MECHANISM AND FACTORS OF TOP DOWN CRACKS BASED ON STRESS RELAXATION

応力緩和に着目した縦表面ひび割れの発生メカニズムとその要因

Top down crack is known as a fracture phenomenon which occurs on the surface of asphalt pavements. This research is to identify the mechanism of top down cracks in HMA layers using improved wheel tracking test. As the results, the crack occurred immediately below the tire by some load conditions and temperature conditions. No cracking appeared on the bottom face. To clarify causes of the phenomenon, each compression action and the tensile action was given to a HMA specimen individually in order to evaluate a change of stress. In case of a cement concrete specimen which is near an elastic body, it shown compression stresses when compression action was given, as well as it shown tensile stress when tensile action was given. On the other hand, an asphalt mixture, shown that compressive stress and tensile stress occur alternately regardless of compression action and tensile action. Then the shape of crack was similar. The result suggests that a crack occurs on the surface of asphalt pavements because of compression action repeatedly.　本研究では，アスファルト舗装の表面に生じる縦ひび割れに着目し，ホイールトラッキング試験を改良して，供試体表面に縦ひび割れを再現することで，そのメカニズムについて検討した．試験の結果，ある条件下で，タイヤ直下の表面にひび割れが生じることが分かった．この要因を明らかにするため，アスファルトコンクリートに圧縮作用と引張作用をそれぞれ繰り返して与え，応力の変化を評価した．試験の結果，弾性体に近いセメントコンクリートでは，圧縮作用時には圧縮応力，引張作用時には引張応力がそれぞれ生じるが，アスファルトコンクリートでは，応力緩和するため，作用方向に関わらず圧縮応力と引張応力が交互に生じる．このことから，アスファルトコンクリートでは，繰返し圧縮作用を受ける車両走行位置の舗装表面において，ひび割れが生じる可能性があることが明らかとなった．

• Record URL:
  https://doi.org/10.2208/jscejpe.72.I_203
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=MECHANISM%20AND%20FACTORS%20OF%20TOP%20DOWN%20CRACKS%20BASED%20ON%20STRESS%20RELAXATION&author=T.%20HIRATO&author=K.%20HIMENO&author=M.%20MURAYAMA&author=M.%20TAKAHASHI&author=O.%20TAKAHASHI&publication_year=2016
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/21856559
• Authors:
  • Hirato, Toshiaki
  • HIMENO, KENJI
  • Murayama, Masato
  • TAKAHASHI, Masato
  • Takahashi, Osamu
• Publication Date: 2016

Language

• English
• Japanese

Media Info

• Media Type: Web
• Pagination: pp I_203-I_210
• Serial:
  • Journal of Japan Society of Civil Engineers, Ser. E1 (Pavement Engineering)
  • Volume: 72
  • Issue Number: 3
  • Publisher: Japan Society of Civil Engineers
  • ISSN: 2185-6559
  • Serial URL: https://www.jstage.jst.go.jp/browse/jscejpe/-char/en

Subject/Index Terms

• TRT Terms: Asphalt pavements; Compressive strength; Cracking; Hot mix asphalt; Mechanical relaxation; Tension
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 01633678
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Apr 28 2017 4:51PM