Accession Number:

AD0849305

Title:

Initial Production Test of Drier-Mixer, Bituminous-Concrete Materials.

Descriptive Note:

Final rept. Jun-Dec 68,

Corporate Author:

ARMY ARMOR AND ENGINEER BOARD FORT KNOX KY

Personal Author(s):

Report Date:

1969-02-05

Pagination or Media Count:

44.0

Abstract:

Test objectives were to determine if the drier-mixer satisfactorily produces high-grade, hot bituminous mixes and portland cement concrete mixes if the drier-mixer can be adequately maintained with tools, repair parts, and manuals authorized and if the performance and maintenance characteristics of the drier-mixer meet user requirements. One test item was tested for 81 test hours and subjected to 744 miles of transport. The second test item was used for maintenance evaluation only. The test item was operated through four 10-hour missions drying aggregate, producing asphalt, and producing concrete. The test item met criteria except with respect to output capacity, reliability, lack of capacity indicator in charging hopper, and exposure of parts with high operating temperatures to operating personnel. Seventeen deficiencies and 11 shortcomings were reported. The maintenance ratio of 0.59 0.59 man-hours of maintenance required per operational hour was unacceptable to USAARENBD. The MTBF was 20.25 hours the MTTR was 2.3 man-hours. The calculated reliability of the test item was 37.2 percent at a 90-percent confidence level. USAARENBD concluded that the Drier-Mixer produces high-grade mixes but is not satisfactory with respect to output capacity and safety aspects the performance characteristics and reliability of the test drier-mixer do not meet user requirements and the Drier-Mixer, Model HTD-A-67 is unsuitable for issue to troops pending correction of all deficiencies and as many as practicable of the shortcomings.

Subject Categories:

  • Construction Equipment, Materials and Supplies
  • Surface Transportation and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE