JP4692830B2 - Filled water retention material for water retentive pavement - Google Patents

Description

  The present invention is a water-retaining pavement that retains moisture such as rainwater in the pavement, evaporates the moisture of the pavement retained during rainy weather and cools the road surface by removing the heat of vaporization, and alleviates the heat island phenomenon. It is related with filling water retention material.

  In recent years, heat island phenomenon in which the temperature rises due to heat from asphalt pavement or concrete buildings, radiant heat from reflection, exhaust heat from air conditioning of buildings, etc. has been seen as a problem in urban areas and densely populated areas. ing.

  As measures to mitigate this heat island phenomenon, various proposals have been made in recent years to keep rainwater in the pavement by water-retaining pavement, and to take away the heat of the road surface by the heat of vaporization when moisture evaporates in fine weather and suppress the temperature rise. It is made.

  As the basic structure of the water-retaining pavement, a structure in which a water retention material (curable slurry) is filled in the voids of an open-graded asphalt mixture is generally used. Has been.

  For example, in Patent Document 1 below, cement milk made of water, cement, fibers, and a surfactant in a pavement void having 15-30% voids in a surface layer portion of a road pavement located on a roadbed or a base layer A road pavement filled with is proposed.

  Also, in Patent Document 2 below, after forming a porous cured body (open particle size asphalt mixture), a slurry-like filler containing cement, clay-based fine powder, water, etc. is filled into the continuous voids of the porous cured body. A pavement has been proposed.

  Furthermore, in the following Patent Document 3, water for water-retaining solidified body obtained by mixing 30 to 70% by weight of ground granulated blast furnace slag with an average particle size of 50 to 200 μm and an inorganic solidifying material that is alkaline in contact with water. Hardwood has been proposed.

Further, in Patent Document 4 below, 50 to 70% by weight of blast furnace slag part powder, 30 to 50% by weight of inorganic powder containing 50% by weight or more of amorphous SiO ₂ , the blast furnace slag fine powder and the inorganic powder A water retention material composed of a mixed material in which 3-49 parts by weight of an alkali stimulant is added to 100 parts by weight of the powder has been proposed.

In the following Patent Document 5, a blast furnace slag fine powder, an alkali stimulant, and a water-absorbing polymer are further pulverized into an inorganic powder of 100 μm or less and / or 150 μm or less containing 50% by weight or more of amorphous SiO _2. A water-retaining hydraulic solidified product obtained by mixing blast furnace granulated slag has been proposed.
JP 2003-184014 A JP 2003-201705 A JP 2003-95726 A JP 2003-129407 A JP 2003-165760 A

  However, as in the inventions described in Patent Documents 1 to 5, in the case of pavement filled with a water retention material mainly composed of the cement or blast furnace slag fine powder, the water absorption rate and the water absorption amount are insufficient, and the water retention effect is maintained. Is allowed to disappear in 2-3 days. Therefore, when the weather continues, sufficient effects cannot be obtained as a mitigation measure for the heat island phenomenon.

  In addition, since the water retaining material fills the voids of the open-graded asphalt mixture, sufficient fluidity is required, and it is necessary to increase the amount of water compared to ordinary concrete, so that there is a problem such as easy to cause breathing. is there. In addition, since a part of the water retaining material is exposed on the road surface, generation of dust becomes a problem due to wear with the tire, and thus it is necessary to satisfy a required strength.

  On the other hand, a lot of coal ash is emitted as a by-product of thermal power generation using coal. Conventionally, the use of this coal ash has been mostly used as a substitute for cement clay. Along with the decline, it is no longer possible to cope with the increase in the amount of coal ash generated, and there is a strong demand for new effective use.

  Therefore, the main object of the present invention is to focus on the high water absorption of the mixture of fly ash (coal ash), and use fly ash as the main raw material, and in combination with specific materials, fluidity, low breathing rate, strength characteristics Another object is to propose a water-retaining material for water-retaining pavement that sufficiently satisfies various performances such as water absorption and suction performance.

