1 INTRODUCTION
Commonly used adhesives for glued-in rods in timber engineering, cold curing two-components epoxies or polyurethanes, only harden relatively slowly (up to 10 days). Additional constraints associated with aforementioned 2K-adhesives arise from the fact that they usually necessitate some minimum temperature. Thus, depending on the location, bonding onsite can only occur in a limited number of months of a year.
Adhesive curing can be accelerated by a series of methods, e.g. increasing the temperature. One of the most used technique is electromagnetic induction. If metallic adherends are considered, induction heating acts on them; if inductive heating is to be used on non-conductive adherends, it is necessary to ensure that the adhesive reacts to electro-magnetic fields; this is mostly achieved by adding appropriate particles.
Previous investigations by the authors investigated to the potential of inductive heating with Curie-particles. Curie-particles are made of material that interacts with electromagnetic fields below a certain temperature (Curie temperature, TC), but are (almost) insensitive to it beyond TC; this properties makes of Curie-particle an effective tool for controlling induction processes.

1.1 Scope
1.1.1 Upscaling
Samples size was scaled up to 120x120mm², requiring significant changes in the induction process that started with selecting appropriate Curie-particles, adapting the geometry of the induction coils, and the frequency of the alternating electromagnetic field.

1.1.2 2K-adhesives
Using 2K-EPX and 2K-PUR was considered because these two classes of adhesives would, as opposed to their 1K counterparts, cure even under normal temperature conditions. This particular feature would ensure that any parts of the adhesive only partially uncured would not imperil strength of the joint. Another benefit of 2K-adhesives is that accelerated curing could be limited to partial curing of the adhesive, e.g. to achieve some minimum handling strength.

2 Discussion
2.1 Preliminary tests
All adhesives considered in this study were 2K-epoxies or polyurethanes. These 2K adhesives, according to their TDS, require between from xxh to up to 10d for full cure. The preliminary tests on the adhesives proved that their curing can be substantially accelerated to cure within five minutes.

2.1.1 Curie-particles
The Curie-particles were thermally characterised. It was shown that they were susceptible to the electromagnetic field, and that they increased the temperature. Depending upon the mass fraction added, temperatures could be raised at different paces. However, independently of the proportion of particles, temperatures converged towards an upper limit, which was the Curie-temperature of the considered material. For filler contents of 30% and beyond, the increase of temperature was sufficient to allow for curing all considered adhesives.

2.2 Large-scale tests
2.2.1 Joint capacity
Experimental determination of the joint capacity of all investigated adhesives was performed twice: firstly, for cold-cured probes; secondly, after 10 min of induction and then tested after 24 hours. A third set of probes was tested 2h after inductive curing. If compared to the cold cured GiR, inductively cured achieved strengths of roughly 75%, except for the 2K-PUR, which reached only half the reference strength. If tested after 2h, with adhesives still exhibiting temperatures of 35°C, two thirds of final strength achieved.

3 Conclusions
Curing of glued-in-rods was accelerated inductively by mixing Curie-particles to commercial available and commonly used 2K-adhesives (PUR and EPX). Although preliminary investigations showed that 2K-adhesives can be significantly cured, with reductions from hours to days down to minutes, resulting joint capacities of large scale GiR proved slightly lower, if compared to that of cold-cured probes. Additional investigations showed that the technique presented allows to obtain significant handling strengths within 2h. The somewhat lower joint capacities were posited to result from the relatively high mass fraction of particles. Further studies might attenuate these issues.