JP6785548B2 - Concrete placing method - Google Patents

Description

The present invention relates to a concrete placing method for placing concrete at a construction site.

In order to install a seismic isolation device such as laminated rubber in the construction of a seismic isolation building, generally, after constructing the floor slab of the seismic isolation layer, the seismic isolation foundation that is the base of the seismic isolation device is constructed. .. To construct the seismic isolation foundation, in addition to the reinforcing bars rising from the floor slab, the necessary reinforcement work was performed, and then the lower base plate of the seismic isolation device for bolting the seismic isolation device was placed over the base plate. Temporarily fix the base plate to the slab or the adjustment stand by adjusting the horizontal accuracy and plane position of.
The main body of the lower base plate of the seismic isolation device is an iron plate, and a large number of bag nuts and studs protrude from the lower surface so that it is fixed and integrated with the seismic isolation foundation. In the central part, there is a casting hole for placing concrete, and concrete is poured from this hole through a funnel or the like to construct a seismic isolation foundation.

As shown in FIG. 4, after the lower base plate is fixed at an accurate position on the slab, the formwork is set around the base plate, and then concrete is placed on the seismic isolation foundation from the casting hole through a funnel or the like. Fill. At this time, since the base plate is wide and a large number of bag nuts and studs are projected on the lower surface, the concrete does not flow well and stays to separate the concrete compounding components, and air tends to collect on the lower surface of the base plate. was there.

In addition, in order to finish placing concrete in one seismic isolation foundation and then place concrete in the next seismic isolation foundation, the tip of the ready-mixed concrete placing hose is moved by a worker. At this time, the hose is clogged with ready-mixed concrete, and if the refilling work is not performed smoothly, not only is it time-consuming, but also the possibility of separation of concrete compounding components and air contamination increases in terms of quality.

Patent Document 1 discloses a method of placing concrete on a portion separated and independent from the upper floor. In this method, pipes are set to separate and independent parts by penetrating the upper floor formwork, so it is possible to avoid obstacles such as floor formwork and arrange and move pipes in a narrow space. Work can be reduced. Specifically, the hose for placing the ready-mixed concrete can be moved only on the floor formwork that has not been installed yet, such as the support material and the wall formwork.

By such a concrete placing method, the workability of the refilling work is improved by avoiding obstacles such as the floor formwork, but the concrete once discharged from the ready-mixed concrete placing hose on the formwork receives too much pressure. Without it, it will fall to the casting location via the concrete casting tool. There is no particular problem if the casting location is a general part such as the waist wall, but in a casting location where compaction work is difficult and internal air bubbles are difficult to escape, such as under the lower base plate in the seismic isolation foundation. It is necessary to fill concrete with little separation and air contamination with a natural concrete flow without sufficient compaction work, and it is not good for the quality of concrete to move or drop it violently.

Japanese Unexamined Patent Publication No. 2013-032637

An object of the present invention is to facilitate concrete placing work and improve concrete filling property at a placing place where compaction work is difficult and internal air bubbles are difficult to escape, such as under a lower base plate. It is to provide a setting method.

In the present invention, in the seismic isolation building construction work, in order to construct the seismic isolation foundation that is the base of the seismic isolation device, the high-fluidity concrete pumped from the concrete pump truck can be placed horizontally with adjustable mounting height. From the press-fitting pipe attached to the center of the lower base plate of the seismic isolation device, press-fitting into the seismic isolation foundation by pump pumping pressure via a horizontal pulling pipe placed horizontally on a movable trolley. This is a concrete placement method that causes overflow . The trolley is located between the lower base plate and the concrete pump truck, one end of the horizontal pulling pipe is connected to the press-fitting pipe, and the other end of the horizontal pulling pipe is from the concrete pump truck. It is connected to an extended flexible hose, and the lower base plate has a plurality of air bleeding and casting confirmation holes, and a flow stop is stopped at the upper edge of the outer periphery.

