• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.2
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• pp.67-73
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• 2015

This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.135-140
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• 2017

As an elementary investigation to develop vegetation concrete with a relatively low pH value, magnesia-phosphate composites (MPC) were examined according to the phosphate types including Monoammonium, Monosodium, Monopotassium, Monocalcium, Diammonium, Disodium, Dipotassium, and Diacalcium phosphates. All of the MPC binders, the ratio of magnesia to phosphate was fixed to be 7:3. MPC mortars activated with Disodium, Dipotassium, and Diacalcium phosphates showed no compressive strength gain, even at age of 28 days. Meanwhile, MPC mortars with Monoammonium and Monosodium phosphates developed 28-day compressive strength of more than 34MPa, and showed a relatively low pH value below 9.8. Hence, Monoammonium and Monosodium phosphates have potentials as an activator for producing MPC-based vegetation concrete.

• KCI Concrete Journal
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• v.14 no.4
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• pp.161-169
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• 2002

The mechanical properties of fiber reinforced porous concrete for use as a planting material were investigated in this study. Changes in physical and mechanical properties, subsequent to the addition of carbon fiber and silica fume, were studied. The effects of recycled aggregate were also evaluated. The applicability as planting work concrete material was also assessed. The results showed that there were no remarkable changes in the void and strength characteristics following the increase in proportion of recycled aggregate. Also, the mixture with 10% silica fume was found to be the most effective for strength enforcement. The highest flexural strength was obtained when the carbon fiber was added with $3\%$. It was also noticed that PAN-derived carbon fiber was superior to Pitch-derived ones in view of strength. The evaluation of its usage for vegetation showed that the growth of plants was directly affected by the existence of covering soil, in case of having the similar size of aggregate and void.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1244-1248
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• 2007

This study aims at investigating the in situ applying grass concrete system in river environments which widely used nowadays and reviewing the effect and flow resistance for grass concrete structure through the physical experiments by hydraulic model test and developing application method in river bed which has rigid flood resistance. Grass concrete structure has been independently tested under high velocity flow under the super critical condition, as well as sud critical flow measuring velocity and water surface elevation along the cross section. This results shows grass concrete system is also suited to use in aggressive river environments such as repairing a flood damaged embankment that had placed at risk the adjacent drainage channel with vegetation.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.779-784
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• 2002

Porous concrete with a great deal of continuous porosity enables to contain water and to pass air freely through firmly hardened material, and allow necessary nutrients to reach roots of vegetation. Therefore, this paper deals with the voluntary properties and efficiency for planting of plant porous concrete. The results of experiment showed that void volumes were 17% to 31%, and compressive strength ranged between 80kgf/cm$^2$ and 180kgf/cm$^2$ when the ratio of the paste to aggregate was 0.3-0.5 When the aggregate size are 20-30mm, the paste to aggregate ratio is 0.3, and the length of Paranial Ryegress came up as 32cm. Ut supra the efficiency of planting goes through Paranial Ryegrass in result the length of plant are in compliance with void volume and aggregate size.

• Journal of Environmental Science International
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• v.14 no.8
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• pp.739-748
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• 2005

The purpose of this study is to analyze seasonal changes in structure and landscape of Gongji stream corridor in Chuncheon, and to suggest some guidelines to contribute to creating a desirable close-to- nature stream. The study seasonally surveyed floodplain and revetment conditions, channel micro-topography, streamflow level and velocity, and vegetational cover. Flooding, water level, and vegetation were major factors of affecting seasonal changes in streambed structure and stream landscape. Small sand bars and islands were considerably disturbed by flooding and water level change. However, large islands and sand bars in the upper and middle section of the study stream remained or reappeared even after flooding. Flooding also tended to repeat channel sedimentation at the same spot. Controlling water volume of the Euiam Lake, which is adjacent to the study stream, caused higher water level downstream in the dry seasons. The majority of vegetation in sand bars and islands was washed away by the floods. Vehicle passing, crop cultivation, and ball game were other elements which disturbed vegetation in the floodplain. Creating a close-to-nature stream should reflect micro-topographical changes of channel by flooding, prevent improper vehicle entry and human use, and remove concrete material in the revetment and floodplain.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.1
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• pp.207-215
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• 2003

