CN112374778A - High-strength non-shrinkage road portland cement and preparation method thereof - Google Patents

Abstract

A high-strength non-shrinkage road portland cement and a preparation method thereof. The invention belongs to the technical field of building materials, and particularly relates to high-strength non-shrinkage road portland cement and a preparation method thereof. Aiming at the defects in the prior art, the invention provides the high-strength shrinkage-free road portland cement with high early strength, high fracture resistance, high wear resistance and the like, and excellent crack resistance and the preparation method thereof. After the high-strength non-shrinkage road portland cement is made into a concrete pavement, the high-strength non-shrinkage road portland cement has high strength and high wear resistance, has excellent bending resistance, wear resistance and crack resistance, can obviously prolong the service life of national key road engineering such as high-speed railways, expressways, airport runways and the like, and reduces the later maintenance cost.

Description

High-strength non-shrinkage road portland cement and preparation method thereof

Technical Field

The invention belongs to the technical field of building materials, and particularly relates to high-strength non-shrinkage road portland cement and a preparation method thereof.

Background

The high-speed railways, the highways and the airport runways are used as important infrastructures for national transportation, bear the junction effect of national economic development and are of great importance to the national civilization. Portland cement is used as an important basic raw material for engineering construction of high-speed railways, expressways, airport runways and the like, and is a key factor for determining the construction level of the infrastructures.

At present, researchers at home and abroad focus on improving the fracture resistance and wear resistance of cement for road engineering, but reports on improving the crack resistance of road cement are less. The road portland cement produced according to GB/T13693-2017 road portland cement has the characteristics of high strength, high fracture resistance and excellent wear resistance. Compared with common portland cement, the road portland cement has a more remarkable effect of improving the quality of the road surface.

However, it is known that cement, as a hydraulic binder, has physicochemical characteristics that determine its hardening process, which generally represents a bulk volume reduction, during which apparent and deep cracks tend to appear, thus reducing the strength properties of the pavement. Meanwhile, aggressive ions can rapidly invade into the concrete structure through the cracks, so that the structural damage of the cement concrete pavement is accelerated, and the method is extremely unfavorable for the quality and safety of national key projects such as high-speed railways, expressways, airport runways and the like. However, the present road portland cement cannot effectively solve the worldwide problem of cracking of road concrete.

Therefore, in order to improve the crack resistance of pavement concrete such as high-speed railways, expressways, airport runways and the like, a technical route of 'compensating shrinkage and optimizing the mineral composition of high-crack-resistance pavement portland cement clinker' is provided, and a high-crack-resistance pavement portland cement is designed and developed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the high-strength shrinkage-free road portland cement with high early strength, high fracture resistance, high wear resistance and the like, and excellent crack resistance and the preparation method thereof.

In order to achieve the purpose, the invention provides the following technical scheme:

comprises the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 52% -93%;

shrinkage-compensating component: 1% -10%;

auxiliary cementing material: 4% -30%;

gypsum: 2% -8%.

The high-strength shrinkage-free road silicate clinker comprises the following components in percentage by weight:

C₃S：50%~65%；

C₂S：15%~30%；

C₃A：0%~8%；

C₄AF：15%~22%。

the shrinkage-compensating component is one or more of steel slag, steel slag powder, anhydrous calcium sulphoaluminate, magnesium oxide and/or calcium oxide.

The auxiliary cementing material is one or more of fly ash, mineral powder, limestone powder and/or silica fume.

The gypsum is one or more of natural dihydrate gypsum and/or desulfurized gypsum.

The specific surface area of the high-strength non-shrinkage road portland cement is 300-380 m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement comprises the following steps of:

1) preparing raw materials; mixing and grinding a calcareous raw material, a silicon-aluminum raw material and an iron correction raw material to prepare a cement raw material;

2) preparing clinker; calcining the cement raw material at 1400-1500 ℃ for 20-50 min, and then cooling to room temperature at least at a cooling rate of 40 ℃/min by using a grate cooler to prepare the high-strength shrinkage-free road silicate clinker;

3) preparing cement; the prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

The calcareous raw material in the step 1) is one or two of limestone and/or carbide slag with CaO content more than or equal to 45 percent.

The silicon-aluminum raw material in the step 1) is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂One or more than two of shale, clay and fly ash with the content of more than or equal to 50 percent are compounded.

The iron correction raw material in the step 1) is Fe₂O₃One or more than two of iron ore, copper slag and iron powder with the content of more than or equal to 40 percent are compounded.

The invention provides a technical route of 'shrinkage compensation + mineral composition optimization of high-crack-resistance road portland cement clinker', the two aspects of cement clinker and cement preparation are optimized in a unified way, and the volume reduction amount in the cement hardening process is remarkably reduced by regulating and controlling the components of the cement clinker and introducing shrinkage compensation components, so that the crack resistance of the prepared road concrete is improved.

