Standard Method for Sieve Analysis of Fine and Coarse Aggregates (ASTM C136)

Summary

This video demonstrates the dry sieve analysis method for determining particle size distribution of aggregates as per ASTM C136. It involves sieving a known mass of dry aggregate through a series of sieves with decreasing openings to assess material grading and compliance with specifications. Essential tools include a precise balance, test sieves, a mechanical shaker, and an oven. The process starts with drying the sample at 110°C, weighing it, and then sieving it to measure the mass of particles retained on each sieve. The final data provides the particle size distribution, crucial for aggregate quality control in various mixtures.

Takeaways

• 📏 The dry, civic test method is used to determine the particle size distribution of fine and coarse aggregates according to ASTM C136.
• 🔍 The test is crucial for grading materials proposed for use as aggregates and ensuring compliance with particle size distribution specifications.
• 🧐 A balance or scale with specific readability requirements is necessary for testing fine and coarse aggregates.
• 🏗️ Test sieves conforming to ASTM E11 specifications are required, along with a mechanical sieving device to facilitate particle movement.
• 🌡️ An oven capable of maintaining a uniform temperature of 110 degrees Celsius is used to dry the test samples.
• 📐 The test procedure involves nesting sieves in order of decreasing size openings and placing the test sample on the top sieve.
• ⏱️ Sieves are agitated for a sufficient period to ensure accurate particle separation, with no more than 1% of material passing through any single sieve in one minute.
• 🔬 The mass of each sample size increment is measured and recorded to the nearest 0.1 gram after sieving.
• 🔄 The total mass of the sieve sample should closely match the original mass of the test sample, with discrepancies over 0.3% indicating a need to repeat the test.
• 📊 Recording includes the percentage of material passing each sieve, retained on each sieve, and passing consecutive sieves, providing data for particle size distribution.

Q & A

What is the purpose of the dry, civic test method described in the script?

The purpose of the dry, civic test method is to determine the particle size distribution of fine and coarse aggregates in accordance with ASTM C136, which is primarily used to determine the grading of materials proposed for use as aggregates and to ensure compliance with particle size distribution specifications.

What is the main application of the sieve analysis of fine and coarse aggregates?

The sieve analysis is mainly used to determine the grading of materials for use as aggregates, to ensure compliance with specifications, and to provide data for quality control in the production of aggregate products and mixtures.

What devices are required for the sieve analysis test method?

The required devices include a balance or scale, test sieves conforming to ASTM E11 specifications, a mechanical sieving device, an oven capable of maintaining a uniform temperature of 110 degrees Celsius, a sieve brush, a sample container or pan, a sieve pan, a sieve stack cover, and a method to record and analyze test findings.

Why is it important to limit the quantity of test materials on any given sieve during the sieving operation?

It is important to limit the quantity of test materials on any given sieve to ensure that all particles have the opportunity to reach the sieve openings multiple times during sieving operations, which is crucial for accurate particle size distribution analysis.

What is the procedure for preparing the test sample before sieving?

The procedure involves drying the test sample in an oven at a constant temperature of 110 degrees Celsius, measuring the tare weight of the sample container, placing the test sample into the container and measuring its gross weight, and then selecting suitable test sieves with openings that provide enough information as required by the specifications.

How should the test sieves be nested for the sieve analysis?

The test sieves should be nested in order of decreasing size openings from top to bottom, with the largest opening at the top and the smallest at the bottom.

What is the role of a mechanical sieving device in the test method?

A mechanical sieving device is used to agitate the sieves, creating motion that causes the particles to bounce, tumble, or turn, presenting different orientations to the sieving surface, which aids in the separation of particles based on size.

How long should the sieves be agitated during the sieving process?

The sieves should be agitated for a sufficient period of time so that not more than one percent by mass of the material retained on any individual sieve will pass that sieve during one minute of continuous sieving.

What should be done after the sieving process is complete?

After the sieving process, the mass weight of each sample size increment on a scale or balance should be measured and recorded to the nearest 0.1 gram. This process should be repeated for each sieve and the sieve pan.

What should be recorded and analyzed after the sieving process to determine the particle size distribution?

The total percentage of material passing each sieve, the mass of the material retained on each test sieve and pan, and the percentage of material retained passing consecutive sieves should be recorded and analyzed to determine the particle size distribution of the test sample.

What should be done if the total mass of the sieve sample differs by more than 0.3 percent from the original dry sample mass?

If the total mass of the sieve sample differs by more than 0.3 percent from the original dry sample mass, the results should not be used, and the test should be repeated.