CN101817655B - Novel shrinkage reducing compacting agent special for concrete - Google Patents

Abstract

The invention relates to products which belong to the technical field of concrete admixture. The technology is characterized by the following steps of: preparing stock solution which comprises the following components: deionized water, calcium oxide, sulphur powder and catalyst, wherein the catalyst consists of mixed solution of methoxypolyethylene glycol, dimethyl 1,3-propanediol and alkylphenolpolyoxyethylene ether sodium sulfate; and then preparing an inorganic waterproof shrinkage reducing compacting agent for inorganic concrete, wherein the inorganic waterproof shrinkage reducing compacting agent comprises the following components: the deionized water, the stock solution, triethanolamine, the methoxypolyethylene glycol, the dimethyl 1,3-propanediol, the alkylphenol polyoxyethylene ether sodium sulfate, silicate and a defoaming agent DF-642. The novel shrinkage reducing compacting agent special for the concrete can effectively reduce early shrinkage of the concrete, reduce crack risk, improve compactness of the concrete, improve porosity structure, realize waterproof function and seepage-proof function with low intermingled quantity (0.1 to 2 percent), and improve durability of the concrete to physical corrosion and chemical corrosion. The invention relates to an III type compacting agent used for increasing the compactness and improving the strength of the concrete. The novel shrinkage reducing compacting agent special for the concrete is most suitable for the engineering field requiring high concrete strength and high waterproofing quality.

Description

A kind of reduction compacting agent special for concrete

Technical field

The invention belongs to technical field of concrete additives, concrete can change through in concrete mix, mixing some material in the performance of newly mixing and stirring under the hardening state, and this has benefited from the develop rapidly of concrete admixture industry over nearest 50 years.There have been hundreds of additive products selling now on the market.In some country, 70%～80% concrete is mixed with one or more admixtures.

Admixture alters a great deal on component, from tensio-active agent and soluble salt to polymkeric substance and insoluble mineral.Generally, they are used to improve concrete workability, and accelerate or delay time of coagulation, control strength development and improve concrete unfreezing, temperature difference cracking, the alkali aggregate expands, the weather resistance of sulphate attack and steel bar corrosion.

Background technology

Civil engineering structure is such as bridge, harbour engineering, tunnel, railway, underground works, municipal fabrication, airport etc. in modern times, and concrete is most important material of construction.The weather resistance of fabrication more and more becomes the focus that people pay close attention to and study.Therefore, improve in the civil engineering structure concrete environment weather resistance down under arms, then become the major measure of raising works weather resistance.

Comprehensive, the concrete structure weather resistance of environment under arms probably can be divided into following several kinds of degradation mechanism:

(1) physical action: alternation of wetting and drying, freeze-thaw damage, shrinkage cracking, salt freezes destruction etc.;

(2) chemical action: chemical mediator corrodes, sulphate attack, carboniogenesis, steel bar corrosion, alkali etc.;

Concrete material itself is a kind of porous material, its void distribution in from the microcosmic hole of tens nanometers to millimetre-sized macroscopical visible bore, and macroscopic crack etc.Research shows that above-described concrete degradation mechanism in time is all closely related in concrete perviousness, comprises that the perviousness of water, the perviousness of gas, various ionic are infiltrative.In the presence that does not have water, concrete destruction deterioration risk can reduce greatly.Therefore, improve concrete waterproof, barrier performance is the important measures that improve concrete durability always.

The factor relevant with concrete permeability mainly contains two: pore fluid of concrete structure and crack.

Improve the pore fluid of concrete structure, comprise the connectedness that reduces big hole number, reduces hole, the measures such as surface tension that reduce the concrete hole wall, can reduce intrusion and the infiltration of moisture in hole effectively.

The crack is another important factor that influences concrete permeability.The concrete that do not ftracture does not fully almost have.Thereby the volumetric shrinkage that the reason of concrete cracking probably has self-constriction, dry shrinkage to cause causes cracking; Thermal stress shrinkage cracking that causes owing to the concrete hydrating temperature rise etc.The volumetric shrinkage that these reasons cause is approximately 0.04%～0.06% of own vol.These bring very big harm shrink for concrete volume stability, weather resistance, are embodied in: 1) crack on concrete destroys 2) concrete permeability resistance is bad causes seepage failure 3) the open crack of concrete caused steel bars in concrete corrosion 4) concrete contraction can influence concrete volume stability.Therefore through reducing the early stage volumetric shrinkage of concrete, be the important measures that reduce the concrete cracking risk.

For a long time, prevent and handle problems to be the problem that causes that engineering circle is paid attention to about fissured, general counter-measure is exactly an admixture swelling agent in concrete always.Swelling agent is that a kind of concrete (comprising mortar and cement paste) that in the cement setting process of setting, makes produces controllable expansion to reduce the admixture that shrinks.Its rely on self chemical reaction or with the reaction of other compositions of cement, produce certain confined expansion in hydration period, with the contraction of compensating concrete.

