JP5693282B2 - Cement-based solidifying material composition used for spraying construction and its spraying method - Google Patents

Description

The present invention relates to, for example, a cement-based solidifying material composition used for spraying construction to be sprayed onto a construction target surface for forming a method frame and a spraying method thereof.

  In general, the cement-based solidifying material composition is blended so that the volume ratio of cement to aggregate is 1: 3 to 1: 4 in order to develop necessary strength in the mortar or concrete to be formed. Used.

  However, cement is a limited resource, and it is desired to reduce the amount of cement used in the cement-based solidifying material composition as much as possible from the viewpoint of environmental problems.

  As for aggregates, particularly in the field of fine aggregates used for mortars, there is a search for fine aggregates that can be stably supplied and that can replace high-quality sand that is becoming difficult to collect. Among them, the use of lime crushed sand (crushed limestone that has been adjusted to sand) as a fine aggregate has been studied, but it has become widespread due to poor workability and high costs. Not in.

The present invention has been made in view of the above-mentioned circumstances, and the object thereof is to reduce the cost and reduce the cost of cement, and to provide a cement-based solidifying material composition that is used for spraying with good sprayability . And providing a spraying method thereof.

In order to achieve the above object, the cement-based solidifying material composition used in the spraying construction according to the present invention includes 14 to 22 parts by weight of cement, and 70 to 83 parts by weight of lime crushed sand as fine aggregate, and 3 to 10 parts by weight of limestone powder with a particle size distribution having a peak frequency at least two portions of 5~20μm and 80 to 180 [mu] m, viewed free so that 100 parts by weight in total, the limestone fine The powder contains 25% or more of fine powder having a particle size of 5 to 20 μm and 15% or more of fine powder having a particle size of 80 to 180 μm (Claim 1).

In order to achieve the above object, a method for spraying a cement-based solidifying material composition according to the present invention is performed in a state where the cement-based solidifying material composition used in the spraying construction according to claim 1 is mixed with water. The target surface is sprayed ( Claim 2 ).

In the inventions according to claims 1 and 2 , a cement-based solidifying material composition used for spraying construction with good spraying workability and its spraying method can be obtained, which can save resources and reduce costs of cement. .

  That is, in the present invention, 14 to 22 parts by weight of cement, 70 to 83 parts by weight of crushed lime sand as fine aggregate, and 3 to 10 parts by weight of limestone fine powder will be 100 parts by weight in total. As a result, it becomes easier to reduce the blending ratio of the cement, and hence the amount of use, compared to the conventional cement-based solidifying material composition, which contributes to resource saving and cost reduction.

  In addition, when the blending ratio of the cement is lowered in the conventional cement-based solidifying material composition, the strength of the mortar decreases. However, if the cement-based solidifying material composition of the present invention is used, the amount of cement used can be reduced as described above. While reducing, the strength of the mortar to be formed can be increased, and a crack preventing effect is also imparted. The mechanism is that fine limestone powder with a small particle size (5 to 20 μm) improves the solidity as a mortar by entering between the lime crushed sand particles and cement particles, and the particle size is large (50 to 200 μm). This is considered to be because the fine limestone powder maintains an appropriate distance between the crushed lime sand particles and uniformly disperses the cement particles to help complete the coating of the cement on the crushed lime sand.

  In addition, if the blending ratio of cement is simply lowered in the conventional cement-based solidifying material composition, the (ball) bearing function for smoothly transporting the fine aggregate that the cement bears is insufficient, and the mortar fluidity and construction Will be reduced. However, in the cement-based solidifying material composition of the present invention, the mixing ratio of the cement is not simply lowered, but the limestone fine powder having the same particle size as the cement particles, and larger than the cement particles and more than the lime crushed sand particles. By blending with limestone fine powder having a small particle size, the bearing function and fluidity of the mortar, which are impaired by the reduction of cement, are complemented and enhanced, and not only maintenance of workability but also improvement is expected.

  And in carrying out the spraying method of the present invention, in addition to the cement-based solidifying material composition and water, a water reducing agent or fiber may be added and mixed (kneaded) as necessary. Therefore, the required amount of expensive high-performance water reducing agent, which was indispensable when using a conventional cement-based solidifying material composition, is reduced. Is achieved.

  In general, an excessive or too small amount of water added to the cement-based solidified material composition prevents the formation of a good quality mortar, but the cement-based solidified material composition of the present invention does not absorb lime crushed sand having the property of not absorbing water. Because it is included as a fine aggregate, the amount of water that is not absorbed by the fine aggregate (external to the fine aggregate) is made constant compared to conventional blends that use water-absorbing sand as the fine aggregate This makes it very easy to stabilize the quality of the mortar to be formed, and to help simplify the production of good quality mortar.

