JP5422316B2 - Lightweight mortar construction method and lightweight mortar - Google Patents

Description

The present invention relates to a method for constructing a lightweight mortar containing cement and resin foam to be constructed on a building or the like. Moreover, it is related with the lightweight mortar constructed by the construction method.

  Conventionally, lightweight mortar containing cement and resin foam has been used as a heat insulating material in buildings. For example, Patent Literature 1 describes a heat insulating material containing cement, shirasu balloon, and urethane foam or polystyrene.

  However, sufficient studies have not been made on the curability of lightweight mortar containing cement and resin foam.

  On the other hand, there is a method in which mortar or concrete using cement as a binder is rapidly cured, and the liquid quick setting agent is mixed immediately before mortar or concrete construction (for example, Patent Document 2). .

Japanese Patent Laying-Open No. 2005-281051 (Claims etc.) JP 2002-129895 A (Claims etc.)

  However, lightweight mortar containing cement and resin foam contains several times as much water as cement contained in lightweight mortar at the time of construction, and the construction thickness is thick when constructed as a heat insulating material. Therefore, it took time to cure. And since time was required for hardening, there existed problems, such as dripping with dead weight before hardening. In particular, in the case of construction by spraying, the viscosity at the time of construction of the lightweight mortar is often set low considering the appropriateness of the material for the spraying coating machine, and such a problem is remarkable.

  In addition, although a method for quickly curing mortar or concrete using cement as a binder has been studied, a method for quickly curing lightweight mortar containing cement or resin foam has not been sufficiently studied. .

  This invention solves the said problem, Comprising: It aims at providing the construction method which hardens the lightweight mortar containing a cement and a resin foam rapidly.

  Another object of the present invention is to obtain a lightweight mortar that is obtained by quickly curing and that does not sag due to its own weight and has a low thermal conductivity.

As a method for solving the above-mentioned problem, the invention according to claim 1 is a mixture of a liquid A containing cement , water and a resin foam and a liquid B containing silicate as a quick setting agent immediately before construction. It is a construction method of a lightweight mortar having a specific gravity of 0.1 to 1.0, and the A liquid and the B liquid are joined together by mixing the A liquid and the B liquid, and the A liquid and the B liquid are mixed. By adjusting the pumping amount of the A liquid and the B liquid by adjusting the pump for pumping the B liquid, the mixing ratio of the cement and the quick setting agent is set to a solid content of the quick setting agent with respect to 100 parts by mass of the cement. A liquid and B liquid are mixed so that it may become 30-80 mass parts .

  The invention according to claim 2 is characterized in that, in the construction method of the lightweight mortar according to claim 1, the solid content of the quick setting agent in the liquid B is 20 to 60% by mass. .

Invention of Claim 3 is the construction method of the lightweight mortar of Claim 1 or 2, Said A liquid contains 50-200 mass parts of said water with respect to 100 mass parts of said cement. It is characterized by.

Invention of Claim 5 is the lightweight mortar constructed by the construction method in any one of Claims 1-4.

According to the construction method of claim 1, it is possible to provide a construction method to sufficiently promote the curing by B solution containing a quick-setting admixture of the A solution containing cement, water and resin foam, construction It is possible to prevent the excessive quick-setting agent from leaking out together with the water from the mixture of the liquid A and the liquid B.

According to the construction method according to 請 Motomeko 2, in addition to the effect of claim 1, together with a curable mixture of liquid A and liquid B can be sufficiently improved, after mixing liquids A and B Sufficient pot life until construction can be obtained.

According to the construction method of Claim 3 , in addition to the effect of Claims 1-2 , mixing is easy and it is excellent also in construction workability | operativity.

According to the light weight mortar of the fourth aspect , it is possible to obtain a light weight mortar having a small thermal conductivity and excellent heat insulating performance .

  This invention is the construction method of the lightweight mortar containing a cement and a resin foam, Comprising: A liquid containing a cement, water, and a resin foam, and B liquid containing a quick setting agent are mixed just before construction. A lightweight mortar is obtained by applying and curing the mixture obtained in this manner. By mixing the A liquid and the B liquid immediately before the construction, the constructed mixture is quickly cured.

