JPH0262363B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to the use of cement compositions (hereinafter referred to as cements) obtained by adding and kneading water to cement, aggregate, etc. such as mortar and concrete slurry. Concerning pouring methods.

[Problem that the invention seeks to solve]

There are many voids (0.5 mm or more) inside the hardened mortar, which is a major factor in deteriorating the physical properties of the hardened mortar. In addition, when pouring mortar with high fluidity using a concrete pump, large voids of about 0.1 to 5 mm are created due to air being drawn in, and the strength decreases due to the high water-to-cement ratio and cracks due to shrinkage. There were problems such as outbreaks.

This invention was made in view of the above circumstances. The objective was to develop a method for placing mortar that can be easily applied to placing mortar by pumping with a conventional concrete pump, and that can produce a hardened material with extremely few voids and high strength. There are suggestions.

[Means for solving problems]

This method of placing mortar is to force-feed mortar through a feeding pipe, provide a large number of through holes at the tip of the feeding tube, and a cap having a discharge port covering the through holes. The method is characterized in that, while applying vibration to the part, the composition is forced out from the through hole into the cap, and further discharged from the discharge port for casting.

Examples will be described below with reference to the drawings.

FIG. 1 shows the tip of a mortar feed pipe 1 used in this casting method. The tip of the feed tube 1 is spherical and has a large number of through holes 2, and a cap 3 is attached to cover this spherical portion. cap 3
has a cylindrical central part, a truncated conical shape at both ends, one end is fixed to the feed pipe 1, the other end has a discharge port 4 at the tip, and has a spherical part inside. A space 5 for temporarily retaining mortar is provided between the caps, and an exhaust pipe 6 that communicates with a vacuum pump is opened near the base end of the cap 3. Further, an oscillator 7 is attached to the feed pipe 1 at a position close to the cap.

FIG. 2 also shows the tip of the feed pipe 1 used in this casting method. The distal end of the feed tube 1 is cylindrical and has a large number of through holes 2, and the distal end is conical and concave, and a cap 3 is attached to cover the circumference. Near the proximal end of the cap 3 and at the center of the feed pipe 1, an exhaust pipe 6 extending to communicate with a vacuum pump opens into the space 5. Further, an oscillator 7 is attached to the feed pipe 1 at a position close to the cap 3.

To place mortar using this method, for example, as shown in FIG. Cap 3 shown
Install a pouring device consisting of, etc. Mortar is force-fed through the feed pipe 1, an oscillator 7 is operated to give vibration to the tip of the feed pipe, and at the same time a vacuum pump is operated to reduce the pressure in the space 5 within the cap 3. The compressed mortar is forced out into the cap interior space 5 through the through hole 2 at the tip of the vibrating feed pipe 1, and is further discharged from the discharge port 4 and placed at a predetermined position. Further, when pouring, it is preferable to continuously pour the discharge port 4 as close as possible to the surface of the mortar that has already been hammered out.

In this pouring method, the shape of the hole can be circular in cross section, polygonal, oval, etc., and the diameter is several mm.
~ several centimeters, and is selected by considering the aggregate diameter of mortar, slump value, etc. For example, in the case of mortar made of sand with a particle size of less than 1.2 mm, a suitable pore size of 7.8 mm was found. By increasing the hole diameter, it is possible to cast mortar using aggregate with a large particle size. The vibration frequency ranges from about 6000 to 14000 vpm. In the embodiment, air bubbles in the mortar were actively removed by attaching an exhaust pipe to the cap and reducing the pressure in the internal space, but it is not necessarily necessary to reduce the pressure.

[Effect]

In this casting method, mortar is squeezed out from a narrow through hole that is subject to vibration, remains in a relatively narrow space inside the cap, and is discharged from a discharge port. The mesh between them separates and resistance to shearing force is lost, resulting in liquefaction and significantly increased fluidity. Therefore, the elimination of air bubbles in the mortar is facilitated, and the mortar can be densely filled without causing defects during pouring, and a cured product with extremely few voids can be produced.

〔Effect of the invention〕

As described above, this casting method significantly reduces the voids in the cast mortar and has the effect of developing high strength. In addition, it is highly practical because it can be constructed by simply attaching a simple device to the conventional pumping method.

[Brief explanation of the drawing]

1 and 2 are sectional views of the tip of the feed pipe used in this casting method, and FIG. 3 is a partial cross-sectional view showing the state of construction by this casting method. 1...Feeding pipe, 2...Through hole, 3...Cap,
4...Discharge port, 5...Space, 6...Exhaust pipe,
7... Oscillator, 8... Concrete pump truck.

Claims (1)

[Claims] 1 A cement composition obtained by adding and kneading water to cement, aggregate, etc. is pumped through a feed pipe, and a cap having a large number of through holes at the tip of the feed pipe and a discharge port covering the through holes is formed. and applying vibration to the distal end of the feed pipe, the composition is forced out from the through hole into the cap, and further discharged from the discharge port for casting. Method.