26.11. Problems

Try these first

1. 1.

   What is theoretical specific gravity?

   Hint

   Think about density without gaps.

2. 2.

   State the formula for calculating air voids.

   Hint

   Relate this formula to the gravity values.

3. 3.

   What is the formula for calculating theoretical specific gravity?

   • A: G_t = (W1 + W2 + W3 + Wb) / (W1/G1 + W2/G2 + W3/G3 + Wb/Gb)
   • B: G_m = W_m / (W_m – W_w)
   • C: V_v = (G_t - G_m) / G_t * 100

   Hint

   Look for the formula that accounts for weights and specific gravities.

4. 4.

   True or False: The bulk specific gravity value is affected by air voids.

   • True
   • False

   Hint

   Consider how density is impacted by gaps.

5. 5.

   Calculate theoretical specific gravity and bulk specific gravity for a mix with weights of 1000g in air and 900g in water.

   Hint

   Use the specific gravity formulas.

6. 6.

   If a Marshall mix test gives 500 kg stability with 15% flow - determine if it meets requirements of a minimal 340 stability and appropriate flow.

   Hint

   Refer back to the specification table.