In order to solve the above-mentioned problem, the present invention according to claim 1 is a filled water retention material for water retention pavement mainly composed of fly ash, wherein the filled water retention material is fly ash, gypsum, slaked lime, cement and water. As the gypsum, heat-treated at a temperature of 85 ° C. or higher is mixed at a ratio of 6 parts by weight or more with respect to 100 parts by weight of fly ash, and the slaked lime is added to 100 parts by weight of fly ash. 4 parts by weight or more, and the cement is mixed at a ratio of 6 parts by weight or more with respect to 100 parts by weight of fly ash, and the weight percentage of water to the fly ash, gypsum, slaked lime and cement (water powder) Ratio) in the range of 70-110%,
P funnel flow value: 9 to 11 seconds, breathing rate (24 hours); 3% or less, water absorption rate (material age 28 days); 50% or more, sucking speed within 180 minutes / 10 cm (sucking speed; φ5 cm × 10 cm time required for the specimen is saturated from specimens of the bottom (water immersion depth 5mm) is water absorption), compressive strength; water retention that satisfies the 1N / mm ² or more various performances Filled water retention materials for pavement are provided.

As the present invention according to claim 2, there is provided a water-retaining material for water-retaining pavement according to claim 1 , wherein the setting retarder is added at a ratio of 0.05 to 0.1% by weight with respect to the total powder amount. Is done.

According to a third aspect of the present invention, there is provided a water-retaining material for water-retaining pavement according to any one of the first and second aspects , wherein fly ash type II conforming to JIS A6201 is used as the fly ash .

According to a fourth aspect of the present invention, there is provided a water-retaining material for water-retaining pavement according to any one of the first and second aspects , wherein a blast furnace cement is used as the cement .

The 40 degreeC dry density of the said filling water holding material is 0.8-1 g / cm < ³ > as this invention which concerns on Claim 5 The filling water holding material for water retention paving in any one of Claims 1-4 is provided. Is done.

  As described above in detail, according to the present invention, it is possible to obtain a filled water retention material for water retention pavement that sufficiently satisfies various performances such as fluidity, low breathing rate, strength characteristics, water absorption, and suction performance.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Filled water retention material]
The filled water retention material for water retention pavement according to the present invention is a filled water retention material mainly composed of fly ash, and the filled water retention material is a mixture composed of fly ash, gypsum, slaked lime, cement and water, As the gypsum, dihydrate gypsum or desulfurized gypsum heat-treated at a temperature of 85 ° C. or higher is used, P funnel flow value: 9 to 11 seconds, breathing rate (24 hours); 3% or less, water absorption rate (material) Age 28 days); 50% or more, suction speed within 180 minutes / 10 cm (suction speed; φ5 cm × 10 cm) until the specimen is saturated due to water absorption from the bottom surface (water immersion depth 5 mm) Time required), compressive strength; various performances of 1 N / mm ² or more are satisfied.

  More preferably, the filled water retaining material is a mixture of fly ash, gypsum, slaked lime, cement and water, and the gypsum is fly ash obtained by heat-treating dihydrate gypsum or desulfurized gypsum at a temperature of 85 ° C or higher. 6 parts by weight or more with respect to 100 parts by weight, the slaked lime is mixed with 4 parts by weight or more with respect to 100 parts by weight of fly ash, and the cement is 6 parts by weight with respect to 100 parts by weight of fly ash. Mixing at a ratio of at least parts, and mixing the fly ash, gypsum, slaked lime and cement with a weight percentage of water (water powder ratio) in the range of 70 to 110% to satisfy the various performances. is there.

First, regarding the various performances, the present filled water retaining material is naturally filled in a void portion of a pavement constituent material such as open-graded asphalt concrete and becomes a part of a member constituting a surface layer of the pavement. Therefore, in order to ensure the self-filling property with respect to the gap, the P funnel flow value (the time required for the slurry to flow down from the P funnel) is 9 to 11 seconds, preferably 9 to 10 seconds (8. 2 seconds). Further, it is desirable that the breathing rate (24 hours) is 3% or less, preferably 0%, from the viewpoint of ensuring quality as a paved body. Furthermore, in order to prevent dust from being generated due to friction with the tire running on the road surface, the compressive strength shall be at least 1 N / mm ² (compression that is easy to test due to the correlation between the amount of dust and compressive strength) (Evaluated by strength test value).

