JPH1164329A - Method for estimating content of cement in mud sand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate a content of cement before being solidified, by adding water to a cement-containing mud sand wherein the cement is mixed with a mud sand of a known ratio of sand and water while the amount of the cement is changed, measuring a volume amount of a resulting supernatant, obtaining a change of the content of the cement, and comparing the volume amount with a volume amount of the supernatant of the cement-containing mud sand of an unknown amount. SOLUTION: Water is forcibly added to a cement-containing mud sand before solidified which is a mixture composed of sand, water and cement generally in a stable state, whereby a material separation is brought about. A volume amount of a supernatant generated by the material separation is measured. A change of the volume amount of the supernatant to a change of the amount of cement is obtained beforehand as a relationship between the change of the amount of cement and change of the volume amount of the supernatant. The volume amount of the supernatant generated from a mud sand actually collected at the spot is applied to the relationship, whereby a content of cement of the mud sand is estimated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating a cement content of a cement-containing mud before consolidation.

[0002]

2. Description of the Related Art As a method for estimating the cement content of consolidated cement-containing mud, a method of quantifying calcium oxide by chemical analysis of Portland cement (JIS R) is known.
5202-1989) are known. As a method for estimating the cement content of the cement-containing mud before consolidation, a quantitative test method for cement and lime using a calcium ion-selective electrode (Japan Road Association: Pavement Test Handbook, p.216 to p.220) is known. I have. Furthermore, the Japan Highway Public Corporation Standard (KODAN207) for a cement stabilization mixture which is a part of road pavement is known.

[0003]

The above-mentioned conventional method for estimating the cement content of mud has the following problems. <A> In the method of quantifying calcium oxide by the chemical analysis method of Portland cement, since the mud after consolidation is a measurement target, it is not possible to measure the mud before consolidation. <B> According to the quantitative test method of cement and lime using the calcium ion selective electrode and the KODAN method, the target cement content is gravel, sand, a part of road pavement, cement stable mixed with cement and a small amount of water. Because it is a treated mixture, it can be confirmed whether or not it contains cement, but because it exceeds the permissible range of measurement, it was difficult to use it for a liquefied mixture of soil, water, and cement like cement-containing mud. .

[0004] The present invention has been made to solve the above problems, and an object of the present invention is to make it possible to estimate the cement content even before cement setting.
It is to provide a method for estimating the cement content of mud.

[0005]

According to the present invention, there is provided a method for estimating the cement content of cement-containing mud before consolidation, wherein only the amount of cement is changed to mud having a predetermined soil and water content. Water is added to the mixed plural types of cement-containing mud, the volume of supernatant water generated in each is measured, the change in cement content is determined, and an unknown amount of cement is mixed with the mud having the same composition as the mud. Precipitate by adding water to the contained mud, measure the volume of supernatant water generated according to the cement content, and apply the volume value of the supernatant water to the change in cement content by the volume measurement of the supernatant water. ,
A method for estimating the cement content of mud, comprising estimating the cement content of mud. The present invention also provides
In the above-described method for estimating the cement content of mud, the volume ratio of cement-containing mud and water before consolidation is based on volume,
It is a method for estimating the cement content of mud, which is 20 to 80 parts and 20 to 80 parts, respectively. Further, the present invention provides the method for estimating the cement content of mud as described above, wherein the cement content of the cement-containing mud before consolidation to be measured is 50 kg to 8 kg / m ^{3 of} cement-containing mud.
It is a method for estimating the cement content of mud, which is characterized by being 00 kg.

[0006]

First Embodiment A method for estimating the cement content of mud according to the present invention will be described below with reference to the drawings.
The method for estimating the cement content of mud according to the present invention includes a method of reusing cement-containing mud, which is surplus mud generated due to soil improvement work, as muddy water for fluidization treatment, etc. It is necessary to estimate the amount of cement to be used, and this is a method for performing this quickly and easily.

