• International Journal of Highway Engineering
• /
• v.18 no.1
• /
• pp.43-55
• /
• 2016

PURPOSES : This study aims to develop a repair material that can enhance pavement performance, inducing rapid traffic opening through early strength development and fast setting time by utilizing MgO-based patching materials for repairing road pavements. METHODS : To consider the applicability of MgO-based patching materials for repairing domestic road pavements, first, strength development and setting time of the materials were evaluated, based on MgO to $KH_2PO_4$ ratio, water to binder ratio, and addition ratio of retarder (Borax), by which the optimal mixture ratio of the developed material was obtained. To validate the performance of the developed material as a repair material, the strength(compressive strength and bonding strength) and durability (freezing, thawing, and chloride ion penetration resistance) was checked through testing, and its applicability was evaluated. RESULTS : The results showed that when an MgO-based patching material was used, the condensation time was reduced by 80%, and the compressive strength was enhanced by approximately 300%, as compared to existing cement-based repair materials. In addition, it was observed that the strength (compressive strength and bonding strength) and durability (freezing and thawing, and chloride ion penetration resistance) showed an excellent performance that satisfied the regulations. CONCLUSIONS : The results imply that an emergent repair/restoration could be covered by a rapid-hardening cement to meet the traffic limitation (i.e. the traffic restriction is only several hours for repair treatment). Furthermore, MgO-based patching materials can improve bonding strength and durability compared to existing repair materials.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.6
• /
• pp.77-81
• /
• 2009

This study was performed to evaluate applicability of patching materials for underwater dam concrete structure. Two kinds of patching materials was investigated. Laboratory experimentals were conducted by workability, compressive strength, bond strength, chloride ion penetration, abrasion resistance. Test results showed that the most performances are relatively good except chloride ion penetration.

• International Journal of Highway Engineering
• /
• v.14 no.3
• /
• pp.59-67
• /
• 2012

This study presents the evaluation of the patching materials that are used to repair the distress of asphalt pavement. Four kinds of patching materials currently used in practice were tested in both laboratory and field. The laboratory tests included the dry and soaked Marshall stability test, indirect tensile test, wheel tracking test and adhesive strength between the asphalt pavement and the repairing material was tested as a performance test. The field study was conducted using the slab samples placed on the location of vehicle tire passing and the performance of the repairing materials were investigated as passing the traffic load. The result of the laboratory tests were satisfied with the current design criteria and material standard except for water-immersion stability. Type C patching material showed the highest adhesive shear strength among the patching materials tested. However, the mature distress, such as rutting and stripping were monitored after construction in 10 days. It was found that performance of patching material is lack of quality behavior when they were applied in the field and required to develop and applu to prevent the mature distress of the current patching materials.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.4
• /
• pp.167-172
• /
• 2017

In this study, high performance patching repair mortars with light weight and sulfuric acid resistance properties were suggested. Their performance estimation were investigated based on KS F 4042 using patching repair mortar with light weight aggregate and soluble polymer of Type I and sulfuric acid resistance mortar of Type II, From these results, it was confirmed that these motors were satisficed and improved by all standard tests of KS F 4042.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.617-620
• /
• 2008

When the RC structure repaired by patching repair method, which method refilles with patching repair material after removes degraded area, It is necessary to determine chloride ion's permeation from outside of the RC structure repaired by patching repair material. Therefore, in this study, damage from sea environment of structure was predicted, moreover, diffusion coefficient of concrete also determined to figure out rebar's corrosion and concentration of chloride ion. RCPT(Rapid Chloride Permeability Test) was used for ditermination of patching repair material's diffusion coefficient, also connection between material thickness and effect of chloride ion's permeation was examined in analytically. Results which derived by experimental test was used in FEM(Finite Element Method) and equation suggested by JSCE to predict concentration of chloride ion in different distance from surface.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.12
• /
• pp.2070-2077
• /
• 2001

An experimental investigation of the effect of composite patching repair was conducted to characterize the fatigue crack growth behavior in thick A16061-T6 (6mm) panels with single bonded patch by fiber reinforced composite patch. Four patch lengths and no patch plate were examined. An analytical procedure, involving three-dimensional finite element method having three layers to model cracked aluminum plate, epoxy by adhesive and composite Patch, is calculated the stress intensity factors. From the calculated stress intensity factors, the fatigue crack growth rates are obtained. At the single patching type, different fatigue crack growth ratios through the palate thickness were investigated by using the experimental and analytical results. The results demonstrated that there was a definite variation in fatigue life depending on the size of composite patch. While crack reached the patch end, retardation of crack growth was also revealed in the bonded repair.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.359-364
• /
• 2001

The purpose of this study is to develop the repair system for RC members with damaged by rebar corrosion using new corrosion inhibitor which was high nitrite content. In the experiments, the acceleration corrosion test of rebar was conducted using the specimen which was applied by various repair system. As a result, it was confirmed that the new repair system without concrete patching had high anti-corrosion property compared with other repair systems and was very effective as a spray type corrosion inhibitor in concrete containing chloride (0.1% of NaCl).

• Transactions of the Korean Society of Automotive Engineers
• /
• v.1 no.2
• /
• pp.134-143
• /
• 1993

The trajectory planning for the manipulator installed on "the automatic pothole repair vehicle" is discussed and the final surface of the patched pot hole is simulated in this work. The relationship between the accumulation data of the mixture with and without the movement of the manipulator is identified to utilize the latter data for the calculation of the former one. Based on this relationship, the method to calculate the accumulation of the mixture when the manipulator changes the speed and the direction is also introduced. The trajectory is determined to make the final surface smooth under the condition that the pothole is cut to hexahedron before patching and only the spacing and the shifting of the manipulator is controllable. Final surface is simulated by the computer to prove the adequacy of the determined trajectory.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1995.04a
• /
• pp.212-218
• /
• 1995

This study experimentally evaluated the performance of damaged section which was repaired using polymer materials in reinforced flexural flexural members Six different materials, two types of polymer, two types of polymer-cement and two types of cement, were used by means of injection method on prepacked concrete and spray mortar patching method. As results, the repair works could be done easily and surfaces of the repaired section were smooth.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.292-298
• /
• 2001

An experimental investigation of the effect of composite patching repair was conducted to characterize the fatigue crack growth behavior in thick A16061-T6 (6mm) panels with single bonded patch by fiber reinforced composite patch. Four patch lengths and no patch plate were examined. An analytical procedure, involving three-dimensional finite element method having three layers to model cracked aluminum plate, epoxy by adhesive and composite patch, is calculated the stress intensity factors. From the calculated stress intensity factors, the fatigue crack growth rates are obtained. At the single patching type, different fatigue crack growth ratios through the plate thickness were investigated by using the experimental and analytical results. The results demonstrated that there was a definite variation in fatigue life depending on the size of composite patch. While crack reached the patch end, retardation of crack growth was also revealed in the bonded repair.