C in the Cement Clinker of the present invention₄AF (tetracalcium aluminoferrite) componentThe wear resistance of the pavement concrete is ensured. C in cement clinker₃S (tricalcium silicate) and C₂The S (dicalcium silicate) component ensures the strength performance of pavement concrete, wherein the former contributes to early strength and the latter contributes to later strength.

The crack resistance of the road concrete is derived from C in the clinker₄AF (tetracalcium aluminoferrite, wherein the hydration product of tetracalcium aluminoferrite has a toughening effect), and on the other hand, shrinkage cracking problems caused by drying shrinkage and chemical shrinkage are reduced by introducing shrinkage compensation components (namely, steel slag powder, anhydrous calcium sulphoaluminate, magnesium oxide and calcium oxide which can generate volume micro-expansion after hydration reaction).

After the high-strength non-shrinkage road portland cement is made into a concrete pavement, the high-strength non-shrinkage road portland cement has high strength and high wear resistance, has excellent bending resistance, wear resistance and crack resistance, can obviously prolong the service life of national key road engineering such as high-speed railways, expressways, airport runways and the like, and reduces the later maintenance cost.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the detailed description of the embodiments, structures, characteristics and effects of the high-strength non-shrinkage road portland cement according to the present invention is provided below with reference to the preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Example 1

The high-strength non-shrinkage road portland cement consists of the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 93 percent

Shrinkage-compensating component: 1 percent of

Auxiliary cementing material: 4 percent of

Gypsum: 2 percent of

The high-strength shrinkage-free road silicate clinker comprises the following components in percentage by weight:

C₃S：50%；

C₂S： 30%

C₃A：2%；

C₄AF：18%

the shrinkage compensation component is anhydrous calcium sulphoaluminate.

The auxiliary cementing material is fly ash.

The gypsum is natural dihydrate gypsum.

The specific surface area of the high-strength non-shrinkage road portland cement is 340m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement is characterized by comprising the following steps of:

1) and (4) preparing raw materials. Mixing the calcium material, the silicon-aluminum material and the iron correction material, and grinding to prepare the cement raw material.

2) And (5) preparing clinker. Calcining the cement raw material at 1450 ℃ for 30min, and then cooling to room temperature by a grate cooler at a cooling rate of 50 ℃/min to prepare the high-strength shrinkage-free road silicate clinker.

3) And (5) preparing cement. The prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

The calcareous raw material is limestone with CaO content more than or equal to 45 percent, and the silicon-aluminum raw material is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂Shale with content not less than 50%, and Fe as correction raw material₂O₃Copper slag with content more than or equal to 40 percent.

And (3) evaluating the crack resistance of the cement according to JC/T2234-2014 'test method for early crack resistance of cement'. The dry shrinkage resistance of cement is evaluated according to JC/T603-2004 'Cement mortar dry shrinkage test method', and the strength performance of cement is evaluated according to GB/T17671-1999 'Cement mortar Strength test method (ISO method)'. The hydration heat release of the cement is measured by GB/T12959-2008 'method for measuring hydration heat of cement', and the performance test result is shown in Table 1.

Example 2

The high-strength non-shrinkage road portland cement is characterized by comprising the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 75 percent of

Shrinkage-compensating component: 5 percent of

Auxiliary cementing material: 15 percent of

Gypsum: 5 percent of

The high-strength shrinkage-free road silicate clinker comprises the following components in percentage by weight:

C₃S：55.0%；

C₂S：23.0%

C₃A：0.0%；

C₄AF：22.0%

the shrinkage-compensating component is steel slag powder.

The auxiliary cementing material is S95 mineral powder.

The gypsum is natural dihydrate gypsum.

The specific surface area of the high-strength non-shrinkage road portland cement is 320m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement comprises the following steps of:

1) and (4) preparing raw materials. Mixing the calcium material, the silicon-aluminum material and the iron correction material, and grinding to prepare the cement raw material.

2) And (5) preparing clinker. Calcining the cement raw material at 1400 ℃ for 40min, and then cooling to room temperature by a grate cooler at a cooling rate of 40 ℃/min to prepare the high-strength shrinkage-free road silicate clinker.

3) And (5) preparing cement. The prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

Further, the calcareous raw material in the step 1) is limestone with CaO content not less than 45%, and the silicoaluminophosphate raw material is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂Clay with content not less than 50% and Fe as correction raw material₂O₃Iron ore with the content of more than or equal to 40 percent.