  Moreover, as described above, the fine aggregate contained in the cement-based solidified material composition of the present invention is crushed lime sand that does not absorb water, so the amount of water added when forming mortar is higher than that of conventional blending. The present invention contributes to resource saving (water saving) in this respect as well, and even if the amount of water added is reduced in this way, the limestone fine powder that prevents the separation of water prevents an appropriate amount of mortar. Moisture can be retained.

  In addition, if an appropriate amount of water is added to the cement-based solidifying material composition of the present invention, the separation of water can be prevented by the limestone fine powder, and furthermore, the mortar hardness and adhesion are in a good state, so It is also possible to reduce and prevent rebound loss (dispersion loss due to rebound on the construction target surface) when sprayed on the surface, and runoff (flowing down from the construction target surface) after spraying.

  Further, since the cement-based solidifying material composition of the present invention uses crushed lime sand that can be stably supplied throughout the country as a fine aggregate, the spraying construction of the present invention can be suitably carried out throughout the country. .

BRIEF DESCRIPTION OF THE DRAWINGS It is whole structure explanatory drawing which shows roughly the spraying method of the cement-type solidification material composition which concerns on one embodiment of this invention. It is a graph which shows the result of the particle size distribution measurement performed about the limestone fine powder mix | blended with the said cement-type solidification material composition.

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

  The cement solidifying material composition spraying method (hereinafter abbreviated as spraying method) according to the present embodiment is a cement supplied in a mixed (kneaded) state as shown in FIG. A mortar (an example of a cement-based mixture) 4, which is a mixture of the system solidifying material composition 2 and water 3, is sprayed onto the slope N (an example of a construction target surface) to form a method frame 5.

  Specifically, a net 6 such as a wire mesh is stretched on the slope N, and reinforcing frame 7 is arranged on the net 6 in a lattice shape to form a method frame spraying portion. On the other hand, the curing sheet 8 is arranged, and the mortar 4 is sprayed so as to cover the grid-like reinforcing bars 7 to form a grid-like frame 5, and then the curing sheet 8 is peeled off and the vegetation containing plant seeds and fertilizer The base material 9 is sprayed into the frame of the frame 5 to protect the slope N from being greened.

  In FIG. 1, reference numeral 10 denotes an air compressor, which is connected to the pressure feeder 1 for supplying compressed air. Reference numeral 11 denotes a spray nozzle, which is provided on the downstream side of a pipe (hose) 12 connected to the pressure feeder 1.

  And the cement-type solidification material composition 2 used in this embodiment includes 14 to 22 parts by weight of cement, 70 to 83 parts by weight of crushed lime sand as fine aggregate, and 3 to 10 parts by weight of limestone fine powder. In a total of 100 parts by weight.

  Here, as the cement, for example, portland cement such as ordinary portland cement, moderately hot portland cement, low heat portland cement, early-strength portland cement, mixed cement, and the like can be used.

  As said lime crushed sand, what has an average particle diameter (average particle diameter) of 0.6-1.2 mm can be used, for example, The lime crushed sand used by this embodiment is the aggregate based on JISA1102. As a result of the sieving test, the results shown in Table 1 (coarse grain ratio 2.68) were obtained.

  As said limestone fine powder, at least two places of 5-20 micrometers (a particle size comparable as a cement particle) and 50-200 micrometers (a particle size larger than a cement particle and smaller than a lime crushed sand particle, Preferably it is 80-180 micrometers). It has a particle size distribution with a frequency peak at 5 to 20 μm and a fine particle with a particle size of 50 to 200 μm and a fine powder with a particle size of 50 to 200 μm, each containing 25% or more (based on the integrated value of frequency), and a particle size of 80 to 180 μm Using a fine powder of 15% or more (based on the integrated frequency). The fine limestone powder used in this embodiment was measured with a laser diffraction / scattering particle size distribution measuring apparatus (LA-950, manufactured by Horiba, Ltd.), and the results shown in FIG. 2 (peaks at around 10 μm and around 100 μm). Is obtained).

  Such crushed lime sand and fine limestone powder can be obtained by, for example, a known crushing device or granulating device.

  In the cement-based solidifying material composition 2 of the present embodiment, 14 to 22 parts by weight of cement, 70 to 83 parts by weight of crushed lime sand as fine aggregate, and 3 to 10 parts by weight of limestone fine powder are combined. Thus, the volume ratio of the cement constituting the cement-based solidified material composition 2 to the aggregate (crushed limestone + limestone fine powder) is 1: 4 to 1: 7 ( In this embodiment, it is about 1: 5). Therefore, in comparison with the conventional cement-based solidifying material composition in which the volume ratio of cement to aggregate is 1: 3 to 1: 4, it becomes easy to reduce the blending ratio of cement and hence the amount used. Contributes to resource saving and cost reduction.

