CN101817653A - Aluminate-aluminosilicate expanding agent and preparation method thereof - Google Patents

Abstract

The invention relates to an aluminate-aluminosilicate expanding agent and a preparation method thereof. The aluminate-aluminosilicate expanding agent is prepared from 40 to 60 weight percent of anhydrite, 10 to 20 weight percent of kaolin, 10 to 20 weight percent of metakaolin and 10 to 20 weight percent high-aluminium grog, wherein the SO3 content of the anhydrite is over 46 percent; the Al2O3 content of the kaolin is over 35 percent; the Al2O3 content of the metakaolin is over 40 percent; and the Al2O3 content of the high-aluminium grog is over 50 percent. All components are mixed and ground in a proportion until the specific surface area is 200 to 350m<2>/kg, the fineness is 80mu m, and a screen residue is less than or equal to 10 percent. The aluminate-aluminosilicate expanding agent has the advantages of low alkaline content, less admixture, low expanding difference, low slump loss, low strength loss, environmental protection, accordance with the requirement of pump concrete and excellent social and economic value.

Description

A kind of aluminate-aluminosilicate expanding agent and preparation method thereof

Technical field

The present invention relates to a kind of cement expansive material and preparation method thereof, especially relate to a kind of aluminate-aluminosilicate expanding agent and preparation method thereof.

Background technology

Utilizing high-efficiency expanding agent to prepare expansive concrete is an important technique measure that prevents concrete cracking.Cement expansive material is in existing 20 years of development of China, experienced that high-alkali height is mixed, the low alkali low-mix three phases of blending in the middle alkali.In the most of usefulness of alumina of the nineties in last century and early stage swelling agent is alunite and calcined alunite, the alkali content of this swelling agent is big, volume is big, expansion energy is low, easily reinforcing bar is caused and corrode and cause concrete generation alkali-aggregate reaction, the work-ing life that can reduce Steel Concrete.Though later swelling agent had used sulplo-aluminate, aluminate clinker etc. to grind with anhydrite powder in 2000, alkali content and volume decrease, but also have the expansion drop and shrink shortcomings such as concrete slump loss big, preparation is big, strength degradation is big.Has very big realistic meaning so develop the swelling agent of low alkali, low-dosage, low bulk drop, low slump loss and low strength loss.

The contriver is analysing in depth, research and absorb on the basis of domestic and international technological achievement, through repeatedly analyzing experiment, work out a kind of aluminate-aluminosilicate expanding agent that possesses low alkali, low-dosage, low bulk drop, low slump loss and low strength loss novel the time, to satisfy a day high performance concrete performance requriements higher to swelling agent.

Summary of the invention

The purpose of this invention is to provide a kind of aluminate-aluminosilicate expanding agent that possesses low alkali, low-dosage, low bulk drop, low slump loss and low strength loss simultaneously, and the preparation method of this high performance aluminate-aluminosilicate expanding agent.

For reaching above-mentioned purpose, the present invention has adopted following technical scheme:

The invention provides a kind of aluminate-aluminosilicate expanding agent, wherein contain following component by weight percentage:

The anhydrite of 40-60%

The kaolin of 10-20%

The metakaolin of 10-20%

The high alumina of 10-20%.

SO in the wherein described by weight percentage anhydrite ₃Content is greater than 46%, Al in the used kaolin ₂O ₃Content is greater than 35%, Al in the used metakaolin ₂O ₃Content is greater than 40%, Al in the used high alumina ₂O ₃Content is greater than 50%.

Described swelling agent wherein further contains the additive that is selected from water reducer, retardant, frostproofer, hardening accelerator

The present invention also provides the manufacture method of described aluminate-aluminosilicate expanding agent, wherein described anhydrite, kaolin, metakaolin and high alumina is mixed, and grinding is to specific surface area 200-350m2/kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.

After a kind of aluminate sulphur raw material anhydrite and aluminum raw material kaolin, metakaolin and high alumina mixed by a certain percentage, remittance generated a large amount of ettringite in the gelling system hydration process of cement-swelling agent, produced and expanded.The hydration reaction formula of ettringite is:

C ₄A ₃S+8CaSO ₄+6CaO+9H ₂O→3C ₃A·3CaSO ₄·32H ₂O。

Aluminate of the present invention-silicoaluminate swelling agent can directly add when reality is used in the concrete as pure swelling agent use; Also can with the multi-functional aluminate of the compound preparation of chemical admixture-silicoaluminate swelling agent.The latter is except that having compensate for shrinkage, reduce shrinkage fall, the function such as anti-crack and anti-seepage, having multiple workabilities such as diminishing, slow setting, strong, high-strength, antifreeze and pumping early simultaneously.