  On the other hand, regarding the most important water absorption characteristics, the water absorption rate is 50% or more, preferably 70% or more as the water retention performance, and the absorption speed is defined as a performance value for absorbing and evaporating underground water to the ground surface. Stipulate. The suction speed is defined as the time required for water to be saturated from the bottom surface (water immersion depth 5 mm) of a φ5 cm × 10 cm specimen, and within 180 minutes / 10 cm, preferably Within 120 minutes / 10 cm, more preferably within 90 minutes / 10 cm.

  The filled water retaining material is a mixture of fly ash, gypsum, slaked lime, cement and water.

  The fly ash is preferably a fly ash type II or a type II equivalent product according to JIS A6201, but may be a non-standard product. Alternatively, fly ash raw powder collected in a coal-fired power plant can be used as it is without adjusting the particle size (classification treatment) or adjusting the particle size. When adjusting the particle size, the average particle size is preferably about 20 μm.

The gypsum includes desulfurized gypsum, dihydrate gypsum (CaSO ₄ · 2H ₂ O), hemihydrate gypsum (CaSO ₄ · 1 / 2H ₂ O), and anhydrous gypsum (CaSO ₄ ). The desulfurized gypsum is a gypsum generated as a by-product from an exhaust device installed in a power plant or factory, etc., and the dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum are classified according to the difference in crystal water. Heat treatment of gypsum or dihydrate gypsum at 120 to 160 ° C loses moisture to give hemihydrate gypsum, and heating at higher heating temperature (around 180 ° C) gives anhydrous gypsum.

The gypsum used in the filled water retaining material of the present invention is obtained by heat-treating desulfurized gypsum or dihydrate gypsum at a temperature of 85 ° C. or higher. That is, desulfurized gypsum or dihydrate gypsum that has been heat-treated at a heating temperature (less than 120 ° C.) that does not reach half-water gypsum, hemihydrate gypsum that has been treated at a heating temperature of 120 ° C. Anhydrous gypsum treated before and after is the target.

  As will be apparent from the experimental examples to be described later, since a remarkable difference is observed in the breathing rate with a heating temperature of 85 ° C. as a boundary value, in order to satisfy the breathing performance standard: less than 3%, it is 85 ° C. or higher. It is necessary to use gypsum heat-treated at temperature. Moreover, the optimal range of heating temperature is the range of 110-150 degreeC from which the remarkable effect is seen by the water absorption rate and the suction speed from the below-mentioned experiment example.

  The addition amount of the gypsum is mixed at a ratio of 6 parts by weight or more with respect to 100 parts by weight of fly ash. As will be apparent from the experimental examples described later, when the amount is less than 6 parts by weight, the breathing rate may exceed 3% and the compression strength standard may not be satisfied. Furthermore, although the suction speed can be satisfied, the water absorption rate may be less than 50%.

  The slaked lime is a white powder produced by reacting quick lime and water, but it is desirable that the slaked lime is mixed at a ratio of 4 parts by weight or more with respect to 100 parts by weight of fly ash. As will be apparent from the experimental examples described later, the addition of slaked lime does not significantly affect the P funnel flow value, the breathing rate, and the water absorption rate, but a great improvement can be seen in a small amount with respect to the compressive strength characteristics. In addition, when blast furnace cement is used, by adding slaked lime, there is an effect that the amount of boron dissolved in fly ash can be significantly reduced. When the slaked lime addition rate is gradually increased, the wicking rate tends to increase and the compressive strength also tends to decrease toward the decreasing trend.