And (3) evaluating the crack resistance of the cement according to JC/T2234-2014 'test method for early crack resistance of cement'. The dry shrinkage resistance of cement is evaluated according to JC/T603-2004 'Cement mortar dry shrinkage test method', and the strength performance of cement is evaluated according to GB/T17671-1999 'Cement mortar Strength test method (ISO method)'. The hydration heat release of the cement is measured by GB/T12959-2008 'method for measuring hydration heat of cement', and the performance test result is shown in Table 1.

Example 3

The high-strength non-shrinkage road portland cement is characterized by comprising the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 65 percent;

shrinkage-compensating component: 7 percent;

auxiliary cementing material: 23 percent;

gypsum: 5 percent.

Further, the high-strength non-shrinkage road silicate clinker comprises the following components in percentage by weight:

C₃S：58%；

C₂S：18%

C₃A：8%；

C₄AF：16%。

the shrinkage compensation component comprises steel slag powder and anhydrous calcium sulphoaluminate, and the mass ratio of the components is 1: 1.

the auxiliary cementing material is limestone powder.

The gypsum is desulfurized gypsum.

The specific surface area of the high-strength non-shrinkage road portland cement is 360m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement comprises the following steps of:

1) and (4) preparing raw materials. Mixing the calcium material, the silicon-aluminum material and the iron correction material, and grinding to prepare the cement raw material.

2) And (5) preparing clinker. Calcining the cement raw material at 1500 ℃ for 20min, and then cooling to room temperature by a grate cooler at a cooling rate of 60 ℃/min to prepare the high-strength shrinkage-free road silicate clinker.

3) And (5) preparing cement. The prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

The calcareous raw material in the step 1) is carbide slag with CaO content more than or equal to 45 percent, and the silicon-aluminum raw material is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂Fly ash with content more than or equal to 50 percent and Fe as a corrected raw material₂O₃Iron powder with the content of more than or equal to 40 percent.

And (3) evaluating the crack resistance of the cement according to JC/T2234-2014 'test method for early crack resistance of cement'. The dry shrinkage resistance of cement is evaluated according to JC/T603-2004 'Cement mortar dry shrinkage test method', and the strength performance of cement is evaluated according to GB/T17671-1999 'Cement mortar Strength test method (ISO method)'. The hydration heat release of the cement is measured by GB/T12959-2008 'method for measuring hydration heat of cement', and the performance test result is shown in Table 1.

Example 4

The high-strength non-shrinkage road portland cement is characterized by comprising the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 58 percent;

shrinkage-compensating component: 8 percent;

auxiliary cementing material: 27%;

gypsum: 7 percent.

Further, the high-strength non-shrinkage road silicate clinker comprises the following components in percentage by weight:

C₃S：61%；

C₂S：18%；

C₃A：6%；

C₄AF：15%。

the shrinkage-compensating component is magnesium oxide.

The auxiliary cementing material is coal ash and silica fume, and the mass ratio of the auxiliary cementing material to the coal ash is 5: 1.

the gypsum is natural dihydrate gypsum and desulfurized gypsum, and the mass ratio of the natural dihydrate gypsum to the desulfurized gypsum is 1: 2.

The specific surface area of the high-strength non-shrinkage road portland cement is 380m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement comprises the following steps of:

1) and (4) preparing raw materials. Mixing the calcium material, the silicon-aluminum material and the iron correction material, and grinding to prepare the cement raw material.

2) And (5) preparing clinker. Calcining the cement raw material at 1450 ℃ for 50min, and then cooling to room temperature by a grate cooler at the cooling rate of 50 ℃/min to prepare the high-strength shrinkage-free road silicate clinker.

3) And (5) preparing cement. The prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

The calcareous raw material in the step 1) is a mixture of limestone and carbide slag with CaO content not less than 45%, and the mass ratio is 1:1, the silicon-aluminum raw material is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂Fly ash and clay with the content of more than or equal to 50 percent in a mass ratio of 2:1, and Fe as a corrected raw material₂O₃Copper slag with content more than or equal to 40 percent.

And (3) evaluating the crack resistance of the cement according to JC/T2234-2014 'test method for early crack resistance of cement'. The dry shrinkage resistance of cement is evaluated according to JC/T603-2004 'Cement mortar dry shrinkage test method', and the strength performance of cement is evaluated according to GB/T17671-1999 'Cement mortar Strength test method (ISO method)'. The hydration heat release of the cement is measured by GB/T12959-2008 'method for measuring hydration heat of cement', and the performance test result is shown in Table 1.

Example 5

The high-strength non-shrinkage road portland cement is characterized by comprising the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 52 percent;

shrinkage-compensating component: 10 percent;

auxiliary cementing material: 30 percent;

gypsum: 8 percent.