<A> Estimation Principle The estimation of the cement content of the mud according to the present invention is carried out by forcibly adding the cement-containing mud, which is a mixture of soil, water and cement, which is normally in a stable state, before consolidation. Water is added to cause material separation, and the volume of the supernatant water generated by the material separation is measured, and the change in the volume of the supernatant water with respect to the change in the amount of cement in advance is, for example, the change in the amount of cement and the volume of the supernatant water. The volume of the supernatant water generated from the mud actually collected at the site is applied to this by making a relational chart showing the change in the amount. Hereinafter, a specific estimation principle will be described. Here, as an example of the constituent components of the cement-containing mud to be estimated, the specific gravity of the soil (in the case of soil, the density) is
2.38 to 2.78 g / cm ³ [published by the Japan Geotechnical Society,
Method and explanation of soil test, p. 46, Table-2.1.2],
The specific gravity of water is 1.0 g / cm ³ (liquid), and the specific gravity of cement (blast furnace cement B) is 3.04 g / cm.
³ [Corporation of Cement Association, common sense of cement '89,
p. 28, 29 below], and each has a different specific gravity.

Therefore, even if the stability is maintained immediately after mixing,
As the time elapses, the specific gravity is low, and the liquid water tends to separate and rise. On the contrary, soil and cement, which are other components, settle down due to specific gravity, so that a phenomenon in which the amount of water in the upper portion increases and a breathing phenomenon occur. There are various factors in the mechanism of soil and cement sedimentation at this time, but in principle, it is due to the difference in specific gravity with water.
Then, for the cement-containing mud in which the composition of the soil and the cement water content is known in advance, the breathing rate after the water addition can be measured by changing the cement amount and measuring the volume of the supernatant water after the water addition. It is possible to estimate the cement content of the cement-containing mud, which is the estimation target, by plotting this numerical value as a relation diagram showing the change in the cement amount and the change in the volume of the supernatant water. At this time, the target soil and the water content included in the cement-containing mud to be estimated are known in advance, and the volume of the supernatant water is calculated by adding a different amount of cement to the mud having the same specific gravity and water content as the target soil. Based on the graph of the measured amount, the amount of cement in the cement-containing mud to be estimated can be estimated. In the present invention, in particular, the cement content is 50 to 800 k / m ³ in the cement containing mud.
g, which is suitable for estimating the cement content of a cement-containing mud having a small sedimentation amount and a small supernatant water capacity.

<B> Target mud According to the method for estimating the cement content of the present invention, the cement-containing mud before consolidation to be measured is a mixture liquefied by mixing earth and sand, water, and cement. However, construction sludge which solidifies when left to stand is preferred.

<C> Volume ratio If the volume ratio of the cement-containing mud before consolidation and water is 20 to 80 parts and 20 to 80 parts by volume, respectively, sedimentation occurs in the cement-containing mud before consolidation, It is possible to measure the amount of supernatant water generated by causing a breathing phenomenon. At this time, the volume standard of the cement-containing mud and water is:
It is preferable to use 25 to 75 parts and 25 to 75 parts in the above range. The reason that the volume basis of the cement-containing mud and water is limited to the above range is that if the volume ratio of the cement-containing mud before consolidation, the water deviates from the upper limit or the lower limit of the above range, the volume value of the supernatant water is small or This is because the reliability of the measured value of the supernatant water becomes too low, and the estimation effect cannot be exhibited.

[0011]

EXAMPLE 1 Cement-containing mud composed of marine clay (water content: 181.8%), water, and blast furnace cement, as shown in FIG. To obtain the mud samples (No. 1 to No. 5). Next, the mixture ratio of each sample of cement-containing mud and water was set to [50 parts by volume, 50 parts by volume] and [33 parts by volume, 67 parts by volume] on a volume basis.
m ³ , put into a measuring cylinder container, and left for 3 hours. The volume of supernatant water generated by precipitation of each sample was measured. FIG. 2 shows the measurement results. In addition, cement-containing mud 1m
Change in blast furnace cement content per ³ and mixture 100
FIG. 3 is a relational diagram showing a change in the volume of the supernatant water after standing for 3 hours in 0 m ³ . As shown in FIG. 3, an increase in the volume of the supernatant water was observed due to an increase in the cement content in the cement-containing mud. In addition, even with the same cement content, a difference in the volume of the supernatant water was confirmed due to the difference in the mixing ratio of the cement-containing mud and the water, and it was confirmed that the volume of the supernatant water was larger as the mixing ratio of the water was larger.

