현장 아스팔트혼합물 변형강도(SD) 수준의 통계적 분석 연구

초록

The deformation strength (SD) was developed to create a load-induced spot deformation which is similar to the one created by a static wheel, and to measure the material’s resistance against the deformation at high temperatures. The SD is currently used as a mix-design criteria for rut resistance of asphalt pavement mixture. The criteria for the surface course of 2nd class road pavement and of 1st class highway pavement are  ≥3.2 MPa and  ≥4.25 MPa, respectively, which were set forth by Ministry of Land, Infrastructure and Transport, Republic of Korea. However, not many statistical data of field asphalt mixtures were collected and evaluated yet. Therefore, in this study, random samples of 31 PG64-22 (normal asphalt) mixtures and 18 PG76-22 (polymer-modified asphalt: PMA) mixtures for surface course were collected from nation-wide field sites. Three specimens (100 mm in diameter) were made using a gyratory compactor for measuring SD for each site mixture. The statistical data for SD were analyzed to estimate population mean and standard deviation. Assuming the SD population follows normal distribution, the current process mean of SD (  ) was found for each binder mixture (64-22 and 76-22). Statistical data shows that both SD means satisfied the respective mix-design criterion. The coefficient of variation (Vc) of normal mixes was approximately 10%, which is decent level of variation, and Vc of PMA mixes were found to be 8.63%, which is lower than that of normal mixes. In general, the strength quality in the field mixes was found to be controlled properly in SD point of view

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