Theses and Dissertations

ORCID

https://orcid.org/0009-0006-4517-5308

Advisor

Franca, Tamara S.

Committee Member

Franca, Frederico

Committee Member

DuBien, Janice

Committee Member

Ohno, Katie

Committee Member

Arango, Rachel

Date of Degree

5-16-2025

Original embargo terms

Immediate Worldwide Access

Document Type

Dissertation - Open Access

Major

Forest Resources (Sustainable Bioproducts)

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Forest Resources

Department

Department of Sustainable Bioproducts

Abstract

The increasing use of cross-laminated timber (CLT) in construction necessitates a deeper understanding of adhesive bonding properties, biological durability, and preservative treatments to enhance its performance. This dissertation investigates these aspects through three interrelated studies focusing on hardwood CLT and preservative-treated southern pine CLT. The first study evaluates the adhesive bonding performance of hardwood CLT fabricated from red oak (Quercus spp.), sweetgum (Liquidambar styraciflua), and yellow poplar (Liriodendron tulipifera), using southern pine (Pinus spp.) as a control. Shear block and delamination tests revealed significant variation in bond strength and moisture durability among species. While red oak exhibited the highest delamination, its bond strength was superior to that of the control samples. Yellow poplar demonstrated bond durability comparable to southern pine, suggesting its suitability for CLT applications. The second study assesses the biological durability of hardwood CLT against fungal decay and termite attack. Red oak demonstrated superior resistance to both Gloeophyllum trabeum (brown rot) and Irpex lacteus (white rot) fungi, as well as Reticulitermes spp. termites, outperforming sweetgum, yellow poplar, and the nondurable southern pine control. These findings highlight red oak’s potential as a durable CLT material, while sweetgum and yellow poplar may require preservative treatments for enhanced performance. The third study examines the efficacy of copper azole (CA-C) and micronized copper azole (MCA) treatments in improving the decay and termite resistance of southern pine CLT. Preservative treatments significantly reduced fungal and termite-induced mass loss, with both CA-C and MCA offering comparable protection. Additionally, the study highlights a complex interaction between the number of laminates, preservative treatment, and fungal species, suggesting that lamination configuration may influence decay resistance.

Sponsorship (Optional)

USDA Wood Innovation Grant

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