INVENTION

Technical problem: the purpose of the present invention is to overcome the problem of aggregate separation and bleeding in underwater pouring cement concrete, with industrial solid waste (slag) as cementing material, medium and coarse sand, crushed stone are respectively fine and coarse aggregates. , using NaOH and liquid sodium silicate as activators, and then adding an appropriate amount of polyacrylamide as a non-dispersible agent to prepare an alkali-activated concrete material specially suitable for underwater pouring.

Technical scheme: an alkali-excited concrete material specially suitable for underwater pouring, its raw material composition and mass percentage are as follows: the cementitious material is 95%-80% of blast furnace granulated slag powder (the dosage is 313.5-264kg/m ³ ); Finely ground slaked lime powder 5%—20% (content 16.5—66kg/m ³ ); fine aggregate is medium-coarse sand (content 651kg/m ³ ); coarse aggregate is crushed stone (content 1056kg/m ³ ) ; The activator is liquid sodium silicate with modulus 1-3 (dosage 88kg/m ³ ); caustic soda (dosage NaOH 17.6kg/m ³ ); water (dosage 92.4kg/m ³ ); inseparable underwater The powder is polyacrylamide 2%-10% (the dosage is 6.6-33kg/m ³ ).

Use the above-mentioned non-dispersible alkali-excited concrete material specially suitable for underwater pouring: including weighing batching and mixing process, preparation process and pouring process, and the specific methods are as follows:

(1) Weighing ingredients and mixing process: First, add the weighed NaOH to the mixing water according to the mixing ratio, stir evenly and let it stand to cool; at the same time, weigh the blast furnace granulated slag powder, slaked lime powder and polyacrylamide. Ingredients, then put the three materials into the mixer and mix for 5 minutes to form a uniform mixture;

(2) Preparation process: add the NaOH solution cooled to room temperature into the stirring pot, then add the mixture, firstly stir slowly for 10 seconds and then quickly stir for 20 seconds. Then add liquid sodium silicate and medium-coarse sand and stir for 30 seconds. Finally, add crushed stone and stir for 30 seconds, and you can prepare for pouring;

(3) Pouring process: The prepared alkali-excited concrete material can be directly poured underwater.

The slag is S95 grade granulated blast furnace slag micropowder that meets the requirements of the GB/T 18046-2008 standard. The blast furnace granulated slag is treated by magnetic separation to remove iron, and ball-milled to make the specific surface area ≥ 400m ² /kg, wherein the particle size is greater than or equal to 400m 2 /kg. The ultrafine-grained blast furnace slag fine powder less than 30μm accounts for more than 90% of the total mass.

The slaked lime is the slaked lime powder after the quicklime powder is fully digested and dried, and the sieve allowance of the 0.08mm square-hole sieve is 0.

The liquid sodium silicate activator is an activator with a modulus between 1.0-3.0 and a Baumé degree between 37°-41°.

The NaOH is flake alkali, industrial grade, and the purity is ≥95%.

Beneficial effects: the present invention uses S95 grade granulated blast furnace slag micropowder and slaked lime powder as cementitious materials, medium and coarse sand and crushed stone are respectively fine aggregate and coarse aggregate, and liquid sodium silicate and NaOH are used as activators. An appropriate amount of polyacrylamide is used as an underwater non-dispersible agent to prepare an alkali-activated concrete material specially suitable for underwater pouring. Alkali-activated concrete uses industrial solid waste as the main raw material, which can replace cement concrete, slow down the excessive consumption of limestone raw materials by cement manufacturing, turn waste into treasure, and gradually eliminate various environmental pollution problems caused by the accumulation of industrial solid waste. environment, with significant environmental and social benefits. Compared with the prior art, it has the following advantages:

1) Can be directly poured underwater

Traditional cement concrete cannot be directly poured underwater due to the influence of aggregate separation and bleeding, while alkali-activated concrete is activated by liquid sodium silicate and NaOH, and its workability is obviously better than that of cement concrete, and it is not easy to produce aggregate separation and bleeding. Phenomenon. At the same time, the addition of polyacrylamide makes the alkali excited concrete have the characteristics of underwater non-dispersibility, which can be directly poured underwater. This is because polyacrylamide is a long linear organic polymer, which can absorb a large amount of free water and alkali to stimulate the gel particles, so that the long linear polymer chain is continuously stretched to form a closed three-dimensional space network organic polymer polymerization thing. The spatial network organic polymer can effectively seal the alkali-excited concrete, so that the alkali-excited concrete cannot be miscible with free water.