In order to install a seismic isolation device such as laminated rubber in the construction of a seismic isolation building, generally, after constructing the floor slab of the seismic isolation layer, the seismic isolation foundation 1 that is the base of the seismic isolation device is constructed. To do. To construct the seismic isolation foundation part 1, in addition to the reinforcing bars 18 rising from the floor slab, necessary reinforcement work is performed, and then the lower base plate 10 for bolting the seismic isolation device is covered from above, and the base plate is constructed. Temporarily fix the base plate to the slab or level adjustment stand 17 by adjusting the horizontal accuracy and plane position.
The main body of the lower base plate 10 is an iron plate, and a large number of bag nuts 11 and headed studs 12 project on the lower surface, and the lower base plate 10 is fixed to the seismic isolation foundation 1 and integrated. In the central part, there is a casting hole 14 for placing concrete, and concrete is poured from this hole through a funnel or the like to construct a seismic isolation foundation part 1.

According to the present invention, the "high-fluidity concrete" pumped from the concrete pump truck P is "press-fitted" into the seismic isolation foundation 1 by the pump pumping pressure from the press-fitting pipe 20 attached to the center of the lower base plate. Compared to the method of placing concrete from the casting hole 14 through a pump or the like, compaction work is difficult and internal air bubbles are difficult to escape. There is no separation of concrete even at the casting location, and there are few air bubbles. Real concrete can be cast.

High-fluidity concrete generally refers to concrete with a slump flow value of 50 cm or more in the slump flow test, but since it is easy to separate concrete with a too large slump flow value, seismic isolation with many obstacles such as reinforcing bars and studs. The slump flow value in the case of the foundation part is preferably in the range of 50 to 63 cm at the tip of the cylinder.

The press-fitting method is a method in which a press-fitting opening is provided in the lower part of a formwork or the like in a steel pipe concrete or an RC member having complicated reinforcement arrangement, a concrete press-fitting pipe port is directly connected to the opening, and press-fitting is performed by pump pressure feeding. Instead of dropping the concrete from the top, the press-fitting pressure pushes the concrete up from the bottom or pushes it sideways from behind, so there is little separation of concrete, and solid concrete with few bubbles, beans, and voids can be constructed. It is said that.

Further, according to the present invention, the high-fluidity concrete pumped from the concrete pump truck P is placed on the trolley 40 whose mounting height is adjustable and can be moved horizontally, "horizontally mounted horizontal pulling pipe 30". Since it is press-fitted into the seismic isolation foundation 1 via the above, even if it is press-fitted, compared to the case where the flexible hose for concrete placement is directly connected to the press-fitting pipe 20 without going through the horizontal pulling pipe 30. Since the height is maintained and the hose is connected in a straight line, the flexible hose 50 can be shortened and the concrete path during pumping can be smoothly fixed. Since the flexible part is short, there is little vibration and impact, it is difficult for the pumping path to form a loop shape or U-shape, there is little partial change in the pumping speed, and a constant pumping pressure can be maintained. Does not separate, and air does not easily collect in the concrete.

In addition, the refilling work of placing concrete on the seismic isolation foundation 1 in one place and placing concrete on the next seismic isolation foundation 1'is not wasted by moving the dolly horizontally. It can be performed smoothly, there is little vibration and impact, it does not take a long time to work, and the possibility of separation of concrete compound components and air contamination is reduced.

It is a perspective view which shows the state which carried out the concrete placing method of one Embodiment of this invention. It is a perspective view of the seismic isolation foundation part. It is sectional drawing of the seismic isolation foundation part. It is a perspective view which shows the conventional concrete placing method.

FIG. 1 is a perspective view showing a state in which the concrete placing method of one embodiment of the present invention is implemented, FIG. 2 is a perspective view of a seismic isolation foundation portion, and FIG. 3 is a cross-sectional view of the seismic isolation foundation portion. is there.

The seismic isolated building, which is the target structure of this construction, is a foundation seismic isolated building having a seismic isolation layer between the foundation of the building and the superstructure, and the superstructure is supported by a plurality of laminated rubbers in the seismic isolation layer. ing.

