JPS59102477A - Spraying method of mortar - Google Patents

Abstract

PURPOSE:To enable installation of a force feeder for mortar in the position substantially apart from working face by feeding forcibly the mortar contg. foam, mixing an accelerator therewith in a spraying position to annihilate the foam and spraying the mortar. CONSTITUTION:Mortar prepd. at a small ratio between water and cement is weighed from a batcher 11 in the position substantially apart from working face in the state of spraying the mortar in the construction of tunnel or the like. Aggregate and a foaming agent are put into this mortar and the mixture is kneaded in a mixer 3 and is forcibly fed by a hopper 2 and a pump 1 into a transport pipe 4. The force feeding is thus easily accomplished. An accelerator, etc. are supplied and mixed to and with the motar in the spraying position from a mixer 5 and the boom 7 of a sprayer 6 is operated to annihilate the foam and to spray the mortar from a hose 4' through a nozzle 8 and a rotary nozzle 9 to a rock wall 10. An excavation operation is thus carried out without bringing any surplus apparatus to the front of the working face.

Description

[Detailed Description of the Invention] Recently, in tunnel construction, etc., mortar is sprayed instead of shoring, and excavation is carried out as a secondary lining.

In the case of this work, since jumbo machines, pick-up machines, etc. come in and out near the face, the mortar mixer and pressure feeding equipment for spraying work were carried out at least 100 meters away from the face if possible. A large cement ratio would make it easier to pump, but since the mortar was soft, it would drip when sprayed, making it impossible to pump it over long distances. This invention solves the above-mentioned difficulties by setting the spraying mortar mixing plant away from the face, allowing the spraying work to be carried out easily, and at the same time,
This is to allow tunnel excavation work to proceed smoothly without bringing unnecessary equipment in front of the face. To explain this with a diagram, for example, we measure mortar with a small water/cement ratio from batcher 11, add aggregate such as sand, add foaming agent to it, mix it with mixer 3, make it into foaming mortar, hopper 2, pump 1. If it is pumped through pipe 4, even if the water/cement ratio is small, the fluidity is good due to the presence of air bubbles, so mortar with a large QW that would cause blockage in pipe 4 when there are no air bubbles can be pumped through mixer 5. A quick setting agent and the like are mixed and sprayed onto the rock wall 1o from a hose 4' through a nozzle 8 or a rotary nozzle 9 by operating the spraying material 6 boom 7. At this time, the air bubbles are collapsed by the mechanical impact of the spraying, so that a sprayed wall with good consolidation properties can be obtained. When a rotary nozzle is used, the mortar is subjected to friction and impact on the blade surface within the rotary nozzle, which further reduces the number of air bubbles and improves the adhesion of the mortar to the rock wall. Figure 2 shows a batcher 11' in which mortar with relatively small QW and good fluidity is measured and sent out through pump 1, or air bubbles are added to it to add fluidity and the mortar is pumped through pipe 4 into a mixer. 5, and a separate powder cement or a powder additive is added to the cement, mixed with the mortar in the mixer 5, the QW is increased, and the powder is sprayed onto the rock wall 10 through the nozzle 8 or the rotary nozzle 9. In this case, the powder mortar is transferred to the cement tank 12 by the compressor 13.
If compressed air is put in and the powder is pumped from valve 14 through pipe 15, the powder has good pumping properties and can send several hundred pieces, so the mortar pump can be placed at a sufficient distance from the face.

[Brief explanation of the drawing]

Figures 1 and 2 are side schematic diagrams 1 and mortar pump 2 of the present invention. Hopper 4.4 Transport pipe 5, mixer
6. Spraying device7. boom

Claims (1)

[Scope of Claims] 1) A mortar spraying method characterized in that mortar containing air bubbles is pumped through a transport pipe using a mortar pump, and a quick-setting agent is mixed in at the spraying location and sprayed. 2. Claims 1) A mortar spraying method according to IIC, characterized in that a rotary is used at the spraying end to extinguish air bubbles before spraying. 3) Transparent mortar or mortar containing air bubbles is sent through the transport pipe using a mortar pump, and at the same time, powder cement and quick-setting agent are separately pumped through the transport pipe in a dry manner, mixed at the spraying location, and then sprayed. A mortar spraying method characterized by attaching.