2) Reduce the consumption of non-renewable resources

Alkali-activated concrete usually uses industrial solid waste as cementitious material, which can gradually replace cement and reduce the demand for cement. Therefore, the application of alkali-activated concrete can not only alleviate the excessive consumption of limestone, clay and energy in cement production, and alleviate the problems of high energy consumption and high pollution caused by cement production, but also can turn waste into treasure and gradually eliminate industrial solid waste. All kinds of environmental pollution problems caused by a large number of accumulations.

3) Speed up the construction progress and reduce the difficulty and cost of construction

Because cement concrete cannot be directly poured underwater, underwater engineering construction often has the disadvantages of difficulty, long construction period and high cost. However, the alkali-excited concrete has the characteristics of non-dispersibility under water, and can be directly poured under water, which significantly simplifies the construction process, reduces the construction difficulty, speeds up the construction progress, and significantly reduces the construction cost.

4) Significant environmental and social benefits

Underwater pouring alkali-excited concrete has the characteristics of underwater non-dispersibility, which can effectively alleviate the dispersion and segregation phenomenon caused by underwater pouring alkali-excited concrete, and significantly reduce the pollution caused by concrete pouring to the construction water area, which has significant environmental benefits. At the same time, alkali-activated concrete uses industrial solid waste as a cementitious material, which can not only realize the resource utilization of waste, but also replace cement concrete and reduce the demand for cement. The social benefits generated will be immeasurable.

Advantages: The present invention uses slag and slaked lime as main raw materials, uses NaOH and liquid sodium silicate as activators, and supplements polyacrylamide as underwater non-dispersible agent to prepare an alkali-excited concrete material that can be directly poured underwater. Substitute cement concrete for direct underwater pouring, gradually reduce the demand for cement, and alleviate the problems of high energy consumption and high pollution caused by cement production. At the same time, the alkali-excited concrete poured underwater has the characteristics of underwater non-dispersibility, which significantly speeds up the construction progress, significantly reduces the construction difficulty and cost, and has significant environmental and social benefits.

Detailed ways

Embodiment 1: an alkali-excited concrete material specially suitable for underwater pouring, its raw material composition and mass percentage are as follows: the cementitious material is 95% of S95 grade granulated blast furnace slag powder (the dosage is 313.5kg/m ³ ); Fine slaked lime powder 5% (dosage 16.5kg/m ³ ); liquid sodium silicate with modulus 2.75 (dosage 88kg/m ³ ); flake soda (dosage NaOH 17.6kg/m ³ ); water (dosage 92.4kg/m ³ ); polyacrylamide 2% (dosage 6.6kg/m ³ ); fine aggregate is medium-coarse sand (dosage 651kg/m ³ ); coarse aggregate is crushed stone (dosage 1056kg/m 3 ) ³ ).

Table 1 Test mix ratio kg/m ³

Using the above-mentioned alkali-excited concrete material specially suitable for underwater pouring, its preparation process includes weighing batching and mixing process, preparation process and pouring process, and the specific methods are as follows:

(1) Weighing ingredients and mixing process: First, add the weighed NaOH to the mixing water according to the mixing ratio, stir and let stand to cool; at the same time, weigh the slag powder, slaked lime powder and polyacrylamide, and then mix The three ingredients are put into the mixer and mixed for 5 minutes to form a homogeneous mixture.

(2) Preparation process: add the NaOH solution cooled to room temperature into the stirring pot, and add the mixture, first slowly stir for 10 seconds and then quickly stir for 20 seconds. Then add liquid sodium silicate and medium-coarse sand and stir for 30 seconds. Finally, add crushed stone and stir for 30 seconds to prepare for pouring.

(3) Pouring process: The prepared alkali-excited concrete material can be directly poured underwater. According to the concrete strength inspection and evaluation standard (GB/T50107-2010), the measured compressive strength is shown in Table 4.

