JP4572079B2 - Water-retaining material composition for pavement and construction method of water-retaining pavement - Google Patents

Description

  The present invention relates to a pavement water-retaining material composition and a water-retaining pavement construction method, and provides a new pavement water-retaining material composition with excellent water absorption, which is used to suppress the so-called "heat island phenomenon" in urban areas. The present invention relates to a technology that is effectively used for the construction of effective water retention pavement.

  In urban areas, asphalt pavement is adopted from the viewpoints of easy construction, early traffic opening (starting traffic after construction), low prices, etc., and the building is made of concrete as its height increases. There are many. Asphalt and concrete easily store heat in the daytime and release the heat stored at night, so a special artificial climate appears in urban areas with many high-rise buildings and asphalt-covered roads. In other words, in the summer, the road surface rises to over 60 ° C, the tropical night becomes normal, and torrential rains occur. This is called the “heat island phenomenon” and the isotherm is drawn in descending order of temperature. The phenomenon that can be regarded as a high temperature island occurs. This phenomenon tends to be further promoted by an increase in the use of energy by air conditioners and the like, and an increase in waste heat due to excessive traffic concentration in urban areas. One cause of such a heat island phenomenon is that the ground originally covered with soil has been replaced with asphalt or concrete. In other words, when the ground is soil, when it rains, water accumulates in the internal space, and it evaporates in fine weather to take away heat of vaporization, lowering the atmospheric temperature, and increasing the temperature of the ground itself. In order to retain moisture in the interior, it is heated only to about 50 ° C. at most, so that the above phenomenon hardly occurs. On the other hand, when the surface layer is asphalt or concrete, rainwater hardly penetrates into the surface layer and flows into the drainage ditch etc., and evaporative heat cooling can be expected only by rainwater partially accumulated on the pavement surface. It lasts only ~ 3 hours. In addition, even if there is a large amount of rainfall, a large amount of rainwater flows into the sewer, and some of it overflows into the river, so there is a new problem of urban flooding.

  In order to solve the above problems such as heat island, it is effective to reduce solar radiation and reflection and reduce the amount of heat storage. Specifically, asphalt and concrete pavement (hereinafter referred to as asphalt pavement) are returned to the soil. Or increase the greening area. However, when the pavement is returned to the soil, many conveniences such as “comfortable walking”, “comfortable driving”, and “preventing the lifting of dust and the like” obtained by adopting asphalt pavement are lost. In addition, the increase in the greening area has advantages such as “reduction of carbon dioxide emission to the atmosphere” and “improvement of landscape”, but not only there is a restriction on the site area where greening is possible, but also the new management of plants. It cannot be easily adopted in urban areas that require a lot of work.

  Therefore, recently, a new civil engineering and building material having a property capable of retaining water therein has been proposed, and attempts have been made to replace it with asphalt pavement or the like. The material is roughly divided into two from the viewpoint of the water retention mechanism. One is to mix an organic material such as a water-absorbing resin in an inorganic material such as cement, and the other is to form fine pores in the solidified body and retain water by capillary action. The former has a simpler manufacturing method than the latter, but problems such as high cost of the organic resin and difficulty in separating the organic resin during recycling remain unsolved. The latter is made of an inorganic material, and can be manufactured by firing at a specific temperature after adjusting the particle size of the raw material. Since the cost is relatively low, it is applied to some roads.

By the way, as a pavement using such a water retaining material, open-graded asphalt represented by drainage pavement (pavement in which the particle size of the aggregate is adjusted so as to exclude the intermediate region of the particle size distribution and the gap is increased) A technique for injecting a fluid holding material into the gap is disclosed. For example, a perforated surface layer such as a water-permeable asphalt mixture having 15 to 35% voids or water-permeable cement concrete is filled with a silt-based filler (see, for example, Patent Document 1).
In addition, silt is silt and is a sediment which is finer than sand but coarser than clay.
In this case, 20 to 60% of powder having a particle size of 5 to 75 μm and a silt content of 50% by weight or more is used, 5 to 50% of cement-based solidified material, and 25 to 50% of water. A mixed silt-based filler is used, and a water retention material having a maximum strength of 20 MPa after curing for 7 days is obtained. Also, 50 to 70% by weight of granulated blast furnace slag, 30 to 50% by weight of inorganic powder containing 50% by weight or more of amorphous SiO ₂ , a total of 100 parts by weight of the blast furnace slag fine powder and the inorganic powder In contrast, a hydraulic material for a water-retaining solid body containing 3 parts by weight or more of an alkali stimulant is also disclosed (see Patent Document 2). Further, in a porous surface layer using an asphalt mixture having 15 to 25% voids, fine silica sand having an average particle diameter of 80 to 200 μm having water retention and water permeability and pumping capacity in a filled state is obtained. A pavement filled with 80 to 160 kg per 1 m ³ and a method for forming the same are disclosed (see Patent Document 3). In addition, after forming a porous hardened body such as an open-graded asphalt mixture, a continuous surface of the porous hardened body is filled with a slurry-like filler containing cement, clay-based fine powder, water, etc. A pavement that suppresses an increase in temperature is also disclosed (see Patent Document 4).
Japanese Patent Laid-Open No. 10-46513 Japanese Patent Laid-Open No. 2002-241151 JP 2003-147717 A JP 2003-201705 A

