Question

The liquid limit and plastic limit of clay soil are 45 % and 25% respectively. The soil consists of 30% of particles finer than the clay size. The classification of the clay based on activity is

• A. Normal
• B. Active
• C. Inactive
• D. Low active

Answer 1

The correct option is C Inactive

$W_L=45\%$
$W_P=25\%$

% Finer than 75 $\mu m$ sieve = 30 %

$A=\frac{I_P}{\%clayfriction}$

$A=\frac{W_L}{\%clay}=\frac{45-25}{30}=\frac{20}{30}=0.67$

$A=0.67<0.75=Inactive$