Example 2: The preparation method is the same as that in Example 1, omitted. The difference is: the composition and mass percentage of the alkali-excited concrete material specially suitable for underwater pouring are as follows: the cementitious material is 90% of S95 grade granulated blast furnace slag micropowder (the dosage is 297kg/m ³ ); ; ground slaked lime powder 10% (mixing volume 33kg/m ³ ); liquid sodium silicate with modulus 2.75 (mixing volume 88kg/m ³ ); flake soda (mixing volume of NaOH 17.6kg/m ³ ); 92.4kg/m ³ ); polyacrylamide 5% (dosage 16.5kg/m ³ ); fine aggregate is medium-coarse sand (dosage 651kg/m ³ ); coarse aggregate is crushed stone (dosage 1056kg/m 3 ) ^m3 ).

Table 2 Test mix ratio kg/m ³

Example 3: The preparation method is the same as that in Example 1, omitted. The difference is: the composition of the alkali-excited concrete material specially suitable for underwater pouring and its mass percentage are as follows: the cementitious material is 80% of S95 grade granulated blast furnace slag micropowder (the dosage is 264kg/m ³ ); ; ground slaked lime powder 20% (dosage 66kg/m ³ ); liquid sodium silicate with modulus 2.75 (dosage 88kg/m ³ ); flake soda (dosing NaOH 17.6kg/m ³ ); 92.4kg/m ³ ); polyacrylamide 10% (admixture 33kg/m ³ ); fine aggregate is medium-coarse sand (concentration 651kg/m ³ ); coarse aggregate is crushed stone (concentration 1056kg/m 3 ) ³ ).

Table 3 Test mix ratio kg/m ³

Table 4 Alkali-activated concrete properties with different mix ratios

Claims (6)

1. a kind of alkali-activated carbonatite concrete material for being specially adapted for underwater casting of the present invention, raw material composition and mass percent are such as Under: cementitious material is the (313.5-264kg/m of volume of granulated blast-furnace slag micropowder 95%-80%³)；Levigate hydrated lime in powder 5%-20% (16.5-66kg/m of volume³)；Fine aggregate is medium coarse sand (volume 651kg/m³)；Coarse aggregate is rubble (volume 1056kg/m³)；Exciting agent is liquid sodium silicate (the volume 88kg/m of modulus 1-3³)；Piece alkali (NaOH volume 17.6kg/m³)；Water (volume 92.4kg/m³)；Underwater inseparable powder is the (6.6-33kg/m of volume of polyacrylamide 2%-10%³)。

2. using a kind of above-mentioned alkali-activated carbonatite concrete material for being specially adapted for underwater casting, including weighing ingredient and mixing work Skill, preparation process and casting craft, the specific method is as follows:

(1) ingredient and hybrid technique are weighed: load weighted NaOH being added in mixing water first, in accordance with match ratio, stirring is equal It is even and stand cooling；Granulated blast-furnace slag micropowder, hydrated lime in powder and polyacrylamide are subjected to weighing ingredient simultaneously, then will Three kinds of materials are put into batch mixer and mix 5 minutes, form uniform mixture；

(2) preparation process: agitated kettle is added in the NaOH solution that will be cooled to room temperature, and mixture is then added, first stirs 10 seconds slowly again It stirs fastly 20 seconds.It adds liquid sodium silicate and medium coarse sand and stirs 30 seconds, be eventually adding rubble and stir fastly 30 seconds fastly, that is, be ready for pouring It builds；

(3) casting craft: the alkali-activated carbonatite concrete material for preparing completion can directly carry out underwater casting.

3. the miberal powder is to meet S95 grades of graining blast-furnace cinder micro-powders, granulated blast-furnace mine as defined in GB/T 18046-2008 standard Slag is handled through iron removal by magnetic separation, and ball milling reaches specific surface area >=400m²/ kg, wherein superfine graining mine of the partial size less than 30 μm Slag micro mist accounts for 90% of gross mass or more.

4. the hydrated lime in powder is hydrated lime in powder of the calcium lime powder after sufficiently resolution, drying, the screen over-size of 0.08mm square hole screen It is 0.

5. the liquid sodium silicate exciting agent is the exciting agent that modulus is between 1.0-3.0, Baume degrees is between 37 ° -41 °.

6. NaOH described in is piece alkali, technical grade, purity >=95%.