aashto, soil, classification, system, developed, american, association, state, highway, transportation, officials, used, guide, classification, soils, soil, aggregate, mixtures, highway, construction, purposes, classification, system, first, developed, hogento. The AASHTO Soil Classification System was developed by the American Association of State Highway and Transportation Officials and is used as a guide for the classification of soils and soil aggregate mixtures for highway construction purposes The classification system was first developed by Hogentogler and Terzaghi in 1929 1 but has been revised several times since AASHTO Soil Classification System from AASHTO M 145 or ASTM D3282 General Classification Granular Materials 35 or less passing the 0 075 mm No 200 sieve Silt Clay Materials gt 35 passing the 0 075 mm No 200 sieve Group Classification A 1 A 3 A 2 A 4 A 5 A 6 A 7A 1 a A 1 b A 2 4 A 2 5 A 2 6 A 2 7 A 7 5 A 7 6Sieve Analysis passing2 00 mm No 10 50 max 0 4255 mm No 40 30 max 50 max 51 min 0 0755 mm No 200 15 max 25 max 10 max 35 max 35 max 35 max 35 max 36 min 36 min 36 min 36 minCharacteristics of fraction passing 0 425 mm No 40 Liquid Limit 40 max 41 min 40 max 41 min 40 max 41 min 40 max 41 minPlasticity index 6 max N P 10 max 10 max 11 min 11 min 10 max 10 max 11 min 11 min1Usual types of significant constituent materials stone fragments gravel and sand fine sand silty or clayey gravel and sand silty soils clayey soilsGeneral rating as a subgrade excellent to good fair to poorPlasticity index of A 7 5 subgroup is equal to or less than the LL 30 Plasticity index of A 7 6 subgroup is greater than LL 30 References edit Hogentogler C A Terzaghi K May 1929 Interrelationship of load road and subgrade Public Roads 37 64 See also editUnified Soil Classification System Retrieved from https en wikipedia org w index php title AASHTO Soil Classification System amp oldid 1006095466, wikipedia, wiki, book, books, library,