As shown in FIG. 1, a concrete mixer truck (not shown) supplies fluid uncured concrete, which is also called ready-mixed concrete, to the concrete pump truck P, and the high-fluidity concrete pumped from the concrete pump truck P is placed at a mounting height. Is pumped from the concrete pump truck P from the press-fitting pipe 20 attached to the center of the lower base plate 10 via the horizontal pulling pipe 30 mounted horizontally on the adjustable and horizontally movable carriage 40. Press-fit into the seismic isolation foundation 1 by pressure.

As shown in FIG. 3, in the seismic isolation building construction work, in order to install a seismic isolation device such as laminated rubber, after constructing the floor slab of the seismic isolation layer, the seismic isolation foundation that becomes the base of the seismic isolation device. Build one. To construct the seismic isolation foundation part 1, in addition to the reinforcing bars 18 rising from the floor slab, necessary reinforcement work is performed, and then the lower base plate 10 for bolting the seismic isolation device is covered from above, and the base plate is constructed. Adjust the horizontal accuracy and plane position, and temporarily fix the base plate to the slab or level adjustment stand 17. After the lower base plate 10 is fixed in the correct position on the slab, the side formwork 19 is set around the base plate, and then the seismic isolation foundation 1 is filled with concrete from the casting hole 14.
The main body of the lower base plate 10 is an iron plate, and a large number of bag nuts 11 and headed studs 12 project on the lower surface, and the lower base plate 10 is fixed to the seismic isolation foundation 1 and integrated. In the central part, there is a casting hole 14 for placing concrete, and concrete is poured from this hole to construct the seismic isolation foundation part 1. Basically, a concrete flow is created from the center toward the outer circumference of the plate at the same time, and the air under the plate is driven to the outer circumference. The base plate has a plurality of (8 to 16) air bleeding and casting confirmation holes 13 (φ30 mm to φ50 mm). High-fluidity concrete is press-fitted from the base plate casting hole 14 to create a natural concrete flow, and the construction is basically carried out without compaction by a vibrator. By using high-fluidity concrete, it naturally flows and fills to improve the filling property and reduce the amount of air entrained.

When placing concrete, keep the inside of the formwork sufficiently moist. Since the fluidity of the material affects the filling situation, care should be taken to ensure that concrete with good fluidity can be placed at all times during casting.
When placing concrete, if air is discharged from the air bleeding and placing confirmation hole 13 and concrete is ejected, press it with a thick iron plate or block to prevent backflow of concrete and stain of the base plate.
At the end of casting, concrete overflows slightly from the outer circumference of the base plate beyond the side formwork 19 in order to reduce the residual air under the base plate. At that time, a flow stop 16 is previously attached to the upper edge of the outer circumference of the base plate so that the flow does not flow to the base plate side. In addition, by leaving a surplus on the outer peripheral portion, voids due to sedimentation of concrete can be prevented.
After the concrete movement has settled down, remove the excess part.
By curing for a predetermined period, the concrete is hardened and the seismic isolation foundation 1 of the reinforced concrete structure is formed.

1 Seismic isolation foundation 10 Lower base plate 11 Bag nut 12 Stud with head 13 Air bleeding and driving confirmation hole 14 Driving hole 15 Press-fit pipe fixing jig 16 Flow stop 17 Level adjustment stand 18 Reinforcing bar 19 Side formwork 20 Press-fit pipe 21 Joint 30 Horizontal piping 40 Formwork 50 Concrete casting flexible hose P Concrete pump truck

Claims (1)

In the seismic isolation building construction work, in order to build a seismic isolation foundation portion serving as a foundation of seismic isolation devices,
High-fluidity concrete pumped from a concrete pump truck is placed in the center of the lower base plate of the seismic isolation device via a horizontal pipe mounted horizontally on a trolley whose mounting height is adjustable and can be moved horizontally. It is a concrete placing method in which a press-fitting pipe attached to a part is press-fitted into the seismic isolation foundation part by pump pressure to overflow.
The trolley is located between the lower base plate and the concrete pump truck.
One end of the horizontal pulling pipe is connected to the press-fitting pipe, and the other end of the horizontal pulling pipe is connected to a flexible hose extending from the concrete pump truck.
A concrete placing method characterized in that the lower base plate has a plurality of air bleeding and casting confirmation holes, and a flow stop is stopped at the upper edge of the outer circumference .

Images