JPS6141949B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a grout material for filling cavities such as abandoned tunnels in coal mines, backfilling in shield construction methods, and abandoned buried pipes. Originally, this type of grout material had three characteristics: (i) the gel time could be adjusted freely according to the site conditions, (ii) it had good fluidity during injection, and (iii) it had a hardening time after injection. (iv) It is desired that the amount of breathing be small. Existing grouting materials for cavity filling include bentonite mortar made of cement, bentonite, sand and water, and bacillus mortar made of alumina, lime, gypsum, sand and water, but these do not have sufficient performance and are not economical. It cannot be said that it is good from a sexual point of view. The inventors of the present invention sought to develop a grout material for filling cavities that would eliminate the drawbacks of conventional grout materials and satisfy the above requirements, and as a result of conducting various studies, they found that water can be used as a grout material for filling cavities. slag,
Ultra-fast hardening cement (hereinafter referred to as
We have found that it is preferable to simply use a mixture of ``ultra-fast hardening cement whose main component is calcium haloaluminate'' or ``ultra-fast hardening cement.'' Next, we will explain the experimental results. Pozzolanic substances used in the experiment The chemical compositions of water slag and flyash are as follows.

[Table] Jet cement (trade name) manufactured by Onoda Suzaku Cement was used as an ultra-fast hardening cement whose main component is calcium haloaluminate. The chemical and mineral composition of jet cement is as follows.

[Table] The above pozzolanic substances and ultra-fast hardening cement were mixed in the proportions shown in Table 3, water was added and kneaded, and the breathing rate (%) of the hardened product was measured. The results are shown in Table 3. I got it. For comparison, Table 3 also shows the case where ordinary Portland cement was used instead of jet cement, and the case where only water lag and fly ash were used. The breathing rate (%) was measured using the Japan Society of Civil Engineers test method.

[Table] Next, experiment numbers 1, 2, 3, 4 and 6 in Table 3
The viscosity of the grout material was measured by the J-Roth method, and the results shown in Table 4 were obtained.

[Table] Table 5 shows the unconfined compressive strength of the grout materials after hardening in Experiment Nos. 1, 2, 3, 4, 5, and 6.

[Table] As is clear from the above experiment, a specific amount of water is added to a grout material in which 5 to 8 parts by weight of ultra-fast hardening cement containing calcium haloaluminate as the main component is added to 100 parts by weight of pozzolan powder. When kneaded, it maintains fluidity for up to 2 hours, exhibits little breathing, and hardens over time. The present invention is based on these findings, and is a cavity-filling grout material comprising 100 parts by weight of a bozolan substance and 5 to 8 parts by weight of an ultra-fast hardening cement containing calcium haloaluminate as a main component. In the present invention, powders such as water slag, flyash, etc. are used as the pozzolanic substance, and as the ultra-fast hardening cement, an ultra-fast hardening cement containing 5 to 60% by weight, preferably 15 to 30% by weight of calcium haloaluminate is used. is desirable. If necessary, add 30% by weight of sand to the pozzolanic material.
It is also possible to use the following instead. In addition, in use, 40 to 90 parts by weight of water, preferably 40 to 90 parts by weight, per 100 parts by weight of the pozzolan substance in the grout material.
It is added in a proportion of 40 to 70 parts by weight and kneaded before use. By using the grouting material of the present invention, not only can cavities be filled with one-liquid, one-step injection, but also the slurry can be sent to a filling object located at a long distance by means such as pumping. Furthermore, since breathing hardly occurs in the filled cavities, there is no need to secondarily fill the cavities with slurry. Next, an example in which the present invention is used for filling an abandoned mine tunnel will be described. A mixture of 100 parts by weight of fly ash and 5 parts by weight of the same jet cement (trade name of Onoda Cement Co., Ltd.) used in the experiment was mixed with 67 parts by weight of water, and this slurry was pumped 2 km. When the slurry was filled into an abandoned mine shaft, the slurry was completely introduced and solidified after 20 minutes, and the unconfined compressive strength of the solidified product after 3 days was 5 kg/cm ² . For comparison, instead of 5 parts by weight of jet cement, 5 parts by weight of Portland cement was mixed with 100 parts by weight of fly ash and 67 parts by weight of mixed water, and a slurry was mixed and pumped 2 km in the same manner as above to fill and solidify. , Due to excessive breathing, it was necessary to perform secondary injection of slurry to fill the cavities.

Claims (1)

[Claims] 1. Grout material for filling cavities consisting of 100 parts by weight of water slag or fly ash and 5 to 8 parts by weight of ultra-fast hardening cement containing calcium haloaluminate as a main component and calcium silicate, etc.