The purpose of this study is to investigate the field application of cold-mixed recycled asphalt using cementless binder. After the test construction, it was not cause problem, such as this stripping, falling and crack of pavement. Also, it was confirmed to be performance of equal or higher than of existing technology.

In this study, impact of high-velocity projectile by mixing steel fiber, polyamide, nylon, polyethylene fiber which have different shape and properties respectively. Scabbing is restrained because of micro-crack caused by the shock wave offset effect and energy dispersive of synthetic fibers are mixed populations.

In this paper, investigate the effect of the quality of fresh UHPC on the mixer type, it was found that the use of twin shaft mixer was fine. On the other hand, pan type mixer is required for adjustment mix proportion.

Traditional methods for demolition of rocks may not adequate specially for urban areas and historical places. Accordingly, an use of soundless demolition chemical agent (SCDA) increases in those areas. In this study, required expansive pressure of SCDA for initiating cracks in maritime bedrock was study. It was found that shape of hole and distance between holes reduced required expansive pressure up to 59%.

This study aims at evaluation of compressive strengths and coefficients of chloride ion diffusion in concrete specimens using plain, chemical admixture PNH deveoped for anti-chloride corrosion, commercially available product of B company and blast furnace of granuate slag(BSF). It is found throughout experiments that most cases of compressive strengths are almost similar except using BSF, but the PNH has the highest resistance against chloride attack.s

A new system to ensure fire resistance of high strength concrete column in high-rise building with an permanent formwork made of insulation materials has been being studied. In this study, the lateral pressure safety performance of concrete column member using newly develope permanent formwork was estimated.

In this study, shear behaviors of various SFRC were predicted using Vector 2 program. Obtained analytical data was compared with preceded experimental data performed by other researchers. It was found that one increase in the span to depth ratio results in 54% decrease in the shear strength. Likewise, 1% increase in the reinforcement ratio causes a 19.9 % increase in the shear strength.

Hokenberry and Lopez (2012) and Aoude et al. (2012) have shown that the steel fiber can be a substitute of the stirrup for shear strengthening. In this study, Vector 2 program which takes into account modified compression field theory tensile softening behaviors of SFRC were used for prediction of the shear capacities of SFRC beams.

In this study, local fracture of concrete was evaluated through high-velocity impact test. As results, increase of bending tension performance by fiber reinforcement did not affect penetration depth Control, but it decreased rear side fracture thickness and diameter. Therefore, it was observed that fiber reinforcement decreases scabbing limit thickness.

Tensile stress and strain of rear by shock wave become the cause of rear side scabbing of concrete subjected to high-velocity impact. Improvement of flexural and tensile performance by fiber reinforcement has great effect on the suppression of the rear scabbing.

In this paper, the improvement methods of working platforms arrangement for NPP(Nuclear Power Plant) construction has been reviewed to enhance the construction accessibility. The working platforms will be enlarged and added because of accessibility of the hi-capacity crane for installation of the SC module and the combined module. The vertical elevator and the working tower have been also proposed to increase construction accessibility. It is concluded that the improvement of constructability is possible based on the consultation of construction company.

Although accelerators can be utilized for the prevention of early frost by developing the strength of concrete in cold weather, no security of workability occurs because early hydration makes them react rapidly. In this study, granulation was used as a method as it can control the response time of the accelerator to secure the workability of fresh concrete.

This paper deals with the recent development of GFRP bars by material hybridization (i.e., “hybrid GFRP bars”). This development attempts to improve the low elastic modulus of GFRP bars to be used for reinforced concrete (RC) structures, especially they were built in a corrosive environment (e.g., waterfront structures). The purpose of material hybridization in this study is to increase the elastic modulus of GFRP bar. Steel wires were inserted to GFRP and dispersed over the cross-section. E-glass fibers and unsaturated polyester resins were pultruded. Several types of the hybrid GFRP bars were tested to evaluate the tensile strength. Mechanical behaviour of hybrid GFRP bars was examined as a function two factors: 1) a ratio of steel to GFRP; 2) a diameter of steel wire. The experimental results showed that the elastic modulus of the hybrid GFRP bar was improved by up to 171% by material hybridization. To ensure the long-term durability of the hybrid GFRP bars in waterfront structure applications, the individual and combined effects of environmental conditions on the hybrid GFRP bar itself as well as on the interface between bar and concrete should be also accessed.

In this study, Criteria for common duct reviewed through comparing of other design standards and criteria specifications whether it is for duplication or contradiction. As a result, It was performed to analysis either to move other codes or to be applied as common duct code according to the classified code system.

In this study, a new foundation in a spiral type was developed for the solar electric power system. Based on the structural analysis considering the existing design code, the superiority of the new foundation system was verified via a finite element analysis on the structural stability and safety.

Recently, the trend toward larger structures continues and accelerates demand for ultra-high-strength concrete (UHSC) which satisfies structural performance. Most of researchers study on the method to increase the strength of ultra-high-strength concrete for the demand of construction market. For the application, however, ultra-high-strength concrete was needed lots of experimental study from material properties and mechanical properties to evaluate structural behavior. Currently, the design standard for concrete shrinkage and creep is limited to a range of 20 MPa to 70 MPa. It should be compensate the previous design standard to using for ultra-high-strength concrete. the ultra-high-strength concrete is appeared large autogenous shrinkage and crack may be occurred in less shrinkage once water to binder ratio is small and unit binder is large. The ultra-high-strength concrete is subjected to critical influence on micro-cracking owing to the small porosity. It should be considered the long-term behavior likely shrinkage and creep while the architectural buildings and long-span bridges are designed. In this study, therefore, the long-term behavior of ultra-high-strength concrete was investigated the parameters of water to cement ratio.

As the results of study, physical characteristics of light weight buoyancy material improve as MMA content was increased. When considering density and abrasion properties of light weight buoyancy, the proper mixing condition is thought to be C1.0.

The purpose of this study is to more accurately predict the compressive strength of concrete according to mixing proportion using UPV(Ultrasonic Pulse Velocity) method. The equation to predict the compressive strength of concrete is proposed based on the results of UPV method.

In this study, the hydration characteristics in winter of low heat concrete with respect to the binder type are investigated experimentally. According to the research results, TBC1(Ternary Blended Cement) applied low heat concrete, the heat of hydration was found to be reduced and the 28 days compressive strength was superior to that of other TBC mixes.

In this study, the concrete compressive strength test conducted according to the replacement ratio of electronic arc furnace oxidizing slag. As higher substitution rate of the electronic arc furnace oxidizing slag aggregates, early concrete compressive strength development is effective and the higher the concrete compressive strength as too.