Determinação do equivalente de areia de solos e agregado miúdo

Summary

This video showcases the laboratory procedure for determining the sand equivalent of soils and fine aggregates. It outlines essential steps, including sample preparation, mixing solutions, and the precise measurement of materials. Viewers learn how to create a specific solution, perform sieving, and use a measuring cylinder to assess the presence of fine plastic elements in soil samples. The process emphasizes careful observation, accurate measurements, and the importance of recording results, ultimately providing a quantitative and qualitative assessment of the soil's fine material content.

Takeaways

• 🔬 The laboratory procedure focuses on determining the sand equivalent of soils or aggregates.
• 💧 A solution is prepared using distilled water and a concentrated solution to evaluate fine plastic elements in a soil sample.
• 🧪 The sample must consist of material that passes through a 4.8 mm sieve, weighing between 500 to 700 grams.
• ⚗️ Proper preparation involves moistening the sample with distilled water before sieving and homogenizing.
• 🔄 The test involves mixing a specific volume of the prepared solution with the soil sample in a controlled manner.
• 📏 Accurate measurements are crucial, including ensuring the solution reaches the designated marks in the measuring cylinder.
• ⏳ The sample must rest undisturbed for specific time intervals to allow proper settling and measurement.
• 📊 The sand equivalent is calculated by comparing the levels of sand and clay in the sample.
• 🔍 Further tests for Atterberg limits may be necessary to assess the characteristics of the fine materials present.
• ✅ The final result is expressed as a percentage, providing insights into the composition of the soil sample.

Q & A

What is the purpose of the laboratory tests conducted by CCR?

The laboratory tests are designed to evaluate the quantity and quality of fine plastic elements contained in soil or fine aggregate samples.

How much distilled water is initially prepared for the sand equivalent test?

A total of 4875 ml of distilled water is prepared, to which 125 ml of concentrated solution is added, completing a total of 5 liters.

What is the recommended weight of the sample used for the sand equivalent test?

The sample should weigh between 500 to 700 grams and should pass through a 4.8 mm sieve.

What is the role of the rubber stopper and copper tubes in the testing process?

The rubber stopper with two copper tubes is placed over the flask's opening to facilitate the controlled release of the solution during the test.

What should be done after pouring the solution into the measuring container?

After pouring, the sample must be leveled off, and the bottom of the measuring container should be pressed firmly to remove air bubbles.

How long should the sample be left undisturbed in the measuring container?

The sample should be left undisturbed for 20 minutes to allow proper sedimentation.

What is the significance of the 38 cm reference line in the test?

The 38 cm reference line indicates where the liquid should be when the agitation process has been completed.

How is the sand equivalent calculated?

The sand equivalent is calculated by dividing the reading at the top of the sand layer by the reading at the top of the clay layer, then multiplying by 100 to express it as a percentage.

What should be done if the value of the sand equivalent is less than 20?

If the value is less than 20, it indicates that the fine particles present are primarily clayey, necessitating further tests to determine Atterberg limits.

What does the process aim to achieve regarding fine materials in the sample?

The process aims to quantify and qualify the percentage of fine materials contained in the soil or aggregate sample.