The curing reaction of thermosetting resins is associated with chemical shrinkage which is overlapped with thermal expansion as a result of the exothermal enthalpy. Final material properties of the polymer are determined by this critical process. For adhesive anchor systems the overall shrinkage behavior of the material is very important for the ultimate bond behavior between adhesive and the borehole wall. An approach for the insitu measurement of 3-dimensional shrinkage and thermal expansion with digital image correlation (DIC) is presented, overcoming the common limitation of DIC to solids. Two polymer-based anchor systems (filled epoxy, vinylester) were investigated and models were developed, showing good agreement with experimental results. Additionally, measurements with differential scanning calorimetry (DSC) provided supporting information about the curing reaction. The vinylester system showed higher shrinkage but much faster reaction compared to the investigated epoxy.

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Thermosetting polymers are used in building materials, for example adhesives in fastening systems. They harden in environmental conditions with a daily temperature depending on the season and location. This curing process takes hours or even days effected by the relatively low ambient temperature necessary for a fast and complete curing. As material properties depend on the degree of cure, its accurate estimation is of paramount interest and the main objective in this work. Thus, we develop an approach for modeling the curing process for epoxy based thermosetting polymers. Specifically, we perform experiments and demonstrate an inverse analysis for determining parameters in the curing model. By using calorimetry measurements and implementing an inverse analysis algorithm by using open-source packages, we obtain 10 material parameters describing the curing process. We present the methodology for two commercial, epoxy based products, where a statistical analysis provides independence of material parameters leading to the conclusion that the material equation is adequately describing the material response.