The lightweight mortar is a lightweight mortar having an apparent specific gravity of 0.1 to 1.0 (particularly 0.2 to 0.5), which contains a resin foam with cement as a binder, and is mainly used for construction. It is used as a heat insulating material for things. If the apparent specific gravity is too small, the strength is weak and the shape tends to collapse. If the apparent specific gravity is too large, the thermal conductivity is large and it is difficult to obtain sufficient heat insulation.

  The liquid A is a fluid obtained by mixing cement, water, a resin foam, and other fillers and additives, and the water content is preferably 50 to 200 mass with respect to 100 mass parts of cement. About a part. When the water content is within this range, mixing is easy and the workability is excellent.

  The cement is not particularly limited as long as it is a hydraulic cement. For example, normal Portland cement, early-strength Portland cement, ultra-early strength Portland cement, medium heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, blast furnace cement Various cements such as fly ash cement, white Portland cement, ultrafine particle cement, high belite cement, ultrafast cement, alumina cement, and ecocement can be used.

  The resin foam is a porous body obtained by foaming a synthetic resin. For example, foamed polystyrene, foamed urethane, foamed phenol, foamed polyethylene, foamed polypropylene, or the like can be used. Further, if these resin foams have an apparent specific gravity of 0.015 to 0.5, a lightweight mortar having a specific gravity of 0.1 to 1.0 can be easily obtained. A resin foam having an apparent specific gravity of less than 0.015 is brittle in aggregate and easily breaks when mixed with cement or water. In addition, a resin foam having an apparent specific gravity of more than 0.3 needs to increase the volume of the resin foam to be closed in the light weight mortar, so that the weight of the mortar cannot be reduced efficiently. Moreover, if the volume of the resin foam closed in a lightweight mortar increases, the bending strength of a lightweight mortar will fall.

Among the resin foams, it is preferable to use foamed polystyrene for the lightweight mortar constructed by the construction method of the present invention. If foamed polystyrene is used, the resin foam is less likely to be deformed or damaged when the A liquid is mixed or when the A liquid and the B liquid are mixed. In particular, when the liquid A is pumped by a pipe, the resin foam may shrink due to pressure, but such foaming can be suppressed by using foamed polystyrene.

In addition, if a foamed polystyrene is a foamed polystyrene, a foaming means, a shaping | molding method, etc. will not be specifically limited. For example, bead method expanded polystyrene (EPS), extruded expanded polystyrene (XPS), etc. can be used. In order to obtain a predetermined particle diameter, these may be used by crushing the molded body, or pre-expanded beads before molding may be used. Moreover, the low foaming thing of foaming ratio less than 10 times and the high foaming thing of 10 to 70 times foaming ratio can be used.

The resin foam is preferably in the form of particles, the average particle diameter is preferably in the range of 0.5 to 15 mm, more preferably in the range of 1 to 10 mm, A range of 8 mm is particularly preferable. If the average particle size is too small, the specific surface area of the resin foam is increased, so that when the liquid A is mixed or when the liquid A and the liquid B are mixed, the liquid A or the mixture of the liquid A and the liquid B Kneading may be difficult. In such a case, it may be easy to knead by adding a lot of water or the like, but if such treatment is performed, the strength of the lightweight mortar obtained by curing may be weakened. Conversely, if the average particle size is too large, it becomes difficult to sufficiently mix the liquid A and the liquid B in a short time. In particular, when the A liquid and the B liquid are mixed by joining a pipe for pumping the A liquid and a pipe for pumping the B liquid, it is difficult to sufficiently mix the A liquid and the B liquid. On the other hand, if the average particle size of the resin foam is too large, clogging of the resin foam tends to occur in the pipe when the liquid A is pumped through the pipe.

  The resin foam content in the lightweight mortar is preferably 50 to 90 parts by volume of the resin foam with respect to 100 parts by weight of the lightweight mortar. If the content of the resin foam is within this range, a lightweight mortar having a specific gravity of 0.1 to 1.0 can be easily obtained.

Moreover, you may make the said A liquid contain a filler and an additive other than cement and a resin foam as a compound. What is necessary is just to use suitably what is used for a normal mortar and a lightweight mortar as a filler and an additive.