  The technique disclosed in Patent Document 1 has a large water retention effect and can be relatively easily constructed on an actual road. However, it takes time and effort to adjust the particle size of silt that can be used as a raw material, and there remains a problem in the procurement of raw materials for large-area construction. Further, the water retention material described in Patent Document 2 has an advantage of having a high water retention capacity and a constant strength. However, when this was actually applied to the road surface, it was found that there was a problem with the water absorption speed. That is, in general, the road is provided with a gradient of about 1 to 1.5% with respect to the horizontal so that rainwater does not stay on the road surface for a long time when it rains, and drains into the drainage in a short time. ing. A material having a low water absorption rate cannot absorb water sufficiently in rainy weather, and therefore the amount of water that can be evaporated in fine weather is small, and therefore the road surface cooling performance is low. This problem is the same when watering properly with a water truck. In order to solve this problem, for example, it is necessary to provide a weir or the like around the water retentive pavement, and soak the water retentive pavement for a long time. Although it is possible to immerse the water-retaining pavement constructed by the technique of Patent Document 2 for a long time, it is disadvantageous in terms of construction cost and maintenance cost.

  The technique of filling mineral fine particles described in Patent Document 3 is effective in reducing road surface temperature because it provides a pavement that has high water permeability and can retain rainwater and the like. However, in order to uniformly fill the pavement with the water-retaining material, it is necessary to repeat the operation of spraying a small amount on the surface of the pavement and then putting it into the pavement with a vibration plate, etc. is there. In addition, due to concentrated heavy rain that has frequently occurred in urban areas in recent years, surface layer mineral powder particles flow out, so the effect of reducing road surface temperature disappears, or it is necessary to refill mineral matter particles after rain Had drawbacks. In order to improve this drawback, it is conceivable to add a resin or the like as a binder, but the voids often do not reach the initially assumed amount. In the technology described in Patent Document 4, since a filler containing clay-based fine powder and cement is used, clay minerals (especially montmorillonite is preferable) gradually release moisture over a long period of time, thereby reducing road surface temperature. The effect can be maintained for a long time. However, the water retention derived from the structure of the clay-based fine powder itself functions only after it is uniformly dispersed in an open particle size asphalt or the like, and there is a problem in ensuring its uniformity.

  In view of such circumstances, the present invention provides a water-retaining material composition for pavement that can be produced without using a special production apparatus and that hardly deteriorates in performance even after one year or more has passed since it was used for pavement construction. In addition, a method for constructing a water-retaining pavement using the water-retaining material composition for pavement and capable of efficiently absorbing rain water even in a short period of intensive rain and having a road surface cooling ability capable of suppressing a heat island phenomenon. The purpose is to provide.

  The inventor has intensively studied to achieve the above object, and the results have been embodied in the present invention.

That is, the present invention has a particle size distribution in which a powder having a particle size of 5 to 425 μm is 60% by mass or more, and contains 50% by mass or more of SiO _{2 made of} silica sand, silica sand powder, silica stone powder, or silica fume. powder and calcium carbonate, lime powder, or either one or both the total of 70 to 99.95% by weight of an inorganic powder containing CaCO ₃ consisting of limestone powder 50 mass%, 0.05 to blast furnace slag It is a water-retaining material composition for pavements characterized in that 1 to 35 parts by mass of cement is added to 100 parts by mass of a mixture consisting of 30% by mass. Further, the present invention has a particle size distribution in which a powder having a particle size of 5 to 425 μm is 60% by mass or more, and an inorganic powder containing 50% by mass or more of amorphous SiO ₂ is 70 to 99.95% by mass. Water retention for pavement characterized in that 1 to 35 parts by mass of an alkali stimulant and / or cement is added to 100 parts by mass of a mixture comprising 0.05 to 30% by mass of granulated blast furnace slag. It is a material composition.

