JP2008266130A - High-strength concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide concrete having high compressive strength, while preventing the occurrence of the autogeneous shrinkage of concrete and the crack caused thereby. <P>SOLUTION: The high-strength concrete is prepared by using a waste tile which is a porous ceramic as an aggregate, while setting the water-cement ratio during kneading to 15-40%, wherein the resulting high-strength concrete has a compressive strength at a material age of 28 days of 60 N/mm<SP>2</SP>or more, preferably 70 N/mm<SP>2</SP>or more. The aggregate comprises the waste tile in an amount of 10 to 40% of the total volume of the aggregate. In this case, it is preferred to use an expansive additive and/or a shrinkage-reducing agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to a technical field related to high-strength concrete formed by kneading at least cement, water, and aggregate.

In recent years, defective products after firing in a clay straw manufacturing plant, clay straw as waste from roof replacement work, processed scraps and damaged pieces of clay straw in roof construction, clay straw as waste from building demolition work For the purpose of effectively reusing waste tiles such as, it has been proposed to use waste tiles as aggregates of concrete (for example, see Patent Document 1). In this way, concrete using waste tiles as aggregate is lighter than sand and gravel aggregates because of the porous tiles, has low thermal conductivity, and has excellent heat insulation and sound absorption characteristics. It will be a thing.
JP 2000-34155 A

By the way, in order to increase the compressive strength of concrete, it is necessary to reduce the water cement ratio (W / C) as much as possible when kneading cement, water, and aggregate (gravel, sand, etc.). When the water-cement ratio is reduced, there is not enough reaction water for the cement hydration reaction, so there is no moisture in the gaps in the concrete and the concrete self-shrinks, which causes cracks in the concrete. The possibility increases. Therefore, the water cement ratio is usually about 50% even if it is small. In Patent Document 1, the water cement ratio is 101%, and the compressive strength at the age of 28 days is 3.14 N / mm ^2. It has become. For this reason, in patent document 1, waste tile is not utilized effectively for the high intensity | strength of concrete. Also, conventionally, increasing the compressive strength of concrete while preventing the self-shrinkage and cracking of concrete has been achieved by using expansion material, artificial lightweight aggregate, coal ash artificial lightweight aggregate, porous polymer particles, etc. Otherwise, it was usually considered difficult.

  Therefore, as a result of earnestly studying whether or not the characteristics of the porous ceramics such as waste tiles can be utilized for suppressing the self-shrinkage of the concrete, the present inventors have reduced the water cement ratio, It has been found that by mixing porous ceramics, compressive strength equal to or higher than that of non-mixed concrete can be obtained, and self-shrinkage and cracks caused by the compressive strength can be suppressed, leading to the present invention.

  The present invention has been made in view of such a point, and an object of the present invention is to increase the compressive strength of concrete while preventing the self-shrinkage of the concrete and cracks caused thereby.

In order to achieve the above object, in the present invention, porous ceramic is used for the aggregate, the water cement ratio at the time of kneading is set to 15% or more and 40% or less, and the compressive strength at the age of 28 days is 60 N / mm ² or more. High strength concrete of preferably 70 N / mm ² or more was obtained.

Specifically, in the first aspect of the invention, for high-strength concrete obtained by kneading at least cement, water, and aggregate, the aggregate includes porous ceramics, and the water-cement ratio at the time of kneading is high. It is 15% or more and 40% or less, and the compressive strength at the age of 28 days in high-strength concrete is 60 N / mm ² or more.

In the invention of claim 2, in the invention of claim 1, the compressive strength at the age of 28 days in the high-strength concrete is 70 N / mm ² or more.

  According to the invention of claim 1 or 2, even if the water-cement ratio is small and there is little reaction water for the hydration reaction of the cement, by containing water in the voids of the porous ceramics, In the hardening process of the concrete, water is supplied from the voids into the pores of the concrete, thereby suppressing the self-shrinkage of the concrete and eventually cracking (internal curing effect).

Further, in addition to the strength of porous ceramics being higher than that of conventional artificial lightweight aggregates, a lot of hydration products are generated by the water supplied from the pores of the porous ceramics. The structure is strengthened and the strength reduction due to the porous ceramics is suppressed. Moreover, since water-cement ratio is less and less 40% 15%, it becomes a dense concrete compressive strength at the age of 28 days 60N / mm ² or more, high-strength concrete which is preferably 70N / mm ² or more Is easily obtained. Therefore, the compressive strength of the concrete can be increased while preventing the self-shrinkage of the concrete and the cracks caused thereby.

