Improvement of shear strength, wood failure percentage and wet delamination of cross-laminated timber (CLT) panels made with superheated steam treated (SHST) layers of larch wood

Author

Yeonjung Han

• Department of Forest Products, National Institute of Forest Science, Seoul 02455, Korea
• Other articles by this author:
• De Gruyter OnlineGoogle Scholar

 / Yonggun Park

 / Yoon-Seong Chang

 / Hyunwoo Chung

 / Chang-Deuk Eom

 / Hwanmyeong Yeo

Published Online: 2017-06-22 | DOI: https://doi.org/10.1515/hf-2017-0008

Abstract

Cross-laminated timber (CLT) panels – consisting of several cross-wise stacked layers of glued boards – have a high dimensional stability. However, the outer surfaces of CTL are exposed to environmental humidity changes and thus to swelling and shrinking. To improve CLT’s dimensional stability further, the layers of kiln dried (KD) CLT were substituted partly (on the surfaces) and entirely with superheated steam treated (SHST) wood. The effects of SHST wood and the performance of the one-component polyurethane resin (PUR) were tested by block shear and delamination tests after water soaking. Under various conditions, the shear strength ranged from 1.3 MPa to 4.7 MPa and the wood failure percentage (WFP) from 76% to 92%. The optimal parameter were ascertained as pressing time (30–45 min), pressure (0.98 MPa) and adhesive amount (175–200 g m−2). The water soaked delamination of CLT manufactured with SHST wood was approximately 50% lower than that of CLT made of KD wood.

Keywords: cross-laminated timber (CLT); delamination; failure mode; larch; polyurethane resin (PUR); shear strength; wood failure percentage (WPC)

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About the article

Received: 2017-01-14

Accepted: 2017-05-12

Published Online: 2017-06-22

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Citation Information: Holzforschung, ISSN (Online) 1437-434X, ISSN (Print) 0018-3830, DOI: https://doi.org/10.1515/hf-2017-0008.

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