  The cement can be any of ordinary cement, early-strength cement, and blast furnace cement. Of these cement types, heavy metals contained in fly ash (arsenic, hexavalent chromium, selenium, boron) Blast furnace cement is desirable in order to suppress elution. The addition amount is desirably 6 parts by weight or more with respect to 100 parts by weight of fly ash. The amount of cement added has a strong correlation with the compressive strength. However, when the addition rate is increased, the water absorption rate and the speed of absorption are decreased, so that it is desirable to add it at a ratio of 10 parts by weight or less.

  Furthermore, the amount of water added is adjusted so that the weight percentage (water powder ratio) of water to the fly ash, gypsum, slaked lime and cement is in the range of 70 to 110% and mixed. Since the water addition rate affects the P funnel flow value and the breathing rate, it is desirable to determine mainly in the range of 80 to 90% so that these numerical values are within the standard.

The total amount of the fly ash, gypsum, slaked lime and cement is preferably 20 to 30% by weight with respect to 100 parts by weight of fly ash. Moreover, it is desirable to adjust each material so that the said total powder amount may become 40-1 degreeC dry density of a filling water retention material 0.8-1 g / cm < ³ >.

  By the way, a setting retarder can be added to the filled water retaining material for the purpose of delaying gelation in consideration of workability. It is desirable to add a setting retarder from 0.05 to 0.1% by weight of the total powder amount. If the amount added exceeds 0.1% by weight, breathing tends to occur.

  The filled water retaining material according to the present invention is mainly fly ash, and is a material in which gypsum, slaked lime, cement and water are mixed together with this fly ash, and it is necessary to determine the optimum blending range of each.

Hereinafter, experiments conducted for determining the optimum blending range will be described in detail.
(1) Basic formulation setting In order to effectively determine the optimum formulation of various materials, the basic formulation shown in Table 1 below was set based on the results of preliminary tests.

(2) Gypsum
(2) -1 Gypsum heat treatment temperature (dehydration treatment)
A commercially available dihydrate gypsum (Tiger Calcy made by Yoshino gypsum) and each desulfurized gypsum subjected to dehydration treatment at various heating temperatures were used to examine the optimum heat treatment temperature as a filling water retaining material. The results are shown in Table 2 below.

  As a result of the test, it was found that the breathing rate greatly exceeded the reference value (3%) when the treatment was performed at a heating temperature of 80 ° C. or less.

  Furthermore, in order to obtain the boundary value of the heating temperature, an experiment was performed with the temperature from 70 ° C. to 110 ° C. being incremented by 5 ° C. The results are shown in Table 3 below.

  From the test results shown in Table 3, it was found that the boundary value of the heating temperature was 85 ° C., and as this filled water retaining material, the breathing rate could be reduced to 0% by using gypsum heated at a temperature of 85 ° C. or higher. There was found.

(2) -2 Gypsum blend amount Next, in order to determine the optimum blend of gypsum, each case where the blend amount was changed in increments of 4% by weight between 0 and 16% by weight per 100 parts by weight of fly ash. The test was conducted. The results are shown in Table 4 below.

From the test results shown in Table 4, it was found that the compression strength can satisfy the standard value (1 N / mm ² or more) by mixing at a ratio of 6 parts by weight or more with respect to 100 parts by weight of fly ash.

(3) Optimal formulation of slaked lime In order to determine the optimal formulation of slaked lime, tests were conducted on each case where the blending amount was changed in increments of 4% by weight between 0 to 16% by weight with respect to 100 parts by weight of fly ash. It was. The results are shown in Table 5 below.

From the test results shown in Table 5, it was found that the compressive strength can satisfy the standard value (1 N / mm ² or more) by mixing at a ratio of 4 parts by weight or more with respect to 100 parts by weight of fly ash. The cement described later also contributes to an increase in compressive strength. However, as can be seen from a comparison between the case where slaked lime is added at 0% by weight and the case where 4% by weight is added, the compressive strength is greatly increased by adding a small amount. It was also found that it could be increased.

(4) Optimum blending of cement In order to determine the optimum blending of cement, a test was conducted for each case where the blending amount was changed from 2 to 8% by weight in increments of 2% by weight with respect to 100 parts by weight of fly ash. It was. The test was conducted on two types of early strong cement and blast furnace cement. The results are shown in Table 6 and Table 7, respectively.

