This paper’s aim is to assess the rail wear evolution of railway tracks under mixed traffic conditions for sharp curves. Field investigations were conducted over a period of five years, at 800 points on a rail track, for two curves that underwent maintenance interventions: sleeper and rail replacements during measurements. Lateral and vertical wear measurements were monitored with mechanical instruments, and Prokon and Sap simulations were performed in order to determine the bearing capacity of the rail at different stages of wear. The results obtained after five years of investigation show wear speed propagation on the outer rail of small-radius curves as well as the bending moments and admissible stress variation. At more than 18% of the studied points, lateral wear exceeded the maximum admissible limit, showing a faster propagation speed on the outer rail compared to the vertical wear rate.

The network arch bridge (NAB) is a new structural form of arch bridge that was devised 60 years ago by the Norwegian engineer Per Tveit, who is now prof. dr. docent emeritus at the University of Agder, Norway. The network arch is a tied-arch (also known as a bowstring-arch) bridge that combines the benefits of tied-arch bridges and trusses in a single system. While in a classical tied arch, the hangers are vertical, in a network arch, the suspension of the deck to the arch is ensured through a network of inclined hangers that intersect each other at least twice. Thus, the core of the NAB is the hanger arrangement that minimizes the bending moment in the arch to very small values, leading to compression in the arch. Compression with only small bending leads to very slender cross-sections for the elements of the bridge, and deep reductions in terms of materials used and economic and environmental costs. This paper reviews the research into the structural form proposed by Per Tveit and extended by researchers and engineers worldwide. The research methodology included bibliometric literature research, obtained by interrogating the ISI Web of Science (WoS) database and the cited references from the articles on WoS. While the first structural form of a network arch is still in use today and it has proven to be a good idea for spans around 100–120 m, engineers worldwide devised new bridge cross-sections. A brief view of the types of bridge cross-section in use today is given, with details about the bridges chosen as representative. Using analysis of Prof. Tveit’s map, Structurae database and literature review, a database of the network arches around the world was created, emphasizing the development of network arches from the perspectives of continental distribution, opening year, number of structures in different structural forms, and bridge purposes. The structural form was assessed from the perspective of materials used for the arch and the tie, span, purpose and number of lanes, the presence/absence of upper wind-bracings and arch disposition in the vertical plane. In the last part of this review, the newest research into the development of the network arch is discussed. In the past 15 years we have seen an acceleration in network arch development from multiple perspectives: new materials used, such as glulam for the arch or carbon fiber-reinforced plastic for the hangers; span lengths of 250 m and 380 m for large bridge widths; architectural constraints that lead to the outward inclination of the arch, that is pleasing to the eye, but difficult to address from an engineering perspective; the most slender arch bridge in the world, with very slender cross-sections for the arch and the tie.

This paper aims to study the on-going problem of traffic generated noise pollution, focusing on the influence of speed breakers on specific areas of the noise spectrum. We studied different types of speed breakers around the metropolitan area of Cluj-Napoca, measuring a sound spectrum from 20 Hz to 20 kHz. Speed breakers have an extensive use all over the world as safety measures near parks, schools, residential areas, but the question to answer is whether they also contribute to the increase in noise pollution and to what measure this contribution is. The study considers the different types of speed breakers used in the metropolitan area and the degree of usage the speed breakers have.

The first Network Arch Bridge (NAB) was opened to traffic 60 years ago and since then the idea spread around the world. It is a type of a tied arch bridge that combines the benefits of tied arch bridges and trusses in a single system, thus it has a very good stiffness even in the case of extremely slender structures. In a Network Arch the hangers are inclined and some of them intersect each other at least twice. The core of a NAB is the hanger arrangement that minimizes the bending moment in the arch to very small values, leading thus to compression in the arch. This paper reviews the Network Arch idea devised by prof. Tveit and extended by researchers and engineers worldwide. A comprehensive review of the literature about the Network Arch is provided and the situation of NABs around the world from the standpoint of location, span, structural system used for the cross-section, bridge type (road, railway, combined or pedestrian) and opening year is discussed.

Rising humidity in old and historical buildings is a current issue that affects their structure, due to water capillarity and its propagation inside the walls, a key factor in heritage preserving and its functionality. It is also responsible for materials degradation exposed to frost and defrost cycles, biodegradation and salt crystallization. Moisture also increases the heating costs of the affected buildings, due to high thermal conductivity of the moist masonries. The paper presents an unconventional method for humidity removal or stabilisation due to infiltration of capillary water into the masonries, using electromagnetic waves systems that result in changing the water polarity inside the affected walls and pushing it out of the construction. The system consist of a small box, connected to the power supply, installed inside the building, remaining on the same location throughout the entire life of the construction. By means of this procedure, not only do the walls of the structure stay moisture-free, but also the foundations and the surrounding soil. Through this process, not only the walls of the construction remains dry, but also the foundations and the soil around them. The electromagnetic wave method was applied on five different historical buildings, located in Romania, Cluj Napoca’s historical centre, in the vicinity of Somes river, with rising damp due to water capillarity. Measurements were conducted at every six months after the system installation, for a period of minimum 24 months, using the same marked locations, at a depth of 5 cm in the walls. All buildings studied are made of stone and stone with plain brick, with different chemical, type, pore direction and porosity characteristics. The measured values show in most cases, a clear decrease of wall humidity levels or a stagnation of the capillarity rise in the monitored walls, after a minimum of 24 months after the system installation. The electromagnetic wave system, as a non-destructive method, can be applied to cases with no accidental water source or high raised groundwater, for historical buildings where no exterior works are possible or interior invasive interventions.