gravel
Enable an AI agent to recognise gravel, describe its grain population and condition, and assess whether a particular deposit or lot is suitable for an intended use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an AI agent to recognise gravel, describe its grain population and condition, and assess whether a particular deposit or lot is suitable for an intended use.
Gravel is an unconsolidated granular material composed predominantly of rock fragments in a particle-size class coarser than sand, with the class boundaries depending on the geological or engineering classification used.
It can be Classify a representative sample under a selected gravel classification convention.; Compare a lot's measured grading and condition with requirements for a stated use.; Identify whether screening, washing or controlled blending could address a measured mismatch.; Plan sampling that detects fines migration, segregation and variation across a deposit or stockpile.; Estimate quantity from measured mass or volume using condition-specific evidence.; Flag lots requiring further durability, contamination or hydraulic testing before use..
Distinguishing features
An examined sample consists of discrete grains rather than a coherent rock mass; cemented material requires a boundary decision.
Measured grain sizes support a gravel designation under an explicitly named classification convention; appearance alone is insufficient.
The gravel-sized fraction and the classification of the whole mixture are recorded separately, preventing a sand-rich mixture from being described solely by its largest grains.
Particle shape and processing history distinguish rounded or naturally fragmented gravel from crushed aggregate where the selected terminology makes that distinction.
A material lot is distinguished from a gravel bed or commercial product name by an explicit sampling and quantity boundary.
Scope
+ Grain-size distribution and the convention used to classify gravel
+ Particle shape, rock composition, weathering and unwanted constituents
+ Natural deposits, extracted lots and processed gravel with traceable origins
+ Moisture, fines, packing and segregation within a described quantity
+ Evidence of suitability for a stated application and permitted processing
- Individual rock specimens and their full geological classification
- Sand, silt and clay as independently modelled materials
- Cemented conglomerate and other coherent rock masses
- Quarries, river systems and landforms containing gravel
- Concrete, asphalt, roads and drainage systems incorporating gravel
- Extraction equipment, transport vehicles and operating organisations
Characteristics
- Classification convention
- Named classification system, version and applicable context Controls grain-size boundaries and the meaning of the gravel designation.
- Particle-size distribution
- Percentage by dry mass passing or retained at stated sieve apertures in mm Establishes size composition and supports application-specific grading checks.
- Fine-material content
- Percentage by dry mass below an explicitly stated size threshold and test method Helps assess drainage, handling and sensitivity to water without assuming all fines behave alike.
- Particle shape and surface texture
- Roundness, angularity, flatness, elongation and texture using a stated assessment method Supports distinction between material types and assessment of packing and mechanical behaviour.
- Rock composition
- Constituent rock types and estimated proportions with mass, volume or particle-count basis A gravel lot can contain multiple rock types with different durability and application constraints.
- Origin and processing history
- Source deposit or supplier lot linked to extraction, screening, washing, crushing and blending records Connects current properties to provenance and identifies changes requiring reassessment.
- Water content
- Percentage water mass relative to dry material mass, with method and sampling time Supports dry-mass comparisons and interpretation of handling and condition.
- Bulk density
- kg/m³ with moisture and loose, settled or compacted condition stated Allows defensible mass-volume conversion for the measured condition.
- Weathering and particle degradation
- Observed weathering, friability and breakage, supported by relevant test results Identifies material that may change grading or lose performance during handling or service.
- Unwanted constituents
- Identified constituents with concentration or proportion, method and detection limits where applicable Supports decisions about acceptance, separation, further testing or restricted use.
- Hydraulic conductivity
- m/s with grading, packing, saturation and test conditions Provides evidence for drainage use rather than inferring performance from the gravel label.
- Application acceptance
- Unassessed, accepted, conditionally accepted or rejected against named requirements Prevents suitability for one use from being treated as universal approval.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Grain identity Establishes what the gravel designation means for the material being assessed.
Gravel identity depends on grain-size conventions and mixture boundaries, not simply on a familiar appearance.
Size classification
Connects measured sizes to an explicit classification system.
Gravel size boundary
Record the governing size limits and the evidence supporting the assigned class.
- Which classification convention and version define gravel for this assessment? definition
- What proportion of the sample falls within that convention's gravel-size interval? measurement
Material sense
Separates grain-size terminology from geological and commercial naming.
Gravel and neighbouring materials
Resolve whether the designation refers to a size fraction, a whole sediment mixture or a supplied aggregate product.
- Does gravel name the whole material, its coarse fraction or a commercial product designation? definition
- How does the selected convention distinguish this material from crushed stone, sandy gravel and cemented conglomerate? boundary
Particle makeup Describes the grains and accompanying constituents that make up the gravel.
Lots with similar grain sizes can differ substantially in composition, shape and particle integrity.
Rock and shape
Characterises constituent rock types and grain geometry.
Constituent grain population
Record composition and shape distributions rather than assigning one rock type or shape to every grain.
- Which rock types occur, in what proportions, and on what measurement basis? measurement
- How are roundness, angularity, flatness, elongation and surface texture distributed across the sampled grains? measurement
Fines and particle condition
Examines accompanying fine material, grain coatings and damaged particles.
Fines, coatings and weathering
Distinguish loose fines, adhering coatings and degrading grains because they call for different assessments.
- How much fine material is present, and is it loose, attached to grains or generated by particle breakdown? measurement
- What evidence identifies weathered, friable or otherwise unwanted particles and constituents? measurement
Deposit and lot provenance Connects a described quantity of gravel to its origin, processing and sampling history.
A sample from one part of a deposit or stockpile cannot automatically represent every quantity sharing its name.
Origin and transformation
Tracks source material and operations that changed its grain population.
Source to current material
Maintain a traceable account of where the gravel came from and how the assessed lot was produced.
