Highway Materials, Soils and Concretes

$4-$ Given: a$-$ Using the AASHTO Classification System classify the following soil sample.

Test results:

Sieve size

$\%$ passing

$1^{\text{'}\text{'}}$

$100$

No$.10$

$62$

No$.40$

$45$

No$.200$

$21$

$LL$ or $WL=31$

PI or IP $=20$

Find: Use the AASHTO Chart and write the steps left to right explaining why it is not a certain classification.