  In the invention of claim 3, in the invention of claim 1 or 2, waste tile is used as the porous ceramics of the aggregate.

  In other words, the waste tile has a water absorption rate that is suitable for supplying water appropriately to the pores in the concrete, and even if most of the voids in the waste tile release water, Since it has a diameter that does not easily shrink and has higher strength than conventional artificial lightweight aggregates, it is an aggregate suitable for high-strength concrete. Therefore, it is possible to easily obtain high-strength concrete that does not cause the self-shrinkage of the concrete and cracks caused by the reuse of the waste tile.

  In the invention of claim 4, in the invention of claim 3, 10% or more and 40% or less of the total volume of the aggregate is composed of waste tiles.

  According to the inventions of claims 5 to 7, in the invention of claim 4, the waste tile is used with coarse aggregate and fine aggregate alone or in combination of coarse aggregate and fine aggregate. And

  That is, within the above ratio range, by appropriately combining the amount of waste tile contained in coarse aggregate and fine aggregate, it is possible to flexibly and easily obtain high-strength concrete in which self-shrinkage is effectively reduced. it can. Incidentally, the coarse aggregate and the fine aggregate here are in accordance with general classification.

  The invention according to claim 8 includes the expansion material and / or the shrinkage reducing agent in any one of the inventions according to claims 4 to 7. Then, the self-shrinkage can be further effectively reduced by the combination of the waste tiles and these.

As described above, according to the high-strength concrete of the present invention, the porous ceramic is used for a part or all of the aggregate, the water cement ratio at the time of kneading is set to 15% or more and 40% or less, and the compression is 28 days old. strength 60N / mm ² or more, preferably so was set to be 70N / mm ² or more, while so autogenous shrinkage and cracking due to its concrete does not occur, it is possible to increase the compressive strength of the concrete.

  Hereinafter, embodiments of the present invention will be described in detail.

The high-strength concrete according to the embodiment of the present invention is obtained by kneading cement, water, an aggregate, an admixture, an admixture and the like, and the water cement ratio at the time of kneading is 15% or more and 40% or less. . Compressive strength at the age of 28 days of high-strength concrete, 60N / mm ² or more, preferably there is a 70N / mm ² or more.

  The cement is preferably low heat Portland cement with low self-shrinkage, but is not limited to this, and various materials such as ordinary Portland cement and medium heat Portland cement can be used. Silica fume may be added as appropriate in order to increase the fluidity of the cement and increase the strength.

  The said admixture is suitably added as needed, and is a water reducing agent, AE agent, an antifoamer, a shrinkage reducing agent, etc. In particular, it is preferable to add a high-performance water reducing agent (for example, a polycarboxylic acid ether type high-performance water reducing agent) from the viewpoint of favorably dispersing cement particles, and from the viewpoint of reducing self-shrinkage of concrete, a shrinkage reducing agent. It is preferable to add a predetermined amount (for example, a lower alcohol-based shrinkage reducing agent). Specifically, if the component of the shrinkage reducing agent is a lower alcohol, a standard amount ± 4 kg / m 3 can be added. Moreover, in the case of components, such as a polypropylene glycol and an ethylene oxide methanol adduct, 1-6 weight% can be added with respect to cement total amount.

  Moreover, the said admixture is also added suitably as needed, and is a pozzolan, an expansion | swelling material, etc. In particular, from the viewpoint of reducing self-shrinkage of concrete, it is preferable to add a predetermined amount of an expansion material (for example, ettringite lime composite expansion material). Can be replaced with wood.

  The aggregates are classified into fine aggregates having a particle size of 5 mm or less and coarse aggregates having a particle size of 5 mm or more. The fine aggregates include natural aggregates such as sand, and the coarse aggregates include gravel and crushed stones. Includes natural aggregate. In the present embodiment, at least one of the fine aggregate and the coarse aggregate further includes porous ceramics. The water absorption of the porous ceramic is preferably 5% to 12%, and water is previously contained in the voids (pores) of the porous ceramic before the kneading. In this way, in the hardening process of the concrete, moderate water is supplied from the voids of the porous ceramics into the pores of the concrete, so that the water-cement ratio is small and there is little reaction water for the cement hydration reaction. Even if it exists, the self-shrinkage | contraction of a concrete and by extension, a crack can be suppressed effectively.

