AASHTO T27
Full Name
AASHTO T27 – Standard Method of Test for Sieve Analysis of Fine and Coarse Aggregates
Scope
AASHTO T27 is a standard test method used to determine the particle size distribution (gradation) of fine and coarse aggregates. Gradation is the distribution of different particle sizes within an aggregate sample, and it is a critical factor in the performance of asphalt and concrete mixtures. This test is essential for quality control in aggregate production, mix design, and construction specifications compliance.
Key aspects of AASHTO T27:
- Purpose: the primary objective of sieve analysis is to quantify the percentage of aggregate particles passing through a series of standard sieves with progressively smaller openings. This information helps assess the suitability of aggregates for various applications and ensures that the aggregates meet the specified gradation requirements.
- Test procedure: the test involves sieving a known mass of the aggregate sample through a nested set of sieves with different opening sizes. The sieves are stacked in descending order of opening size, with the largest sieve at the top. The sample is shaken or vibrated for a specified duration, allowing the particles to pass through the sieves based on their size. The mass of material retained on each sieve is measured, and the percentage passing each sieve is calculated.
- Significance: the gradation of aggregate significantly affects the performance of asphalt and concrete mixtures. It influences the workability, strength, durability, permeability, and overall performance of the final product. By determining the gradation, engineers and contractors can select appropriate aggregates for specific applications and optimize mix designs to achieve the desired properties.
Applications of AASHTO T27:
- Aggregate quality control: this test is routinely used by aggregate producers to monitor the quality and consistency of their products. It helps ensure that the aggregates meet the specified gradation requirements and conform to industry standards.
- Mix design: the sieve analysis results are used in mix design calculations to determine the proportions of different aggregate sizes required to achieve the desired properties of the asphalt or concrete mixture.
- Construction specifications: many construction specifications include gradation requirements for aggregates. This test is used to verify that the aggregates used in the project comply with the specified gradation limits.
AASHTO T27 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T27 standard.
Our laboratory offers comprehensive aggregate testing services, including sieve analysis according to AASHTO T27. Our experienced technicians utilize calibrated sieves and standardized procedures to ensure accurate and reliable results for your construction projects.
Contact us for more information.
Resources
Keywords
sieve analysis; gradation; aggregate; fine aggregate; coarse aggregate; particle size distribution; sieve; sieve size; fineness modulus