  Examples of the filler include inorganic particles such as river sand, quartz sand, cold water sand, ceramic pulverized material, glass pulverized material, calcium carbonate, and lightweight inorganic materials such as perlite, vermiculite, shirasu balloon, glass foam, diatomaceous earth, and the like. Inorganic fillers such as aggregates, organic fillers such as resin particles and hollow resin particles, inorganic fibers such as rock wool, slag wool, and glass fibers, acrylic fibers, vinylon fibers, polyamide fibers, aromatic polyamide fibers, polyester fibers, etc. These organic fibers can be used as appropriate.

  Examples of the additive include a synthetic resin (synthetic resin emulsion, re-emulsification type powder resin, etc.), a thickener, a water absorption inhibitor, a water repellent, a water reducing agent, a fluidizing agent, a water retention agent, and the like serving as a binder. It can be used as appropriate.

  The B liquid is a fluid containing a quick setting agent.

The quick setting agent reacts with the cement in the liquid A when the liquid B is mixed with the liquid A,
It is a substance that eliminates the fluidity of the mixture of the B liquid and the A liquid and cures the mixture of the B liquid and the A liquid. Specifically, silicates such as sodium silicate and potassium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, sulfates such as sodium sulfate, potassium sulfate and magnesium sulfate, CaO · _{Al 2 O 3, 12CaO · 7Al} 2 O 3, CaO · 2Al 2 O 3, 3CaO · Al 2 O 3, 3CaO · 3Al 2 O 3 · CaF 2, calcium aluminate such as _{11CaO · 7Al 2 O 3 · CaF} 2 One or more selected from calcium salts such as calcium oxide, calcium hydroxide, calcium hydroxide and calcium chloride, or colloidal silica is preferably used. Moreover, when making these contain in B liquid, these may be added directly and these aqueous solutions etc. may be added.

  Among these quick setting agents, it is preferable to use silicate as the quick setting agent because the use of silicate can particularly quickly cure the mixture of the B liquid and the A liquid.

  Moreover, in the said B liquid, you may contain water and an additive other than the said quick setting agent as a compound.

  In addition, 20-60 mass% is preferable and, as for the solid content of the quick setting agent which occupies in B liquid, 30-50 mass% is more preferable. When there is too little said content, the sclerosis | hardenability of the mixture of A liquid and B liquid cannot fully be improved, but it will take time for hardening of a mixture. Conversely, if the content is too large, curing proceeds rapidly during mixing of the A liquid and the B liquid, and the A liquid and the B liquid may not be sufficiently mixed. Moreover, since hardening is too early, sufficient pot life until construction after mixing cannot be obtained.

  As a method of mixing the A liquid and the B liquid, there is a method in which the A liquid and the B liquid are put into the same container and stirred. Further, it is also possible to use a method of mixing the A liquid and the B liquid by pumping the A liquid and the B liquid through separate pipes, and joining the pipe feeding the A liquid and the pipe feeding the B liquid together. .

As a method of adding and stirring the A liquid and the B liquid in the same container, for example, there is a method of using a stirrer such as a mortar mixer. However, such a mixing method is suitable for mixing a large amount of material at a time, but is not suitable for mixing a small amount of material. Since the mixture of the liquid A and the liquid B is hardened quickly, it must be applied in a short time after mixing, so it is not necessary to stir in large quantities. In other words, it is necessary to apply the solution in a short time before curing after mixing the liquid A and the liquid B, but once mixed in a large amount, it may be difficult to apply the mixed material in a short time. is there.

Therefore, it is preferable to adopt a method suitable for mixing only the amount that can be applied in a short time as a method of mixing the A liquid and the B liquid. As such a method, it is preferable to use a method in which a pipe for feeding A liquid and a pipe for feeding B liquid are merged. According to this method, it is easy to mix the A liquid and the B liquid in a necessary amount.
In this method, since the merged liquid A and liquid B are mixed, the liquid A and liquid B can be mixed only in a necessary amount by adjusting the amount to be pumped. Moreover, if the speed which pumps A liquid and B liquid is adjusted, a required quantity can also be mixed at any time.