Furthermore, the present invention is, for any water retaining material 100 parts by mass of the composition described above, water was added 50-1 50 parts by weight, the water slurry was adjusted to P funnel flow time is 8 to 20 seconds Is injected into an open-graded asphalt pavement.

  Here, the P funnel flow time is the flow time of the water slurry measured by a so-called “P funnel test” in which the time for the liquid to flow through the pore funnel is measured. It is an index for evaluating the degree of penetration of the liquid flowing down the pores.

  According to the present invention, a water-retaining material composition for pavement that is used as a part of a pavement material and hardly deteriorates in performance even after one year or more after pavement construction is provided without using a special manufacturing apparatus. it can. As a result, a road or the like mixed with the water-retaining material composition for pavement can efficiently absorb rain water even in a intensive rain for a short time, and enhance the road surface cooling effect. That is, it is effective for suppressing the occurrence of the heat island phenomenon.

In order to achieve the present invention, an inorganic powder having a particle size of 425 μm or less of 60% by mass or more and containing 50% by mass or more of one or both of SiO ₂ and CaCO ₃ is 70%. It is important to solidify a mixture composed of ˜99.95% by mass and blast furnace granulated slag of 0.05 to 30% by mass.

First, the inventor reviewed the technique described in Patent Document 1 and focused on a water retaining material to be injected into the voids of the open-graded asphalt represented by drainage pavement. In other words, slag alkali reaction occurs between the raw materials during the production of the water retaining material, but the pores formed by such a chemical reaction are mainly small ones of 0.1 μm or less, and are retained in the pores. This is because the water that has been released is gradually released over time, and is effective in maintaining water retention. Therefore, the inventor examined the water retention effect in more detail, and the raw material of the water retention material has a particle size distribution in which the granulated blast furnace slag and the powder having a particle size of 425 μm or less are 60% by mass or more, and SiO 2 A mixture of inorganic powder containing 50% by mass or more of either one or both of Ca ₂ and CaCO ₃ and water, the inorganic powder is 70 to 99.95% by mass, and granulated blast furnace slag is 0.8. It was found that by setting the content to 05 to 30% by mass, the water absorption rate was higher than before and the performance of the water retaining material obtained by solidification was hardly lowered, and the present invention was completed.

As granulated blast furnace slag, pulverized granulated blast furnace slag after granulation, blast furnace slag fine powder added with a predetermined amount of gypsum, and slag powder collected as dust collection powder in granulated slag magnetic separation process However, the present invention is not limited to these. Moreover, the content of the granulated blast furnace slag needs to be 0.05 to 30% by mass, a more preferable range is 0.05 to 15% by mass, and a more preferable range is 0.05 to 10%. % By mass. If the granulated blast furnace slag exceeds 30% by mass, the solidification reaction proceeds too much, and the average pore diameter tends to decrease. Even if there is a large amount of rainfall in a short time of about 1 hour, most of the rainfall is This is because they are discharged without being absorbed into a river or the like through a drainage basin. Even when a certain amount of water absorption can be secured by long-term rainfall, the water absorbed in the fine pores is not released in a short time even when heated, and the pavement surface cooling effect is reduced. Therefore, in order to produce a solidified body made of a water retaining material composition having a pore size capable of absorbing and releasing water in a short time, the amount of granulated blast furnace slag must be in the above range. Further, when no granulated blast furnace slag is contained, the solidified body does not have a structure of CaO—SiO ₂ —Al ₂ O ₃ —H ₂ O, and the formation of fine pores becomes insufficient, which is not preferable. .

  In the present invention, the inorganic powder is required to be in the range of 70 to 99.95% by mass, more preferably in the range of 85 to 99.95% by mass, and still more preferably in the range of 90 to 99.95. % By mass. When the inorganic powder is less than 70% by mass, the amount of granulated blast furnace slag is relatively increased, and the solidification reaction proceeds with time, resulting in a decrease in average pore diameter. If it exceeds 99.95% by mass, fine pores and reaction forming pores using granulated blast furnace slag are lost, which is not preferable.