  In addition, when the blending ratio of the cement is lowered in the conventional cement-based solidifying material composition, the strength of the mortar is decreased. However, when the cement-based solidifying material composition 2 of the present embodiment is used, the use of the cement as described above. While reducing the amount, the strength of the mortar 4 to be formed can be increased, and a crack preventing effect is also imparted. The mechanism is that fine limestone powder with a small particle size (5 to 20 μm) improves the solidity of the mortar 4 by entering between the lime crushed sand particles and cement particles, and further, the particle size is large (50 to 200 μm is preferable) 80 to 180 [mu] m) is considered to maintain a proper distance between the crushed limestone particles and uniformly disperse the cement particles, thereby assisting in the complete coating of the cement on the crushed limestone. .

  Moreover, if the blending ratio of the cement is simply lowered in the conventional cement-based solidifying material composition, the (ball) bearing function for smoothly transporting the fine aggregate that the cement bears is insufficient, and the flowability of the mortar 4 Workability will fall. However, in the cement-based solidifying material composition 2 used in the present embodiment, the mixing ratio of the cement is not simply lowered, but the limestone fine powder having an equivalent particle size of cement particles and crushed lime sand larger than the cement particles. By blending with limestone fine powder having a particle size smaller than the particle, the bearing function and fluidity of the mortar 4 that are impaired by the reduction of cement are complemented and enhanced. Is expected.

  Here, the present inventor has confirmed that the spray construction using a cement-based solidified material composition containing only cement and crushed lime sand without any fine limestone powder cannot be applied successfully. The facts suggest the importance of fine limestone powder.

  And when implementing the spraying method of this embodiment, a water reducing agent, a fiber, etc. are added to the pressure feeder 1 other than the cement-type solidification material composition 2 and the water 3 as needed, and mixing (kneading). However, since the fluidity of the mortar 4 can be improved as described above, the required amount of expensive high-performance water reducing agent, etc. that was indispensable when using a conventional cement-based solidifying material composition is reduced. As a result, cost reduction is also achieved.

  In general, an excessive or too small amount of water added to the cement-based solidifying material composition prevents the formation of good quality mortar, but the cement-based solidifying material composition 2 of the present embodiment has a property of not absorbing water. Since the crushed sand is included as fine aggregate, the amount of water that is not absorbed by the fine aggregate (outside the fine aggregate) is constant compared to the conventional formulation that uses water-absorbing sand as the fine aggregate This makes it very easy to stabilize the quality of the mortar 4 to be formed, and also to simplify the production of a high-quality mortar 4.

  Moreover, as described above, the fine aggregate contained in the cement-based solidified material composition 2 is crushed lime sand having no water absorption, so that the amount of water added when forming the mortar 4 is reduced as compared with the conventional blending. The cement-based solidifying material composition 2 contributes to resource saving (water saving) in this respect as well, and even if the amount of water added is reduced in this way, the limestone fine powder that prevents separation of water An appropriate amount of moisture can be retained as the mortar 4.

  Further, the mortar 4 made of the cement-based solidifying material composition 2 can prevent water from being separated by the limestone fine powder, and the hardness and adhesion of the mortar 4 are in good condition, so that it is sprayed on the slope N (surface to be constructed). Rebound loss (dispersion loss due to rebound on the slope N) and run-off after spraying (flow off from the slope N) can be reduced and prevented.

  Moreover, since the cement-type solidification material composition 2 uses the crushed lime sand which can be stably supplied in various places as a fine aggregate, the spraying construction of this embodiment can be suitably implemented in various places throughout the country.

  In addition, this invention is not limited to said embodiment at all, Of course, it can change and implement variously in the range which does not deviate from the summary of this invention. For example, the following modifications can be given.

  Although the spraying method of this embodiment is for formation of the method frame 5, it is not restricted to this, The application to formation of another structure is also possible. Moreover, in the spraying method of this embodiment, although the pumping machine 1 using the compressor 10 is used, it can replace with this, for example, can also use a pump type pumping machine, and is used by the well-known spraying method in this way. Various configurations can be employed in the spraying method of the present invention.

  The cement-based solidifying material composition 2 of the present embodiment is suitable for forming the mortar 4, but is not limited thereto, and may be configured to be suitable for forming concrete, for example.

2 Cement-based solidifying material composition 3 Water N Slope (surface to be constructed)

Claims (2)

14 to 22 parts by weight of cement, 70 to 83 parts by weight of lime crushed sand as fine aggregate, and 3 to 10 having a particle size distribution with frequency peaks in at least two locations of 5 to 20 μm and 80 to 180 μm a limestone fine powder parts, viewed free so that 100 parts by weight in total,
A cement-based solidifying material composition used for spraying construction, wherein the limestone fine powder contains 25% or more of fine powder having a particle size of 5 to 20 μm and 15% or more of fine powder having a particle size of 80 to 180 μm . A spraying method in which the cement-based solidifying material composition used in the spraying construction according to claim 1 is sprayed onto a construction target surface in a state of being mixed with water.

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