Fabrication of Glulams

 

 

 

 

 

Structural properties can exceed sawn lumber (by 30-40%) because defects can be excluded or dispersed.

 

 

Balanced vs Unbalanced

• highest quality lams can be placed where stresses will be the highest (especially tension)
• balanced:  continuous-span and cantilever  (top and bottom subject to tension)
• unbalanced:  simple-span

 

 

Composite with Transformed Section Analysis

• ASTM D3737
• already done for building designer

 

 

Bending around strong axis = transverse load ⊥ to wide face of lams
Bending around weak axis = transverse load // to wide face of lams  (e.g. bridge decks)

 

 

Shrinkage needs to be considered.

 

 

Adhesives

• dry-use
• wet-use

 

 

Finger Joints (glued)

 

 

Edge Joints (not glued)

• Single widths of stock are used for the complete width dimension for members less than 275mm (10-7/8") wide. 
• However, members wider than 175mm (6-7/8") may consist of two boards laid side by side. 
• All members wider than 275mm (10-7/8") are made from two pieces of lumber placed side by side, with edge joints staggered within the depth of the member.
  -- source

 

 

Quality Control:  ANSI/AITC A190.1

 

 

Grade Stamps