Inorganic powder used in the present invention is an inorganic powder containing amorphous SiO ₂ inorganic powder containing 50 mass% or more, or an inorganic powder and / or CaCO ₃ containing SiO ₂ more than 50 wt% to 50 wt%. In the inorganic powder containing 50% by mass or more of amorphous SiO ₂ , the reaction between Ca—Si—H proceeds by adding an alkali stimulant and / or a solidifying material and contributes to an increase in fine pores. The inorganic powder containing 50% by mass or more of SiO ₂ itself does not contribute to the reaction, but exhibits a water retention effect because it forms voids that retain water between the particles. Similarly, an inorganic powder containing 50% by weight or more of CaCO ₃ is not expected to have its own reactivity, but exhibits a water retaining effect because it forms voids that retain water between the particles. The inorganic powder containing 50% by mass or more of amorphous SiO ₂ , the inorganic powder containing 50% by mass or more of SiO ₂ , and the inorganic powder containing 50% by mass or more of CaCO ₃ have a portion of 5 to 425 μm of 60% by mass or more. is required. If the amount exceeds 40% by mass, the separation of the material is likely to occur when water is added to the water retention material composition for paving of the present invention to form a slurry, and it is injected from the surface into a so-called “open grain asphalt”. This is because clogging occurs when it is difficult to inject.

  Blast furnace granulated slag is fine powder at the time of manufacture and may be used as it is. In particular, in the case of blast furnace slag fine powder obtained by pulverizing blast furnace granulated slag used for blast furnace cement or the like, the average particle diameter is about 10 μm or less, and therefore, it can be suitably used. Cement and alkali stimulants react when water is added and the particle size changes, but cement is generally a fine powder with an average particle size of about 5 μm, and many of the materials used as alkali stimulants are water-soluble. In addition, industrial slaked lime and magnesium hydroxide also have a maximum particle size of 100 μm or less and an average particle size of 5 μm or less. Therefore, even if they are used as they are, there is no problem such as clogging when injecting into open-graded asphalt.

Examples of the inorganic powder containing 50% by mass or more of amorphous SiO ₂ used in the present invention include clinker ash and the like, and any inorganic powder having the characteristics of amorphous SiO ₂ can be used without any problem. It is not limited to examples. Examples of the inorganic powder containing 50% by mass or more of SiO ₂ include silica sand, silica sand powder, silica stone powder, and silica fume . Et al is, the inorganic powder containing CaCO ₃ 50 mass%, for example calcium carbonate, lime powder, stone powder, etc. limestone and the like. Inorganic powder S iO ₂ containing inorganic powder and CaCO ₃ containing more than 50 wt% to 50 wt%, as long as it satisfies the predetermined particle size, including for example sand, inorganic components such as coal ash You can leave. In the present invention, the inorganic powder containing 50% by mass of amorphous SiO ₂ , the inorganic powder containing 50% by mass or more of SiO _2, and the inorganic powder containing 50% by mass or more of CaCO ₃ may be mixed at an arbitrary ratio. it can. That is, a mixture of all the three inorganic powders described above may be used, or only one of them may be used. The ratio is arbitrary and can be freely selected.

The alkali stimulant and / or cement used in the present invention needs to be in the range of 1 to 35 parts by mass with respect to 100 parts by mass of the total amount of blast furnace granulated slag and inorganic powder. The alkali stimulator is not particularly limited as long as it has a function of dissolving and reacting amorphous SiO ₂ , but in view of economic efficiency and availability, an alkali metal represented by sodium hydroxide is used. Alkali earth metals such as hydroxide and magnesium hydroxide and / or cement can be used. This alkali stimulant mainly promotes the pozzolanic reaction by dissolving SiO ₂ or SiO ₂ and Al ₂ O _{3 in} inorganic powder containing 50% by mass or more of granulated blast furnace slag and amorphous SiO _2. Although it promotes hardening, it improves fluidity when it is slurried by adding water even when the content of inorganic powder containing 50% by mass or more of granulated blast furnace slag or amorphous SiO ₂ is low. It has a function to make it. Therefore, even when the content of inorganic powder containing 50 mass% or more of granulated blast furnace slag and amorphous SiO ₂ is small, an alkali stimulant may be added. When using an inorganic powder containing 50% by mass or more of amorphous SiO ₂ , the content of the alkali stimulant needs to be in the range of 1 to 35 parts by mass, and more preferably in the range of 1 to 15 parts by mass. . If the amount is less than 1 part by mass, the above-described alkali stimulation reaction is unlikely to occur, which is not preferable. If the amount exceeds 35 parts by mass, the water retention function is deteriorated, which is not preferable.

