Search

The use of timber as a building material is becoming increasingly popular thanks to its superior environmental performance compared with concrete and steel. However, timber structures rely on solid connections to improve their weak expansibility. Steel connections can be prone to corrosion over time, leading to the decreased structural integrity. Additionally, steel connections require more material and energy to manufacture and install compared with timber connections. This article focuses on the flexural performance of cross-laminated timber (CLT) panels with adhesive-free edge connections under four-point bending tests. First, numerical models of experimentally tested CLT panels were constructed using the finite element (FE) software ABAQUS. Then, these FE models were validated with the comparisons of their results with those of the experimental tests. Afterward, four new adhesive-free edge connections using timber for the CLT panels were developed in this study, helping sustainable construction. Utilizing the designed edge connections of the current study, forty-one parametric studies were numerically conducted on the connected CLT panels to investigate their ultimate loads, strains, displacements, moment capacities, failure modes, and effective stiffness. The factors affecting the edge connections’ load-bearing capacity were also examined and discussed. The study provides helpful insights into the development of CLT as a sustainable construction material with improved adhesive-free edge connections.

With concrete's key role in construction and infrastructure, the reduction of its carbon footprint is critical for addressing global carbon emissions. One strategy to reduce environmental impact from concrete production is to replace cement clinker or fine aggregates in concrete with industrial wastes. Mine tailings, being a high-volume under-utilized resource, possess properties making it suitable for use as a partial substitute for cement or fine aggregates. This review article provides an overview of the recent findings within the topic of tailings-based concrete (TBC). Many of the identified publications aimed to describe the mechanical performance of TBC, and to optimize the concrete mix with respect to the strength and durability. The recommended cement replacement ranged from 5 to 25% and the recommended fine aggregate replacement ranged from 20 to 60%. In general, the compressive strength was decreased with increasing use of tailings as a replacement of cement. For the use of tailings as replacement for fine aggregates, the correlation was more complex, normally the mechanical performance enhanced at low replacement levels, until it reached an optimum after which it decreased. CO2 savings for replacing fine aggregate with tailings were up to 12% and for the cement replacement up to 30%. When assessing the environmental performance, most of the publications did not account for the loss of its mechanical performance, which could lead to the risk of underestimating the environmental impact. This review not only provides a basis for understanding the mechanical, toxicological, and environmental performances of TBCs, but also links the perspectives together, unveiling the connections between them. Moreover, this review presents an organized overview of the topic of TBC and points out topics for future research.

Here, it is presented a possible methodology and experimental model for benchmarking of air quality in cities. The concept behind the methodology is that a city's inherent structure affects the potential for contaminant removal due to the resistance it poses to inflow. The approach is based on homogenous emission across the street surface network, representing a worst-case situation. Different levels of complexity can be used for benchmarking, making it valuable for evaluating different layouts. Additionally, an urban ventilation index suitable for these kinds of experimental studies has been suggested.