6 Do some research and explain how the stress grades are den

6. Do some research and explain how the stress grades are denoted for a glulam that is

a. Primarily a bending member fabricated with visually graded laminations.

b. Primarily a bending member fabricated with E-rated laminations.

c. Primarily an axial-load-carrying member.

d. What are the appearance grades of glulam members, and how do they affect the grading for strength?

Solution

Axial load carrying member

For members stressed primarily in axial tension or axial compression ,where the stress are uniform over the cross section of the member, single grade lamination layups are recommended since there is no benefit of using a grade layup.

Appearance classification is as follows:

In exposed surfaces all knot holes and voids measuring over ¾ inch shall be filled with a wood tone filler or clear wood insert selected for similarity with the grain and color of adjacent wood

The wide face of lamination exposed to view shall be free of loose knots and open knot holes shall be filled.

Exposed surfaces shall be surfaced smooth with no misses permitted

The corners of the wide face exposed to view shall be eased.

3.Industrial appearance

Voids appearing on the edges of lamination need to be filled.

Loose knots and knot holes appearing on the wide face of the lamination exposed to view shall be filled

Members are required to be surfaced on two side only and the appearance requirements apply only to these sides.

4.Framing appearance

Manufacturing characteristics including low lamination,end joint offset and glueline squezeout are permitted.

Lumber characteristics permitted for the given layup combination may include knot holes, splits andwane.

Voids appearing on the edge of lamination need not be filled.

Members are required to be surfaced hit or miss on twoo sides only and the appearance requirements apply only to these sides.