Duration of load effect on LVL beams: Part 2. Long term load tests under constant and cyclic humidity

Alpo Ranta-Maunus, Shankare Gowda, Markku Kortesmaa

Research output: Book/ReportReport

1 Citation (Scopus)

Abstract

A research study on the long term load effects of Kerto laminated veneer lumber (LVL) was carried out at VTT in co-operation with other partners of a European project. Before the start of the long term tests, short term reference tests on Kerto LVL beams were completed (Fonselius and Ranta-Maunus 1996). The selection of load levels for the long term tests were determined based on the short term strength results. The results of long term bending experiments made by VTT are published in this report. A total of 40 LVL beams were loaded under long duration loading. Nearly structural size beams were loaded to failure under monthly increasing stepwise loading under controlled humidity conditions, including both constant (85 % RH) and cyclic humidity. The bending stress at failure when extrapolated to 6 months load duration was 67 to 75 % of the short term strength of similar beams having the same moisture content, which is equal or better than predicted by Madison curve (67 %).
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages64
ISBN (Print)951-38-5290-3, 951-38-5291-1
Publication statusPublished - 1998
MoE publication typeNot Eligible

Publication series

SeriesVTT Tiedotteita - Meddelanden - Research Notes
Number1899
ISSN1235-0605

Fingerprint

Veneers
Lumber
Atmospheric humidity
Loads (forces)
Moisture
Experiments

Keywords

  • structural timber
  • laminated wood
  • life (durability)
  • laminated veneer lumber
  • loads (forces)
  • bending tests

Cite this

Ranta-Maunus, A., Gowda, S., & Kortesmaa, M. (1998). Duration of load effect on LVL beams: Part 2. Long term load tests under constant and cyclic humidity. Espoo: VTT Technical Research Centre of Finland. VTT Tiedotteita - Meddelanden - Research Notes, No. 1899
Ranta-Maunus, Alpo ; Gowda, Shankare ; Kortesmaa, Markku. / Duration of load effect on LVL beams : Part 2. Long term load tests under constant and cyclic humidity. Espoo : VTT Technical Research Centre of Finland, 1998. 64 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1899).
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Ranta-Maunus, A, Gowda, S & Kortesmaa, M 1998, Duration of load effect on LVL beams: Part 2. Long term load tests under constant and cyclic humidity. VTT Tiedotteita - Meddelanden - Research Notes, no. 1899, VTT Technical Research Centre of Finland, Espoo.

Duration of load effect on LVL beams : Part 2. Long term load tests under constant and cyclic humidity. / Ranta-Maunus, Alpo; Gowda, Shankare; Kortesmaa, Markku.

Espoo : VTT Technical Research Centre of Finland, 1998. 64 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1899).

Research output: Book/ReportReport

TY - BOOK

T1 - Duration of load effect on LVL beams

T2 - Part 2. Long term load tests under constant and cyclic humidity

AU - Ranta-Maunus, Alpo

AU - Gowda, Shankare

AU - Kortesmaa, Markku

PY - 1998

Y1 - 1998

N2 - A research study on the long term load effects of Kerto laminated veneer lumber (LVL) was carried out at VTT in co-operation with other partners of a European project. Before the start of the long term tests, short term reference tests on Kerto LVL beams were completed (Fonselius and Ranta-Maunus 1996). The selection of load levels for the long term tests were determined based on the short term strength results. The results of long term bending experiments made by VTT are published in this report. A total of 40 LVL beams were loaded under long duration loading. Nearly structural size beams were loaded to failure under monthly increasing stepwise loading under controlled humidity conditions, including both constant (85 % RH) and cyclic humidity. The bending stress at failure when extrapolated to 6 months load duration was 67 to 75 % of the short term strength of similar beams having the same moisture content, which is equal or better than predicted by Madison curve (67 %).

AB - A research study on the long term load effects of Kerto laminated veneer lumber (LVL) was carried out at VTT in co-operation with other partners of a European project. Before the start of the long term tests, short term reference tests on Kerto LVL beams were completed (Fonselius and Ranta-Maunus 1996). The selection of load levels for the long term tests were determined based on the short term strength results. The results of long term bending experiments made by VTT are published in this report. A total of 40 LVL beams were loaded under long duration loading. Nearly structural size beams were loaded to failure under monthly increasing stepwise loading under controlled humidity conditions, including both constant (85 % RH) and cyclic humidity. The bending stress at failure when extrapolated to 6 months load duration was 67 to 75 % of the short term strength of similar beams having the same moisture content, which is equal or better than predicted by Madison curve (67 %).

KW - structural timber

KW - laminated wood

KW - life (durability)

KW - laminated veneer lumber

KW - loads (forces)

KW - bending tests

M3 - Report

SN - 951-38-5290-3

SN - 951-38-5291-1

T3 - VTT Tiedotteita - Meddelanden - Research Notes

BT - Duration of load effect on LVL beams

PB - VTT Technical Research Centre of Finland

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ER -

Ranta-Maunus A, Gowda S, Kortesmaa M. Duration of load effect on LVL beams: Part 2. Long term load tests under constant and cyclic humidity. Espoo: VTT Technical Research Centre of Finland, 1998. 64 p. (VTT Tiedotteita - Meddelanden - Research Notes; No. 1899).