• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.53-59
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• 2012

In this study, strength and durability of a geo-polymer grout material(HIT) was investigated through unconfined compression strength tests(UCS)), scanning electron microscope(SEM), elution tests, and surface observations. UCS tests showed high initial strength and rapid continuous strength increments when compared to labile wasser glass(LW) and space grouting rocket system (SGR) grout materials, which showed strength reduction after 28 days. The higher strength was also reflected in SEM results which showed calcium silicate hydroxide(C-S-H) gels of the dense hydrate range, indicating higher strength and durability. Additionally, elution tests and grout surface observations showed HIT was in good condition and the decrease in weight was minor when under water for six months. LW and SGR showed the grout surface to be constricted and lower durability due to higher weight increase. These results and observations show HIT to be better suited for coastal structural applications than LW and SGR in long terms of strength and durability.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.73-81
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• 2002

Nowadays , the grouted-reinforcing method, which is called FRP(Fiberglass-reinforced-plastic) pipe .reinforcing method, has been introduced in the community of pound reinforcements. The resistance to corrosion and chemical attack high strength to weight ratio, and ease of handling make these pipes a better alternative to steels in tunnel. However, to fully utilize FRP pipes as grouted reinforcing members at the face and the crown in tunnel, their mechanical properties and behaviors and the grout-reinforced underground have to be verified. Laboratory shear tests were conducted to evaluate the mechanical properties for FRP pipes, the grout-reinforced members and the grout-reinforced body of FRP pipes. According to the test results, it was observed that FRP pipes play a dominant role in shearing behavior of the grout-reinforced members and that their shearing resistance exerts after the shearing displacement increases to some extent.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.61-65
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• 2008

In this study, a newly modified soil nailing technology named as the PGSN (Pressurized Grouting Soil Nailing) system is proposed. Effects of various factors related to the design of the pressurized grouting soil nailing system, such as the length of re-bars and type of reinforcement materials, were examined throughout a series of the displacement-controlled field pull-out tests. 9 displacement-controlled field pull-out tests were performed and the ratio of injected grout volume to grout hole volume were also evaluated based on the measurements. In addition, short-term characteristics of pull-out deformations of the newly proposed PGSN system were analyzed and compared with those of the ordinary soil nailing system by carrying out field pull-out tests. The test results were shown that the displacements of pressurized grouting soil nailing system were decreased 30~36% in comparison with using gravity grouting soil nailing system by the pressurized effect. The displacements of steel tube were diminished 31~32% comparison with using deformed bar by the reinforcement type change from the field pull-out tests.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.989-1002
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• 2018

Grouting for the rock joint is to strengthen the rock strata by infiltrating cement grout materials into the rock joints. Grouting is one of a field of study which is difficult to develop deterministic and quantitative design approach because of multiphase behaviors of grout materials and 3 dimensional features of rock joints. Therefore, GIN (Grouting Intensity Number) can be a good index with appropriate monitoring of pressure and volume of grout. In this paper, we investigate the effects of joint roughness (JRC) and rheology of cement material during the infiltration of cement grout material into rock joint through CFD (computational fluid dynamics) analyses. With rough joint surface and increase of WC ratio, the frictional resistance during the grouting increases. The results have been summarized with polynomial correlations.

• Journal of the Korean GEO-environmental Society
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• v.20 no.8
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• pp.13-20
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• 2019

In order to ground reinforcement, the chemical grouting, the anchor, the soil nailing system, the micropile, etc. can be mentioned by the methods widely used in domestic. The above ground reinforcement methods are developed by various methods depending on the type of reinforcement, installation method, presence of prestress, grouting method, etc. However, in common, the strength of reinforcement, the friction force of grout and reinforcement and the friction force of grout and ground are the main design variables. Therefore, the optimized ground reinforcement is a material with a high tensile strength of the reinforcement itself, the friction force between the reinforcement and the grout is high, and the application of an optimal grouting method is necessary to improve the friction force between the grout and the ground. In this study, a total of 20 model tests were conducted to analyze the reinforcement effects according to the shape of the reinforcement and the grouting method. As a result of the test, As a result of the experiment, it is judged that the reinforcing effect is superior to the perforated + wing type reinforcement and post grouting method.

• Resources Recycling
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• v.27 no.6
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• pp.30-37
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• 2018

A series of experiment was conducted to evaluate basic performances of low-pH, anti-washing grouts incorporating gypsum which applied for reinforcing underwater cavities in limestone- grounds. Various types of mix proportions were designed and the fluidity, strength and environmental impact of these mixtures were evaluated. The flowability was evaluated under two conditions, i.e., flows without and with pressing, respectively. Strength was measured for the hardened mixtures fabricated under conditions of air and water injections. The environmental impacts including the pH of the suspension and the suspended solids concentration for the mixtures were evaluated. The low pH of fresh mixture suspension, below than 10, was achieved by incorporation of gypsum. The mix proportions of cement-quartz powder-gypsum binders and chemical agents resulted in mortar natural flow 7-10 cm and uniaxial compressive strength 4 MPa were derived.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.169-176
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• 2023

This study aims to develop a thermally conductive backfill by applying the prepacked concrete concept, in which a coarse aggregate with relatively high thermal conductivity was first filled and then the voild filled with grout. Backfill with improved thermal conductivity can increase the heat exchange efficiency of underground heat exchangers or underground transmission facilities. The backfills was prepared by using crushed concrete as the coarse aggregate, fly ash-based grout, and a small amount of cement for solidification. The results of this study showed that the fly ash-cement-sand-based grout with a flow of at least 450 mm accor ding to ASTM D 6103 could fill the void of pr epactked coar se aggr egates with a maximum size of 25 mm. The thermal conductivity of the backfil with coarse aggregate was over 1.7 W/m·K, which was higher than that of grout-type backfills.

• Resources Recycling
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• v.33 no.1
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• pp.37-47
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• 2024

In grouting, the LW method is commonly employed to induce the gelation of cementitious material using water glass, thereby restricting the extent of material injection. Nevertheless, challenges manifest when materials are lost before gelation, particularly in regions with high groundwater flow rates or significant subsurface voids. This study developed a thixotropic grout material using LFS and GGBFS to mitigate material loss during injection, with an assessment of its flow characteristics, durability in marine exposure, strength, and injection properties. The outcomes revealed that the thixotropic grout material exhibited flow ranging from 105 to 143 mm and enhanced strength and durability compared to the LW method. Furthermore, field tests substantiated that applying vibration and impact improved impermeability.

• Journal of the Korean Geotechnical Society
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• v.15 no.1
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• pp.63-78
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• 1999

For the design of compression anchor, three things should be considered. The first is a resistance force by skin friction, the second is a tension strength of tendon, and the third is a compressive strength of grout. Especially, compressive strength of grout is the most important design parameter of compression anchor. When compression anchor is pulled out from the ground, the compressive strength of grout increases by confining pressure of ground($\sigma_{tg$). Here, $\sigma_{tg$ is the confining pressure which is produced by earth pressure at rest and by lateral expansion of grout. We call this phenomenon of increase of confining pressure "poisson effect". In this paper, the design method of compression anchor called SSC anchor and the computer program for the design are developed through compression tests of anchor body grout.ody grout.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3723-3728
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• 2011

This study investigated the friction behaviors of rock and grout through the small /large scale laboratory experiments. The small-scale laboratory tests were undertaken using a specially designed and fabricated equipments to simulate the contact surface of rock. In calibration chamber test, a artificial rock mass was prepared in soil container to measure the tensile resistance of grout. Test condition includes the grouting method of pressure involvement. The results of the tests show that the pressure grouting increases the frictional resistance significantly.