This study was conducted to examine the workability of LEFC in relation to the types and the mix ratio of different foaming agents. The foam agents act as lightweight aggregates in the concrete matrix and provide an alternative to obtaining the adequate strength level for the foam concrete. The results of the test showed that the synthetic foam agents were able to act properly as replacements for the lightweight aggregates.
In this study, it was developed geopolymer concrete of alkali-activated using the mixed fly ash and blast furnace slag. and it was developed the interlocking block using the developed geopolymer concrete. In addition, the bending strength and water absorption rate of the interlocking block was tested by KS standard. The test results were as follows. The water adsorption ratio of the BSF4 specimen was under 10%, and the flexural strength of that was over 5MPa
In this study, it evaluate the Impact fracture properties of fiber reinforced concrete and fiber reinforced cement composite. The types of fiber are Hooked-ended steel fiber and it was mixed 0.5, 1.0 vol.% in concrete and 1.0, 2.0 vol.% in cement composites. The Impact resistance performance was evaluated by measuring the fracture grade, penetration depth and scabbing depth
This paper was evaluated manufacturing properties for core material of self-healing capsules using cement powder, it was found that coagulants for coagulation of core materials were important factors in manufacturing core materials.
In this study, cement mortar (KS F 4042) used for repairing concrete structures was evaluated for compressive strength and bond strength according to the mixing ratio of polymer. From the experimental results, it was confirmed that as the polymer content increases, the bond strength properties increase, but the compressive strength decreases slightly at a certain rate.
From the test results, it was found that the compressive strength and the resistance of chloride ion penetration were evaluated the slag content of the concrete for bridge pavement. Compressive strength test results showed that initial strength was decreased as slag replacement ratio increased. The chlorine ion penetration performance increased with increasing strength.
In order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of high-filling concrete is required. Therefore, in this study, It was evaluated the filling performance of filling concrete for SCP module according to our mix proportion. Resultingly, the concrete effectively filled the large-sized SCP module.
In recent years, in order to reduce self-weight of structural elements, the use of SCP(Steel Concrete Plate) is getting increased. Since SCP has complicated sectional shape and includes large amount of studs, the use of shrinkage reduction concrete is required. Therefore, in this study, to prevent the restrained shrinkage behavior by stud, the effects of using expansive agent (EA) and shrinkage reducing agent (SRA) was investigated.
The flowability and compressive strength were evaluated to examine the effect of biner mixing ratio on the high-fluidity concrete with low binders. When the binder mixing ratio (OPC, BFS, FA) was 7:2:1, It was most suited for high-fluidity concrete with low binders by increasing workability and compressive strength.
The mechanical properties were evaluated to examine the optimum adding amount of AC and UT viscosity agent by mixing two viscosity agent according to the adding ratio. When the ratio of AC and UT viscosity agent was 5:5, It was most suited for high-fluidity concrete with low binders by increasing workability and effect of reducing viscosity.
The airborne chlorides environment by de-icing salts of the Suam road tunnel in motorway were examined. It was found that higher airborne chlorides were detected inside road tunnel than outside. Therefore, there is a need to appreciate that RC structures inside tunnel might be exposed to salt attack environment.
In this study, Retarder, which shows characteristics of delay hydration reaction and reduce hydration heat in concrete, was processed through granulation and paraffin coat to induce reation by hydration heat. Concrete with Granulated and paraffin coated retarder were prepared and compressive strength was measured by curing at 20℃ and 40℃. As a result, it was confirmed that retarder exhibits performance depending on the curing temperature.
For the use of recycled aggregate concrete, the early strength is evaluated. The test variables are replacement ratio of recycled aggregate, steel fiber and blast furnace slag powder. For this, 6th concrete mixing plan is prepared. As a result, it is evaluated that the early strength depends on the steel fiber volume fraction and replacement ratio of blast furnace slag powder.
In this study, Early compressive strength analysis of low carbon mortar using industrial byproducts and describes relationships between strength property and CO2 indices to evaluate eco-efficient of low carbon binder mortar. Based on the results, this study is to give fundamental data for ability of eco-efficient low carbon binder.
The purpose of this experimental study is to investigate the application of materials of construction with MWNT and TiO2. high performance nano MWNT-TiO2 carrier was fabricated by sol-gel method and performance analyzed by XRD and SEM. As a result, high performance nano MWNT-TiO2 carrier was no significant differences in coating state, crystallinity and microstructure.
This paper presents an experimental study to evaluate complex deterioration resistances of concretes according to addition of modified sulfur. The complex deterioration tests were performed to concretes with freezing-thawing and deicing chemicals. From the test result, it was confirmed that the complex deterioration resistances of modified sulfur cement concrete was higher than that of normal concrete.
In this study, experiment and analysis of high-strength bolt connection under shear fatigue loading was conducted to evaluate reduction of axial force of bolt. Three type of bolt size and initial axial force were applied to specimens. As a results, it was observed that the reduction ratio of axial force, and that would be used to additional parametric study.
In the sliding slab track of railway bridge, a lateral support block is used to control the lateral displacement. Therefore, it is important to analyze the behavior of dowel rebar and the lateral support block of the sliding slab track. In this study, high strength concrete and steel rebar was selected to analyze the behavior of dowel rebar and shear behavior of high strength dowel rebar and the lateral support block were compared to the equations developed by Soroushian et al. (1986) and CEB-FIP (2010).
In general, polymer cement mortars that is made from organic polymer dispersion and cement have good workability compared with ordinary cement due to ball-bearing acting of polymer particles in cement mortar. The purpose of this study is to evaluate the workability of cement mortar according to adding of admixtures such as polymer dispersions, blast-furnace slag and fly ash. From the test results, the flow of polymer-modified mortars is increased with increasing polymer-cement ratio, and also is a little improved according to adding of fly ash compared to blast-furnace slag.