- Which deposit, extraction area or supplier lot is the documented source? provenance
- Which screening, washing, crushing or blending operations occurred before the current assessment? provenance
Sampling and variability
Defines what each observation represents and where variation remains unresolved.
Representative gravel sample
Link sample results to a bounded deposit interval or lot and document potential segregation.
- What physical extent, quantity and sampling date does this sample represent? boundary
- How did sampling account for coarse-particle segregation, fines concentration and spatial variation? provenance
Bulk condition and performance Describes gravel as an assemblage of grains with water and void space.
Drainage, packing and mechanical performance depend on the assembled material's condition as well as its individual particles.
Packing and water
Captures the physical state needed to interpret bulk measurements.
Condition-specific bulk properties
Attach moisture and packing conditions to density, void-space and flow observations.
- What are the measured water content and bulk density, and was the gravel loose, settled or compacted? measurement
- Under what grading, packing and saturation conditions was hydraulic conductivity measured? measurement
Breakdown and service response
Examines whether handling or intended service changes the material's useful properties.
Performance under stated exposure
Record relevant evidence of particle breakdown and durability for the expected loads and exposure.
- Which tests or observations assess particle breakdown under the intended handling and loading conditions? measurement
- Which exposure-specific durability questions remain unresolved for the proposed use? boundary
Use and material adjustment Connects measured gravel properties to application decisions and subsequent processing.
The gravel label alone does not establish suitability, and processing can invalidate earlier measurements.
Application fit
Compares the assessed material with a concrete set of use requirements.
Evidence-based acceptance
Keep acceptance specific to the lot, application, requirements and supporting evidence.
- Which application and named requirements govern grading, cleanliness, durability and other acceptance properties? action
- Which requirements are supported by current lot-specific measurements, and which remain unverified? measurement
Processing and reassessment
Determines appropriate material adjustments and the evidence needed afterward.
Adjust and retest gravel
Link proposed screening, washing or blending to a measured deficiency and a reassessment plan.
- Could screening, washing or controlled blending address the identified mismatch, and what evidence supports that choice? action
- Which properties must be resampled after processing, transport or storage changes the lot? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This entry covers gravel as a granular earth material, not a particular deposit, product grade or individual stone.
- Confirm the intended particle-size classification before assigning numerical boundaries; geological gravel can include cobbles and boulders.
- The standards are recalled without edition verification; product suitability requires checking the applicable edition and testing the actual material.
- Which of these check these first hold for the sense of gravel this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- River gravel
- Beach gravel
- Glaciofluvial gravel
- Pea gravel
- Crushed gravel
- Washed gravel
- Which of these kinds and varieties hold for the sense of gravel this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- ASTM International ASTM D2487: engineering classification of soils, including gravel, under the Unified Soil Classification System.
- ASTM International ASTM C33/C33M: requirements for concrete aggregates, including qualifying gravel coarse aggregates.
- European Committee for Standardization EN 12620: aggregates for concrete.
- European Committee for Standardization EN 13242: aggregates for unbound and hydraulically bound materials used in civil engineering work and road construction.
- Which of these standards and regulation hold for the sense of gravel this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Coarse aggregate in concrete.
- Road base, subbase and unbound road surfacing.
- Drainage layers and trench backfill.
- Graded filter media.
- Landscaping and pedestrian surfacing.
- Which of these real-world use hold for the sense of gravel this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Particle diameter in the Udden-Wentworth sediment classification - 2-256 for granules, pebbles and cobbles; the broader gravel category also includes larger boulders - mm
- Gravel particle size in the Unified Soil Classification System - Passing the 75 mm sieve and retained on the 4.75 mm sieve - mm
- Which of these typical measurements hold for the sense of gravel this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Settlement or rutting under load when placement, grading or compaction is inadequate.
- Clogging of drainage voids by migrating fines or accumulated sediment.
- Particle breakdown under abrasion or freeze-thaw exposure where the constituent rock is insufficiently durable.
- Potential alkali-silica reaction when reactive gravel constituents are used in concrete.
- Respirable dust exposure during handling or crushing, including crystalline silica where present.
- Which of these failure modes and hazards hold for the sense of gravel this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Geological and engineering systems use different gravel size boundaries; US engineering classification commonly uses 4.75 mm as the lower boundary, while several other systems use 2 mm.
- Commercial labels such as pea gravel and numbered gravel grades have locally defined size ranges.
- Local geology controls mineral composition, colour, durability and potential concrete reactivity.
- Which of these regional variation hold for the sense of gravel this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- sand - Sand occupies the finer particle-size class immediately below gravel; the separating size depends on the classification system.
- crushed stone - Crushed stone is produced by mechanically breaking rock; gravel commonly denotes naturally accumulated fragments, although gravel can also be crushed during processing.
- aggregate - Aggregate is a broader material category that includes gravel, sand, crushed stone and other granular constituents.
- conglomerate - Conglomerate is a consolidated sedimentary rock containing rounded gravel-size clasts; gravel is unconsolidated.
- pebble - A pebble is an individual clast in a particular size class; gravel denotes a granular material or a broader sediment-size category.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of gravel this model covers, and on what evidence? provenance
What the second pass must settle
- Which geological, geotechnical and aggregate classification conventions should this registry support, and how should their differing gravel boundaries be represented?
- Does this entry include crushed gravel and commercially labelled crushed stone, or should those materials link to a neighbouring aggregate model?
- Which sampling methods adequately represent each supported form: natural deposit, stockpile and delivered lot?
- Which application-specific test methods and acceptance requirements should be linked for drainage, unbound construction and concrete aggregate uses?
- What existing Vercy models cover sediment, rock and aggregate, and which shared concepts should this model reference rather than duplicate?