In this study, We evaluated the applicability of high performance fiber reinforced cementitious composite (HPFRCC) with compressive strength of 180, 140 and 100 MPa and identical contents in steel fiber. The analysis of the flexure tensile behavior showed that HPRFCC presents deflection hardening after the initiation of cracks and exhibits higher energy absorbing capacity with high compressive strength.

The purpose of this study is to evaluate the impact on flexural strength and compressive strength of the concrete, the mixing rate of the amorphous fibers.

Performance Evaluation was conducted for analyzing fundamental properties of warm-mix asphalt mixture using 100% steel slag. This study tested and compared asphalt mixture used three types of asphalt binder and two types of aggregate.

The field test was conducted for the shotcrete construction using a slurry-type accelerator. Check the efficiency of the equipment and the accelerator was determined using the discharge amount for the accelerator ratio optimization. As a result, the efficiency of a slurry quick-setting admixture mix shotcrete and discharge rate results were evaluated to be excellent.

In recent days, many damages have been detected in superannuated bridges. Especially, the fatigue problems become serious in the maintenance of the bridges. It is important to investigate the load bearing capacity of the girder ends ability when some crack damages have occurred in the steel bridge. In this study, typical crack damages have dealt with analytically; one is the crack which occurred in the vicinity of the welding of the sole plate, the other is the crack which occurred in the vicinity of the gusset section of the web. Based on the analytical results, the relation between the load carrying capacity at the girder end and the crack length/direction is discussed. The crack occurred in the part which a tension field forms with cracks of steel girder on which shearing force acts in analysis in case a crack occurs, it turned out that reduction of ultimate shear strength is large.

FRP(Fiber Reinforced Polymer) reinforced lightweight concrete structures can offer corrosion resistance and weight reduction effect simultaneously, so practical use of the structures may be expected afterwards. During that time, a lot of studies for bond behaviors of FRP bar in normal concrete were conducted, but studies for bond behavior of the FRP bar in lightweight concrete are very limited to date. So, bond characteristic between lightweight concrete and helically deformed GFRP bar was investigated in the former study by the authors. In this study, re-consideration of the bond capacity were performed by using results of the former study, results from additional experiment considering variation of the concrete compressive strength, and results from literature survey.

In the current concrete structure of the highway is still the major problem most of concrete deterioration caused by the freeze-thaw and de-icing salt, which is of issues that are not completely resolved. In particular, a single freezing event does not cause much harm, durability of concrete under multi-deterioration environment by repeated freeze-thaw and de-icing salt is rapidly degraded and reduce its service life. In this study, to considering environmental characteristics when design and construction of concrete structures, the exposure environmental guidelines were established by investigation the application rates of de-icing salt, temperatures and snowfall characteristics during five years (2004∼2008) by regions. Also, damage condition and chloride content of the structural at regions of moderate and severe environmental exposures were investigated.

This paper describes the findings of the study conducted to evaluate early-age strength characteristics of rapid-setting concrete containing waste pottery powder. The experimental variables selected were 5, 10, and 15 percent replacements of cement with waste pottery powder. The findings are summarized as follows: (1) slump of the concrete decreased as the replacement rate of cement with waste pottery powder increased, and (2) compared with the strength of the control specimens with no replacement rate, compressive strength of concrete increased at 5% replacement rate, and was comparable to the control at 10% replacement rate; however, at 15% replacement rate, compressive strength actually decreased.

Korea features mountainous areas, and the exposed slop area is on the rapid rise due to constant spread of national infrastructure and urban development, which leads to accompanied increase of artificial disasters. Thus there is a demand for developing long-lived seed spray materials that will enable stable tree planting and establishing an optimal construction method to suit such a material.

In this study, Analyzed characteristic about permeability cold-mixed recycled asphalt concrete using waste asphalt concrete and MMA. As a result, porosity was 20.4%, Water permeability coefficient was 0.94cm/sec and Skid Resistance test was 50BPN

The mechanical and thermal properties of high temperature aluminate cementitious thermal storage material were investigated in this paper. Alumina cement was used as basic binder and the effect of the replacement of fly ash, silica fume, calcium sulfo aluminate and graphite for alumina cement was investigated.

As the results of study, the difference of marshall stability is insignificant according to steel mesh reinforcement. But property of dynamic stability of steel mesh reinforced asphalt concrete is improved 2.6 times compared to the Plain.

Tensile performance of the recently developed “FRP Hybrid Bar” at Korea Institute of Civil Engineering and Building Technology (KICT) is experimentally evaluated by the authors. FRP Hybrid Bar is introduced to overcome the low elastic modulus of the existing GFRP bars to be used as a structural member in reinforced concrete structures. The concept of material hybridization is adapted to increase elastic modulus of GFRP bars by using steel. This hybridized GFRP bar can be used in concrete structures as a flexural member with a sufficient level of elastic modulus. In order to verify the effect of material hybridization on tensile properties, tensile tests are conducted. The results for both FRP Hybrid Bar and the existing GFRP bars are compared. The results indicate that the elastic modulus of FRP Hybrid Bar can be enhanced by up to approximately 250 percent by the material hybridization with a reasonable tensile strength. To ensure the long-term durability of FRP Hybrid Bar to corrosion resistance, the individual and combined effects of environmental conditions on the bar itself as well as on the interface between rebar and concrete are currently under investigation.

This study reviewed sulfuric acid resistance of high acid resistance of inorganic binder based on industrial by-products. As the results of test, the mix of high acid resistance of inorganic binder showed the excellent chemical resistance against aqueous solution of 10% H2SO4 comparing to the mix of OPC, however, the mass of inorganic binder rather increased while approximately 3.4% of mass loss ratio appeared during 7 days of material age of soaking in case of using portland cement usually.

This paper presents an analysis technique considering double-layer concrete and time-dependent diffusion behavior, and the results are compared with those from the previous test results through reverse analysis. Through consideration of time effect, the relative error decreases, which shows more reasonable results. Utilizing the diffusion coefficients from Life365, relative errors increases and it needs deeper penetration depth(e) and lower diffusion coefficient ratio(D1/D2) due to higher diffusion coefficient.

In the recent remodeling construction for old apartment, it is general to extend the parking space for the increased cars for residents. This paper reviews the extension methods of parking space and presents the problems that must be solved for the construction. In this paper, three extension cases of parking space in the remodeling projects were reviewed. As a result, the demand for the extension needs to be analyzed for the various cases and the technologies for the best-fitted construction should be suggested based on the demand.

Carbon nanotube(CNT), carbon nanotube-fiber(CNT-fiber) and graphene are representative nano materials which gained much attention by the research community owing to their excellent mechanical, electrical and heat conducting properties surpassing the existing materials by far. The utilization of these properties in construction materials is being actively studied. This paper summarizes the previous studies conducted by the authors regarding the utilization of nanotechnology into construction materials.

Preliminary tests confirmed that the addition of nanoscale composites possess significant potential to provide mortars with purification properties.

This paper investigated the influence of moisture level on the piezoresistivity of carbon nano-tube/cement composites. Test results indicate that the piezoresistivity sensitivities of carbon nano-tube/cement composites decreased as moisture contents in the composites increased.

The present study concerns a measurement of porosity at the nano-fibre interface in concrete. Concrete cast with a centrally located nano-fibre (Ø0.39 × 15.0 mm) was segmented for microscopic observation at a bascattered electron (BSE) image. As a result, it was found that the pores generated in the vicinity of the nano-fibre ranged from 5.40 to 11.45%, equivalent to 0.51 - 1.08% of air void in a bulk concrete.