TY - EJOU
AU - Guo, Nan
AU - Ren, Jing
AU - Li, ng
AU - Zhao, Yan
AU - Wu, Mingtao
TI - Long-Term Loading Test of Reinforced Glulam Beam
T2 - Journal of Renewable Materials
PY - 2022
VL - 10
IS - 1
SN - 2164-6341
AB - Due to creep characteristics of wood, long-term loading can cause a significant stress loss of steel bars in reinforced glulam beams and high long-term deflection of the beam midspan. In this study, 15 glulam beams were
subjected to a 90-day long-term loading test, and the effects of long-term loading value, reinforcement ratio
and prestress level on the stress of steel bars, midspan long-term deflection, and other parameters were compared
and analyzed. The main conclusions drawn from this study were that the long-term deflection of the reinforced
glulam beams accounted for 22.5%, 20.6%, and 18.2% of the total deflection respectively when the loading value
was 20%, 30%, and 40% of the estimated ultimate load under the long-term loading. The higher the loading level
was, the smaller the proportion of the long-term deflection in the total deflection was. Compared with ordinary
glulam beams, the long-term deflection of the reinforced glulam beam was even smaller. Under the condition of
the constant loading level, the total stress value of the steel bars decreased by 17.5%, 13.6%, and 9.1%, and the
proportion of the long-term deflection of the beam midspan in the total deflection was 26.9%, 24.2%, and
20.6% respectively when the reinforcement ratio was 2.05%, 2.68 %, and 3.39%. With the increase of the reinforcement ratio, the stress loss of the steel bars decreased, and the proportion of the long-term deflection decreased
as well. When other conditions remained constant and the prestress level of the steel bars was 0 MPa, 30 MPa, and
60 MPa, the total stress value of the steel bars decreased by 9.1%, 9.4%, and 10.2%, respectively, and the proportion of the long-term deflection in the total deflection was 20.6%, 26.1%, and 64.9%, respectively. With the
increase of the prestress value, the stress loss of the steel bars increased, and the proportion of the long-term
deflection increased as well.
KW - Reinforced glulam beams; long-term loading tests; creep characteristics; prestress; total stress of steel bars
DO - 10.32604/jrm.2021.015756