A bonded concrete overlay consists of a concrete layer poured over a deteriorated pavement. Its mechanical performance depends on the quality of the bond between the lower and the uppermost layers. This paper reports an extensive experimental program to evaluate bond strength between Conventional Concrete (CC) and Asphalt Concrete (AC) substrates and Self-Compacting High-Performance Concrete (SCHPC) overlays. In all, 8 interface treatments are tested under Direct Tension, pure shear “LCB”, and compressive Slant Shear tests. The results show that direct pouring of the SCHPC overlay over CC and AC substrates produces similar or higher strengths than the other treatments analyzed.Peer ReviewedPostprint (author's final draft

The success of educational institutions is fundamentally intertwined with the well-being and academic progress of their students. In this context, indoor air quality (IAQ) and thermal comfort play a critical role in creating conducive learning environments that support both health and academic performance. This work evaluates six ventilation systems and strategies for enhancing IAQ and thermal comfort, which prevail in educational buildings in the Spanish region of Catalonia. To do so, a multi-criteria analysis is performed based on the Analytic Hierarchy Process (AHP) method, considering economic, social, and environmental aspects. Ventilation systems are pairwise compared in terms of six criteria: initial and maintenance cost, classroom air quality, students’ thermal comfort in summer and winter, and energy consumption. Subsequently, weighted combinations of these criteria are established to rank the ventilation systems under five case scenarios. The results indicate that natural ventilation systems, particularly those with atriums and courtyards (N-AAC), offer a balanced solution, achieving satisfactory IAQ and thermal comfort while being more cost-effective and environmentally sustainable in certain contexts. The variation in the best solution across different scenarios demonstrates that the optimal choice is highly context-dependent, influenced by factors such as budget, climate, and infrastructure. This research provides a valuable foundation and methodology for decision-makers in educational institutions, supporting the selection of ventilation systems that maximize sustainability while enhancing students’ comfort and fostering learning environments.

The inductive method has shown to be a good method for the estimation of fiber dosage in steel-fiber-reinforced concrete. The current formulations reported a strong correlation between inductance and fiber content, as well as orientation. The objective of this paper is to study how the inductive measurements are affected by fiber properties, such as its dimensions, magnetic characteristics, and sample temperature. The results obtained from numerical, simulated, and experimental data propose a shape factor to be applied in the measurements to take into account the aspect ratio of fibers. They also show that the magnetic composition of the fibers is of great importance. As for temperature, the error introduced is less than 1%, so a corrective factor is not essential.