Here, the water absorption rate of the aggregate is obtained as follows. That is, the surface water of the aggregate in a wet state (a state where water is adhered to the surface of the aggregate) is completely wiped off to make the surface dry and saturated, and further dried at 100 to 110 ° C. to a constant mass. To be absolutely dry. And the mass of the absolute dry state of the aggregate is A, the mass of the surface dry saturated water state is B,
Water absorption rate = (B−A) / A × 100 (%)
Ask for.

  Moreover, it is preferable that the pore diameter is 0.1 μm to 10 μm for 95% or more of all the pores of the porous ceramic. By doing so, even if water is released from the voids (pores) of the porous ceramic, the porous ceramic is less likely to shrink.

  Furthermore, the crushing value of the porous ceramics (according to BS (British Standard) 812 part 110) is preferably small, but considering the relationship with the water absorption rate, 15% to 25% in the case of coarse aggregate It is preferable that This makes it difficult for the porous ceramics to be damaged when a compressive force is applied to the concrete while obtaining an appropriate water absorption rate.

  If waste tile is used as the porous ceramic, the water absorption rate and the void diameter (pore diameter) are both in the above preferred ranges, and the crushing value is also small. Therefore, it is suitable and available for the high-strength concrete of the present invention. It becomes easy.

  When the fine aggregate contains porous ceramics, the ratio of the volume of the porous ceramics to the total volume of the fine aggregates (total volume of natural aggregates and porous ceramics) is in the range of more than 0 and less than 100%. Although it may be a value, it is particularly preferably 10% or more and 40% or less.

  Further, when the coarse aggregate contains porous ceramics, the ratio of the volume of the porous ceramics to the total volume of the coarse aggregates (total volume of natural aggregate and porous ceramics) is in the range of more than 0 and less than 100%. Although it may be any value, it is particularly preferably 10% or more and 40% or less.

  Further, the same applies to the case where both the fine aggregate and the coarse aggregate contain porous ceramics, and the ratio of the volume of the porous ceramics to the total volume of both aggregates is preferably 10% or more and 40% or less. .

  Considering the viewpoint of self-shrinkage, it is more preferably 20% or more and 30% or less among 10% or more and 40% or less. In particular, when a swelling agent or the like is used in combination, it is preferably about 20%.

  Even if the water-cement ratio at the time of kneading is 15% or more and 40% or less and the amount of water for the hydration reaction of the cement is small due to the porous ceramics, the pores in the porous ceramics (pores) By containing water in the water, water is supplied into the pores of the concrete from the voids, thereby suppressing self-shrinkage of the concrete and eventually cracking (internal curing effect).

In addition, porous ceramics have higher strength than conventional artificial lightweight aggregates (small crush value), and many hydrated products are produced by water supplied from the voids of porous ceramics. As a result, the skeletal structure is strengthened, and the decrease in strength due to the porous ceramics is suppressed. Moreover, since water-cement ratio is small, dense concrete can be obtained, compressive strength at the age of 28 days 60N / mm ² or more, preferably a high strength concrete can be easily obtained, which is a 70N / mm ² or more. Therefore, the compressive strength of the concrete can be increased while preventing the self-shrinkage of the concrete and the cracks caused thereby.

(First embodiment)
Next, a first embodiment specifically implemented with respect to compressive strength will be described.

In this example, cement, water, aggregate and admixture were kneaded at 20 ° C. to produce concrete. The cement, water, aggregate and admixture used at this time were those shown in Table 1, respectively. The low heat Portland cements in Table 1 were premixed with silica fume at a substitution rate of 9.5%, and the compositional compounds of the cements were C ₃ S (27.5%), C ₂ S (51. 4%), C ₃ A (4.7%), C ₄ AF (9.2%), and heat of hydration is 222 J / g at 7 days of age and 281 J / g at 28 days of age. . In addition, the high-performance water-reducing agent used in the admixture is a polycarboxylic acid-based high-performance water-reducing agent manufactured by NMB. ) Was used.

  Further, a part of the fine aggregate or coarse aggregate is used as waste tile, the characteristics of the waste tile as fine aggregate are shown in Table 2, and the characteristics of the waste tile as coarse aggregate are shown in Table 3, respectively.