From the test results shown in Tables 6 and 7, the compressive strength of the early strength cement and the blast furnace cement was mixed at a ratio of 6 parts by weight or more with respect to 100 parts by weight of fly ash, so that the compressive strength was 1 N / mm ² or more).

(5) Elution of heavy metals In cases where blast furnace cement was used and various formulations were changed, tests were conducted to determine whether the elution amounts of arsenic, chromium, selenium, fluorine and boron were within the standard values. In addition, as a reference example, a test was also conducted with only fly ash. The results are shown in Table 8 below.

  From Table 8, in the case of fly ash only, the amount of elution of arsenic, chromium, selenium, and boron exceeded the reference value except for the fluorine compound. On the other hand, in each case where cement was blended, all heavy metals were within the standard value, but in the case of No4 where no gypsum was added, selenium contained significantly more than other cases, and slaked lime was not contained. In the case of No5 which was not added, the result was that boron was contained significantly more than the other cases. Accordingly, it has been found that gypsum and slaked lime are desirably added in order to limit elution of heavy metals.

(6) Dry density In this filled water retaining material, the water absorption rate has a directly proportional correlation with the amount of micropores formed inside the cured water retaining material, and the compressive strength has an inversely proportional correlation with the amount of micropores. It appears to be. That is, to increase the water absorption rate, it is necessary to increase the amount of fine pores (evaluated by dry density), and to increase the compressive strength, it is necessary to reduce the amount of fine pores. In order to satisfy such a contradictory relationship, the correlation between the water absorption rate and the dry density and the correlation between the compressive strength and the dry density were examined. The dry density was 40 ° C. dry density (dried at 40 ° C. for 24 hours).

FIG. 1 shows a correlation graph between water absorption and dry density, and FIG. 2 shows a correlation graph between compressive strength and dry density. As shown in FIG. 1, in order to obtain a water absorption rate of 50% or more, the water retention material needs to have a 40 ° C. dry density of 1 g / cm ³ or less. Moreover, as shown in FIG. 2, it is necessary to set it to 0.8 g / cm ³ or more from the relationship between the dry density and the compressive strength. From the above, in order to satisfy the predetermined compressive strength and water absorption rate, it is important to set the formulation so that the 40 ° C. dry density of the water retaining material is within the range of 0.8 to 1.0 g / cm ^3. It is.

(7) Addition of setting retarder In consideration of workability, the amount of setting retarder was examined when it was necessary to mix it.

  The composition of the filling water retaining material is shown in Table 9 below, and for each case where the addition amount of the solidification retarding material (Pozoris No. 89) was changed in the range of 0 to 0.2% by weight with respect to the total powder amount, the P funnel The change of flow value (S) was investigated. The result is shown in FIG.

  From FIG. 3, when the addition amount was 0.2% by weight, no increase in the P funnel flow value was observed, but the breathing rate was large and the result was unsuitable for construction. Accordingly, it has been found that it is desirable to add the setting retarder in the range of 0.05 to 0.1% by weight.

  Next, the structure example of the water retention pavement using the filling water retention material according to the present invention will be described in detail.

[Water retentive pavement structure]
The water-retaining pavement structure shown in FIG. 4 is an asphalt water-retaining layer 1 that forms a surface layer in which the filled water-retaining material 4 according to the present invention is filled in the gap portion of the open-graded asphalt concrete 3 (hereinafter simply referred to as open-graded asphalt concrete). And a two-layer water-retaining water-retaining pavement comprising a coal ash solidified crushed water reservoir 2 mainly composed of coal ash solidified crushed stone 5 located below the asphalt water retentive layer 1 and compacted to a predetermined density. . In the case of improving the normal asphalt pavement or the concrete pavement to the water retentive pavement of the present invention, it is desirable that this water supply type water retentive pavement is laid on the existing roadbed after removing only the existing surface pavement.

