engineering sampling nasional 2018 rakyat laboratory effort material ASTM bowle CT beba mekanika kementerian direktorat mada gadjah international 2012 university 1744 strength unconfined hardiyatmo characteristic conshohocken pekerjaan state bearing analysi 2011 new konstruksi highway tanah dan mcgraw method compaction learning using 2008 7th pengujian american republik testing purpose transportation compressive york badan DC laboratorium D1883 standardisasi BSN II DAFTAR standard washington marga metode umum indonesia practice tekan da yogyakarta stamford 1964 spesifikasi D2166 geotechnical cengage pres unified soil foundation compacted jembatan bina kuat 5th D2487 california design 2007 classification CBR untuk test hill PUSTAKA AASHTO cohesive 2004 SNI PA D698 jenderal perumahan 1997 association principle 2010 west jalan official jakarta 2014 specification system ratio