Show simple item record

contributor authorMatthew Davies
contributor authorMassimo Fragiacomo
date accessioned2017-05-08T21:59:30Z
date available2017-05-08T21:59:30Z
date copyrightDecember 2011
date issued2011
identifier other%28asce%29st%2E1943-541x%2E0000445.pdf
identifier urihttp://yetl.yabesh.ir/yetl/handle/yetl/68311
description abstractThis paper presents the results of experimental tests undertaken to resolve questions regarding the viability of multistory prestressed timber structures, specifically the reduction in the prestress load over time. Reduced- and large-scale specimens were tested for 1 year in controlled and uncontrolled heated indoor conditions. Specimens included beams and two-bay frames made from radiata pine laminated veneer lumber (LVL) with a box-shaped cross section. The prestress load was applied through the center of the section by using an unbonded tendon. All relevant quantities such as load in the prestress tendon, deflection, timber moisture content, environmental temperature, and relative humidity were monitored throughout the test. Functions were fitted to the one-year experimental curves and then used to indicate more clearly the trends of the prestress losses during the testing. For a beam in which all timber is loaded parallel to the grain, a reduction in prestress of 1.4% was found after 1 year, whereas for a frame in which 11% of its length is loaded perpendicular to the grain, the loss increased to 7% because of the presence of columns. Furthermore, an attempt was made to separate the contributions made to prestress losses by key factors, namely creep and mechano-sorption of the LVL that is parallel and perpendicular to the grain; relaxation of the prestressing strand; and shrinkage/swelling on account of environmental variations. The most important factor is the proportion of timber that is loaded perpendicular to grain compared with the timber loaded parallel to grain.
publisherAmerican Society of Civil Engineers
titleLong-Term Behavior of Prestressed LVL Members. I: Experimental Tests
typeJournal Paper
journal volume137
journal issue12
journal titleJournal of Structural Engineering
identifier doi10.1061/(ASCE)ST.1943-541X.0000405
treeJournal of Structural Engineering:;2011:;Volume ( 137 ):;issue: 012
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record