The purpose of this study is to examine and quantify the effect of chloride content on surface electrical resistivity measurement of concrete. It was obvious that chloride content had influenced the resistivity of concrete and the relationship showed a linear function. That is, concrete with chloride ions had a comparatively lower resistivity. Decreasing rate of resistivity of concrete was clear at early time, however, after 50 days resistivity was constant irrespective of chloride concentration. Conclusively, this paper suggested the quantitive solution to depict the electrical resistivity of concrete with chloride content.

Durability and structural safety of steel structure are severely affected by corrosion caused by deicer material as well as by airborne chlorides in the marine environment. In this study, based on analysis of current status it is suggested that deterioration and durability reduction by the environmental factor such as chlorides should be more reasonably taken into consideration for the accurate inspection and condition evaluation of steel structures.

서울지역 28개 지하구조물에 대한 정밀안전진단 결과를 활용하여 제안된 균열집중구간 및 탄산화 기반 한계상태함수를 산정하여 우선적인 보수구간을 선별하고자 하였다. 상태평가를 위해 분할된 503개 쉬트에 대한 균열밀도는 로그정규분포, 탄산화 및 피복은 정규분포의 현장조사 결과를 얻었다. 각 구간별 실시한 강도, 초음파속도, CO2농도, 철근부식도, 염화물함유량 등을 고려할 수 있도록 환경지수를 도입하여 합리적인 보수 우선순위를 제안하고자 하였다.

The durability of Latex modified concrete(LMC) is increased when compared with conventional pavement concrete. But LMC have a several problems. In odrer to improve the problem of LMC, Remicon latex modified concrete(Remicon LMC) was developed. In this study, the durability of Remcion LMC containing extra admixture was compared with latex ratio. From the results, when latex and admixture was mixed in concrete, the micro-pores are decreased. And, the durability of Remicon LMC is increased comparing to conventional concrete.

In this research, Crushed-stone sludge obtained from production processing of crushed aggregates were recycled to manufacture artificial aggregate. Compressive strength , Elastic modulus, Splitting strength, Flexural strength and freeze/thaw, Carbonation test were conducted for artificial aggregate concrete. The results showed that compressive strength and freeze/thaw and depth of carbonation resistance of concrete using crushed-stone sludge aggregate were higher than those of concrete using normal crushed stone. but elastic modulus, splitting and flexural strength were lower than those of concrete using normal crushed-stone

The purpose of this study is to estimate and quantify the effect of carbonation of concrete on a surface electrical resistivity measurement. Samples of three mixes with difference W/C ratios were prepared and exposed in a carbonation chamber for up to 330 days. The results show that carbonation leads high electrical resistivity. The increase is substantial and has been shown to proportional to the extent of the carbonation by some of extent. The relationship between electrical resistivity and carbonation depth is taken in the study. Resistivity ratio of carbonated concrete to air concrete decreased significantly from the specific carbonation depth, however, Resistivity ratio of carbonated concrete to air concrete had a linear relation with carbonation depth.

철골건축물은 화재시 강재의 내력저하로 인해 안전상의 문제가 발생하므로 내화피복을 실시하고 있다. 이때 국내에서 가장 많이 사용되고 있는 것이 내화뿜칠피복재로 초기제품에 대한 성능평가는 적절히 이루어지고 있으나 내구성에 대한 평가는 전혀 이루어지고 있지 못한 실정이다.이에 내화뿜칠피복재의 장기 내화성능 관리를 위하여 한국건설기술연구원에서는 내화뿜칠피복재의 유지관리지침(안)을 제시하였으나 세부적인 평가방법 보완 및 적용성 평가 등이 요구되었다.따라서, 본 연구에서는 이 내용 중 비교적 단기간에 내구성능평가가 가능한 촉진내구성 평가방법에 대하여 세부기준을 정하고 이에 대해 국내 3개사의 제품에 대한 적용성 평가를 실시하였다.<br>이는 향후 내화뿜칠피복재의 내구성관리에 이용할 수 있는 시험표준 작성의 기초자료가 될 것이며 제정될 표준의 적용성을 확인 할 수 있을 것이다.

Recently, water surface floating solar power system are few appeared some companies in the country. However, it is the reality of most structures using steel and the problem’s occurred in durability for error of design issues and corrosion. In order to solve these problems, research is being conducted for various materials but performance verification is insufficient. In this study, in order to predict the structural behavior of water surface floating solar power structure and to confirm the safety, it tried to understand the mechanical properties of PFRP, synthetic wood instead of steel.

Traditionally main driving force of chloride penetration in concrete have been regarded as diffusion, however, large construction such as tunnel elements and foundations for bridges can be placed on large sea water depths where the water pressure is fairly different from the pressure in the splash zone. Moreover, hydrostatic pressure increases in proportional to measured depth from the surface of water because of the increasing weight of water exerting downward force from above. In this study, new experiment method to estimate chloride penetration of concrete under water pressure is introduced. When the life length for such a concrete structure on a large sea water depth is estimated using the normally used models, the concrete test specimen.

This paper discusses on the durability of developed high-performance shotcrete for Bobsleigh track construction in 2018 Pyongchang winter Olympic Game, concentrating on strength development, rapid chloride permeability, surface scaling, freeze-thaw resistance, and dry shrinkage

Performance tests of low noise expansion joint for durability were carried out. As a result of tests, low noise expansion joint had the fatigue durability and the resistant performance for transverse direction displacement

In case of reinforced concrete based structures, deterioration is mainly due to corrosion of steel rebar. So, the advanced construction rebar materials which have high resistance to corrosion should be developed with the application techniques. In Korea Institute of Construction Technology, the research project on hybrid reinforcing bars have performed since 2013 during 5 years. In this paper, the verification methodologies on corrosion and durability which will be applied to developed hybrid reinforcing bars are suggested

In this study, based on the field and laboratory experiments results of underground box culverts, a residual service life was numerically estimated via the statistical analysis and Monte Carlo simulation.

In this study, the underground box culvert were selected in nine construction sites and the influencing factors of underground structures on concrete degradation were verified through the field and laboratory experiments.

Cold-mixed asphalt concrete is used to resurface locally damaged area as patching technique. However, due to the durability of Cold-mixed asphalt concrete, resurfacing needs recur for the patching conducted area. Throughout marshall stability tests, residual stability tests, and wheel tracking tests of 12 different resurfacing materials, additional quality standards were suggested in this study such as higher than 7350N in stability test, air void range from 3% to 10%, and 750/mm in dynamic stability.

Many researches are conducted to reduce latex content because latex is expensive. In these study, the durability of concrete containing extra admixture was compared with latex mixing ratio. From the results, when latex content was increased, bending strength and bonding strength were increased. However, the compressive strength, relative dynamic young’s modulus and the amount of passing charge did not show a noticeable difference with latex ratio. And, the peak of micro-pores was changed from 100nm to 50nm

The results of the durability analysis of chloride attack and analysis of hydration heat, it was found that it was convenient to obtain the service life and minimum crack index of TBC from a wide range of water-binder ratio. However, it was analyzed that the crack index was difficult to obtain.