PURPOSES : The purpose of this paper is to develop an evaluation method for aged reclaimed asphalt pavements using RAP mortar specimen and FTIR method. METHODS: To evaluate the low-temperature behavior of aged reclaimed asphalt pavements, an indirect tensile strength test was adopted with an RAP mortar specimen. The RAP mortar specimen without a rejuvenator was fabricated with two fine aggregate types as a function of passing sieve sizes. The fabricated RAP mortar specimen was frozen for 24 h at -20℃. The indirect tensile strength was measured as a function of different absolute viscosities. The indirect tensile strength and displacement were varied as functions of the dosage of the rejuvenator. The spectroscopy analysis of four asphalt binders was performed under attenuated total reflection. The four asphalt binders comprised of a virgin binder, two extracted RAP binders, and a mixed virgin and extracted RAP binder. To evaluate the oxidation of the binder, the carbonyl index was calculated. RESULTS : The four extracted RAP binders were measured with an extremely wide range of absolute viscosity from 30,000 poise to 170,000 poise. The indirect tensile strength of the RAP mortar decreased as the absolute viscosity increased. This means that at lower temperatures, the indirect tensile strength can indicate the oxidation of RAP. Also, the indirect tensile strength and displacement changed sensitively as the dosage of the rejuvenator was changed. Based on the FTIR principle, a good relation was observed between the dosage of the rejuvenator and the FTIR absorbance peak. It can be used to estimate the dosage of the rejuvenator in hot reclaimed asphalt mixture. Also, the carbonyl index of the RAP binder was calculated to evaluate asphalt oxidation using the FTIR principle. CONCLUSIONS : There is a good relation between the indirect tensile strength of RAP mortar and its absolute viscosity. This indicates that RAP mortar can be used to estimate the properties of aged RAP. Also, the usage of rejuvenator can be evaluated with both the indirect tensile strength and FTIR absorbance peak. The carbonyl index can be used to predict asphalt oxidation.

Whole body fatigue detection is an important phenomenon and the factors contributing to whole body fatigue can be controlled if a mathematical model is available for its assessment. This research study aims at developing a model that categorizes whole body exertion into fatigued and non-fatigued states based on physiological and perceived variables. For this purpose, logistic regression was used to categorize the fatigued and non-fatigued subject as dichotomous variable. Normalized mean power frequency of eight muscles from 25 subjects was taken as physiological variable along with the heart rate while Borg scale ratings were taken as perceived variables. The logit function was used to develop the logistic regression model. The coefficients of all the variables were found and significance level was checked. The detection accuracy of the model for fatigued and non-fatigues subjects was 83% and 95% respectively. It was observed that the mean power frequency of anterior deltoid and the Borg scale ratings of upper and lower extremities were significant in predicting the whole body fatigued when evaluated dichotomously (p < 0.05). The findings can help in better understanding of the importance of combined physiological and perceived exertion in designing the rest breaks for workers involved in squat lifting tasks in industrial as well as health sectors.