Coupled Numerical Analysis of Anti?crack Mechanism of Large Stone Asphalt Mixture

Stresses　of　pavement　with　flexible　base　of　LSAM-30,ATPB-30　and　AC-30I　at　the　most　adverse　point　under　the　function　of　traffic　load　and　temperature　load　as　well　as　the　coupling　of　them　were　calculated　and　compared　by finite　element　method.　The　result　indicates　that　flexible　bases　of　LSAM?30　and　ATPB?30　are　more　effective　in　the　prevention　of　reflection　crack　Because　of　the　great　volume　of　coarse　aggregate　and　large　maximum　nominal　particle?size,the　LSAM-30　thermal　conductivity　is　greater,and　the　temperature　shrinking　coefficient　is　lower　as　well　as　the　modulus　of　resilience,which　could　reduce　the　emperature　gradient　among　the　structure　layers　effectively　and　then　minish　the　thermal　stress　At　the　same　time,the　adequate　flexibility　performance　of　the　LSAM　may　also　absorb　strain　energy　at　the　crack　of　the　semi?rigid　subbase　sufficiently　As a　result,itpresented　preferable　reflection　crack　resistance　A　case　study　was　conducted　to do　comparative　analysis　of　anti?cracking　performance　of　LSAM-30,ATPB-30　and　AC-30I　flexible　bases　A　long?term　follow?up　observation　of　test　roads　with　the　three　bases　shows　that　the　pavement　with　LSMA　base　is　in　good　condition　and　no　sign　of　crack　found　while　pavements　with　ATPB?30　and　AC?30I　flexible　bases　have　varying　degrees　of　crack　LSMA　flexible　base　has　an　obvious　performance　of　anti-crack     

Research on Adaptability of Semi?rigid Material as Base Course for Long-life Asphalt Pavement

In　the　light　of　semi?rigid　material　as　base　course　for　perpetual　asphalt　pavement,the　bearing　capacity　and　fatigue　life　of　asphalt　pavement　with　semi-rigid　base　cause　and　different　asphalt　layer's　thickness　were　computed　with　BISAR30　after　chosen　typical　pavement　The　impact　of　thickened　layer　on　the　stress　of　the　semi?rigid　base,the　dry　shrinkage　and　temperature　shrinkages　of　the　material　were　analyzed,and　its　adaptability　as　base　for　perpetual　pavement　was　studied　The　result　shows　that　(1)　under　the　same　load,with　thickening　of　the　asphalt　layer,the　compressive　stress　on　the　top　and　the　tensile　stress　at　the　bottom　of　the　semi?rigid　base　decrease　obviously　and　the　fatigue　life　of　the　base　increases　substantially;　(2)the　impact　of　temperature　and　humidity　on　the　semi-rigid　base　is　remarkably　weakened,which　leads　to　the　fractures,erosion　and　reflecting　cracks　of　the　semi?rigid　base　to　be　controlled　effectively