Developed is a new environment-friendly concrete-block retaining wall system. The conventional analysis methods are not directly applicable because the proposed concrete-block wall system is made of by interlocking the blocks with shear keys. Therefore, the shear analysis as well as stability analysis have been conducted to secure the safety of block-wall system. Overall slope stability analysis was also performed. An appropriate strengthening method was developed to ensure the safety when the block-wall system is relatively high. The method of analysis for strengthening the concrete-block wall system was also proposed. The proposed environment-friendly concrete block retaining wall system shows reasonable safety and can be a good construction method for retaining walls and river bank walls.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.143-151
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• 2016

Shoreline armoring is a globally used engineering strategy to prevent shoreline erosion along stream, lake and reservoir coastlines. Armoring alters the land-water interface and has the potential to affect shoreline vegetation by changing nearshore geomorphology, hydrology, sediment composition and water quality. We quantified the effects of the artificial disturbances and alternation of the land-water interface on the community structure and distribution of shoreline vegetation in a large reservoir, Uiam Reservoir, Korea. More than 60% of shorelines were disturbed by armoring with retaining wall of concrete block, riprap and gabion in the Uiam Reservoir. The results of detrended correspondence analysis showed that the vegetation structures of the shoreline modified by armoring changed from hydrophyte-dominated to hygrophyte-dominated ecosystems. The shoreline armoring caused the disruption of gradual continuity in the water-land interface and the biological invasion by alien plants. The changes in distribution area of shoreline vegetation showed that the area of hydrophytic vegetation decreased and that of hygrophytic vegetation increased from 2010 to 2013. In conclusion, the human disturbance such as armoring, road construction, recreation etc. could lead to terrestrialization, the loss of transverse continuity and biological invasion in the shoreline vegetation of the Reservoir Uiam. Our findings suggest that redesigning or removing shoreline armoring structures may benefit nearshore hydrophytic vegetation for the conservation of novel shoreline ecosystems.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.449-453
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• 2008

This research focused on analyzing and comparing between the results of hydraulic physical modeling and the results of numerical modeling of Grass Concrete which is newly developed in-situ block system. The physical model was built as a scale of 1:50 by Froude similitude measuring the water levels and the water velocities for before and after vegetation and the effects were analyzed after reviewing the results. In consequence, the water velocities were observed to decrease meanly 19.1%, and the water depth were determined to increase meanly 27.8% in case of the of design flood, $Q=200m^3/sec$. Moreover, the velocities were produced reduction effects of 27.2%, and the water levels were derived from addition effects of the highest 31.3% in case of the probability maximum flood(PMF), $Q=600m^3/sec$. To verifying the hydraulic physical modeling, the numerical modeling was conducted for a close examination of before and after vegetation. HEC-RAS model was for 1 dimensional numerical analysis and RMA-2 was for 2 dimensional numerical analysis. The results of the numerical simulation, under the condition of roughness coefficient calibration, shows similar results of the physical modeling. These satisfactory results show that the accomplished results of hydraulic modeling and the predicted results of numerical modeling corresponded reasonably each others.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.169-176
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• 2011

The purpose of this study is to examine the ecologically suitable restoration characteristics in riparian slopes constructed by continuous fiber soil reinforced system (Geofiber system) which does not contain the concrete materials. The findings are as follows : (1) as the tested soil was not washed away by rainfalls and floods, Geofiber could replace the concrete wall and gravity stone net bag technique from the civil engineering structural point of view; (2) after one year of the construction, it was monitored that land cover ratio was 80-90%, which indirectly shows that vegetation is safely maintained; and (3) at the same time, 5-8 flora species were found in each test grid and more importantly dominant species have been moved from alien species to native herbaceous plants. From the above findings, Geofiber system is recommendable to restore the riparian slopes in terms of stability and natural landscape points. However, a long term monitering is needed considering flora succession process in a given environment as well as suitability tests should be carried out through the comparative investigations in other environments.