はじめに

サンタ・カタリーナ州はブラジル最南端の州のひとつです。この地域は、夏には気温が摂氏32度（華氏90度）に達し、冬には摂氏マイナス5度（華氏23度）まで下がるという、気温の高低差が激しいことで知られています。2015年、サン・ジョアキンとパイネルの町を結ぶ全長55キロ（34マイル）のSC-114道路の補修が必要となりました。

挑戦

SC-114 needed rehabilitation due to fatigue damage and occasional thermal cracking. The original repair plan called for full-depth reclamation (FDR) with cement. However, timing and safety concerns related to traffic interruption associated with the full depth replacement process made the local road authority DEINFRA-SC reconsider the initial plan.

決議

Compasa, a leading Brazilian road construction company, provided an alternative design. The design called for milling of the existing wearing course; paving 2.5 cm (1 in) of HiMA™-enabled SAMI layer; followed by 4 cm (1.6 in) HiMA-enabled wearing course. The ultra-thin HiMA SAMI layer is designed to provide reflective crack protection, while the wearing course would give the pavement long-term distress resistance. The alternative design allowed for much faster project completion time and a substantial reduction in traffic interruption. DEINFRA-SC achieved the desired benefits at a similar or lower cost overall.

Compasa manufactured the Compaflex HiMA polymer-modified bitumen. The asphalt mixtures were produced between 165-170°C (329 – 338°F) and paved at a 143-154°C (290 – 309°F) range. As of June 2020, the pavement has stood up to the test.