  Furthermore, it is possible to attach a spray nozzle to the outlet of a pipe where the pipe for pumping the A liquid and the pipe for pumping the B liquid are joined, and spray the mixture of the A liquid and the B liquid. According to this method, since the mixture of A liquid and B liquid is sprayed immediately after mixing, the mixture of A liquid and B liquid can be applied in a short time after mixing. In the case of adopting this method, it is more preferable to join the pipe for pumping the A liquid and the pipe for pumping the B liquid immediately before the outlet of the pipe.

As what combined the pipe | tube which pumps A liquid and the pipe | tube which pumps B liquid, what is shown to Fig.1 (a) and FIG.1 (b) is mentioned, for example.

In FIG. 1 (a) and FIG. 1 (b), the pipe 11 for pumping the liquid A and the pipe 12 for pumping the liquid B merge, and the liquid A and the liquid B are mixed in the portion of the pipe 13 after the merge. A mixture of the liquid A and the liquid B is discharged from the outlet of the tube 13. Further, it is possible to attach a spray nozzle to the outlet of the pipe 13 and spray the mixture of the liquid A and the liquid B immediately after mixing.

In addition, when the method of mixing A liquid and B liquid by joining the pipe | tube which pumps A liquid and the pipe | tube which pumps B liquid is employ | adopted, A liquid and B liquid are mixed in A liquid. It is preferable that the mixing ratio of the cement and the rapid setting agent in the B liquid is mixed so that the solid content of the quick setting agent is 20 to 90 parts by mass with respect to 100 parts by mass of the cement. It is more preferable to mix at a ratio of 30 to 80 parts by mass. When the ratio of the solid content of the quick setting agent is less than 20 parts by mass with respect to 100 parts by mass of the cement, the mixing of the liquid A and the liquid B is insufficient, and the mixture of the liquid A and the liquid B Curing cannot be promoted sufficiently. Specifically, the curing rate of the applied mixture is uneven, and a part where the curing is slow occurs. On the contrary, when the ratio of the solid content of the quick setting agent exceeds 90 parts by mass with respect to 100 parts by mass of the cement, curing proceeds during mixing of the liquid A and the liquid B, and the liquid A and the liquid B are sufficiently obtained. Cannot mix. Moreover, since hardening is too early, it hardens | cures in the pipe | tube after merging, and a pipe | tube may generate | occur | produce clogging. Moreover, the surplus quick-setting agent oozes out with water from the mixture of A liquid and B liquid after construction, and the layer of quick-setting agent may be formed on the surface of a lightweight mortar.

Further, when the solid content ratio of the quick setting agent exceeds 90 parts by mass with respect to 100 parts by mass of cement, the thermal conductivity of the lightweight mortar obtained by curing the mixture of the liquid A and the liquid B increases. The heat insulation performance of lightweight mortar will be reduced. When the ratio of the solid content of the quick setting agent is 90 parts by mass or less with respect to 100 parts by mass of cement, a lightweight mortar having a low thermal conductivity and excellent heat insulating performance can be obtained.

  As a method of constructing a mixture of Liquid A and Liquid B on a building, etc., it is not limited to the construction by spraying, but adopting a method of painting using construction tools such as a roller and a rower. Can do.

A lightweight mortar was constructed using the apparatus outlined in FIG.
FIG. 2 shows an outline of an apparatus for mixing the A liquid accommodated in the A liquid container 21 and the B liquid accommodated in the B liquid container 22 and spraying them on the concrete wall surface 50.
At the time of construction, the A liquid is sent to the A liquid pressure feed pipe 11 by the A liquid pressure feed pump 31, and at the same time, the B liquid is sent to the B liquid pressure feed pipe 12 by the B liquid pressure feed pump 32. From the compressor 33, air for injecting a mixture of the liquid A and the liquid B from the spray nozzle 14 is sent to the air pipe 34.
By doing so, the pipe 34 first joins the pipe 12 so that the B liquid and the air mix, and it joins the pipe 11 to mix the A liquid and the B liquid. The mixture 23 of the A liquid and the B liquid obtained as described above is sprayed and sprayed from the spray nozzle 14 attached to the outlet of the pipe toward the wall surface 50.
At this time, by adjusting the pump 31 and the pump 32, the amount of liquid A and liquid B can be adjusted. Moreover, the pressure of the air compressed by the compressor 33 can be adjusted according to the property of the material to spray.

