JP2006169077A - Cavity-filling grout material using coal ash - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that there is the possibility of generating fine cracks at a filler since bentonite has properties expanding 5-10 times in volume when water is contained and shrinking to its original volume when the bentonite is dried while the bentonite compounded as a grout material is fine particle, which has excellent viscosity and fluidity, which is well bonded to an air gap inner wall, which has water leak preventing effect and which is useful for increasing characteristics as the grout material, and the distinctive use of the grout material is difficult since the cavity is actually invisible though three kinds of conventional grout material of soft-consistency, middle-consistency and stiff-consistency are distinctively used on states of ground and cavity and the grout material has poor durability since the grout material has weak expression strength and the grout material is brittle. <P>SOLUTION: The grout material compounding a fly ash and a surfactant instead of the bentonite is easy to regulate fluidity and the material has excellent separating resistance and large strength and the material copes with from a large cavity to a small cavity and an injection interval can be increased and the material has excellent long term durability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention is a method for blending a grout material used for filling a cavity generated during civil engineering work and improving soft ground.

For filling the cavity, a material which is generally rich in fluidity and hardly causes bleeding, shrinkage, deformation and cracking in the curing process is selected. Therefore, cement, bentonite, aluminum powder, and water are mainly used as the cavity-filled grout material, and there are soft kneading, medium kneading, and solid kneading depending on the blending ratio of the materials, and they are properly used depending on the state of the cavity.

Actually, even if it is limited to a single cavity, the internal volume and shape are different, and there are also a wide variety of loose spots on the ground around the cavity. Further, since the hollow state is not visible, it is very difficult to properly use the soft, medium, and hard grout materials.

Bentonite blended as a grout material is a very fine clay mineral and has excellent viscosity and caking properties, so the fluidity of the grout material, adhesion to the inner wall of the void, and the effect of preventing water leakage outside the cavity It helps to improve the properties of grout. However, when bentonite comes into contact with water, water enters the montmorillonite crystal (interlayer), which is the main component of bentonite, and the volume swells 5 to 10 times. When the swollen montmorillonite is dried, it releases water and shrinks to its original volume, so that the filling using bentonite may cause micro cracks after filling.

Patents relating to the production of grout materials include blending of grout materials for the purpose of effective use of fly ash and void filling methods.
Self-hardening void filling material and void filling method

Bentonite is used as a grout material, but bentonite has a high degree of swelling and shrinks when dried, so that it does not have high strength in the air and water, and there is a problem in long-term stability.

When bentonite is used, the caking force is reduced, but it may be mixed with the sediment in the cavity and the earth and sand remaining in the cavity to further reduce the strength and become brittle.

Wastewater containing bentonite at construction sites is difficult to treat because montmorillonite, the main clay mineral of bentonite, has fine particles and is difficult to agglomerate. A part of the grout material may elute before the grout material solidifies, which may affect the surrounding environment.

There are three types of grout materials: soft kneading with different fluidity and viscosity, medium kneading, and solid kneading, which are used properly depending on the ground and hollow conditions, but in fact the hollow is not visible so the grout material can be used properly. I can't.

Add fly ash without using bentonite. Fly ash contains a large amount of glass balloons of several tens of microns, so it has excellent fluidity. The volume does not change.

Since it does not contain bentonite, the volume change is small, the density of the packing is high, and no cracks are generated inside, so the type of expansion material to be blended is not limited.

Since fly ash can be expected to have a pozzolanic reaction, an insoluble and hard calcium-silica compound is formed in the packing, and the strength is further increased.

Since the water absorbed by bentonite is unnecessary, the amount of water added when blending the grout material can be reduced. For this reason, the addition of a surfactant can be adjusted to soft kneading, medium kneading or solid kneading.

A grout material using fly ash is characterized by being easy to adapt to water, rich in viscosity, almost no volume reduction, little freezing, and high strength.

By using a surfactant, it is possible to mix a grout material excellent in fluidity and separation resistance, and it is possible to deal with a large gap to a small gap, and to take a large injection interval.

Since it hardens in a stable form after the injection, it is possible to construct a structure having a long-term stability without affecting the surroundings.

It is superior in fluidity and strength compared to the “air pack method” used in tunnel lining work.

It can also be used for Xiamen repair and abutment repair work.

Fly ash, cement, surfactant as a thickener, and expansion material are blended, added and mixed in the same way as conventional grout materials, but fly ash / cement is in the range of 0.5-20. The cement / water is in the range of 0.5 to 1.5. A thickener is used by adjusting a surfactant (cation / anion). In addition, the kind of expansion material is not ask | required.

試験結果

The following table shows the results of a quality test using a conventional medium-kneaded grout material and the grout material of the present invention. The invention product has high strength and is rich in fluidity. In addition, it is thought that the expansion coefficient after solidification does not change because the density inside the grout material is large.

Mixing ratio of materials

Test results

In civil engineering work, it is considered to be widely used in the field of construction and civil engineering such as filling of cavities generated during foundation work, improvement of soft ground, tunnel lining work, Xiamen repair, and abutment repair work.

Claims (4)

Cavity-filled grout material using cement, fly ash, foam, and surfactant. A method of adjusting the viscosity of grout using a surfactant (anion, cation). A grout material containing a fly ash / cement mixture ratio in the range of 0.5 to 2.0. A grout material containing a cement / water mixture ratio in the range of 0.5 to 1.5.