• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.258-264
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• 2018

In this study, the improved performance of sprayed green soil was evaluated by incorporating functional additives. The optimal mixing ratio of the thickener and super-absorbent polymer, as an additive for moisture supply to the growth of plants within the range of mixing ratios that gives sufficient strength of green soil, was 5% and 1%, respectively. Using Portland cement as a main binder, the pH of the green soil was 9.1. To solve this alkali problem, the mixing proportion was improved so that the pH of the green soil was approximately 7.2 by mixing more than 10% of the chelate resin. The soil conductivity was measured to be 280 ~ 350mS/m under all the mixing conditions. This satisfied the criterion of less than 1000mS/m on the slope surface. As a result of measuring the soil hardness of the green soil prepared under the optimal mixing conditions of functional additives, it satisfied the criteria of 18 ~ 23mm when sprayed under a 1 bar pressure. The rebound rate was less than 15% when spraying green soil on a 75 % slope, and the hardness of the sprayed green soil was more than 18 mm.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.482-488
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• 2022

In this study, the durability of ultra rapid hardening mortar for sewage pipe was evaluated by type of mortar binder. As a result of analyzing the internal structure for each type of mortar, it was confirmed that Al₂(OH)₃ was generated in the internal structure of the CAC-based mortar, and its corrosion resistance was superior to that of other types of mortar. As a result of the compressive strength test, OPC had the tsmallest strength, followed by CAC100 > CAC100P > CAC80. This trend was similar to the previous study results. Chloride ion penetration resistance and freeze-thaw test showed similar trends. That is, CAC and C12A7 were better than OPC, and CSA was worse than OPC. This is mostly beacuse of cracks caused by expansion of CSA-based mortar. CAC100P mix showed the best chemical resistance. It is thought that this is because the alumina gel formed inside the mortar and the polymer combine to make the internal structure more dense.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.289-298
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• 2023

In this study, the development of a self-healing concrete waterproofing agent was examined, focusing on its manufacturing and waterproofing properties. The optimal ratio using microcapsules for the concrete waterproofing agent was determined through assessments of flow, compressive strength, and permeability conducted during the mortar stage. These findings aimed to provide fundamental data for evaluating the self-healing properties of the concrete waterproofing agent designed for use in concrete structures. The self-healing concrete waterproofing agent was comprised of three types of inorganic materials commonly used for repair purposes. From experimental results, a composition ratio with a high potassium silicate content, referred to as SIM-2, was found suitable. A surfactant mixing ratio of 0.03 % was identified to enhance the dispersibility of the concrete waterproofing agent, while a mixing ratio of 0.2 % distilled water was deemed suitable for viscosity adjustment. For the magnetic self-healing concrete waterproofing agent's healing agent, using microcapsules in the range of 0.5 % to 0.7 % met the KS F 4949 and KS F 4926 standards.