In this case, part or all of the alkali stimulant may be replaced with cement, and the amount of the alkali stimulator and cement may be 1 to 35 parts by mass. Since cement also exhibits alkalinity in water, amorphous SiO ₂ can be dissolved to cause a reaction. In addition, cement itself functions as a solidifying material. Also in this case, when the total amount of the alkali stimulant and cement or the amount of cement is 1 part by mass, the alkali stimulation reaction hardly occurs, and when it exceeds 35 parts by mass, the water retention function is lowered, which is not preferable.

In addition, when the content of ground granulated blast furnace slag or the content of inorganic powder containing 50% by mass or more of amorphous SiO ₂ is small, self-curing due to pozzolanic reaction can hardly be expected even if an alkali stimulant is used. It is necessary to use cement as. As this cement, ordinary Portland cement, early-strength Portland cement, fast-hardening cement, ultrafast-hardening cement, blast furnace cement and the like can be used, and a mixture thereof can be used. When applying the above-mentioned water retention material for pavement according to the present invention to an actual road applied with open grained asphalt or the like, it is often required to start passing as soon as possible after construction. Often used. The amount of cement used is required to be 1 to 35 parts by mass, more preferably 5 to 30 parts by mass, and still more preferably 10 to 25 parts by mass. If it is less than 1 part by mass, the strength of the water retention material obtained when water is added to the water retention material composition and cured is hardly expressed. If it exceeds 35 parts by mass, the amount of cement is too high and granulated blast furnace slag or inorganic powder This is not preferable because the gap formed by the plug is closed.

  As described above, the water-retaining material composition for pavement according to the present invention is excellent in water absorption, and its performance degradation is small after construction of the water-retaining pavement. A deterrent effect can be expected.

Next, since the invention was made also about the utilization method of the said water retention material composition for pavements, it demonstrates below. It, in addition 50-1 50 parts by weight of water per 100 parts by weight of the輔装the water retaining material for composition, after the water slurry having an adjusted P funnel flow time 8 seconds to 20 seconds, open-graded asphalt pavement It is a construction method of a water-retaining pavement that is poured into the interior.

The reason why water is added to 50 parts by mass or more with respect to 100 parts by mass of the water retention material composition for pavement is that when the amount of water is less than 50 parts by mass, most of the water is used for the alkali reaction. This is because you cannot expect. Moreover, since the upper limit of the water to be added is defined by the particle size of the raw material, it is difficult to uniquely determine it, but it is necessary to increase the amount of water as the particle size of the inorganic powder used decreases. That is, when a raw material having a particle size of about 5 to 425 μm is used, the upper limit of the amount of water is sufficient to be 150 parts by mass . What slave, amount of water added, depending on the particle size of the paving water retaining material composition used may be appropriately selected in the range of 50 to 1 50 parts by weight. In this case, it is necessary to adjust the P funnel flow time in the range of 8 to 20 seconds. More preferably, it is the range of 8 seconds-15 seconds. In the case of water slurry exceeding 20 seconds, since the viscosity of the slurry is high, it takes a long time to inject into the open particle size asphalt or the like, which is not preferable. If it is less than 8 seconds, the injection is easy, but the curing time becomes long and the time required for opening the road may become too long, which is not preferable. The measurement of the P funnel flow time is a method defined by the Japan Society of Civil Engineers and described in JSCE-1986. Using a cast aluminum funnel having a 38 mm outflow pipe, the outflow time of a 1725 cc sample is measured.

(Examples 1-4)
Using ground granulated blast furnace slag as granulated blast furnace slag and fly ash (100% by mass of 425 μm or less) as an inorganic powder containing 50% by weight or more of amorphous SiO ₂ , 100 parts by mass of the combined mixture were subjected to alkali stimulation. After adding slaked lime as an agent and quick-hardening cement as a solidifying agent in an appropriate ratio and mixing them, and adding water in an appropriate ratio to the whole powder and kneading for 4 minutes, the diameter is 10 cm and the height is 10 cm. Was cast in a room kept at a constant temperature and humidity of 20 ° C. and 50% RH (humidity) for 3 days to obtain a cylindrical solidified body according to the present invention. The raw material composition is shown in Table 1-1.

