Marco multiannual convention FRO1855, and the cooperation with WBI/AGCID SUB2019/419031 (DIE19-0005) and the Belgian Scientific Research Fund FNRS for financial support. The authors would also like to thank O. Milis for its technical support.

This article is focused on the study of the contribution of aramid fibers in a hybrid carbon-aramid fiber twill weave used to reinforce epoxy resin. To evaluate the influence of the aramid fibers, a comparative study between carbon and carbon-aramid woven-reinforced composites, considering the mechanical behavior of both materials under several loading conditions, is performed. The tests used in this study are meant to analyze the effect of aramid reinforcements on the composite stiffness, strength, impact, and fracture performance. Higher values of energy absorption and fracture toughness were exhibited by the carbon-aramid composite. The mechanical tests performed indicated that the aramid phase present in the hybrid carbon-aramid composite induced an important enhancement on the impact (37.9% in energy absorption) and fracture resistance (12.7% for fracture initiation and 43% for steady state regime), compared to small reductions on the material stiffness. In addition, the ultimate strain and the through thickness compression strength were favorably affected, with an increase up to 19.5% and 8.3%, respectively, by the presence of aramid fiber that presents a more ductile response with respect to the carbon reinforcement.

Full range constant strain rate tests are required for accurately characterizing initial yield point, strength differential effect and direct identification of constitutive laws describing the plastic behavior of materials. These tests require the use of a closedloop control in order to achieve the constant strain rate, however this feature is not available in many laboratories. An alternative method is proposed here for full range constant strain rate with testing machines that can be configured for user-defined displacements of the cross head prior to testing. Tests performed at a constant die speed include a variable strain rate response for the specimen involved. Significant deformation rate variation occurs between the elastic and plastic range with consequences for initial yield point identification. To overcome this drawback, appropriate user-defined displacements can be computed and applied, allowing for both tensile and compression tests to be performed at a constant strain rate. The method is validated using a compression test of Ti6Al4V alloy at room temperature, as

Recent catastrophes that occurred during seismic events suggest the importance of developing new seismic-resistant materials for use in building construction. Ordinary concrete is one of the most common materials in buildings. However, due to its low ductility and flexural strength, its seismic behavior can be improved upon by different additives. In this regard, wood-concrete composites exhibit desirable structural properties not achievable by either wood or concrete alone, making it an interesting material from a seismic point of view. This work analyzes and compares the performance of blocks built with ordinary concrete versus blocks built using different wood additives (sawdust and wood shavings). This includes the construction of concrete blocks in a lab, determination of their construction and seismic-resistant properties, as well as an analysis of their performance in buildings with a different number of storeys. The results show how blocks with wood aggregates comply with current regulations for structural materials in a seismic country like Chile, while also considerably outperforming traditional concrete blocks in the event of an earthquake.

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