  Furthermore, FIG. 1 shows the relationship between the pore diameter in the waste tile and the pore volume (volume of pores per unit mass). As the pores of the waste tile, there are many pores having a pore diameter of 1 μm to 5 μm, and the pore diameter of 95% or more of all pores is 0.1 μm to 10 μm.

  And when using the said waste tile for a part of coarse aggregate, the ratio of the volume of the waste tile with respect to the volume of the whole coarse aggregate is 40% (Example 1), and 20% (implementation) Example 2) is prepared, and when the waste tile is used as a part of the fine aggregate, the ratio of the volume of the waste tile to the total volume of the fine aggregate is 40% (Example 3), 20 % (Example 4).

  Table 4 shows the blending ratios of Examples 1 to 4. As shown in Table 4, the water cement ratio (W / C) at the time of kneading is 15%. The symbol “W” in Table 4 is water, and the other symbols are the same as those described in Table 1.

  Concrete was prepared with the blends of Examples 1 to 4 above, and the compressive strength of the concrete at 7 days of age and 28 days of age was measured. In addition, the concrete curing was a simple heat insulation curing using polystyrene foam.

  Further, as a comparative example, both the fine aggregate and the coarse aggregate include only natural aggregate (the fine aggregate includes only natural aggregate (symbol “S” in Table 1)), and the coarse aggregate is natural bone. Including only the material (symbol “G” in Table 1), the volume of the fine aggregate is 166 liters, and the total volume of the coarse aggregate is 323 liters, other conditions are the same as in Example 1 above. Concrete was produced in the same manner as ˜4, and the compressive strength of the concrete at 7 days and 28 days was measured.

  The measurement result of the compressive strength of the said Examples 1-4 and a comparative example is shown in FIG. From this result, it can be seen that the compression strength of concrete at 28 days of age can be improved by using a part of fine aggregate or coarse aggregate as waste tile. Here, even in the comparative example, although the compressive strength is comparatively large, the concrete has a considerably large self-shrinkage or tensile stress due to self-shrinkage, which is not practical. On the other hand, in Examples 1 to 4, there is no large self-shrinkage or tensile stress due to self-shrinkage in the concrete, and the compressive strength is higher than that of the comparative example. Therefore, when the fine aggregate or the coarse aggregate includes the waste tile, the compressive strength of the concrete can be increased while preventing the self-shrinkage of the concrete and the cracks caused thereby.

  In Examples 3 and 4 (including waste tiles as fine aggregates), the compressive strength at 7 days of age in concrete is lower than in Examples 1 and 2 (including waste tiles as coarse aggregates). However, this is probably because waste tiles as fine aggregates are less mixed than waste tiles as coarse aggregates, and the total amount of water in the voids (pores) is accordingly small. However, in Examples 3 and 4, the strength increase with the passage of time is remarkable, and at the age of 28 days, the compressive strength is almost equivalent to that of Examples 1 and 2, and finally, the same effect as that of coarse aggregate. It has become. In the case of fine aggregates, the contact area with cement is increased and the dispersibility is improved compared to coarse aggregates.

  Therefore, high-strength concrete with high compressive strength can be obtained even when waste tile is used alone for either coarse aggregate or fine aggregate, and waste tile is used for both coarse aggregate and fine aggregate. Even in such a case, a high-strength concrete having a high compressive strength and a good balance can be obtained.

(Second embodiment)
Next, a second embodiment that is specifically implemented with respect to self-contraction will be described.

  In this example, the materials shown in Table 5 were used as concrete materials.

  The cement (symbol “SFLC” in Table 5) in this example is a premix cement (density 3.08 g / cm 3, specific surface area 6470 cm 2/2) in which 10 ± 1% by weight of the low heat Portland cement in Table 5 is replaced with silica fume. Used in the state of g). Further, a lower alcohol-based shrinkage reducing agent was used as the shrinkage reducing agent for the admixture, and an ettringite-lime-based low-added expansion material was used as the expanding material for the admixture. The high-performance water reducing agent and antifoaming agent are the same as in the first embodiment.

  And, as shown in Table 6, one formulation using normal Portland cement (symbol “NC” in Table 6) and 6 formulations using the premix cement (SFLC) (symbol “G0” in Table 6) Concrete with a total of 7 blends was prepared, where the symbol “W” of the material used in Table 6 is water, and the other symbols are the same as those described in Table 5.