Owing to adopted above technical scheme, made the present invention possess following technique effect:

(1), alkali content is low.Alkali content is between 0.3-0.4, far below the requirement of stipulating in the cement expansive material standard;

(2), volume is low.The 6%-8% of interior water mixing mud weight, during volume 6%, 7 days limited expansion rates of mortar reach 3.15 * 10 ^-4, can reach good compensate for shrinkage effect;

The expansion drop is low when (3) using, expansion character good, the loss that collapses is little, and loss of strength is low.Volume is 8% o'clock, 7 days is 5.0-7.0MPa with mortar mixing folding strength, and 28 days is 8.0-9.0MPa; Ultimate compression strength 7 days was 28-31MPa, and 28 days is 48-50MPa; 7 days limited expansion rates of maintenance are 0.03-0.04% in the water, and 28 days limited expansion rates are 0.04-0.05%; 90 days limited expansion rates are 0.06-0.07%.Volume is 8% o'clock, and with the concrete mixed preparing, ultimate compression strength 7 days was 27-29MPa, and 28 days is 41-44MPa; 7 days limited expansion rate 2.10-2.25 * 10 of maintenance in the water ^-4, 14 days limited expansion rates are 2.25-2.50 * 10 ^-4Slump-loss is 35-40mm; The divergence loss is 90-105mm;

(4) the raw material main body that adopts of the present invention by with environmental coexistence good the environmental health material--inorganic mineral material is formed, so aluminate of the present invention-silicoaluminate swelling agent also possesses the technique effect of environmental protection.

In a word, aluminate of the present invention-silicoaluminate swelling agent alkali content is low, volume is low, the expansion drop is low, slump-loss is low, loss of strength is low, environmental protection; Has preferable social economic value.Satisfy the requirement of pump concrete, use the HPEC of aluminate of the present invention-silicoaluminate swelling agent preparation to possess high application property, good structure properties and high-durability energy simultaneously.

Embodiment

Embodiment 1:

Aluminate-aluminosilicate expanding agent is formed by anhydrite, kaolin, metakaolin and high alumina mixed configuration, and its weight percent is an anhydrite: kaolin: metakaolin: high alumina is ripe=and 40%: 20%: 20%: 20%.SO in the wherein used anhydrite ₃Content is 48%, Al in the used kaolin ₂O ₃Content is 38.9%, Al in the used metakaolin ₂O ₃Content is 43.1%, Al in the used high alumina ₂O ₃Content is 53.1%.

The preparation method of above-mentioned aluminate-aluminosilicate expanding agent is mixed in proportion described anhydrite, kaolin, metakaolin and high alumina, and grinding is to specific surface area 200-350m ²/ kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.Obtain described aluminate-aluminosilicate expanding agent A.Its performance index are seen application example table 1-5.

Embodiment 2:

Aluminate-aluminosilicate expanding agent, anhydrite, kaolin, metakaolin and high alumina mixed configuration form, and its weight percent is an anhydrite: kaolin: metakaolin: and high alumina is ripe=and 50%: 15%: 15%: 20%.SO in the wherein used anhydrite ₃Content is 48%, Al in the used kaolin ₂O ₃Content is 38.9%, Al in the used metakaolin ₂O ₃Content is 43.1%, Al in the used high alumina ₂O ₃Content is 53.1%.

The preparation method of above-mentioned aluminate-aluminosilicate expanding agent is mixed in proportion described anhydrite, kaolin, metakaolin and high alumina, and grinding is to specific surface area 200-350m ²/ kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.Obtain described aluminate-aluminosilicate expanding agent B.Its performance index are seen application example table 1-5.

Embodiment 3:

Aluminate-aluminosilicate expanding agent, anhydrite, kaolin, metakaolin and high alumina mixed configuration form, and its weight percent is an anhydrite: kaolin: metakaolin: and high alumina is ripe=and 60%: 15%: 15%: 10%.SO in the wherein used anhydrite ₃Content is 48%, Al in the used kaolin ₂O ₃Content is 38.9%, Al in the used metakaolin ₂O ₃Content is 43.1%, Al in the used high alumina ₂O ₃Content is 53.1%.

The preparation method of above-mentioned aluminate-aluminosilicate expanding agent is mixed in proportion described anhydrite, kaolin, metakaolin and high alumina, and grinding is to specific surface area 200-350m ²/ kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.Obtain described aluminate-aluminosilicate expanding agent C.Its performance index are seen application example table 1-5.

Embodiment 4:

Aluminate-aluminosilicate expanding agent, anhydrite, kaolin, metakaolin and high alumina mixed configuration form, and its weight percent is an anhydrite: kaolin: metakaolin: and high alumina is ripe=and 60%: 10%: 10%: 20%.SO in the wherein used anhydrite ₃Content is 48%, Al in the used kaolin ₂O ₃Content is 38.9%, Al in the used metakaolin ₂O ₃Content is 43.1%, Al in the used high alumina ₂O ₃Content is 53.1%.

