【第5回舗装工学講演会講演論文集 2000年12月】

舗装工学論文集 Vol. 5, 76-85, 2000.12

アスファルト舗装模型上の繰返し平板載荷試験における
たわみと弾性係数について

廣津栄三郎・吉田信之・西勝・神吉秀成

正会員東亜道路工業株式会社技術部課長(〒106-0032 東京都港区六本木七丁目3‐7)
正会員Ph.D. 神戸大学助教授都市安全研究センター(〒657 神戸市灘区六甲台町)
正会員工博神戸大学名誉教授(〒657 神戸市灘区六甲台町)
正会員協和設計株式会社(〒567−0877 茨木市丑寅2−1−34)

 

高温時におけるアスファルト舗装の弾性係数をFWDと同様にたわみ量から推定するために,実路を再現した4 種類の舗装断面の大型舗装模型を作成し,アスファルト混合物施工直後・常温・60℃の3 種類の温度条件で繰返し平板載荷実験を行った.たわみの測定結果から,施工直後の場合には載荷板近傍のたわみ量が大きいが,温度低下とともに荷重分散能力が回復したわみ量は小さくなる一方で載荷板から離れたたわみ量は若干増加することがわかった.また,実測たわみ量から逆解析によって算定したアスファルト混合物の弾性係数とその平均温度との関係では,既往の実験研究で示されているように,アスファルト混合物層の平均温度が上がるとその弾性係数は低下する傾向が認められた.しかしながら,実験結果ならびに逆解析方法についてさらに詳細に検討する必要性を示唆した.

Key Words: VMA,Model ashalt pavement, repeated plate-loading test,deflection,extended Bayesian Method,elastic modulus..


DEFLECTION AND ELASTIC MODULUS IN REPEATED PLATE-LOADING TESTS ON MODEL ASPHALT PAVEMENTS

Eizaburou HIROTSU, Nobuyuki YOSHIDA, Masaru NISHI, and, Hideya KANKI

To evaluate the behavior of asphalt pavement in high temperature based on deflection just like FWD a repeated plateloading test was carried out on relatively-large scaled model asphalt pavements with 4 different sections under three different temperatures conditions, as immediately after construction, normal temperature and 60℃. As a result, a large deflection near the loading plate took place for the temperature condition of immediately after construction. But as temperature goes down, the deflection decreases near the loading plate and a bit increases away from the loading plate due to rejuvenation of the stiffness, as load transmissibility of asphalt mix layer accompanied with temperature decrease. From the back-analysis of measured deflection, a tendency was observed that the elastic modulus asphalt mix layer decreased with its average temperature and that the estimated values of elastic modulus were a bit larger than those of past studies at a relatively high temperature. It was also indicated that there was a room for research and investigation on the back-analysis method and interpretation of the test results on ground that the modified asphalt mix layer was a bit more sensitive to temperature than the straight one exhibiting a bit lower elastic modulus at a relatively high temperature, which seem to contradict the reality.