Answer :
To determine the AASHTO and USCS classifications for the soil based on the provided sieve analysis and Atterberg limits, let's follow the procedures for classification.
Properties calculated:
1. Liquid Limit (LL) = 26
2. Plastic Limit (PL) = 18
3. Plasticity Index (PI) = LL - PL = 26 - 18 = 8
Sieve Analysis Results:
- Based on the given table, the total mass in the pan is 168.2 grams.
- The mass passing through the No. 200 sieve (0.075 mm) is 127.2 grams.
To calculate the percentage passing through the No. 200 sieve:
[tex]\[ \text{Percent finer (0.075 mm)} = \frac{127.2 \, \text{grams}}{168.2 \, \text{grams}} \times 100 \approx 75.62\% \][/tex]
AASHTO Classification:
- Since LL = 26 and PI = 8, we check the criteria for classification:
- A soil with LL < 41 and PI < 11 typically falls under the fine-grained classifications.
- The percent finer through the No. 200 sieve is greater than 35%, which points towards fine-grained soils.
- Given these values, the soil can be classified as "A-4" in the AASHTO system, which typically includes silty soils and clayey sands.
USCS Classification:
For USCS classification:
- More than 50% passes the No. 200 sieve (75.62% finer).
- With a LL of 26 and PI of 8, we check the following:
- If LL < 50 and PI > 7, the soil is typically classified as "CL," which represents inorganic clays with low to medium plasticity.
Summary:
- AASHTO Classification: A-4
- USCS Classification: CL
This classification gives us valuable information about the type of soil, which is essential for understanding its behavior in engineering applications, like construction.
Properties calculated:
1. Liquid Limit (LL) = 26
2. Plastic Limit (PL) = 18
3. Plasticity Index (PI) = LL - PL = 26 - 18 = 8
Sieve Analysis Results:
- Based on the given table, the total mass in the pan is 168.2 grams.
- The mass passing through the No. 200 sieve (0.075 mm) is 127.2 grams.
To calculate the percentage passing through the No. 200 sieve:
[tex]\[ \text{Percent finer (0.075 mm)} = \frac{127.2 \, \text{grams}}{168.2 \, \text{grams}} \times 100 \approx 75.62\% \][/tex]
AASHTO Classification:
- Since LL = 26 and PI = 8, we check the criteria for classification:
- A soil with LL < 41 and PI < 11 typically falls under the fine-grained classifications.
- The percent finer through the No. 200 sieve is greater than 35%, which points towards fine-grained soils.
- Given these values, the soil can be classified as "A-4" in the AASHTO system, which typically includes silty soils and clayey sands.
USCS Classification:
For USCS classification:
- More than 50% passes the No. 200 sieve (75.62% finer).
- With a LL of 26 and PI of 8, we check the following:
- If LL < 50 and PI > 7, the soil is typically classified as "CL," which represents inorganic clays with low to medium plasticity.
Summary:
- AASHTO Classification: A-4
- USCS Classification: CL
This classification gives us valuable information about the type of soil, which is essential for understanding its behavior in engineering applications, like construction.
