摘要: |
On September 9, 1997, an ADIEM II (Advanced Dynamic Extension Module) was installed on Interstate 5 near Salem, Oregon. The ADIEM II offered a redirecting, energy-absorbing crash cushion and end treatment for portable and permanent protection of concrete barriers. A three-person crew completed installation of the sloping concrete base and lightweight crushable concrete modules in about two hours. This device was selected for use as an end treatment because of space limitations imposed by steep fill at the site. The Oregon Department of Transportation Research Group monitored the performance of the system for three years, particularly the weather resistance of the crushable concrete modules. The module developed soft spots after two years. An attempt was made to repair and re-coat the blocks. The new coating did not prevent soft spots. A corrugated plastic covering was also installed, and seemed to remain intact, though no analysis of the concrete inside the cover was performed. The lightweight concrete modules were replaced in October of 1999. The new modules were coated with a different type of water proofing material (Garna-Thane). |