[0012]

Example 2 In Example 2, standard sand and dry clay were used, and the mixing ratio of standard sand and dry clay was [50 parts by weight, 50 parts by weight] and [25 parts by weight,
75 parts by weight], and three kinds of sample soils used for producing a cement-containing mud are composed of two kinds of mixed ratio soils and one kind of dry clay. Next, water was mixed with the three types of sample soil so that the water content was 75, 100, and 125%, respectively.
Construct 9 types of cement-free sample soils. Subsequently, the blast furnace cement content was small (150 kg), medium (300 kg), and large (450 kg) per 1 m ^{3 of the} cement-containing mud in the nine types of cement-free sample soils described above.
kg), and the blast furnace cement and water for adjustment are mixed to form 27 types of cement-containing mud shown in FIG. Note that the above cement content in the present embodiment is an example, and it is a matter of course that the estimation range is further widened by finely dividing the content.

Then, using the various types of cement-containing mud constructed as described above, 1000 cm ^{3 of} water was added so that the mixing ratio of cement-containing mud and water was [33 parts by volume, 67 parts by volume], respectively, on a volume basis. Is charged into a measuring cylinder container. Then, after the mixture was allowed to stand for about 3 hours, the volume of the supernatant water generated by the precipitation of the constituent materials was measured, and the measured value as shown in FIG. 4 was obtained. FIG. 5 is a relationship diagram showing a change in the blast furnace cement content per 1 m ^{3 of the} cement-containing mud and a change in the volume of the supernatant water after standing for 3 hours in 1000 m ^{3 of the} mixture. As shown in FIG. 5, an increase in the volume of the supernatant water was observed due to an increase in the cement content in the cement-containing mud. Also, even with the same cement content, the difference in the volume of supernatant water was confirmed due to the difference in the mixing ratio of standard sand and dry clay in the cement-containing mud and the amount of water, and the larger the mixing ratio of the standard sand, the larger the water volume. It can be seen that the volume of clear water increases.

[0014]

As described above, the present invention has the following effects. <a> An accurate cement content can be estimated for mud before consolidation. <B> Since the mixing ratio of soil, water and cement before consolidation is known, the strength after consolidation can be estimated. <C> The cement-containing mud as a consolidation material can be used for applications corresponding to required strength.

[Brief description of the drawings]

FIG. 1 is a table showing a weight mixing ratio of a sample soil for estimating a cement content.

FIG. 2 is a table showing changes in the volume of supernatant water in Example 1.

FIG. 3 is a relationship diagram 1 showing a change in cement content and a change in volume of supernatant water.

FIG. 4 is a table showing changes in the volume of supernatant water due to an increase in cement content.

FIG. 5 is a relationship diagram 2 showing a change in cement content and a change in volume of supernatant water.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Noriyuki Mori 1 Asahi, Oaza, Tsukuba, Ibaraki Pref. Public Works Research Institute, Ministry of Construction (72) Inventor Goro Kuno 4-2-1, Otsuka 15 Bunkyo-ku, Tokyo Jotaro Iwabuchi 1-34-34 Konan, Minato-ku, Tokyo Tokyo Nissan Port Building Central Technology Research Institute, Japan Construction Management Association (72) Inventor Masao Sekiguchi 1-34-34 Konan, Minato-ku, Tokyo Minato Building Inside the Central Technical Research Institute, Japan Construction Management Association

Claims (3)

[Claims] 1. A method for estimating a cement content in a cement-containing mud before consolidation, comprising a method of estimating a cement content of a mud having a soil component and a water content ratio which are previously determined by changing only the cement amount. Water is added to the mud, the volume of the supernatant water generated in each is measured, the change in the cement content is determined, and the mud of the same composition as the mud is mixed with an unknown amount of cement and added to the cement-containing mud to precipitate. The volume of the supernatant water generated according to the cement content is measured, and the volume value of the supernatant water is applied to the change in the cement content by the volume measurement of the supernatant water to determine the cement content of the mud. A method for estimating the cement content of mud, characterized by estimating. 2. The method for estimating the cement content of mud according to claim 1, wherein the volume ratio between the cement-containing mud before consolidation and water is 20 to 80 parts and 20 parts by volume, respectively.
A method for estimating the cement content of mud, characterized in that the amount is up to 80 parts. 3. The method for estimating the cement content of mud according to claim 1, wherein the cement content of the cement-containing mud before consolidation to be measured is 50 kg to 800 kg per 1 m ^{3 of} cement-containing mud. A method for estimating the cement content of mud.