  The open particle size ascon 3 of the asphalt water retention layer 1 is a heated mixture composed of coarse aggregate, fine aggregate, filler, and asphalt and has a 2.5 mm sieve passage in a synthetic particle size in the range of 15% to 30%. It is a pavement surface layer material that is generally used as drainage pavement, and provides load resistance against traffic loads.

  The filled water retaining material 4 filled in the gaps of the open particle size ascon 3 has an ettringite-based interstitial phase formed in the composition, so that the solidified body of the filled water retaining material has very high water absorption and As described above, it has water retention, but has fluidity so that it can penetrate to the coal ash solidified crushed stone reservoir 2 and is self-filled (filled by natural penetration) into the gaps of the open-graded ascon 3. The And the continuity of a capillary phenomenon is ensured between the structures of the said asphalt water retention layer 1 and the coal ash solidification crushed water reservoir 2.

  On the other hand, the coal ash solidified crushed stone 5 constituting the coal ash solidified crushed water reservoir 2 is formed by adding lime and gypsum to the coal ash as additives, kneading with water, and then curing the kneaded product. It is a crushed stone-like solid body obtained by crushing a cured solid body. In addition, since the quality of the coal ash used as the material varies considerably due to fluctuations in the characteristics of the coal ash, as shown in Japanese Patent No. 3455184, in order to obtain a solidified body of stable quality while responding to the above-described fluctuations, A product produced by controlling and managing the fluid number of the kneader, the temperature of the kneaded product, the bulk specific gravity of the molded product, the compressive strength of the solidified body during curing, and the coarse particle ratio of the granular solidified body can be suitably used. .

  The coal ash solidified crushed water reservoir 2 adjusts the coal ash solidified crushed stone 5 with a particle size distribution of M40 or the like (pavement particle size regulation value) and compacts it with a predetermined density to ensure load resistance performance as a roadbed material. .

  The coal ash solidified crushed water reservoir 2 is composed of coal ash solidified crushed stone 5 and free water in the gaps. When the coal ash solidified crushed water reservoir 2 is in a wet state, the coal ash solidified crushed stone 5 is in a state of being retained by surface water and internal water. Free water, surface water, and internal water of the coal ash solidified crushed stone reservoir 2 rise to the asphalt water retention layer 1 through the capillaries formed by adjacent particle arrays. Most of the water stored in the coal ash solidified crushed water reservoir 2 is consumed for temperature cooling of the road surface by capillarity in the two-layer structure and evapotranspiration on the road surface.

[Construction of water retentive pavement]
The water-retaining pavement has a coal ash solidified crushed stone 5 at the upper part of the existing roadbed, and a layer thickness of 5 to 10 cm (to completely replace the existing roadbed with coal ash solidified crushed stone in order to ensure the sustainability of the cooling effect. 10-20 cm), and the coal ash solidified crushed water reservoir 2 is formed. Then, an open-graded ascon 3 is laid on the upper surface of the coal ash solidified crushed water reservoir 2 so that the layer thickness is preferably 5 cm or more. To do. After that, the filled water retaining material 4 is self-filled in the gaps of the open-graded ascon 3 and penetrates to the interface with the coal ash solidified crushed stone reservoir 2 to give a continuity of a two-layer structure. Since gypsum is used for the filled water retaining material, the surface layer portion that comes into contact with air within 3 hours becomes clay-like, so that the clay-like surplus slurry solidified body present on the road surface is cleaned. According to this construction method, traffic can be opened in about 3 hours after the filling water retaining material 4 is filled, and construction can be performed quickly.

[Cooling mechanism of this water supply type water retaining pavement]
During rainwater, as shown in Fig. 5 (A), rainwater penetrates into the lower layer while being retained in the asphalt reservoir 1 and is stored in the coal ash solidified crushed reservoir 2 and excess water penetrates into the existing roadbed. To do. When the temperature is high in midsummer, as shown in FIG. 5B, moisture is taken away from the surface of the asphalt water retention layer 1 as heat of vaporization, and the rise in the surface temperature is suppressed. The water is continuously supplied from the coal ash solidified crushed water reservoir 2 to the asphalt water retention layer 1 by the capillary phenomenon in the two-layer structure, and the cooling effect of the road surface temperature is maintained. As for the road surface cooling effect, the coal ash solidified crushed stone and the composition of the filled water retaining material 4 and the layer thickness of the asphalt water retaining layer 1 are set so that the road surface temperature in summer can be maintained at 40 ° C. or lower for at least four consecutive days. It is desirable to set the composition of 5 and its layer thickness.

