CN100354224C - Water release factor for controlling after expansion capacity of closed concrete and its preparation and use - Google Patents

Abstract

The present invention belongs to the field of building material and particularly relates to a water release factor used for controlling the after expansion capacity of closed concrete and the preparation and the application. The water release factor used for controlling the after expansion capacity of closed concrete is characterized in that the water release factor comprises the following components with the percentages accounting for the total weight: 55 to 65% of SiO2, 18 to 25% of Al2O3, 6 to 10% of Fe2O3, 0.5 to 2% of FeO, 4 to 6% of CaO or/and MgO, and 2 to 5% of K2O or/ and Na2 O, wherein when CaO and MgO account for 4 to 6%, an arbitrary mixture exists between CaO and MgO; when K2O and Na2O account for 2 to 5%, an arbitrary mixture exists between K2O and Na2O. The water release factor of the present invention can quantitatively release water in the concrete hardening process at real time so that the expansion physical reaction of concrete can be normally carried out and the technical problem of the shortage of after expansion capacity of the closed concrete is solved.

Description

Be used to control water release factor and the preparation and the application of closed concrete late expansion amount

Technical field

The invention belongs to building material field, be specifically related to a kind of water release factor and preparation and application that can be used for controlling closed concrete late expansion amount.

Background technology

Under some special engineering background (as concrete filled steel tube, post-cast strip structure) for structural safety design or aspect other consideration of performance requriements must make concrete produce a certain amount of volumetric expansion.Concrete volumetric expansion generates the swelling property material by expansion sources such as CaO, MgO, anhydrous calcium sulphoaluminate and water generation chemical reaction and produces, and reaction formula is seen as shown in the formula 1:

CaO type swelling agent reaction formula: CaO+H ₂O → Ca (OH) ₂

MgO type swelling agent reaction formula: MgO+H ₂O → Mg (OH) ₂

Sulplo-aluminate type swelling agent (UEA) reaction formula:

C ₄A ₃S+6Ca(OH) ₂+8CaSO ₄+90H ₂O→3C ₃A·3CaSO ₄·32H ₂O

Obviously, the expansion reaction prerequisite of above all kinds swelling agent is to need competent water, the swell increment deficiency of expansion that concrete can not produce under the lack of water condition or generation.Can not enter inside concrete for the extraneous moisture of closed concrete (as concrete filled steel tube), and the moisture of inside concrete reduces gradually along with hydrated cementitious, cause closed concrete the aquation later stage because of lacking the swell increment that water supply can not produce design, be difficult to reach design purpose.

Summary of the invention

The object of the present invention is to provide a kind of water release factor and preparation and application that can be used for controlling closed concrete late expansion amount, can solve closed concrete can not produce the swell increment of design because of the later stage lack of water problem.

To achieve these goals, technical scheme of the present invention is: be used to control the water release factor of closed concrete late expansion amount, it is characterized in that: it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO be or/and MgO, (6) K ₂O is or/and Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂55～65%, Al ₂O ₃18～25%, Fe ₂O ₃6～10%, FeO 0.5～2%, and CaO is or/and MgO 4～6%, K ₂O is or/and Na ₂O 2～5%, and wherein, CaO and MgO are 4～6% o'clock, and CaO and MgO are any proportioning each other, K ₂O and Na ₂O is 2～5% o'clock, K ₂O and Na ₂O is any proportioning each other; And the content of each component satisfies following formula:

$\frac{{\mathrm{<figure-callout\; id="2"\; label="SiO"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">SiO</figure-callout>}}_2+A{l}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{O}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$ Formula 2

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O;

The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount is characterized in that comprising the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂55～65%, Al ₂O ₃18～25%, Fe ₂O ₃6～10%, FeO 0.5～2%, and CaO is or/and MgO 4～6%, K ₂O is or/and Na ₂O 2～5%, and wherein, CaO and MgO are 4～6% o'clock, and CaO and MgO are any proportioning each other, K ₂O and Na ₂O is 2～5% o'clock, K ₂O and Na ₂O is any proportioning each other; And the content of each component satisfies following formula:

$\frac{{\mathrm{<figure-callout\; id="2"\; label="SiO"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">SiO</figure-callout>}}_2+A{l}_2{O}_3}{{\mathrm{Fe}}_2{O}_3+\mathrm{RO}+R_{2}O+F_{e}O}=3.5~10,$

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight; The per-cent sum of the shared gross weight of each component is 100% to choose raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains (being a kind of water release factor that can be used for controlling closed concrete late expansion amount, hereinafter to be referred as water release factor) are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Apparent particle density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Be used for controlling the application of the water release factor of closed concrete late expansion amount: it is characterized in that water release factor is applied to concrete,

Water release factor needs under vacuum state full water 5～30min before use or embezzles water 24h～36h in the pond; Will make water release factor keep saturated surface dry condition before feeding intake, water release factor is mixed concrete in the mode that the equal-volume ratio replaces sand, the moisture of water release factor is not counted in the concrete unit consumption of water; Water release factor should gather materials with other sandstones, could drop into water reducer after the cement uniform mixing;

The addition content of water release factor is Q, and the concrete amount of sand is S, and the water-intake rate of water release factor is x%, and the volume fraction that water release factor replaces sand is n%; Then the addition content Q of water release factor calculates by formula 3:

Q=S/2650 * n% * 1450 * (1+x%) formulas 3

Sand consumption S on the coagulation ₀Calculate by formula 4:

S ₀The formula 4 of=S * (1-n%)

The yardstick of water release factor is selected:

The yardstick of water release factor is selected to decide according to concrete intensity size and execution conditions, and concrete intensity is greater than more than the 50MPa, and water release factor should be controlled 25～50mm; Concrete intensity adopts the water release factor of 25～75mm during less than 50MPa; The addition content of water release factor determines that according to the concrete swell increment of design the volume fraction n% that water release factor replaces sand is 10～20%.

The invention provides and a kind ofly can store gauge water on demand in advance and release the granule medium of water at the later stage timely and appropriate discovery, the present invention is defined as water release factor with this granule medium.

Water release factor of the present invention can absorb moisture content, water-intake rate (1h): 4～8%, the moisture of water release factor does not participate in chemical reaction when the normal aquation of concrete, early stage, concrete expansion physical reaction water was provided by free water, when the later stage needs concrete to produce certain swell increment, water release factor just quantitatively discharges water outlet, carries out to keep the concrete expansion reaction.And under the condition that provides or do not provide moisture, can both keep good bonding and not influence concrete other performances with concrete.

Water release factor of the present invention can discharge moisture in good time, quantitatively in course of hardening, so that concrete expansion physical reaction normally carried out, thereby solve the technical barrier of closed concrete in the late expansion quantity not sufficient.Can realize accurate control to concrete late expansion amount, thus the effectively contraction of compensating concrete, the weather resistance and the security that improve concrete structure.

Description of drawings

Fig. 1 is the concrete expansion curve figure of the 1#～5# of example 1 of the present invention

Fig. 2 is the concrete expansion curve figure of the 1#～4# of example 2 of the present invention

Embodiment

Example 1:

Be used to control the water release factor of closed concrete late expansion amount, it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO and MgO, (6) K ₂O and Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃24.5%, Fe ₂O ₃6%, FeO 0.5%, CaO2%, and MgO 2%, K ₂O 1%, Na ₂O 1%, and the content of each component satisfies following formula:

$\frac{{\mathrm{<figure-callout\; id="2"\; label="SiO"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">SiO</figure-callout>}}_2+{\mathrm{Al}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{O}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount comprises the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃24.5%, Fe ₂O ₃6%, FeO 0.5%, CaO2%, and MgO 2%, K ₂O 1%, Na ₂O 1%, chooses raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Apparent particle density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Example 2:

Be used to control the water release factor of closed concrete late expansion amount, it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO and MgO, (6) K ₂O and Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂55%, Al ₂O ₃25%, Fe ₂O ₃7%, FeO 2%, and CaO 2%, and MgO 4%, K ₂O 2%, Na ₂O 3%, and the content of each component satisfies following formula:

$\frac{{\mathrm{<figure-callout\; id="2"\; label="SiO"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">SiO</figure-callout>}}_2+{\mathrm{Al}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{O}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount comprises the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂55%, Al ₂O ₃25%, Fe ₂O ₃7%, FeO 2%, and CaO 2%, and MgO 4%, K ₂O 2%, Na ₂O 3%, chooses raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Apparent particle density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Example 3:

Be used to control the water release factor of closed concrete late expansion amount, it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO and MgO, (6) K ₂O and Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂61%, Al ₂O ₃22%, Fe ₂O ₃8%, FeO 1%, and CaO 2%, and MgO 2%, K ₂O 2%, Na ₂O 2%, and the content of each component satisfies following formula:

$\frac{{\mathrm{SiO}}_2+{\mathrm{Al}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount comprises the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂61%, Al ₂O ₃22%, Fe ₂O ₃8%, FeO 1%, and CaO 2%, and MgO 2%, K ₂O 2%, Na ₂O 2%, chooses raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Tap density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Example 4:

Be used to control the water release factor of closed concrete late expansion amount, it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO, (6) K ₂O; The per-cent of the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃18.5%, Fe ₂O ₃10%, FeO 0.5%, and CaO 4%, K ₂O 2%, and the content of each component satisfies following formula:

$\frac{{\mathrm{SiO}}_2+{\mathrm{Al}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

In the formula: RO represents CaO, R ₂O represents K ₂O; The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount comprises the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃18.5%, Fe ₂O ₃10%, FeO 0.5%, and CaO 4%, K ₂O 2%, chooses raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Tap density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Example 5:

Be used to control the water release factor of closed concrete late expansion amount, it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) MgO, (6) Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃18%, Fe ₂O ₃6%, FeO 2%, and MgO 6%, Na ₂O 3%, and the content of each component satisfies following formula:

$\frac{{\mathrm{SiO}}_2+{\mathrm{Al}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3}{{\mathrm{Fe}}_2{\mathrm{<figure-callout\; id="3"\; label="O"\; filenames="C20051001812200121.png"\; state="\{\{state\}\}">O</figure-callout>}}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

In the formula: RO represents MgO, R ₂O represents Na ₂O; The control loss on ignition is 3～5% of a gross weight.

The above-mentioned preparation method who can be used for controlling the water release factor of closed concrete late expansion amount comprises the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂65%, Al ₂O ₃18%, Fe ₂O ₃6%, FeO 2%, and MgO 6%, Na ₂O 3%, chooses raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

The performance index of the product that obtains are:

Particle scale: 25～75mm;

Surface shape: irregular particle shape, fineness coefficient 1.2～1.4;

Particle cylindrical compress strength: more than the 6.0MPa;

Tap density: 1450～1450kg/m ³

Water-intake rate (1h): 4～8%, select according to requirement of engineering.

Example 6:

Be used for controlling the application of the water release factor of closed concrete late expansion amount: water release factor is applied to concrete,

Water release factor needs under vacuum state full water 5～30min before use or embezzles water 24h～36h in the pond; Will make water release factor keep saturated surface dry condition before feeding intake, water release factor is mixed concrete in the mode that the equal-volume ratio replaces sand, the moisture of water release factor is not counted in the concrete unit consumption of water; Water release factor should gather materials with other sandstones, could drop into water reducer after the cement uniform mixing;

The addition content of water release factor is Q, and the concrete amount of sand is S, and the water-intake rate of water release factor is x%, and the volume fraction that water release factor replaces sand is n%; Then the addition content Q of water release factor calculates by formula 3:

Q=S/2650 * n% * 1450 * (1+x%) formulas 3

Concrete sand consumption S ₀Calculate by formula 4:

S ₀The formula 4 of=S * (1-n%)

The yardstick of water release factor is selected:

The yardstick of water release factor is selected to decide according to concrete intensity size and execution conditions, and concrete intensity is greater than more than the 50MPa, and water release factor should be controlled 25～50mm; Concrete intensity adopts the water release factor of 25～75mm during less than 50MPa; The addition content of water release factor determines that according to the concrete swell increment of design the volume fraction n% that water release factor replaces sand is 10～20%.