  After removing these solidified bodies, steam curing was further performed at 60 ° C. for 7 days in a constant temperature and humidity chamber. Thereafter, after drying at 60 ° C. for 1 day, the water absorption height and the weight reduction rate were determined in order to confirm the water absorption performance and water retention performance of these solidified bodies. In order to obtain the water absorption height and the weight reduction rate, a water absorption test was performed, and the maximum water absorption mass and the water absorption mass for 1 hour were measured. Here, the water absorption mass for 1 hour is a value obtained by immersing a portion corresponding to 5 mm from the lower end of the solidified body in running water after measuring the mass of the solidified body, measuring the mass after 1 hour, and subtracting the initial mass. Yes, corresponding to the amount of water absorbed by the solidified body during one hour. The maximum water absorption mass is a value obtained by subtracting the mass before water absorption from the mass after water absorption of the solidified body whose water absorption mass has been measured for 1 hour, by further immersing and holding the whole in water for 24 hours.

  Using these values, the water absorption height is obtained by the following formula.

Water absorption height (cm) = solidified body height x (1 hour water absorption mass / maximum water absorption mass)
The height of the solidified body this time is 10 cm.

  Further, the solidified body whose maximum water absorption mass was obtained was kept at 40 ° C. and dried for 24 hours, the mass after drying was measured, and the mass before the water absorption test of the solidified body was subtracted to obtain the water absorption amount after drying. . Using this water absorption after drying and the maximum water absorption, the weight reduction rate is obtained by the following equation.

Mass reduction rate (%) = (maximum water absorption amount−water absorption amount after drying) / maximum water absorption amount × 100
(Examples 5 to 8)
Blast furnace slag fine powder as granulated blast furnace slag, silica sand powder (425 µm or less is 60% by mass) as inorganic powder containing 50% by weight or more of SiO ₂ is used as a mixture, slaked lime is used as an alkali stimulant, and fast hardening is used as a solidifying material. Using cement, solidified bodies were prepared in the same manner as in Examples 1 to 4, and the water absorption height and the weight reduction rate were determined. The raw material composition is shown in Table 1-2.

(Examples 9 to 12)
Blast furnace slag fine powder as granulated blast furnace slag, calcium carbonate as inorganic powder containing 50% by weight or more of CaCO ₃ is used as a mixture, slaked lime as alkali stimulant, fast hardening as solidification material Using cement, solidified bodies were prepared in the same manner as in Examples 1 to 4, and the water absorption height and the weight reduction rate were determined. The raw material composition is shown in Table 1-3.

（参考例１〜４）
高炉水砕スラグとして高炉スラグ微粉末を、ＳｉＯ_２を５０重量％以上含む無機粉末としてシリカフューム（４２５μｍ以下が１００質量％）を用いて混合物とし、アルカリ刺激剤として消石灰を、固化材として速硬セメントを用い、実施例１〜４と同じ方法で固化体を作製し、吸水高さ及び重量減少率を求めた。原料配合を表１−４に示す。

( Reference Examples 1-4 )
Blast furnace slag fine powder as granulated blast furnace slag, silica fume (425 μm or less is 100% by mass) as inorganic powder containing 50% by weight or more of SiO ₂ , slaked lime as alkali stimulant, fast-hardened cement as solidification material The solidified body was produced by the same method as in Examples 1 to 4, and the water absorption height and the weight reduction rate were determined. The raw material composition is shown in Table 1-4.

(Examples 17 to 20)
Blast furnace slag fine powder as granulated blast furnace slag, fly ash (100% by mass of 425 μm or less) as inorganic powder containing 50 wt% or more of amorphous SiO _2, and silica sand powder as inorganic powder containing 50 wt% or more of SiO ₂ (425 μm or less is 60% by mass) to make a mixture, using slaked lime as an alkali stimulant and fast-hardening cement as a solidifying material, producing a solidified body in the same manner as in Examples 1 to 4, and the water absorption height and weight The reduction rate was obtained. The raw material composition is shown in Table 1-5.

(Examples 21 to 24)
Blast furnace slag fine powder as granulated blast furnace slag, fly ash as inorganic powder containing 50% by weight or more of amorphous SiO ₂ (100% by mass of 425 μm or less), calcium carbonate as inorganic powder containing 50% by weight or more of CaCO ₃ (425 μm or less) 70% by mass), and after mixing slaked lime as an alkali stimulant and inorganic powder made of fast-hardening cement as a solidifying material, a solidified body is prepared by the method of Examples 1 to 4, and the water absorption height The weight loss rate was determined. The raw material composition is shown in Table 1-6.