The swelling agent kind of using on the engineering at present is more; Chemical ingredients and expansion principle different according to them are broadly divided into following several types: sulplo-aluminate is that swelling agent, lime swelling agent, iron powder are conventional expanded agent such as swelling agent, Natural manganese dioxide type swelling agent, compound swelling agent.

Swelling agent is mainly used in for minimizing dry shrinkage expansive concrete with in order to utilize bulging force to prepare self-stressing concrete.Expansive concrete is used for the seepage control and crack resistance of buildings, tank, retention basin, road surface, slab bridge face, underground works etc.

The purpose of using cement expansive material is: 1) improve concrete crack resistance, reduce and prevent fissured appearance; 2) block the infiltration of concrete pore, improve concrete impervious grade standard; 3) make over-long reinforced concrete structure keep continuity, satisfy the architectural design requirement; 4) do not establish the post-cast strip to speed up the work, prevent to handle the bad vault infiltration that causes because of the post-cast strip.

But the above traditional expansion economization agent effect is single, volume is bigger; Be generally 5% one 10% of cement amount in the concrete, and have the risk of late expansion, the lesson of existing many cases engineering failure; Mix swelling agent and cause the excessive cracking of concrete late expansion, quickened the damage of structure.Therefore, at present in engineering practice the use of swelling agent be still very careful.

In addition, the present water-resisting agent product category of China is more, inorganic water-proof agent is arranged, organic waterproof agent and composite water-proof agent.Effect is many to reduce hole and filling capillary channel, and it is main reducing the perviousness of material under hydrostaticpressure.Wherein inorganic water-proof agent mainly comprises chloride salt water-resisting agent, water glass system (water glass class) water-resisting agent, aluminium salt water-resisting agent and other inorganic water-proof agents.More common chloride salt water-resisting agent has water-resisting agents such as calcium chloride water-resisting agent, iron(ic)chloride water-resisting agent, aluminum chloride, such water-resisting agent ability and C ₃A, generation indissolubles such as calcium hydroxide are separated the colloid material, fill and seal the micropore between the cement sandstone, improve the density and the impermeability of cement stone; Water glass system (water glass class) water-resisting agent is many to be that base-material is aided with configurations such as copper sulfate, potassium aluminium sulfate and forms oily liquids with water glass; Mainly be to utilize water glass and hydrated cementitious product calcium hydroxide to generate insoluble Calucium Silicate powder; Stop up capillary channel; Improve the cement density, wherein Sulfates then plays the effect that promotes cement to produce gelatinous mass; Inorganic aluminate water-proof agent is many to be main raw material with aluminium salt and lime carbonate, is aided with plurality of inorganic salt, and volume is generally the 3%-5% of cement consumption.But use the concrete pouring conditional request of inorganic salts water-resisting agent high, also possibly produce corrosion, and the later stage waterproof effect is bad concrete reinforcement.

Organic type of water-resisting agent be tensio-active agent normally, can be divided into hydrophobic nature fluidizer, emulsion water-proof agent and trifling dose.Product has methyl silicon sodium alcoholate, fluorine sodium silanolate, trolamine class, soap class, rubber latex etc., but because such water-resisting agent amount of air entrainment is too big, concrete strength is had detrimentally affect.

Though and composite water repellent is being used the characteristics that combined the good organic waterproof material of inorganic waterproof material, present product type variety is few, environment for use is required high.Secondly in practical applications, most water-resisting agents can strengthen contraction, are the one of the main reasons that causes concrete cracking and shrink excessive.See that with physical condition at present product has powdery and liquid, but is this product volume height of powder-like product mostly, generally about 5%, have up to 8%-10%.

Summary of the invention

The object of the present invention is to provide a kind of preparation method of inorganic water-proof contraction reducing type compacting agent.The invention is characterized in that said method contains following steps successively:

Step (1) preparation stoste

Mix deionized water with quicklime; Stirring heating becomes milk of lime between 70 ℃～90 ℃; Slowly add sulphur powder and catalyzer then successively, keep Heating temperature and stir 40～60min, look solution takes on a red color and stop heating when not having deposition and stir; Obtain preparing the stoste of said inorganic water-proof contraction reducing type compacting agent after the cooling, specifically each proportion of raw materials is:

Deionized water: 224g, sulphur powder: 96g～192g, quicklime: 56g～112g,

Catalyzer: 25g～50g is 15% methoxy poly (ethylene glycol) by the total mass mark, dimethyl--1, and ammediol and alkyl phenol polyethenoxy ether sodium sulfate mixing solutions are formed, and wherein three's pure substance mass ratio was followed successively by 1: 2: 2,

Step (2) preparation inorganic water-proof contraction reducing type compacting agent

By following prescription each material mixing and stirring is promptly got:

Deionized water: 100g,

The stoste that obtains in the step (1): 50g～100g,

Dimethyl--1, ammediol: 0g～10g,

Methoxy poly (ethylene glycol): 10g～0g,

Alkyl phenol polyethenoxy ether sodium sulfate: 0g～10g,

Trolamine: 0g～5g,

Water glass or lithium silicate or potassium silicate: 10g～0g,

Skimmer DF-642:0g～1g.

