Bond between glulam and NSM CFRP laminates

With the aim of evaluating the bond behaviour between glulam and carbon fibre reinforced polymer laminates strips, an experimental program using pull-out tests was carried, when the near-surface strengthening technique is applied. Two main variables were studied: the bond length and the type of pull-out test configuration. The instrumentation included the loaded and free-end slips, as well as the pull-out force. Based on the obtained experimental results, and applying an analytical-numerical strategy, the local bond stress-slip relationship was determined. In this work the tests are described, the obtained results are presented and analysed, and the applicability of an inverse analysis to obtain the local bond law is demonstrated.This work is supported by FEDER funds through the Operational Programme for Competitiveness Factors - COMPETE and National Funds through FCT - Portuguese Foundation for Science and Technology under the project PTDC/ECM/74337/2006. The authors also like to thank all the companies that have been involved supporting and contributing for the development of this study, mainly: S&P Clever Reinforcement Iberica Lda., Portilame, MAPEI and Rothoblaas

Development of photocatalytic 3D-Printed cementitious mortars: influence of the curing, spraying time gaps and TiO2 coating rates

This work evaluated the photocatalytic activity of 3D-printed cementitious mortar specimens functionalized with TiO2 nanoparticles to obtain a multifunctional and smart concrete. This research aims to assess the influence of different parameters related to the functionalization process such as adsorption, coating time gaps, and coating rates on the degradation efficiency of the functionalized cementitious specimens. Each specimen was evaluated under the degradation of Rhodamine B (RhB) in an aqueous solution using a sun-light simulation. The obtained results showed a decrease in adsorption (under dark condition) with increasing the sample curing age. The highest photocatalytic efficiency was observed for coated samples aged 7 days. By increasing the coating rates, the photocatalytic efficiency is enhanced. Nonetheless, regardless of the coating rates, all the specimens showed an increase in photocatalytic efficiency for longer time periods of light exposition, i.e., after 8 h of irradiationThis work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020. The authors acknowledge the support of the DST group construction company for funding the project Chair dst/IB-S: Smart Systems for Construction. The first two authors would like to acknowledge the PhD grants SFRH/BD/143636/2019 and SFRH/BD/137421/2018 provided by the Portuguese Foundation for Science and Technology (FCT). Additionally, the authors would like to acknowledge FCT for the financing this research work by the project NanoAir PTDC/FIS-MAC/6606/2020 and the Strategic Fundings UIDB/04650/2020-2023 and UIDB/04029/202

Evaluation of the best solution for the functionalization of photocatalytic, superhydrophobic, and self-cleaning properties on asphalt mixtures

This research aims to develop asphalt mixtures with new capabilities with photocatalytic, superhydrophobic, and self-cleaning capabilities. Different solutions were prepared combining nano-TiO2 and micro-PTFE on water, and ethyl alcohol and dimethyl ketone with different concentrations. The solutions were sprayed over the asphalt mixtures and the new capabilities were evaluated via decolourization of Rhodamine B dye aqueous solution under simulated solar irradiation and Water Contact Angle measurements. Among the combinations analysed, the best solution was TiO2 PTFE with ethyl alcohol (8 g/L)