  G10, G20, and G30 are blends in which a part of coarse aggregate is replaced with waste tile (G roof tile), and 10, 20, and 30% of the total volume of the coarse aggregate are sequentially replaced with waste tile. Yes. On the other hand, G0EX differs from G0, and G20EX differs from G20 in that it contains an expansion material and a shrinkage reducing agent, respectively. The expansion material replaces about 1.5% by weight of the total amount of cement, and the shrinkage reducing agent adds about 4% by weight to the total amount of water. Note that the water binder ratio or the water cement ratio during kneading is set to 15%.

  Each blend of concrete was produced by the process shown in FIG. That is, each cement and fine aggregate (including an admixture when an admixture is present) were added to a biaxial forced stirring mixer and stirred for a predetermined time (empty kneading step). After the empty kneading step, a predetermined amount of water and an admixture were added while stirring was stopped, and kneaded for a predetermined time (first kneading step). Then, after the first kneading step, a predetermined amount of coarse aggregate was charged in a state where stirring was stopped, and kneaded for a predetermined time (second kneading step). The kneaded concrete was immediately poured into a mold, left standing for one day under predetermined conditions, removed from the frame, covered with a film, aluminum tape, etc., and cured in a state where moisture reduction was suppressed (sealing) Curing).

  A self-shrinkage test for measuring the self-shrinkage strain of the concrete and a rebar restraint test for measuring the restraint stress generated in the rebar by self-shrinkage were performed on the concretes thus prepared. In addition, according to the measurement result of the compressive strength separately performed for these concretes, all the concretes were high-strength concretes exceeding 100 N / mm 2 at the age of 28 days.

  The self-shrinkage test was carried out in accordance with JCI's “Concrete self-shrinkage test method (draft)” using an embedded strain gauge (manufactured by Tokyo Sokki Kenkyujo Co., Ltd .: KM-100BT). The reinforcing bar restraint test (reinforcing bar ratio 2.0%) was carried out in accordance with JCI's “Concrete self-stress test method (draft)”.

  The results of the self-shrink test are shown in FIGS. FIG. 4 compares the effects of the expansion material and the shrinkage reducing agent, and FIG. 5 compares the effects of the replacement of the waste tile.

  First, as for the effects of the expansion material and the shrinkage reducing agent, as shown in FIG. 4, the strains of the two compositions (G20, G20EX) in which 20% of the coarse aggregate is replaced with waste tiles are both replaced with waste tiles. It became a value smaller than 2 blends (G0, G0EX) without any. On the other hand, by including an expansion material and a shrinkage reducing agent, an effect of reducing self-shrinkage of about 250 μm was recognized regardless of whether or not the waste tile was replaced.

  Next, with regard to the effect of replacement of waste tiles, as shown in FIG. 5, the combination of waste tile replacement (G10, G20, G30) rather than the combination without waste tile replacement (NC, G0). However, there was a tendency for the strain to decrease with increasing the replacement rate of waste tile among the formulations with replacement of waste tile. However, in the case of G30, the tendency which expand | swells at the initial stage was recognized.

  Then, the result of a reinforcing bar restraint test is shown in FIG.6 and FIG.7. FIG. 6 compares the effect of the expansion material and the shrinkage reducing agent, and FIG. 7 compares the effect of replacing the waste tile.

  In the reinforcing bar restraint test, the same results as in the self-shrinkage test were recognized, and the combination of waste tile replacement (G10, G20, G30) was more restrained than the combination without waste tile replacement (NC, G0). However, among the blends with replacement of waste tiles, the higher the replacement rate of waste tiles, the lower the restraining stress. However, in the case of G30, there was a tendency to generate restraint stress due to expansion in the initial stage.

  Table 7 shows the values of the self-shrinkage strain and the reinforcing steel restraint stress of each formulation at the age of 14 days when the change settled down and became a substantially steady state.

  As shown in the table, it was found that in the case where the waste tile was replaced, at least in the range of 10% to 30%, the strain and restraint stress decreased as the replacement ratio increased, which was preferable from the viewpoint of self-shrinkage. . Among them, 20% of the coarse aggregate is replaced with waste tile, and the combination (G20EX) containing the expansion material and the shrinkage reducing agent is the most preferable combination from the viewpoint of self-shrinkage with the smallest strain and restraint stress. I understood.

