PURPOSES: The objective of this study is to evaluate the durable performance of combined organic and inorganic hybrid mortar as repair material (HRM mortar) for concrete road facilities via comparison with that of cement repair materials (IRM mortar). METHODS : To produce HRM mortars, inorganic materials as binder and 2 mineral fillers were adopted. The ratio of main resin versus hardener was fixed at 1:2. For comparison, IRM mortars made with cement repair materials were also manufactured. Compressive, flexural, and bonding strengths were measured at predetermined periods. For durability assessment, the scaling resistance, freezing & thawing resistance, rapid chloride penetration resistance, and acid attack resistance of those mortars were experimentally monitored. RESULTS: The durability performances of HRM mortars, especially with respect to freezing & thawing, rapid chloride penetration and acid attack, were identified to be much better than those of IRM mortars. This result implies that HRM is a highly promising and versatile material because of its excellent durability. CONCLUSIONS: It is concluded that the application of the combined organic and inorganic hybrid mortars is possibly an option for the repair of concrete road facilities exposed to aggressive environments.

PURPOSES : The objective of this study is to evaluate the performance of combined organic and inorganic hybrid mortar used as repair materials (UM mortar) for concrete road facilities by comparison with cement repair materials (RM mortar). METHODS: In order to produce UM mortar, four different levels of inorganic materials were adopted and the ratio of main resin to hardener was fixed at 1:2. For comparison, RM mortar made with cement repair materials was also produced. Fluidity, strength characteristics, length change, and freezing-thawing resistance of the mortars were measured at the predetermined periods. In addition, the microstructures of the mortars was performed on the 28-day mortar samples to examine the properties of the interfacial transition zone (ITZ). RESULTS : It was observed that the mechanical properties, except for compressive strength, and freezing-thawing resistance of UM mortars were much better than those of RM mortar. Furthermore, showing a densified ITZ properties on the UM mortars from the microstructural observation, the usage of UM mortars exhibited a beneficial effect on the enhancement of mortar properties. CONCLUSIONS: It is concluded that the application of combined organic and inorganic hybrid mortars is a possible option for the repair of deteriorated concrete road facilities.

Cold spray deposition using Titanium powder was carried out to investigate the effects of powder morphology and powder preheating on the coating properties such as porosity and hardness. The in-flight particle velocity of Ti powder in cold spray process was directly measured using the PIV (particle image velocimetry) equipment. Two types of powders (spherical and irregular ones) were used to manufacture cold sprayed coating layer. The results showed that the irregular morphology particle appeared higher in-flight particle velocity than that of the spherical one under the same process condition. The coating layer using irregular morphology powder represented lower porosity level and higher hardness. Two different preheating conditions (no preheating and preheating at ) were used in the process of cold spraying. The porosity decreased and the hardness increased by conducting preheating at . It was found that the coating properties using different preheating conditions were dependent not on the particle velocity but on the deformation temperature of particle. The deposition mechanism of particles in cold spray process was also discussed based on the experimental results of in flight-particle velocity.

This study is to analyze the causes of damage on additional facilities in road. In this study, lab test was performed using field core sample. The result of The compressive strength of concrete is met with the design regulations. However, the chloride content of in concrete increased up to 2cm. The microstructure and reactant analysis identified an expanding substance on the surface. However, as the time increases, the depth is expected to be deep.

This thesis will provide the baseline data of a suitable road repairing solution by analyzing the freeze-and-thaw resistance of inorganic-organic hybrid mortar. The resilience of polymer mortar and high-elastic mortar to freeze thaw resistance showed that the high-elastic mortar showed excellent resistanc

This research provides the baseline data for choosing the inorganic/organic hybrid material as the repairing solution by analyzing its efficiency in securing high vibration resistance and very low permeability. As a result of analysis of the mechanical properties of hybrid composite mortar, the strength increased with age. Therefore, it is considered that an inorganic binder having a certain amount or more is required for high strength development.