Technique effect of the present invention is to significantly improve the impervious cracking that shrinks, prevents with minimizing.It is the compound composition of inorganic materials and water soluble organic substance; Under low-dosage (be present like product 1/tens to 1/tens); Through analyse certainly nano particle fill concrete micropore or with concrete in material generation chemical reaction, generate and to have the closely knit material that expands.Its major functions and features is that volume is little, and it is obvious to reduce the anticracking effect, and does not have other adverse side effect.The silicon that contains in this agent and the cement, calcium, sodium, magnesium etc. are through chemical reaction, and the sulphur agglutinate and the xln of generation can effectively stop the water molecules infiltration, significantly improve intensity, and impervious pressure generally can reach 2.0Mpa, reaches as high as 4.0Mpa; Shrink 30%, especially in the low length of time, can reduce and shrink more than 50% in that bonding can be reduced more simultaneously, this ftractures very important for effective control.These article Modulatory character is big, the simple environmental protection of synthesis technique, and synthesis material economy is easy to get.This product appearance is an orange, stable homogeneous solution, PH11-13.Sealing is preserved.

Embodiment:

Under laboratory condition, use beaker, whisking appliance, instruments such as electric mantle synthesize this product.Relate to the chemically pure reagent that material is purchase, the setting of the amount of getting is the result for measuring through a large amount of concrete experiments.Synthetic stoste has possessed the good densification of reducing, and in view of gained stoste and other water-soluble organic functions compounds have consistency preferably, and can not influence former effect; We carry out composite on the basis of stoste; Obtain the more powerful and stable composite product of effect, function and reducing is closely knit; Waterproof, functions such as resistance rust are the many types of densifying agent product of one.

The practical implementation method:

Take by weighing each amount of substance according to following prescription, quicklime (CaO), SULPHUR POWDER etc.Stirring heating lime milk solution between 70～90 ℃, slowly with the sulphur powder, catalyzer adds successively then, keeps Heating temperature and stir when 40～60min. solution takes on a red color the nothing deposition stopping heating and stirring, obtains inorganic densifying agent mother liquor after the cooling.That is:

Deionized water 224g quicklime 56g～112g

Catalyzer 25g～50g is 15% methoxy poly (ethylene glycol) by the total mass mark, dimethyl--1, and ammediol and alkyl phenol polyethenoxy ether sodium sulfate mixing solutions are formed, and wherein three's pure substance mass ratio was followed successively by 1: 2: 2.

Sulphur powder 96g～192g

Specific embodiment

The composite densifying agent of III type

With following formula I II type stoste and each material mixing and stirring, promptly get the composite densifying agent of III type, that is:

Deionized water 100g, III type stoste 50g～100g,

Dimethyl--1, ammediol 0g～10g, methoxy poly (ethylene glycol) 0g～10g,

Alkyl phenol polyethenoxy ether sodium sulfate 0g～10g, trolamine 0g～5g,

Silicate (water glass, lithium silicate, potassium silicate) 0g～10g,

The France skimmer DF-642 0g～1g of Rhodia.

Specific embodiment is:

Above product has all carried out compressive strength rate according to water-resisting agent industry standard (JC474-2008), the getting up early shrinkage ratio, and tests such as chloride diffusion coefficient ratio, wherein the normal concrete proportioning is:

Cement: 330kg

Medium sand: 744kg

Stone (5～25mm): 1116Kg

Water: 200kg

Wherein detect the densifying agent that concrete all adds cement quality 0.2%, test intensity, shrinkability and chloride diffusion coefficient each length of time.The The performance test results of each instance is following:

Claims (1)

1. concrete inorganic water-proof contraction reducing type compacting agent is characterized in that the preparation method contains following steps successively:

Step (1) preparation stoste

Mix deionized water with quicklime; Stirring heating becomes milk of lime between 70 ℃～90 ℃; Slowly add sulphur powder and catalyzer then successively, keep Heating temperature and stir 40～60min, look solution takes on a red color and stop heating when not having deposition and stir; Obtain preparing the stoste of said inorganic water-proof contraction reducing type compacting agent after the cooling, specifically each proportion of raw materials is:

Deionized water: 224g,

Quicklime: 56g～112g,

Sulphur powder: 96g～192g,

Catalyzer: 25g～50g is 15% methoxy poly (ethylene glycol) by the total mass mark, dimethyl--1, and ammediol and alkyl phenol polyethenoxy ether sodium sulfate mixing solutions are formed, and wherein three's pure substance mass ratio was followed successively by 1: 2: 2,

Step (2) preparation inorganic water-proof contraction reducing type compacting agent

By following prescription each material mixing and stirring is promptly got:

Deionized water: 100g,

The stoste that obtains in the step (1): 50g～100g,

2: 0g～10g,

Methoxy poly (ethylene glycol): 10g～0g,

Alkyl phenol polyethenoxy ether sodium sulfate: 0g～10g,

Trolamine: 0g～5g,

Water glass or lithium silicate or potassium silicate: 10g～0g.