Water-intake rate is 8% water release factor application:

The water release factor of water-intake rate higher (6%～8%) can be used for preparing the high-strength expansive concrete of C60.By table 1 as seen, mixing of such water release factor do not make concrete intensity that tangible reduction is arranged.1#, 2# concrete do not have the admixture water release factor in the table 1, and 1# adopts standard conditions (relative humidity is more than 95%) maintenance, and 2# adopts the sealing condition maintenance.As seen from Figure 1, concrete 28 days rate of expansion of 1# reach 3.8 * 10 ^-4, concrete 28 days rate of expansion of 2# have only 2.3 * 10 ^-4, illustrate that concrete late expansion rate is very low under sealing condition.Adopting after 15% water release factor replaces sand, concrete under the normal curing condition 28 days rate of expansion (3#) reached 4.2 * 10 ^-4Even, under sealing condition, adopted 15% water release factor to replace after the sand, 28 days rate of expansion of concrete (4#) reach 3.2 * 10 ^-4Contrast 2# and 4# concrete illustrate the adding of water release factor, make concrete still keep rate of expansion preferably in the later stage.Continue to improve the volume (bringing up to 20% by 15%) of water release factor, concrete 28 days rate of expansion of 5# can reach 3.5% in the table, illustrate, along with the concrete late expansion amount of the raising of water release factor volume can be controlled.

Table 1 C60 concrete mix/Kg/m ³

Numbering	Cement	Water	Flyash	Coarse aggregate	Sand	Water reducer	Swelling agent	Water release factor	Curing condition	Ultimate compression strength/MPa
											1#	460	185	70	1050	655	1.7％	55	-	Normal curing	69
2#	460	185	70	1050	655	1.7％	55	-	The sealing maintenance	66
											3#	460	185	70	1050	557	1.7％	55	58	Normal curing	68
4#	460	185	70	1050	557	1.7％	55	58	The sealing maintenance	67
											5#	460	185	70	1050	525	1.7％	55	77	The sealing maintenance	66

The concrete expansion curve of 1#～5# as shown in Figure 1.

Example 7:

Water-intake rate is 4% water release factor application:

The water release factor of water-intake rate lower (4%～6%) can be used for preparing the high-strength expansive concrete of C40～C50.1#, 2# concrete do not have the admixture water release factor in the table 2, and 1# adopts standard conditions (relative humidity is more than 95%) maintenance, and 2# adopts the sealing condition maintenance.As seen from Figure 1, concrete 28 days rate of expansion of 1# reach 3.6 * 10 ^-4, concrete 28 days rate of expansion of 2# have only 2.3 * 10 ^-4, illustrate that concrete late expansion rate is very low under sealing condition.Adopting after 20% water release factor replaces sand, concrete under the normal curing condition 28 days rate of expansion (3#) reached 3.8 * 10 ^-4Even, under sealing condition, adopted 20% water release factor to replace after the sand, 28 days rate of expansion of concrete (4#) reach 3.3 * 10 ^-4 Contrast 2# and 4# concrete illustrate the adding of water release factor, make concrete still keep rate of expansion preferably in the later stage.Illustrate that mixing of water release factor can make concrete late expansion amount be effectively controlled.

Table 2 C50 concrete mix/Kg/m ³

Numbering	Cement	Water	Flyash	Coarse aggregate	Sand	Water reducer	Swelling agent	Water release factor	Curing condition	Ultimate compression strength/MPa
											1#	410	185	80	1083	638	1.7％	55	-	Normal curing	58
2#	410	185	80	1083	638	1.7％	55	-	The sealing maintenance	56
											3#	410	185	80	1083	510	1.7％	55	73	Normal curing	56
4#	410	185	80	1083	510	1.7％	55	73	The sealing maintenance	57

The concrete expansion curve of 1#～4# as shown in Figure 2.

