JPS59169966A - Reinforced ballast mixed with convertor slag dust to blast furnace water granulated slag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reinforced roadbed material using collected dust gold generated in converter slag crushing equipment as a lucidic stimulant.

Blast furnace granulation is made by quenching molten slag with water and granulating it, and if irritants such as alkaline substances are present, it will cause a water use reaction.
It has a latent hydraulic property that hardens.

The latent hydraulic properties of blast furnace granulated water are promoted even when converter slag is used as an alkaline stimulant, and a sub-base course material made by adding and mixing converter slag crushed stone to blast furnace granulated water has already been proposed in Japanese Patent Application Laid-Open No. 52-14283.
It is disclosed in Publication No. 2.

However, this method uses crushed converter slag that has been mechanically crushed and screened to have approximately the same particle size as granulated blast furnace slag, resulting in the following problems.

■The manufacturing cost of converter slag crushed stone is high.

■Due to the low strength of the mixed material, its use in roadbed materials is limited to lower layer roadbed materials.

In order to compensate for the above-mentioned drawbacks, the present invention uses all of the converter slag dust collected during the production of converter slag crushed stone as an alkaline stimulant for blast furnace granulation, thereby producing a high-strength roadbed material with high added value at a low price. The purpose is to manufacture.

The present invention is a reinforced roadbed material in which 10 to 60% (absolute dry weight ratio) of collected dust generated in converter slag crushing equipment is added and mixed with blast furnace slag, and more preferably the water content is adjusted to an optimum level. This is a composite material that has been adjusted to a ratio close to that of

When converter slag comes into contact with water, all calcium ions are leached out, and the blast furnace slag is stimulated by this and hardens.

In order to improve the water utilization reaction of blast furnace granules, the blast furnace granules and converter slag should be finely pulverized and mixed sufficiently to increase the specific surface area, but in this case, not only will the pulverization cost increase, but the reaction will be reduced. Since it is quick, there is a problem that it hardens during storage.

The present invention is characterized in that the latent hydraulic properties of the granulated blast furnace slag are promoted and the adhesive sound is increased by completely adding and mixing converter slag collection dust consisting of fine particles to the normal granulated blast furnace slag.

Blast furnace slag used in the present invention is a sand-like glassy substance obtained by rapidly cooling molten slag produced when producing pig iron from a blast furnace with high-pressure water, and is mainly used as a raw material for cement and fine aggregate for concrete. has been done. Tables 1 and 2 show the chemical components and particle sizes of the blast furnace granules used in the examples.

On the other hand, the collected dust from converter slag is collected dust generated from the dry type dust collector of converter slag crushing equipment, and the particle size is small and dry as shown in Table 3.

Chemical composition "F!": Shown in Table 4. It can be seen from this that the chemical composition of the collected converter dust is characterized by a higher content of CaO and At203 and a lower content of FeO compared to the crushed converter slag.

Since the present invention uses dried converter slag collection dust as the alkaline stimulant for blast furnace granulation, if it is mixed with a bulldozer or the like, environmental pollution will occur due to head formation.

However, mixing must be done in a mixing facility by adding water to make it moist. In the examples that were mixed using our mixing equipment, little dust was generated and the water retention capacity was high after it was hydrated, so no phenomenon of drying and head formation was observed in the natural state.

In the present invention, the reason why the vJΣ addition of the converter slag collected dust was limited to 10 to 60 in absolute dry weight ratio was determined from the unconfined compressive strength and workability in the examples.

In FIG. 1, the unconfined compressive strength shows a maximum at a mixing ratio i-i' of 20%, and suddenly decreases when it exceeds 60%.

If the mixing ratio exceeds 60 cm, the fine particles will increase and the workability will decrease, so the addition ratio should be adjusted to 10 to 10 cm (bone dry weight ratio).
It was limited to 60%.

Next, embodiments of the present invention will be described.

Examples include a conventional method in which crushed blast furnace slag is added to and mixed with granulated blast furnace slag, and a method in which converter slag dust is mixed in granulated blast furnace slag from the same lot. A comparative test was conducted on the method of the present invention.

The chemical composition and particle size distribution of the blast furnace granulated water used are shown in Tables 1 and 2.

Table 1: Chemical composition list of granulated blast furnace granules) Table 2: Particle size of granulated blast furnace granules (chi) (ability to pass through each sieve v
Table 3 and Table 4 show the chemical composition and particle size distribution of crushed stone and converter slag dust. The mixing ratio of the furnace slag was varied at a pitch of 20% by absolute dry weight relative to the crushed blast furnace slag for both the crushed converter slag stone and the converter slag dust.

The unconfined compressive strength test is asphalt pavement enthusiast edition appendix 4-8 (
After compacting each mixed material with visible particle size at the optimum water content ratio according to the uniaxial compression test for cement stabilization treatment, it was taken out of the mold and coated with Tsukurafudun.It was cured in a constant temperature room at 20℃ for a period of 2p>r. did.

The test results are shown in FIGS. 1 and 2.

Figure 1 shows the effect of the mixing ratio of converter slag on the unconfined compressive strength, based on the results of all materials aged 28 days. Figure 2 shows the relationship between curing material age and unconfined compressive strength for materials with a converter slag mixing ratio of 20%.

The strength of the material mixed with converter slag dust is clearly greater than that of crushed stone from converter slag.

Table 5 shows the modified CBR of the fully mixed material of converter slag dust.
(Indicator showing strength characteristics of roadbed material) Test results are shown.

The test method was based on KODAN 205 (CBR test method for cement stabilization mixtures by the public corporation), and the corrected CBR at a compaction degree of 95 degrees was determined. The test materials were cured indoors for 5 days and then immersed in water at 20°C for 4 days.

Table 5 Modified CBR Test Results As mentioned above, the present invention is a high-strength binder that uses converter slag dust as an alkaline stimulant for blast furnace granulation. The structure becomes thinner, making economical road construction possible, and it can also be advantageously used as a civil engineering material, including the following uses.

■ Ground improvement material ■　Slope preservation material ■ Materials for simple drains cast on site

[Brief explanation of drawings]

Figure 1 shows the relationship between the amount of converter slag added (absolute dry weight ratio) and -axial compressive strength for blast furnace granulation, and Figure 2 shows the relationship between the amount of converter slag added (bone dry weight ratio) and -axial compressive strength. FIG. 3 is a diagram showing the relationship between material age and unconfined compressive strength for mixed materials, both of which show test results for the method of the present invention and the conventional method. Kishi 1) Correct U, ・ 1-・-1-1 Koni L--nino Fig. 1 Sup Su Utsu 3 & 6 K (%) Fig. 2 Oju Cold (Japanese)

Claims (1)

[Claims] A reinforced roadbed material made by adding 10 to 60% by bone dry weight of collected dust generated in converter slag crushing equipment to blast furnace granulation.