Hartman, Anton M.Anton M.HartmanGilchrist, M. D.M. D.Gilchrist2013-10-022013-10-022004 Ameri2004-02Journal of Materials in Civil Engineeringhttp://hdl.handle.net/10197/4668One of the primary structural distress modes found in bituminous pavement layers is fatigue cracking, resulting from repeated application of traffic-induced stresses. The development of a four-point bending test arrangement to determine the dynamic mechanical properties of rectangular beam specimens (305×45×50mm dimensions) of bituminous mixtures is discussed. This novel system allows the crack-damaged surfaces of beam specimens to be inspected and monitored digitally in situ during fatigue tests. The test fixture, which was integrated with a closed-loop servo hydraulic feedback system, incorporates a constant clamping mechanism and uses a combined displacement and loading mode of control. A series of four-point bending fatigue tests were performed on specimens of two standard Irish mixtures: a hot rolled asphalt and dense base course macadam. The digitally imaged information on fatigue cracking was used to measure the extent of damage and to characterize a linear elastic fracture mechanics model.enAsphaltFatigueFracture mechanicsFailure (mechanical)MixingHydraulic systemsCracksJournal Article161606810.1061/(ASCE)0899-1561(2004)16:1(60)2013-09-24https://creativecommons.org/licenses/by-nc-nd/3.0/ie/