PURPOSES : The aim of this study is to review freeze-and-thaw testing apparatuses, develop a freeze-and-thaw testing setup with a test protocol, test the freeze-and-thaw properties of soils collected from different parts of South Korea, and suggest an index for frost susceptibility criteria for soils found in South Korea. METHODS : Based on a literature review, a new freeze-thaw testing setup was developed. In addition, a test protocol was developed for freeze-thaw testing. Soils collected from different parts of South Korea and bedding sand used for block pavements were tested to determine whether the measurements from the newly developed test setup could capture important freeze-thaw characteristics of the soils. Finally, to develop local frost susceptibility criteria, a parameter including both the vertical deformation and thermal conductivity characteristics of the soils was suggested. RESULTS : The results from the laboratory experiments indicate that the newly developed freeze-and-thaw setup captures the required parameters to quantify the responses of soils subjected to cyclic freeze-and-thaw testing. In addition, a vertical deformation of up to 2.437 mm is measured. Moreover, seven soils out of the nine tested soils are classified as having a medium frost susceptibility, whereas the remaining two show low frost susceptibility. The bedding sand experiment also shows that there is a possibility of having a frost susceptible condition based on the moisture content. When submerged, the bedding sand is classified as having a medium frost susceptibility. CONCLUSIONS : The "HEART" freeze-thaw testing setup was able to capture the parameters required for evaluating the frost susceptibility of soils. This setup and testing procedure could be further used to test and prepare criteria for classifying the frost susceptibility of soils found in South Korea.

PURPOSES: It is theoretically well known all over the world, that porous hot mixed asphalt (HMA) with hydrated Lime improves moisture and rutting resistance, and reduces pothole occurrence frequency, as well as the life cycle cost (LCC). METHODS : Addictive in the two different formations of the liquid anti-stripping Agent and powder Hydrated-Lime was applied in this investigation in order to obtain relatively clear results according to their types and conditions. Firstly, the moisture conditions were set, and applied to the porous HMA mixtures with hydrated lime (anti-stripping agent). Next, it was followed by a non-destructive test with the application of three freeze-thaw cycles, which were individually carried out thrice to compare the results of the dynamic moduli. Lastly, the hydrated lime effect related to moisture sensibility to porous HMA has been verified through the analysis of the modulus results regarding the change rate of dynamic modulus per n-cycle. RESULTS: It is clear from this investigation, that the dynamic modulus is inversely proportional to the change in temperature, as the graph representing the rigidity of the thermorheologically simple (TRS) material showed gradual decline of the dynamic modulus with the increase in temperature. CONCLUSIONS: The porous HMA mixture with the anti-stripping agent (hydrated Lime) has been found to be more moisture resistant to freezing and thawing than the normal porous HMA mixture. It is clear that the hydrated lime helps the HMA mixture to improve its fatigue resistance.

노상토의 동상 가능성이 없는 경우 동상방지층을 생략한다. 이러한 조건에서 노상토의 동결 융해가 발생하면, 동상이 없는 상태에서 탄성계수 변화를 수반하고, 포장설계에서 이를 합당하게 고려해야 한다. 동결 융해 과정의 연속적인 탄성계수 변화를 효과적으로 규명하고자 비파괴시험인 충격공진시험(IR, Impact Resonance)을 도입하였다. 동결 융해 과정에서 수분의 공급이 차단된 폐쇄형 동결조건에서 노상토의 탄성계수는 동결 융해 반복횟수에 무관하게 일정한 값으로 나타났다. 또한 시험에 적용한 모든 함수비 및 다짐도 조건에서 동결전의 탄성계수와 동결 융해 후의 탄성계수는 변화가 거의 없이 일정한 값으로 나타났다. 즉 폐쇄형 동결 융해 조건에서는 노상토의 융해 강성도 감소(thaw-weakening)가 발생하지 않았다. 동결시 탄성계수는 다짐도 및 함수비에 따라서 변화하였으나, 포장설계 관점에서는 무시 가능한 수준으로 나타났다.

This study, depending on the concrete mix material by performing the test on the basis of the wet and dry condition and freeze-thaw, and to elucidate the difference in the corrosion initiation time of there steel, in both environments, it is an object of correlation coefficient derived through the results of the accelerated corrosion test in a laboratory corrosion period of the structure of the marine environment.

In this study, EL. 610 test and SHRP H-205.8 test were performed to evaluate the effects of deicing salts on concrete. According to the test results, EL. 610 chemical deicer test method was not enough to evaluate the chemical effects on concrete. On the contrary, the results of SHRP H-205.8 test method showed clear distinction between deicer type A and type B.