  In addition, although the above-mentioned test result uses waste tile as coarse aggregate, if it is used as fine aggregate, the contact area with cement will increase, dispersibility will also increase, and the distribution of aggregate in concrete It is considered that the internal curing effect is also improved.

  By the way, when concrete includes a porous body, generally, a tendency to increase shrinkage strain due to drying is recognized as compared with the case without including a porous body, which is one of the disadvantages of using a porous body. Yes.

  FIG. 8 shows the test results comparing the effects of drying. This test compares the change in strain with that of a state in which a part of unframed concrete (specimen) is uncovered from the seventh day of age and opened to the atmosphere and sealed. In the figure, the specimen with the thick line sealed shows the specimen with the fine line open to the atmosphere.

  As shown in the figure, it was found that the increase in strain due to drying of G10 and the like including waste tiles that are porous bodies is almost the same as that of G0 that does not include waste tiles.

  In addition, FIG. 9 shows test results comparing changes in strain due to drying over a long period of time for G10 and G20, and for blended G40 in which 40% of the volume of the coarse aggregate is replaced with waste tile. In the figure, the vertical axis represents the amount of strain change due to drying (the amount of strain of the dry specimen-the amount of strain of the sealed specimen), and the horizontal axis represents the number of days from the age of 28 days.

  As shown in the figure, there is no significant difference in the amount of change in strain, and it can be seen that there is almost no difference from the strain amount of G0 even with G40 in which 40% of the aggregate is replaced with waste tile.

  Therefore, also from this test result, if waste tile is used for high-strength concrete, even if the blending ratio is somewhat large, specifically, if it is at least 40% or less, the effect of strain due to drying can be suppressed. It becomes possible.

  Considering the above test results comprehensively, when using waste tile as aggregate in high-strength concrete, it is preferable that 10% or more and 40% or less of the total volume of the aggregate is composed of waste tile. Of these, it is particularly preferable that 20% or more and 30% or less be composed of waste tiles. Then, the self-shrinkage can be effectively reduced while increasing the compressive strength.

  Further, by including an appropriate amount of an expansion material and / or a shrinkage reducing agent, an excellent effect can be obtained by combining waste tiles with these. In that case, a more excellent effect can be obtained if approximately 20%, specifically 15% or more and 25% or less, is constituted by waste tiles.

  The present invention is useful for high-strength concrete formed by kneading at least cement, water, and aggregate, and is particularly useful for increasing the strength by setting the water-cement ratio during kneading to 15% to 40%.

It is a graph which shows the relationship between the pore diameter in the waste tile in 1st Example, and the pore volume per unit mass. It is a graph which shows the measurement result of the compressive strength of Examples 1-4 in a 1st example, and a comparative example. It is a figure which shows the preparation methods of the concrete in 2nd Example. It is a graph which shows the measurement result of distortion by self contraction in the 2nd example. It is a graph which shows the measurement result of distortion by self contraction in the 2nd example. It is a graph which shows the measurement result of the restraint stress of the reinforcing bar by the self-contraction in 2nd Example. It is a graph which shows the measurement result of the restraint stress of the reinforcing bar by the self-contraction in 2nd Example. It is a graph which shows the influence by drying in 2nd Example. It is a graph which shows the influence by drying in 2nd Example.

Claims (8)

It is a high-strength concrete formed by kneading at least cement, water and aggregate,
The aggregate includes a porous ceramic,
The water cement ratio during the kneading is 15% or more and 40% or less,
A high-strength concrete having a compressive strength of 60 N / mm ² or more on the age of 28 days. The high-strength concrete according to claim 1,
A high-strength concrete having a compressive strength of 70 N / mm ² or more at 28 days of age. The high-strength concrete according to claim 1 or 2,
A high-strength concrete characterized in that waste tile is used as the porous ceramics of the aggregate. The high-strength concrete according to claim 3,
10% or more and 40% or less of the total volume of the aggregate is composed of waste tiles. The high-strength concrete according to claim 4,
High-strength concrete, wherein the waste tile is used as coarse aggregate. The high-strength concrete according to claim 4,
High-strength concrete, wherein the waste tile is used as fine aggregate. The high-strength concrete according to claim 4,
High-strength concrete, wherein the waste tile is used as coarse aggregate and fine aggregate. The high-strength concrete according to any one of claims 4 to 7,
A high-strength concrete comprising an expansion material and / or a shrinkage reducing agent.

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