Further, the high-strength non-shrinkage road silicate clinker comprises the following components in percentage by weight:

C₃S：65%；

C₂S：15%；

C₃A：5%；

C₄AF：15%。

the shrinkage compensation component comprises magnesium oxide and steel slag, and the mass ratio of the magnesium oxide to the steel slag is 1: 3.

the auxiliary cementing material is coal ash and limestone powder, and the mass ratio of the auxiliary cementing material to the coal ash is 2: 1.

the gypsum is natural dihydrate gypsum.

The specific surface area of the high-strength non-shrinkage road portland cement is 300m²/kg。

The preparation method of the high-strength non-shrinkage road portland cement comprises the following steps of:

1) and (4) preparing raw materials. Mixing the calcium material, the silicon-aluminum material and the iron correction material, and grinding to prepare the cement raw material.

2) And (5) preparing clinker. Calcining the cement raw material at 1450 ℃ for 30min, and then cooling to room temperature by a grate cooler at a cooling rate of 60 ℃/min to prepare the high-strength shrinkage-free road silicate clinker.

3) And (5) preparing cement. The prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

The calcareous raw material in the step 1) is a mixture of limestone and carbide slag with CaO content more than or equal to 45%, and the proportion is 2:1, the silicon-aluminum raw material is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂Fly ash with content more than or equal to 50 percent and Fe as a corrected raw material₂O₃Iron ore and iron powder with the content of more than or equal to 40 percent, and the mass ratio is 1: 1.

And (3) evaluating the crack resistance of the cement according to JC/T2234-2014 'test method for early crack resistance of cement'. The dry shrinkage resistance of cement is evaluated according to JC/T603-2004 'Cement mortar dry shrinkage test method', and the strength performance of cement is evaluated according to GB/T17671-1999 'Cement mortar Strength test method (ISO method)'. The hydration heat release of the cement is measured by GB/T12959-2008 'method for measuring hydration heat of cement', and the performance test result is shown in Table 1.

C₃The hydration product of the A (tricalcium aluminate) mainly contributes to early strength, but the dry shrinkage rate is large, and the dry shrinkage rate of the hardened cement is further reduced mainly by limiting the hydration product to a small proportion.

TABLE 1 physical Properties of high Strength non-shrink Portland Cement for roads prepared in examples 1 to 5

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims (10)

1. The high-strength non-shrinkage road portland cement is characterized by comprising the following components in percentage by weight:

high-strength non-shrinkage road silicate clinker: 52% -93%;

shrinkage-compensating component: 1% -10%;

auxiliary cementing material: 4% -30%;

gypsum: 2% -8%.

2. The high-strength non-shrinkage road portland cement according to claim 1, wherein the high-strength non-shrinkage road portland cement clinker comprises the following components in percentage by weight:

C₃S：50%~65%；

C₂S：15%~30%；

C₃A：0%~8%；

C₄AF：15%~22%。

3. the high-strength non-shrinkage road portland cement according to claim 1, wherein the shrinkage-compensating component is one or more of steel slag, steel slag powder, anhydrous calcium sulphoaluminate, magnesium oxide and/or calcium oxide.

4. The high-strength non-shrinkage road portland cement according to claim 1, wherein the auxiliary cementitious material is one or more of fly ash, mineral powder, limestone powder and/or silica fume.

5. The high-strength non-shrinkage road portland cement according to claim 1, wherein the gypsum is one or more of natural dihydrate gypsum and/or desulfurized gypsum.

6. The Portland cement for high-strength non-shrinkage roads as claimed in claim 1, wherein the Portland cement for high-strength non-shrinkage roads has a specific surface area of 300-380 m²/kg。

7. A method for preparing the high-strength non-shrinkage road portland cement of any one of claims 1 to 6, comprising the following steps:

1) preparing raw materials; mixing and grinding a calcareous raw material, a silicon-aluminum raw material and an iron correction raw material to prepare a cement raw material;

2) preparing clinker; calcining the cement raw material at 1400-1500 ℃ for 20-50 min, and then cooling to room temperature at least at a cooling rate of 40 ℃/min by using a grate cooler to prepare the high-strength shrinkage-free road silicate clinker;

3) preparing cement; the prepared cement clinker, the shrinkage compensation component, the auxiliary cementing material and the gypsum are ground together or respectively ground and mixed to prepare the high-strength shrinkage-free road silicate cement.

8. The preparation method according to claim 7, wherein the calcareous raw material in the step 1) is one or two of limestone and/or carbide slag with CaO content of more than or equal to 45%.

9. The method according to claim 7, wherein the alumino-silica raw material in the step 1) is Al₂O₃The content is more than or equal to 10 percent, and SiO is₂One or more than two of shale, clay and fly ash with the content of more than or equal to 50 percent are compounded.

10. The method as claimed in claim 7, wherein the ferrous correction raw material in step 1) is Fe₂O₃One or more than two of iron ore, copper slag and iron powder with the content of more than or equal to 40 percent are compounded.