scholarly journals PROSPECTS FOR THE USE OF STRUCTURAL MATERIAL BASED ON LOW-VALUE SOFT HARDWOOD WOOD FOR BRIDGES ON HARVESTING ROADS

Author(s):  
Il'ya Medvedev ◽  
D. Vorotnikov

Russia has significant reserves of low-value soft deciduous wood (birch, aspen, alder, poplar), which are practically not processed, the wood rots in the forest and in the lower warehouses. Wood is a good and widespread building material. Due to the significant strength, low volume weight, ease of processing, ease of manufacturing and assembly of structures, wood has long been used for the construction of bridges. At present, despite the widespread use of reinforced concrete bridges, in the forest-rich northern and eastern regions of Russia, wooden bridges can be very useful on logging roads. But wooden bridges have a number of significant drawbacks: they have a short service life, are subject to rot, are not fire-resistant, and do not meet the requirements for passing modern loads. In order to ensure the safe and uninterrupted transport of timber on logging roads, special attention should be paid to the construction material for the construction of bridges. The proposed construction material is based on low-value soft hardwood, has high performance characteristics. To improve the performance of the wood, it is necessary to impregnate it-giving it the desired properties and compress it-thereby increasing the density, hardness and strength. We have developed a technology that combines three main technological operations of wood modification: impregnation, pressing and drying, while allowing us to obtain a structural material with increased performance characteristics, suitable for the manufacture of load-bearing supports, as well as beams of wooden bridges on logging roads.

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Renda Zhao ◽  
Yuan Yuan ◽  
Xing Wei ◽  
Ruili Shen ◽  
Kaifeng Zheng ◽  
...  

AbstractBridge construction is one of the cores of traffic infrastructure construction. To better develop relevant bridge science, this paper introduces the main research progress in China and abroad in 2019 from 13 aspects, including concrete bridges and the high-performance materials, the latest research on steel-concrete composite girders, advances in box girder and cable-supported bridge analysis theories, advance in steel bridges, the theory of bridge evaluation and reinforcement, bridge model tests and new testing techniques, steel bridge fatigue, wind resistance of bridges, vehicle-bridge interactions, progress in seismic design of bridges, bridge hydrodynamics, bridge informatization and intelligent bridge and prefabricated concrete bridge structures.


Author(s):  
Mohamed Cherif Djemai ◽  
Mahmoud Bensaibi ◽  
Fatma Zohra Halfaya

Bridges are commonly used lifelines; they play an important role in the economic activity of a city or a region and their role can be crucial in a case of a seismic event since they allow the arrival of the first aid. Reinforced concrete (RC) bridges are worldwide used type view their durability, flexibility and economical cost. In fact, their behavior under seismic loading was the aim of various studies. In the present study the effect of two structural parameters i.e. the height and the type of piers of reinforced concrete bridges on seismic response is investigated. For that reason, different multi-span continuous girder bridges models with various geometrical parameters are considered. Then, non-linear dynamic analyses are performed based on two types of piers which are: multiple columns bent and wall piers with varying heights. In this approach, a serie of 40 ground motions records varying from weak to strong events selected from Building Research Institute (BRI) strong motion database are used including uncertainty in the soil and seismic characteristics. Modelling results put most emphasis on the modal periods and responses of the top pier displacements, they show the influence of the considered parameters on the behavior of such structures and their impact on the strength of reinforced concrete bridges.


Author(s):  
I.Yu. Belutsky ◽  
◽  
I.V. Lazarev ◽  

Abstract. The publication shows the effectiveness of applying the principle of temporary continuity by combining split span structures into acontinuous couplingusing a temporary joint. The method can be viewed as an option for effort regulation, creating abearing capacity reserveinload-bearing constructions within the span structures of bridges. The calculations provided show the effect on stress rate and bending moment in split span structurescombined into a double-spancontinuous coupling by a temporary joint.


Author(s):  
Diego Carro-López ◽  
Ignasi Fernandez ◽  
Natalie Williams Portal

<p>There is an extensive network of reinforced concrete bridges that give service to roads, highways and railways. These structures where constructed with quality standards of the past, and they suffer of severe problems. Now we consider the idea of substituting them with structural elements with much longer service life. However, there is an important question to be addressed in this area: what to do with the existing infrastructure that would be demolished. Even more if we consider environmental issues.</p><p>One good example of this recurrent problem could be found in the case of the Gullspång bridge (Sweden). It was constructed in 1935 and it was severely damaged with corrosion. The administration decided in the 2016 that no further repair would be done and that the bridge would be demolished and a new erected in substitution. A fraction of the concrete from the old bridge was crushed and processed to produce new aggregate. With this aggregate, using the coarse fraction, it was analyzed the structural effect of replacing natural aggregates with these recycled aggregates. The performance of the new structural elements was positive, and it seems that a high percentage of the natural aggregates could be replaced with recycled ones.</p>


2021 ◽  
Author(s):  
Sara Reichenbach ◽  
Benjamin Kromoser ◽  
Philipp Preinstorfer ◽  
Tobias Huber

<p>With the building industry being one of the main sources of carbon dioxide emission worldwide and concrete being the main construction material, new strategies have to be developed to reduce the carbon footprint thereof. The use of high-performance materials in structural concrete, as for example textile-reinforced concrete (TRC), seems to allow for a reduction of the resource consumption and the carbon emissions. The present paper addresses potential applications of TRC examining the global warming potential (GWP) of a rail platform barrier. The resource consumption is depicted in a parametrical study in terms of the necessary component height and reinforcement area considering both the serviceability limit state (SLS) as well as the ultimate limit state (ULS). The results clearly indicate an achievable reduction of the GWP during construction when using textile reinforcement made of high-performance fibres. Furthermore, an analysis of the European market was conducted to prove the availability of this new reinforcement type. </p>


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