Aggregate Testing
Aggregate Testing - Related Videos
10:10
Aggregates for Concrete and Asphaltic Mixes
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA Concrete and asphalt are by far the most common construction materials used today. Concrete is a composite material consisting of cement, water, air, coarse aggregate, and fine aggregates. Fine aggregates are typically sands and coarse aggregates are natural or crushed rocks. Chemical admixtures to modify certain specific properties are also commonly used (i.e., superplasticizers to make the...
11:23
Tests on Fresh Concrete
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2017
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA Concrete consists of two phases, a cement paste phase comprised of cement, water, and air, and an aggregate phase comprised of coarse and fine aggregates. There are two key considerations when designing a concrete mix. First, the concrete must be workable and easy to cast in the forms in its fresh condition, even when the forms are packed with steel reinforcement. In this condition, it is the...
10:09
Tests of Hardened Concrete in Tension
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA In a previous laboratory focused on concrete in compression, we observed that concrete can withstand very large stresses under uniaxial compressive forces. However, the failures observed were not compressive failures but failures along shear planes where maximum tensile forces occur. Thus, it is important to understand the behavior of concrete in tension and particularly its maximum strength...
11:57
Methods to Study Changes in Inherent Protein Aggregation with Age in Caenorhabditis elegans
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Cited by 7 •
2017
The goal of the method presented here is to explore protein aggregation during normal aging in the model organism C. elegans. The protocol represents a powerful tool to study the highly insoluble large aggregates that form with age and to determine how changes in proteostasis impact protein aggregation.
01:20
Aggregate Demand and Aggregate Supply: A Brief Introduction
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2026
The aggregate demand and aggregate supply model is used to understand how the economy behaves over time. It shows how changes in overall spending and production affect total output and prices. This model helps explain periods of growth and slowdown in a simple way.Aggregate demand is the total amount of goods and services people, firms, governments, and foreign buyers are willing to buy at different price levels. When prices fall, people can buy more with the same income, leading to higher...
FAQs
Sieve analysis separates aggregate particles by size to establish particle-size distribution. Engineers compare the resulting distribution with specification requirements before selecting material or proportioning concrete, asphalt mixtures, or base courses. This information helps identify whether a batch has the size characteristics needed for its intended use and provides a consistent basis for quality control.
Particle shape is examined as a separate property because aggregates with different shapes can affect whether a material satisfies performance and specification requirements. Measuring this characteristic alongside size distribution prevents selection based on particle size alone. The resulting information supports engineering decisions about aggregate suitability and mixture proportioning, particularly when consistency between batches matters.
Specific gravity and water absorption describe different aspects of aggregate behavior that engineers consider during selection and proportioning. Specific gravity contributes to characterizing the material, while absorption indicates how much water the aggregate may take up. High absorption can signal a material likely to absorb excessive water, making these results relevant to mixture control and performance requirements.
Abrasion resistance and soundness evaluate separate ways an aggregate may become unsuitable. Abrasion testing addresses resistance to wear, whereas soundness testing examines behavior under defined conditions that can reveal a tendency to degrade. Considering both results gives engineers a broader basis for rejecting materials likely to deteriorate and for verifying compliance with project specifications.
A typical workflow applies laboratory procedures to an aggregate sample, measures selected properties, and compares the results with performance and specification requirements. Depending on the engineering purpose, testing may include sieve analysis, particle shape, specific gravity, water absorption, abrasion resistance, and soundness. The findings then guide material selection, mixture proportioning, and quality-control decisions.
Engineers use the results when selecting aggregates and proportioning concrete, asphalt mixtures, or base courses. The same data also support quality control by checking whether supplied material meets design standards and by identifying excessive absorption or likely degradation. In this way, testing connects laboratory measurements with decisions intended to improve infrastructure safety, durability, and construction consistency.