The preparation method of above-mentioned aluminate-aluminosilicate expanding agent is mixed in proportion described anhydrite, kaolin, metakaolin and high alumina, and grinding is to specific surface area 200-350m ²/ kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.Obtain described aluminate-aluminosilicate expanding agent D.Its performance index are seen application example table 1-5.

Use example 1:

With reference to industry standard " cement expansive material " (JC476-2001) method of defined to mortar expansion and strength property test carry out.Strength test length of time is 7 days, 28 days values.The limited expansion rate maintaining machine is shaped on two kinds: first kind, survey just long, water support 3 days, 7 days,, 28 days, 56 days, 90 days values; Second kind, survey first long, foster 3 days, 7 days values of water, the sky of becoming a cadre after 7 days (humidity is 60%R.H.) is surveyed 28 days, 56,90 days values (equally counting from first length with water is foster).Wherein, numbering 0 expression does not add the mortar performance of swelling agent; The volume of swelling agent A, B, C is 8%, and the volume of swelling agent D is 8% (D1) and 6% (D2).

The alkali content of each swelling agent of table 1 and mortar strength performance

The mortar limited expansion rate of each swelling agent of table 2

Table 3 expansion drop and compensation efficient

For mortar specimen, press the JC476 regulation, 7 days limited expansion rate in the water intaking

As doing empty initial value of shrinking, deduct the limited expansion rate retention value of doing aerial arbitrary length of time

The expansion drop Δ ε in different length of times that obtain mortar in the drying shrinkage process _RsThe relative expansion drop of representing mortar with Rs.With

The residue limited expansion rate behind the mortar drying shrinkage in arbitrary length of time of swelling agent is mixed in expression,

The residue limited expansion rate behind the drying shrinkage in same length of time of the same proportioning mortar of swelling agent is not mixed in expression, and C represents to compensate efficient (absolute value).

$\mathrm{Rs}=\mathrm{\&Delta;}{\mathrm{\&epsiv;}}_{\mathrm{rs}}/{\mathrm{\&epsiv;}}_{\mathrm{rs}}^7\&times;100\%$

Use example 2:

A, B, C, D swelling agent mixed in the C30 concrete be mixed with expansive concrete, expansive agent dosage A, B, C are 8%, and the volume of D is 8% (D1) and 6% (D2).The concrete strength performance adopts GBJ81-85 " normal concrete mechanical test method " to test, moulding 10cm * 10cm * 10cm test specimen, concrete test mark foster (fog chamber's maintenance) ultimate compression strength during 7 days, the 28 day length of time.The test of concrete limited expansion rate adopts the method for defined in " Technical code for application of admixture in concrete " to carry out, moulding 10cm * 10cm * 40cm concrete limited expansion rate test specimen, support chamber maintenance form removal after 1 day at the concrete mark, (doing empty humidity is 65 ± 5%R.H.), calculates limited expansion rate to survey the length initial, that 3 days, 7 days, 14 days marks are supported 21 days, 28 days, 42 days, 56 days examination bodies behind the length of examination body and the sky of becoming a cadre.Concrete basic proportioning is that gelling material (cement is Lafarge cement) consumption is 360kg/m ³, sand coarse aggregate ratio is 44%, and water-cement ratio is 0.52, and the concrete of swelling agent is not mixed in 1%, No. 0 expression of polycarboxylate water-reducer volume.

The performance of table 4 fresh concrete and concrete intensity

The concrete limited expansion rate (* 10 of table 5 ^-4)

Claims (4)

1. aluminate-aluminosilicate expanding agent is characterized in that containing by weight percentage following component:

The anhydrite of 40-60%;

The kaolin of 10-20%;

The metakaolin of 10-20%;

The high alumina of 10-20%.

2. swelling agent as claimed in claim 1, SO in the wherein described by weight percentage anhydrite ₃Content is greater than 46%, Al in the used kaolin ₂O ₃Content is greater than 35%, Al in the used metakaolin ₂O ₃Content is greater than 40%, Al in the used high alumina ₂O ₃Content is greater than 50%.

3. swelling agent as claimed in claim 1 or 2 wherein further contains the additive that is selected from water reducer, retardant, frostproofer, hardening accelerator.

4. manufacture method of aluminate-aluminosilicate expanding agent according to claim 1, it is characterized in that: described anhydrite, kaolin, metakaolin and high alumina are mixed, and grinding is to specific surface area 200-350m ²/ kg, and fineness is that 80 μ m tail over and are less than or equal to 10%.