Construction of lightweight mortar using this apparatus was performed according to the following procedure.

Example 1
First, A liquid which mixed each material with the following compounding ratio was manufactured, and A liquid was accommodated in the A liquid container 21.
Formulation of liquid A: ordinary Portland cement 100 parts by mass, pearlite 20 parts by mass, re-emulsifying acrylic resin powder 5 parts by mass, vinylon fiber 3 parts by mass, expanded polystyrene (average particle diameter 4 mm, expansion ratio 40 times) 12 parts by mass, 80 parts by weight of water.

  Next, B liquid containing sodium silicate as a quick setting agent was manufactured. Sodium silicate 3 (solid content: 40% by mass) was used as sodium silicate, and water was added to adjust the solid content of sodium silicate to 37% by mass. Accommodated.

  Next, the pump 31 and the pump 32 were adjusted to adjust the pumping amount per unit time of the A liquid and the pumping amount per unit time of the B liquid. The pumping amount per unit time of the cement in the liquid A being pumped was 2 kg / min, and the pumping amount per unit time of the sodium silicate (solid content) in the liquid B being pumped was 1 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and B liquid are pumped, A liquid and B liquid are merged and mixed, and the mixture 23 is sprayed from the spray nozzle 14 to the wall surface. 50 was sprayed at a thickness of about 4 cm.

The sprayed mixture 23 hardened in about 3 minutes after spraying. Due to the rapid curing of the mixture 23, the mixture 23 sprayed on the wall surface 50 did not show any defects such as sagging due to its own weight.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

(Example 2)
After the construction of Example 1 was completed, the pump 31 was left as it was, and only the pump 32 was adjusted to adjust the pumping amount per unit time of the B liquid. The pumping amount per unit time of sodium silicate (solid content) in the liquid B to be pumped was 0.6 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and B liquid are pumped, A liquid and B liquid are merged and mixed, and the mixture 23 is sprayed from the spray nozzle 14 to the wall surface. 50 was sprayed at a thickness of about 4 cm.

The sprayed mixture 23 hardened in about 5 minutes after spraying. Due to the rapid curing of the mixture 23, the mixture 23 sprayed on the wall surface 50 did not show any defects such as sagging due to its own weight.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

(Example 3)
After the construction of Example 2 was completed, the pump 31 was left as it was, and only the pump 32 was adjusted to adjust the pumping amount per unit time of the B liquid. The pumping amount per unit time of sodium silicate (solid content) in the liquid B to be pumped was 1.6 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and B liquid are pumped, A liquid and B liquid are merged and mixed, and the mixture 23 is sprayed from the spray nozzle 14 to the wall surface. 50 was sprayed at a thickness of about 4 cm.

The sprayed mixture 23 hardened in about 2 minutes after spraying. Due to the rapid curing of the mixture 23, the mixture 23 sprayed on the wall surface 50 did not show any defects such as sagging due to its own weight.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

(Comparative Example 1)
After the construction of Example 3 was completed, the pump 31 was left as it was, and only the pump 32 was adjusted to adjust the pumping amount per unit time of the B liquid. The pumping amount per unit time of sodium silicate (solid content) in the liquid B to be pumped was 0.3 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and B liquid are pumped, A liquid and B liquid are merged and mixed, and the mixture 23 is sprayed from the spray nozzle 14 to the wall surface. 50 was sprayed at a thickness of about 4 cm.

Since the sprayed mixture 23 did not sufficiently harden in a short time, the mixture 23 sprayed onto the wall surface 50 was found to sag due to its own weight, and further fell several centimeters downward from the wall surface 50 due to its own weight.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

(Comparative Example 2)
After the construction of Comparative Example 1 was completed, the pump 31 was left as it was, and only the pump 32 was adjusted to adjust the pumping amount per unit time of the B liquid. The pumping amount per unit time of sodium silicate (solid content) in the liquid B to be pumped was 2 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and B liquid are pumped, A liquid and B liquid are merged and mixed, and the mixture 23 is sprayed from the spray nozzle 14 to the wall surface. 50 was sprayed at a thickness of about 4 cm.

