IfcConstructionMaterialResource

Definition from IAI: An IfcConstructionMaterialResource identifies a material resource type in a construction project.

> HISTORY: New Entity in IFC Release 2.0

### Use Definition

Occurrences of IfcConstructionMaterialResource are consumed (wholly or partially), or occupied during a construction work task (i.e. IfcTask).

Similar to IfcConstructionProductResource, sometimes things such as 5000kg of gravel are already instantiated as an IfcProduct because it is a result of a work task e.g. ‘transporting gravel’. In this case, the instance of IfcConstructionMaterialResource can be associated with the product instance ‘5000kg of gravel’ to provide more information for resource uses. Nevertheless, IfcConstructionMaterialResource should only be used to represent resource types, e.g. ‘gravel’, but not product substances, e.g. ‘5000kg of gravel’.

Note: This class is not the same as IfcMaterial; the former can typically represent the type of bulk materials such as sand, gravels, nails and so on (note these can be instantiated from IfcProduct as well depending their uses in the system) used in a construction process. The latter is about physical materials used in a physical building element typically with detailed positioning (e.g. offset) and layering information.

The association of an actual material with an IfcConstructionMaterialResource is handled by IfcRelAssociatesMaterial.

Quantities for an IfcConstructionMaterialResource are defined through IfcRelDefinesByProperty and use IfcElementQuantity.

EXPRESS specification:

ENTITY IfcConstructionMaterialResource
SUBTYPE OF ( | IfcConstructionResource);
Suppliers | : | OPTIONAL SET [1:?] OF IfcActorSelect;
UsageRatio | : | OPTIONAL IfcRatioMeasure;
WHERE
WR1 | : | SIZEOF(SELF\IfcResource.ResourceOf) <=1;
WR2 | : | NOT(EXISTS(SELF\IfcResource.ResourceOf[1])) OR (SELF\IfcResource.ResourceOf[1].RelatedObjectsType = IfcObjectTypeEnum.PRODUCT);
END_ENTITY;

Attribute definitions:

Suppliers | : | Possible suppliers of the type of materials.
UsageRatio | : | The ratio of the amount of a construction material used to the amount provided (determined as a quantity)

Formal Propositions:

WR1 | : | There should only be a single relationship, assigning products to the material resource.
WR2 | : | If a reference to a resource is given, then through the IfcRelAssignsToResource relationship with the RelatedObjectType PRODUCT.

Inheritance graph

ENTITY IfcConstructionMaterialResource;
ENTITY IfcRoot;
GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
ENTITY IfcObjectDefinition;
INVERSE
HasAssignments | : | SET OF IfcRelAssigns FOR RelatedObjects;
IsDecomposedBy | : | SET OF IfcRelDecomposes FOR RelatingObject;
Decomposes | : | SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject;
ObjectType | : | OPTIONAL IfcLabel;
INVERSE
IsDefinedBy | : | SET OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcResource;
INVERSE
ResourceOf | : | SET OF IfcRelAssignsToResource FOR RelatingResource;
ENTITY IfcConstructionResource;
ResourceIdentifier | : | OPTIONAL IfcIdentifier;
ResourceGroup | : | OPTIONAL IfcLabel;
ResourceConsumption | : | OPTIONAL IfcResourceConsumptionEnum;
BaseQuantity | : | OPTIONAL IfcMeasureWithUnit;
ENTITY IfcConstructionMaterialResource;
Suppliers | : | OPTIONAL SET [1:?] OF IfcActorSelect;
UsageRatio | : | OPTIONAL IfcRatioMeasure;
END_ENTITY;