Petranek, M, Korec, S, Golasovská, H & Jiříčková, K 2023, 'How the strength and deformability of thixotropic resins depend on their structure and what is the true thixotropic behaviour of the mixture', in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 623-634, https://doi.org/10.36487/ACG_repo/2325_42 (https://papers.acg.uwa.edu.au/p/2325_42_Petranek/) Abstract: Pumpable resins have already been used in various mining applications for a few decades. They were widely used in coal mining for stabilisation and consolidation of coal seams and surrounding strata, and from coal mining they found their way to civil construction and then into hard rock mining, mainly in connection with the latest development of bolting equipment. With a ‘rapid development’ program and increased productivity of mining equipment, industry was looking for fast-setting bolt grouts to be used with primary and secondary ground support systems. In the last five years, use of Newtonian-type resin grouts found their new application in the form of non-sagging, dense, yet easily pumpable resin pastes in combination with hollow core and selfdrilling rockbolts or pre- and post-groutable cable bolts. These dense, fast-setting, urea silicate resin paste grouts are generally known within industry as ‘thixotropic resins’. Although being commonly called thixotropic, not all really behave as thixotropic materials. A misunderstanding with regards to the performance of these resins also exists, as it is just compared predominantly with uniaxial compressive strength (UCS) only. Normet International Ltd, with the help of their research partner, spent a significant amount of time in past half decade to understand, research and develop truly thixotropic urea silicate resin grout by investigating the mechanical and chemical properties of the mix. Although UCS values are still important, there are other properties of this resin mix which are actually more important than just UCS strength alone. Adhesiveness and plasticity/deformability without loss of strength is a more important parameter than just a high UCS number. Understanding microscopic structure and being able to interpret that structure helped to develop high strength–high deformability yet high adhesive, truly thixotropic urea silicate resin grout. Keywords: thixotropy, organomineral, urea silicate, thixotropic resin bolt grout, deformability without loss of strength, adhesiveness