ASTM D6815

This specification covers the procedure for testing and evaluating duration of load and creep effects of wood and wood-based materials relative to an accepted duration of load adjustment model. This specification is proposed for use for products that are covered by a consensus standard such as lumber, structural composite lumber and structural use panels. The procedure covered in this specification, however, is not intended to evaluate performance of products under impact loading.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification provides a procedure for testing and evaluating duration of load and creep effects of wood and wood-based materials relative to an accepted duration of load adjustment model. This specification was created for products that are currently covered by a consensus standard (for example, lumber, structural composite lumber and structural-use panels). This procedure is intended to demonstrate the engineering equivalence to the duration of load and creep effects of visually graded lumber as specified in Practice D 245 for a product under evaluation used in dry service conditions. This procedure is not intended to evaluate the performance of products under impact loading. Quantification of specific duration of load or creep factors is beyond the scope of this specification. For further guidance regarding the applicability of this specification refer to X1.1 in the Commentary.

1.2 Use of the procedure in this specification to determine equivalence to the Practice D 245 duration of load relationship is limited to solid wood and wood-based products whose long term load behavior is similar to that of solid wood. Equivalence demonstrated in this specification is dependent upon evaluation of a product's 90-day (minimum) creep-rupture performance. In this evaluation, three criteria must be satisfied: (1) adequate strength over a 90-day period, (2) decreasing creep rate, and (3) limited fractional deflection. A summary of the development of these criteria and the underlying assumptions behind them is provided in the Commentary in Appendix X1 and Appendix X2.

1.3 Long term degradation phenomena not described by a creep-rupture model are not addressed in this standard (see Commentary X1.2.4).

2. Referenced Documents

ASTM Standards
D1037 Test Methods for Evaluating Properties of Wood-Base Fiber and Particleboard Panel Materials
D198 Test Methods of Static Tests of Lumber in Structural Sizes
D245 Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber
D2915 Practice for Evaluating Allowable Properties for Grades of Structural Lumber
D3043 Test Methods for Structural Panels in Flexure
D4442 Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials
D4761 Test Methods for Mechanical Properties of Lumber and Wood-Base Structural Material
D5457 Specification for Computing the Reference Resistance of Wood-Based Materials and Structural Connections for Load and Resistance Factor Design
D9 Terminology Relating to Wood
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing

Index Terms

creep rate; creep-rupture; duration of load; fractional deflection; lumber; structural composite lumber; structural-use panels; ICS Number Code 79.080 (Semi-manufactures of timber)

Citing ASTM Standards

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