Claims (3)

1. be used to control the water release factor of closed concrete late expansion amount, it is characterized in that: it is fired by following starting material and forms: (1) SiO ₂, (2) Al ₂O ₃, (3) Fe ₂O ₃, (4) FeO, (5) CaO be or/and MgO, (6) K ₂O is or/and Na ₂O; The per-cent of the shared gross weight of each component is: SiO ₂55～65%, Al ₂O ₃18～25%, Fe ₂O ₃6～10%, FeO 0.5～2%, and CaO is or/and MgO 4～6%, K ₂O is or/and Na ₂O 2～5%, and wherein, CaO and MgO are 4～6% o'clock, and CaO and MgO are any proportioning each other, K ₂O and Na ₂O is 2～5% o'clock, K ₂O and Na ₂O is any proportioning each other; And the content of each component satisfies following formula:

$\frac{{\mathrm{SiO}}_2+{\mathrm{Al}}_2{O}_3}{{\mathrm{Fe}}_2{O}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10$

Formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight.

2. the preparation method who is used to control the water release factor of closed concrete late expansion amount as claimed in claim 1 is characterized in that comprising the steps:

1) choosing of raw material: the per-cent by the shared gross weight of each component is: SiO ₂55～65%, Al ₂O ₃18～25%, Fe ₂O ₃6～10%, FeO 0.5～2%, and CaO is or/and MgO 4～6%, K ₂O is or/and Na ₂O 2～5%, and wherein, CaO and MgO are 4～6% o'clock, and CaO and MgO are any proportioning each other, K ₂O and Na ₂O is 2～5% o'clock, K ₂O and Na ₂O is any proportioning each other; And the content of each component satisfies following formula:

$\frac{{\mathrm{SiO}}_2+{\mathrm{Al}}_2{O}_3}{F{e}_2{O}_3+\mathrm{RO}+R_{2}O+\mathrm{FeO}}=3.5~10,$

In the formula: RO represents CaO or/and MgO, R ₂O represents K ₂O is or/and Na ₂O; The control loss on ignition is 3～5% of a gross weight; The per-cent sum of the shared gross weight of each component is 100% to choose raw material;

2) the above-mentioned raw material of choosing is mixed stirring, get compound;

3) fire: compound is put into rotary kiln, roasting 15～20min under 1100～1300 ℃ of conditions; Tapping temperature is controlled at 800～900 ℃, is chilled to 700 ℃, and chilling period is 1～3min; 700～400 ℃ of slowly coolings, slowly be 20～30min cooling time; 400 ℃ are adopted chilling to room temperature, and chilling period is 1～3min;

4) fragmentation: adopt impact breaker or hammer mill to be crushed to 25～75mm after being cooled to room temperature, stack, promptly get product.

3. the application that is used for controlling the water release factor of closed concrete late expansion amount according to claim 1: it is characterized in that water release factor is applied to concrete,

Water release factor needs under vacuum state full water 5～30min before use or embezzles water 24h～36h in the pond; Will make water release factor keep saturated surface dry condition before feeding intake, water release factor is mixed concrete in the mode that the equal-volume ratio replaces sand, the moisture of water release factor is not counted in the concrete unit consumption of water; Water release factor should gather materials with other sandstones, could drop into water reducer after the cement uniform mixing;

The addition content of water release factor is Q, and the concrete amount of sand is S, and the water-intake rate of water release factor is x%, and the volume fraction that water release factor replaces sand is n%; Then the addition content Q of water release factor is calculated as follows:

Q＝S/2650×n％×1450×(1+x％)，

Concrete sand consumption S ₀Be calculated as follows:

S ₀＝S×(1-n％)，

The yardstick of water release factor is selected:

The yardstick of water release factor is selected to decide according to concrete intensity size and execution conditions, and concrete intensity is greater than more than the 50MPa, and water release factor should be controlled 25～50mm; Concrete intensity adopts the water release factor of 25～75mm during less than 50MPa; The addition content of water release factor determines that according to the concrete swell increment of design the volume fraction n% that water release factor replaces sand is 10～20%.

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