Influence of elevated temperature on glued-in steel rods for timber elements
Influence of elevated temperature on glued-in steel rods for timber elements
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DOI：
10.1016/j.conbuildmat.2017.04.038
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发表时间：
2017-08
影响因子：
7.4
通讯作者：
V. Maria;L. D’Andria;G. Muciaccia;A. Ianakiev
中科院分区：
文献类型：
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作者：
V. Maria;L. D’Andria;G. Muciaccia;A. Ianakiev
胶粘棒 (GiR) 的承载能力受粘合剂温度的显着影响。本文提出了在高温下插入层压木和实木构件中的 GiR 的实验程序。对 24 个具有平行于纹理的单根 8 毫米棒的样本进行了测试，以评估高温对 GiR 性能的影响。为了避免粘合剂中的后固化效应，在温度升高之前，在拉压缩配置中对棒施加恒定的负载。测试了两种类型的粘合剂以及两种不同形状的内孔表面（圆柱形和螺纹），以评估孔的不同几何特性是否会影响高温下的连接性能。实验结果表明，粘合层温度的升高会导致粘合剂的粘合剪切强度相对于冷态显着下降（接近热变形时大约减半）。此外，高温下粘合剂的强度表现出对粘合剂类型的明显依赖性以及对孔的几何形状的可忽略不计的依赖性。
Load bearing capacity of Glued-in Rods (GiR) is significantly influenced by the temperature of the adhesive. This paper presents an experimental program for GiR inserted into both laminated and solid timber elements, when subjected to elevated temperatures. Twenty-four specimens with a single 8 mm rod glued parallel to the grain were tested to evaluate the effect of elevated temperatures on GiR performance. To avoid post-curing effects in the adhesive, a constant load was applied to the bar in a pull-compression configuration prior to temperature increase. Two types of adhesives were tested, as well as two different shapes for the internal hole surface (cylindrical and threaded), in order to evaluate whether different geometrical properties of the hole could affect the performances of the connection subjected to elevated temperatures.Experimental results show that an increase in the temperature of the bonding layer causes a significant decrease in the bond shear strength of the adhesive with respect to the cold state (approximately halves when approaching the Heat Deflection). Furthermore the strength of the adhesive at elevated temperature demonstrates a clear dependence on the adhesive type and a negligible dependence on the geometry of the hole.