ABSTRACT

Glued-in rods (GiR) are a successful class of structura bonded joints for timber engineering applications. However, they suffer from two limitations: relatively slow curing processes, and requirements related to minimum temperatures for the bonding process. Both, to some extent, limit their wider application, in particular on site. Inductive heating was investigated as a method to overcome both drawbacks by speeding up the process, and enabling it under low temperatures. To verify that, a series of four commercially available adhesives was used to manufacture GiR with beech LVL and Ø16 threaded rods embedded by 100 mm, which were then cured under a variety of conditions. Firstly, cold-curing according to the prescriptions of the technical data sheets and inductively, both at +23°C; secondly, inductively at +5°C; and thirdly, at – 10°C. Numerical modelling complementing these studies allowed for insights related to temperature distributions and curing progress otherwise inaccessible through purely experimental means. The results of this study clearly show that, if selecting appropriate adhesives, curing of glued-in rods is not only accelerated from several days down to a few minutes, but that the process can also be carried at much lower temperatures than those prescribed by the technical datasheets. Based thereupon, a completely new range of practical applications, in which gluing of rods can potentially be made independent of ambient temperatures on-site, has been unleashed.

摘要

胶合杆 (GiR) 是木材工程应用的一类成功的结构粘合接头。然而，它们受到两个限制：固化过程相对较慢，以及与粘合过程的最低温度相关的要求。两者都在一定程度上限制了它们更广泛的应用，特别是在现场。感应加热被研究为通过加快过程并使其在低温下实现来克服这两个缺点的方法。为了验证这一点，我们使用了一系列四种市售粘合剂来制造 GiR，其中嵌入了 100 毫米的榉木 LVL 和 Ø16 螺纹杆，然后在各种条件下固化。首先，根据技术数据表的规定进行冷固化和感应，均在+23°C；其次，在 +5°C 时感应；第三，在 – 10°C。补充这些研究的数值模型允许与温度分布和固化进程相关的见解，否则无法通过纯粹的实验手段获得。这项研究的结果清楚地表明，如果选择合适的粘合剂，胶合棒的固化不仅可以从几天缩短到几分钟，而且该过程也可以在比标准规定的温度低得多的温度下进行。技术数据表。基于此，已经释放了全新的实际应用范围，其中可以在现场独立于环境温度进行棒的粘合。这项研究的结果清楚地表明，如果选择合适的粘合剂，胶合棒的固化不仅可以从几天缩短到几分钟，而且该过程也可以在比标准规定的温度低得多的温度下进行。技术数据表。基于此，已经释放了全新的实际应用范围，其中可以在现场独立于环境温度进行棒的粘合。这项研究的结果清楚地表明，如果选择合适的粘合剂，胶合棒的固化不仅可以从几天缩短到几分钟，而且该过程也可以在比标准规定的温度低得多的温度下进行。技术数据表。基于此，已经释放了全新的实际应用范围，其中可以在现场独立于环境温度进行棒的粘合。