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IfcConstructionMaterialResource

Definition from IAI: An IfcConstructionMaterialResource identifies a material resource type in a construction project. Occurrences of IfcConstructionMaterialResource are consumed (wholly or partially), or occupied during a construction work task (i.e. Task).

The product, which is used as a construction material resource, is referenced using the IfcRelAssignsToResource relationship. The inherited relationship ResourceOf.RelatedObjects points to the IfcProduct instance.

ISSUES: See issue and change log for changes made in IFC 2x.
HISTORY: New Entity in IFC Release 2.0

Use Definition

Similar to IfcConstructionProductResource, sometimes things such as 5 tons 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 ‘5 tons 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. ‘5 tons 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.

EXPRESS specification:

ENTITY IfcConstructionMaterialResource
SUBTYPE OF ( IfcResource);
Suppliers  :  OPTIONAL SET [1:?] OF IfcActorSelect;
OrderQuantity  :  OPTIONAL IfcMeasureWithUnit;
DesignMaterial  :  OPTIONAL SET [1:?] OF IfcMaterial;
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.
OrderQuantity  :  The basic quantity for ordering.
DesignMaterial  :  The materials specified by the design process that needs to be procured in the construction processes as the resource.

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.

References (1):

Name Type Referred through Express-G
IfcResource Entity
Subtype
Diagram 1

Inheritance graph

ENTITY IfcConstructionMaterialResource;
ENTITY IfcRoot;
GlobalId  :  IfcGloballyUniqueId;
OwnerHistory  :  IfcOwnerHistory;
Name  :  OPTIONAL IfcLabel;
Description  :  OPTIONAL IfcText;
ENTITY IfcObject;
ObjectType  :  OPTIONAL IfcLabel;
INVERSE
IsDefinedBy  :  SET OF IfcRelDefines FOR RelatedObjects;
HasAssociations  :  SET OF IfcRelAssociates FOR RelatedObjects;
HasAssignments  :  SET OF IfcRelAssigns FOR RelatedObjects;
Decomposes  :  SET OF IfcRelDecomposes FOR RelatedObjects;
IsDecomposedBy  :  SET [0:1] OF IfcRelDecomposes FOR RelatingObject;
ENTITY IfcResource;
ResourceConsumption  :  OPTIONAL IfcResourceConsumptionEnum;
BaseUnit  :  OPTIONAL IfcMeasureWithUnit;
INVERSE
ResourceOf  :  SET OF IfcRelAssignsToResource FOR RelatingResource;
ENTITY IfcConstructionMaterialResource;
Suppliers  :  OPTIONAL SET [1:?] OF IfcActorSelect;
OrderQuantity  :  OPTIONAL IfcMeasureWithUnit;
DesignMaterial  :  OPTIONAL SET [1:?] OF IfcMaterial;
END_ENTITY;