(Examples 25 to 28)
Blast furnace slag fine powder as granulated blast furnace slag, fly ash as inorganic powder containing 50% by weight or more of amorphous SiO ₂ (100% by mass of 425 μm or less), silica sand powder (425 μm as inorganic powder containing 50% by weight or more of SiO ₂ ) The following is 60% by mass), and calcium carbonate (425 μm or less is 60% by mass) as an inorganic powder containing 50% by weight or more of CaCO ₃ is used as a mixture. After mixing inorganic powder, the solidified body was produced by the same method as Examples 1-4, and the water absorption height and the weight reduction rate were calculated | required. The raw material composition is shown in Table 1-7.

(Comparative Examples 1-7)
Tables 2-1 and 2-2 show the raw material blends of the solidified bodies used in the comparative examples. Here, blast furnace slag fine powder and fly ash (425 μm or less is 100% by mass), silica sand powder (425 μm or less is 60% by mass), calcium carbonate (425 μm or less is 60% by mass) mixed as shown in the table To make a mixture. The water absorption test was performed in the same manner as in Examples 1 to 4.

Tables 3 and 4 show the water absorption height and weight reduction rate of the solidified bodies obtained by the above Examples, Reference Examples and Comparative Examples, respectively.

  The solidified bodies obtained in each example had a water absorption height of 5 cm or more in the water absorption test, whereas the solidified bodies obtained in each comparative example had a small water absorption height and a water absorption rate of the examples. It was found to be smaller than Moreover, the solidified bodies obtained in the examples also have a large weight reduction rate, and it is clear that the absorbed water is effectively released.

  The water slurry made with the water retention material of the composition of Example 10 and Comparative Example 1 was poured into 30 cm × 30 cm × 10 cm open grained asphalt (porosity 20%) to prepare a water retention pavement test specimen, and halogen light (130 W ) To measure the surface temperature. In any case, the injection rate of the water retention material was 75% of the effective voids of the open-graded asphalt, and after removing the water retention material adhering to the surface, the surface temperature was measured with a thermocouple. For comparison, a pavement test piece of open-graded asphalt itself without water slurry was prepared by injecting the same amount of water as used in Example 10. FIG. 1 shows the change over time of the surface temperature of each specimen. It shows the temperature transition under the condition that after the construction is held in a room with a humidity of 60% RH, the halogen light is irradiated after 3 hours, and then the irradiation is stopped. From FIG. 1, the test sample of Example 10 and Comparative Example 1 into which the water retention material was injected, compared with the test sample of only the open-graded asphalt, had a low peak temperature, and the temperature after the halogen light irradiation was stopped, The temperature reduction effect of the pavement test specimen is large. And the test body of Example 10 has a much lower peak temperature than the test body of Comparative Example 1, and the effect of lowering the pavement surface temperature is very good.

It is a figure which shows the time-dependent change of the surface temperature of a typical test body.

Claims (3)

A powder having a particle size of 5 to 425 μm has a particle size distribution of 60% by mass or more, inorganic powder containing 50% by mass or more of SiO ₂ composed of silica sand, silica sand powder, silica stone powder, or silica fume, calcium carbonate, lime The total of either or both of inorganic powder containing 50% by mass or more of CaCO ₃ composed of powder or limestone powder is 70 to 99.95% by mass, and blast furnace granulated slag is 0.05 to 30% by mass. A water-retaining material composition for pavements, wherein 1 to 35 parts by mass of cement is added to 100 parts by mass of the mixture. A powder having a particle size of 5 to 425 μm has a particle size distribution of 60% by mass or more, 70 to 99.95% by mass of inorganic powder containing 50% by mass or more of amorphous SiO _2, and granulated blast furnace slag A water retention material composition for pavements, wherein 1 to 35 parts by mass of an alkali stimulant and / or cement is added to 100 parts by mass of a mixture of 0.05 to 30% by mass.   A water slurry prepared by adding 50 to 150 parts by mass of water to 100 parts by mass of the water retention material composition for paving according to claim 1 or 2 and adjusting the P funnel flow time to be 8 to 20 seconds is opened. A water-retaining pavement construction method characterized by pouring into a granular asphalt pavement.

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