Development of CBR Design Cuves for Runways to Be Surfaced with M8A1 (Formerly T10) Steel Landing Mat.

摘要

Accelerated traffic tests, which simulated aircraft taxiing operations, were conducted on test sections constructed on subgrades of various strengths and surfaced with M8A1 (formerly T10) steel landing mat. The purpose of the tests was to obtain data on the service life of the M8A1 mat under various conditions of wheel load, tire pressure, and subgrade strength. From these data, CBR design curves for runways surfaced with M8A1 mat, similar to CBR design curves for bituminous pavements, have been developed. Operations of military aircraft with single-wheel loads ranging from 25,000 to 50,000 lb and tire pressures ranging from 60 to 300 psi and aircraft with twin-wheel assembly loads of 50,000 lb were simulated by means of a test load cart. CBR, water content, and density of the subgrade were measured before and during the traffic tests, and the condition of the test sections was recorded. Traffic was applied until the test sections failed or until it was evident that 700 coverages could be completed by the test load cart. The design curves, which were developed by correlating the M8A1 test data with flexible pavement design relations, are considered adequate for use in designing landing strips to be surfaced with M8A1 steel landing mat. (Author)