pH TEST ON SOIL-CEMENT MIXTURES
B-1. Materials. Portland cement to be used for soil stabilization.
B-2. Apparatus. Apparatuses used are the pH meter (the pH meter must
be equipped with an electrode having a pH range of 14), 150-millilitre
plastic bottles with screw-top lids, 500-millilitre plastic beakers, distilled
water, balance, oven and moisture cans.
a. Standardization. Standardize the pH meter with a buffer solution
having a pH of 12.00.
b. Representative samples. Weight to the nearest 0.01 grams, representa-
tive samples of air-dried soil, passing the No. 40 sieve and equal to 25.0
grams of oven-dried soil.
c. Soil samples. Pour the soil samples into 150-millilitre plastic bottles
with screw-top lids.
d. Portland cement. Add 2.5 grams of the portland cement.
e. Mixture. Thoroughly mix soil and portland cement.
f. Distilled water. Add sufficient distilled water to make a thick paste.
(Caution: Too much water will reduce the pH and produce an incorrect
Stir the soil-cement
and water until thorough blending
h. Transferal After 15 minutes, transfer part of the paste to a plastic
beaker and measure the pH.
If the pH is 12.1
the soil organic matter
content should not interfere with the cement stabilizing mechanism.