The sprayed mixture 23 hardened in about 2 minutes after spraying. Due to the rapid curing of the mixture 23, no dripping due to its own weight was observed in the mixture 23 sprayed on the wall surface 50. However, 30 minutes after the spraying, surplus sodium silicate oozed out on the surface of the mixture 23 and dripped down the surface of the mixture 23.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

(Comparative Example 3)
After the construction of Comparative Example 2 was completed, the B liquid in the B liquid container 22 was discarded, and water was stored in the B liquid container 22 instead of the B liquid. Thereafter, the pump 31 was left as it was, and only the pump 32 was adjusted to adjust the pumping amount of water per unit time. The pumping amount of water per unit time was 2 kg / min.

And the pump 31, the pump 32, and the compressor 33 are operated, A liquid and water are pumped, A liquid and water are merged and mixed, The mixture 23 is sprayed from the spray nozzle 14 to the wall surface 50. Sprayed with a thickness of about 4 cm.

The sprayed mixture 23 does not sufficiently cure even after 6 hours, and the mixture 23 sprayed on the wall surface 50 is drooped by its own weight, and is further shifted by a few tens of centimeters downward from the wall surface 50 by its own weight. fell.
Furthermore, it was cured for 14 days in an environment of a temperature of 23 ° C. and a humidity of 60%, and the mixture 23 was dried and cured to obtain a lightweight mortar.

  As described above, when the A liquid and the B liquid were mixed and applied in an appropriate amount, the mixture 23 hardened quickly and no malfunction occurred. However, if the amount of the quick setting agent in the B liquid is too small relative to the amount of the cement in the A liquid, there is a problem in that it does not cure sufficiently. Moreover, when there was too much quantity of the quick setting agent in B liquid with respect to the quantity of the cement in A liquid, the malfunction that the excess quick setting agent oozed out on the surface of the mixture 23 arose.

  Next, the specific gravity and thermal conductivity of the lightweight mortar obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were measured. The measurement results are shown in Table 1 below.

As shown in Table 1, in the lightweight mortars of Examples 1 to 3, the lightweight mortar of Comparative Example 3 that does not use an accelerating agent, and the lightweight mortar of Comparative Example 1 in which the mixing ratio of the accelerating agent to cement is small. Although there was no big difference in thermal conductivity, the thermal conductivity of the light weight mortar of Comparative Example 2 in which the mixing ratio of the quick setting agent to the cement was large was rapidly increased as compared with those lightweight mortars.

Sectional drawing which shows the outline of the cross section of the pipe | tube of the part which the pipe | tube which pumps A liquid and the pipe which pumps B liquid merge, and mixes A liquid and B liquid Schematic diagram showing the outline of the spraying device used for the construction of the lightweight mortar of this application

11 Pipe for pumping A liquid 12 Pipe for pumping B liquid 13 Pipe for feeding A liquid and pipe for pumping B liquid 14 Spray nozzle 21 A liquid container 22 B liquid container 23 A liquid Mixture 31 and B liquid 31 A liquid pump 32 B liquid pump 33 Compressor 34 Air pipe 50 Wall surface

Claims (4)

A construction method for a lightweight mortar having a specific gravity of 0.1 to 1.0, in which a liquid A containing cement , water and a resin foam and a liquid B containing silicate as a quick setting agent are mixed immediately before construction. The pipe for feeding A liquid and the pipe for feeding B liquid are merged to mix A liquid and B liquid, and the A liquid and B liquid are pumped by adjusting the pump for pumping A liquid and B liquid. By adjusting the amount, the liquid A and the liquid B are mixed so that the mixing ratio of the cement and the quick setting agent is 30 to 80 parts by weight of the solid content of the quick setting agent with respect to 100 parts by weight of the cement. A lightweight mortar construction method characterized by this.   The solid content of the quick setting agent which occupies in said B liquid is 20-60 mass%, The construction method of the lightweight mortar of Claim 1 characterized by the above-mentioned. The said A liquid contains 50-200 mass parts of said water with respect to 100 mass parts of said cement, The construction method of the lightweight mortar of Claim 1 or 2 characterized by the above-mentioned. The lightweight mortar constructed by the construction method according to any one of claims 1 to 3 .

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