Aggregate Selection
Aggregate Selection - 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...
08:52
Generation of Murine Cardiac Pacemaker Cell Aggregates Based on ES-Cell-Programming in Combination with Myh6-Promoter-Selection
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Cited by 13 •
2015
This protocol describes how to produce functional sinus nodal tissue from murine pluripotent stem cells (PSC). T-Box3 (TBX3) overexpression plus cardiac Myosin-heavy-chain (Myh6) promoter antibiotic selection leads to highly pure pacemaker cell aggregates. These “Induced-sinoatrial-bodies” (“iSABs”) contain over 80% pacemaker cells, show highly increased beating rates and are able to pace myocardium ex vivo.
04:12
Protein Aggregate Formation Assay: A Method to Detect and Quantify Protein Aggregation in Cultured Cells upon Induction by Proteasome Inhibitor
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2025
In this video, we demonstrate a cell-based protein aggregation assay using proteasome inhibitors, which block proteasome activity, preventing misfolded, mutant proteins, fused to a fluorescent label, from undergoing ubiquitin-dependent proteasomal degradation, leading to their accumulation within the cell cytoplasm. The protein aggregates are then visualized and quantified by fluorescence microscopy.
09:22
In Vitro Aggregation Assays Using Hyperphosphorylated Tau Protein
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Cited by 21 •
2015
Unmodified and hyperphosphorylated tau proteins were used in two in vitro aggregation assays to reveal the hyperphosphorylation-dependent fast aggregation kinetics. These assays pave the way for future screens for compounds that can modulate the propensity of hyperphosphorylated tau to form fibrils that underlie the progression of Alzheimer’s disease.
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.
FAQs
Gradation determines how coarse and fine particles fit together, influencing packing, workability, and permeability. A suitable distribution of particle sizes can support a more stable aggregate structure, while an unsuitable blend may increase the risk of segregation or reduce constructability. Engineers therefore use particle-size information to proportion blends for concrete, asphalt, road bases, and related materials.
Particle shape and surface texture affect how aggregates pack, move, and interact with a binder. These characteristics influence workability and bonding, which in turn affect the material’s ability to resist load and environmental damage. Evaluating them helps engineers avoid a blend that is difficult to place or that develops inadequate interaction with cement, bitumen, or another binder.
These properties indicate how an aggregate may perform during service. Strength relates to resistance under load, while durability concerns continued performance under environmental exposure. Absorption and chemical stability affect how particles interact with the surrounding binder and environment. Considering all four helps reduce risks such as cracking, excessive wear, and premature failure in the finished material.
The required aggregate characteristics depend on whether the particles will be used in concrete, asphalt, a road base, or another construction material. Each application involves different interactions with cement, bitumen, or other binders and different performance demands. Selection must therefore connect measured aggregate properties with the intended material’s structural, durability, and constructability requirements.
Sieve analysis provides information about the particle-size distribution of an aggregate or blend. Engineers use those results to evaluate gradation and determine whether the proportions of coarse and fine particles are suitable for the intended application. The findings can guide adjustments to the blend before laboratory performance tests assess how it behaves with the selected binder.
Engineers first identify the intended construction material and its performance needs, then assess properties such as gradation, size, shape, texture, strength, durability, absorption, and chemical stability. Sieve analysis helps characterize particle distribution, while laboratory performance tests examine binder interaction and material behavior. The blend can then be selected or proportioned to support performance and constructability.
A suitable blend can improve structural performance, service life, constructability, and resource efficiency. Its properties may also help control permeability, bonding, and resistance to load or environmental damage. By matching aggregate characteristics to the application, engineers can reduce the likelihood of segregation, cracking, excessive wear, and premature failure in concrete, asphalt, road bases, and other materials.