Structural Testing

Structural Testing - Wood CompositesMaine’s economy has always drawn upon its forests. Our wood composites research not only follows this tradition, it allows future generations to do so, as well. International timber competition has forced Maine to become smarter about the lumber goods it produces, which is why the UMaine Advanced Structures and Composites Center has been working with industry to produce value added wood products since its inception in 1996. Focus areas have included FRP-reinforced glulam, structural composite lumber, wood-plastic composites, wood and bio-based panels, nanocellulose, and mass timber construction.

Wood Products Testing Capabilities

ANSI Standard A190.1     Standard for Wood Products- Structural Glued Laminated Timber
ANSI/APA PRG 320     
Standard for Performance-Rated Cross-Laminated Timber (Except Section 6.3)
AITC Test T107    Shear Test
AITC Test T110     Cyclic Delamination Test
AITC Test T119     Full Size End Joint Tension Test
ASTM D143     
Testing Small Clear Specimens of Timber
ASTM D198     Static Tests of Lumber in Structural Sizes
ASTM D245     Structural Grades and Related Allowable Properties for Visually Graded Lumber
ASTM D1037     Evaluating Properties of Wood-Base Fiber and Particle Panel Materials
ASTM D1990     Standard Practice for Establishing Allowable Properties for Visually-graded Dimension Lumber from In-grade Tests of Full-size Specimens
ASTM D2395     Specific Gravity of Wood and Wood-Based Materials
ASTM D2555     Establishing Clear Wood Strength Values
ASTM D3737     Establishing Allowable Properties for Structural Glued Laminated Timber (Glulam)
ASTM D4442     Direct Moisture Content Measurement of Wood and Wood-Base Material
ASTM D4761     Mechanical Properties of Lumber and Wood-Base Structural Material
ASTM D4933     Moisture Conditioning of Wood and Wood-Base Materials
ASTM D5456     Evaluation of Structural Composite Lumber Products
ASTM D6815     Duration of Load and Creep Effects of Wood and Wood-Based Products
BS EN 408  Timber structures – structural timber and glued laminated timber – determination of some physical and mechanical properties

Duration of Load and Creep Effects of Wood Composites

Creep Testing - ASTM
Testing is conducted according to ASTM D6815 – Standard Specification
for Evaluation of Duration of Load and Creep Effects of Wood and Wood-Based Products.

The Duration of Load & Creep Effects Lab at the UMaine Advanced Structures and Composites Center has a complete creep testing facility capable of evaluating duration of load effects on wood composites such as panel products, structural composite lumber (SCL), and wood-plastic composites (WPC). The system includes a well-engineered set of fixtures capable of testing 60 specimens simultaneously under loads up to 2,500 lbs., a computer controlled loading device, and continuous, digital measurement of deflections
using calibrated string potentiometers. Testing is conducted within a temperature and humidity controlled room which reduces mechano-sorptive effects, i.e., deflection due to changing environmental conditions. Temperature and humidity may also be varied to study mechano-sorptive properties.

Purpose of Creep Testing

Creep testing is recommended for all composite materials, especially those going through modifications such as changes of resin systems.
While not required in all product standards, an understanding of the creep behavior of new/modified materials is important. Knowing that a product behaves similarly or better than solid wood in creep allows for use of well-known duration of load design adjustment factors, simplifying product acceptance and specification.

Creep testing