  The water-retaining pavement structure was the water supply type water-retaining pavement shown in FIG. 4, and the heat island suppression effect of the water-retaining pavement using the filled water-retaining material according to the present invention was verified.

  The experiment was conducted according to the present invention in which the weight percentage ratio of the water retaining material was fly ash: desulfurized gypsum (heat treatment at 110 ° C.): Slaked lime: cement = 100: 8: 8: 8, and the water powder ratio was 70%. With respect to the three cases of the water supply type water retaining pavement using the water retaining material, the general dense grained asphalt pavement, and the lawn, the change over time in the road surface temperature was measured. The amount of solar radiation is also shown in the graph.

  The result is shown in FIG. From FIG. 6, it was found that in the case of the water supply type water retaining pavement using the filled solidified material according to the present invention, the road surface temperature can be reduced by about 10 ° C. as compared with a general dense grained asphalt pavement. In addition, the cooling effect could last for about 2 weeks.

[Other examples]
(1) In the above embodiment, the example in which the filled water retaining material is applied to the water supply type water retaining pavement developed by the present applicant has been described. The present invention can be similarly applied to a water retentive pavement in which a water retentive material (curable slurry) is filled in the voids of the asphalt mixture.

It is a graph which shows the correlation with a water absorption and a dry density. It is a graph which shows the correlation of compressive strength and dry density. It is a graph of P funnel flow value at the time of changing a setting retarder addition amount, and elapsed time. It is a structure schematic diagram of the water supply type water retention pavement to which this filling water retention material is applied. It is a figure for demonstrating the cooling mechanism of a water supply type water-retaining pavement, (A) is the figure at the time of rainy weather, (B) is a figure which shows at the time of fine weather. It is a graph which shows the cooling effect verification result of a water supply type water retention pavement.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water supply type water retention layer (asphalt water retention layer), 2 ... Water supply type water storage layer (coal ash solidification crushed water storage layer), 3 ... Open-graded asphalt concrete, 4 ... Filled water retention material, 5 ... Coal ash solidification crushed stone

Claims (5)

A water-retaining material for water-retaining pavement mainly composed of fly ash, wherein the water-retaining material is a mixture of fly ash, gypsum, slaked lime, cement and water, and the gypsum has a temperature of 85 ° C or higher. 6 parts by weight or more is mixed with 100 parts by weight of fly ash, and the slaked lime is mixed at 4 parts by weight or more with respect to 100 parts by weight of fly ash. Mixing at a ratio of 6 parts by weight or more with respect to 100 parts by weight, mixing the weight percentage of water to the fly ash, gypsum, slaked lime and cement (water powder ratio) in the range of 70 to 110%,
P funnel flow value: 9 to 11 seconds, breathing rate (24 hours); 3% or less, water absorption rate (material age 28 days); 50% or more, sucking speed within 180 minutes / 10 cm (sucking speed; φ5 cm X10cm test piece bottom surface (water immersion depth 5mm), time taken to saturate the test piece), compressive strength; 1N / mm ² Filling water retaining material for pavement. Filling water retaining material for retentive pavement according to claim 1 Symbol placement adding a setting retarder in a proportion of 0.05 to 0.1% by weight relative to the total amount of powder. The filled water-retaining material for water-retaining pavement according to claim 1 , wherein fly ash type II according to JIS A6201 is used as the fly ash. The filled water retention material for water retention pavements according to claim 1 , wherein blast furnace cement is used as the cement. The filling water retention material for water retention pavement according to any one of claims 1 to 4, wherein the filling water retention material has a 40 ° C dry density of 0.8 to 1 g / cm ³ .

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