The Gyratory Testing Machine as a Design Tool and as an Instrument for Bituminous Mixture Evaluation : Draft Copy

摘要: One of the main objectives bituminous paving mixture design is to select a bitumen-aggregate combination such that mix so obtained will be as durable possible and yet stable. To accomplish this objective, one critical aspects able produce in laboratory compacted specimen truly representative it In service on road. Most present procedures utilize constant level compactlve effort which Intended densities (at designed asphalt content) comparable those occurring field after period traffic densification. This approach may open question because given compaction cannot considered specimens density all mixtures conditions specified time. It would logical compact Is at time construction then denslfy these by simulating effects traffic. desirable measure stability continuously during process. By procedure should maximum content used under variety without excessive loss stability. The gyratory testing machine can way for design. Based above reasoning seemed useful undertake study evaluate using machine. Accordingly, type commonly Indiana was selected optimum content. gradation were subjected permitted job-mix tolerances. Specimens covering range composition prepared tested simulated densification conditions. contemplated results help studying following factors: 1) Evaluation method. 2) Influence properties. purpose capability mixes any effort. Positive could lead an estimation pavement life. 3) Job formula tolerance limits. sensitivity when job tolerances investigated. Favorable modifying specifications suit