kb/data/en.wikipedia.org/wiki/AASHTO_Soil_Classification_System-0.md

title	chunk	source	category	tags	date_saved	instance
AASHTO Soil Classification System	1/1	https://en.wikipedia.org/wiki/AASHTO_Soil_Classification_System	reference	science, encyclopedia	2026-05-05T09:08:40.762171+00:00	kb-cron

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, but has been revised several times since.

Plasticity 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 ==

== See also == Unified Soil Classification System