scholarly journals Multifunctional Cement Composites Strain and Damage Sensors Applied on Reinforced Concrete (RC) Structural Elements

Materials ◽  
2013 ◽  
Vol 6 (3) ◽  
pp. 841-855 ◽  
Author(s):  
Francisco Baeza ◽  
Oscar Galao ◽  
Emilio Zornoza ◽  
Pedro Garcés
2021 ◽  
Vol 11 (3) ◽  
pp. 1112
Author(s):  
Nikita Belyakov ◽  
Olga Smirnova ◽  
Aleksandr Alekseev ◽  
Hongbo Tan

The problem of damage accumulation in fiber-reinforced concrete to structures supporting underground workings and tunnel linings against dynamic loading is insufficiently studied. The mechanical properties were determined and the mechanism of destruction of fiber-reinforced concrete with different reinforcement parameters is described. The parameters of the Concrete Damaged Plasticity model for fiber-reinforced concrete at different reinforcement properties are based on the results of lab experiments. Numerical simulation of the composite concrete was performed in the Simulia Abaqus software package (Dassault Systemes, Vélizy-Villacoublay, France). Modeling of tunnel lining based on fiber-reinforced concrete was performed under seismic loading.


2021 ◽  
Vol 28 (3) ◽  
pp. 88-102
Author(s):  
Assim Arif ◽  
Saad Raoof

Textile Reinforced Concrete (TRC) can be used as independent structural elements due to its high loading capacity and proper to product light weight and thin walled structural elements. In this study, the bending behavior of TRC plates that reinforced with dry carbon fiber textile and exposed to high temperatures was experimentally studied under 4-points bending loading. The examined parameters were; (a) number of textile fiber reinforcements layers 1, 2 and 3 layers; (b) level of high temperatures 20°C, 200°C, 300°C, and 400°C. Firstly, the mechanical properties of the cementitious matrix and the tensile properties of TRC coupons at each predefined temperature were evaluated. The results showed that the ultimate tensile stress of the TRC coupons did not affect up to 200°C, however, a significant reduction observed at 300°C and 400°C by 19% and 24% respectively. Regarding the compressive strength and flexural strength of the cementitious matrix, the degradation was not severe until 200°C, while it became critical at 400 °C (23% and 22% respectively). The result of the bending of TRC plates showed that doubling and tripling textile fiber reinforcements layers improved the flexural loading. In general, increasing the level of temperatures resulted in decrease in the flexural capacity of TRC plates. The highest decrease recorded for the specimen reinforced with 1-layer of carbon fiber textile subjected to 400 °C and was 33%.


2014 ◽  
Vol 7 (5) ◽  
pp. 723-746 ◽  
Author(s):  
D. M. Santos ◽  
F. R. Stucchi ◽  
A. T. Beck

This paper presents an investigation on the safety of structural elements submitted to pure bending, produced in reinforced concrete, in steel and steel-concrete composites, and designed according to Brazilian codes NBR8681:2003, NBR6118:2007 and NBR8800:2008. The study allows a comparison of the relative safety of beams produced with these materials and designed using these codes. Comparative studies between the performances of different materials are difficult to find in the published literature. The present study shows that reliability indexes for reinforced concrete beams are satisfactory; however, results for steel beams are below limit values established in international design standards. Reliability indexes found herein for steel-concrete composite beams are intermediate to concrete and steel beams.


2018 ◽  
Vol 149 ◽  
pp. 02016 ◽  
Author(s):  
Yehya Temsah ◽  
Ali Jahami ◽  
Jamal Khatib ◽  
M Sonebi

Many engineering facilities are severely damaged by blast loading. Therefore, many manufacturers of sensitive, breakable, and deformed structures (such as facades of glass buildings) carry out studies and set standards for these installations to withstand shock waves caused by explosions. Structural engineers also use these standards in their designs for various structural elements by following the ISO Damage Carve, which links pressure and Impulse. As all the points below this curve means that the structure is safe and will not exceed the degree of damage based on the various assumptions made. This research aims to derive the Iso-Damage curve of a reinforced concrete beam exposed to blast wave. An advanced volumetric finite element program (ABAQUS) will be used to perform the derivation.


2021 ◽  
Vol 44 (2) ◽  
pp. 1-12
Author(s):  
Yago Ryan Pinheiro dos Santos ◽  
Maria Isabela Marques da Cunha Vieira Bello ◽  
Alexandre Duarte Gusmão ◽  
Jonny Dantas Patricio

Soil-structure interaction (SSI) evaluates how soil or rock deformability imposes on the structure a different load path in a hypothesis of fixed supports, altering the loads acting on the structural elements and the ground. This paper discusses the results of the SSI effects in two buildings with a reinforced concrete structure and shallow foundations in a rock mass. The settlements were monitored by field instrumentation in five stages of their construction, making it possible to estimate through interpolation curves the settlements values of some points. The numerical modeling and structural analysis of the buildings were obtained for two different cases of soil-structure interaction. The structure was considered having fixed supports (non-displaceable) and displaceable supports (with stiffness spring coefficients K). The results reveals the occurrence of SSI effects, with a load redistribution between the columns that occurred differently for the different construction stages. Structural modeling proved to be quite representative, pointing to higher vertical load values than the average values present in building edge zones, which contradicts the conventional idea that central columns are more loaded than the edge columns. The soil-structure interaction analyses resulted in different behaviors regarding both towers; pointing out that low settlements and building symmetry in plan minimize the effects of interaction, with no tendency of load redistribution between columns as the structure rigidity increases, as construction development.


2021 ◽  
Vol 9 (1) ◽  
pp. 1-5
Author(s):  
Irina Mayackaya ◽  
Batyr Yazyev ◽  
Anastasia Fedchenko ◽  
Denis Demchenko

Reinforced concrete elements of structures in the form of columns, beams, ceilings are widely used in the construction of buildings and structures of industrial and civil construction. In most cases, the columns serve as supports for other building elements, for example, crossbars, slabs, girders, beams. One of the cycles of the work of reinforced concrete structures is the state of their repair and reconstruction, including the stages of strengthening the elements. There is a problem of strengthening of reinforced concrete columns. The article deals with the issue of reinforcing columns and other structural elements having a cylindrical surface, with polymeric composite materials in the form of carbon fiber lamellae. The use of composite materials allows to increase the service life and strength of reinforced concrete structures used in construction.


Reinforced concrete structures are subjected to deterioration due to many factors such as corrosion of reinforcing steel. Ultimate strengths of structural elements can be greatly affected by these deteriorating factors. There are numerous methods and techniques used to protect these structural elements. The mortar layer (Plastering) is considered the first defense line against all the deteriorating factors. The main goal of this research is to investigate to what extent the plastering layer can protect reinforced concrete beams against corrosion. The aim of the experimental program is to study the effect of plastering layer on corrosion resistance of reinforced concrete beams. Four reinforced concrete beams (1002001100 mms) and four Lollypop specimens (cylinders 100200 mms) were tested and described as follows: • A beam and a lollypop specimen without any plastering layer (control). • A beam and a lollypop specimen with traditional plastering layer (cement + sand + water). • A beam and a lollypop specimen with modified plastering (traditional plastering + waterproof admixtures). • A beam and a lollypop specimen with painted and modified plastering layer (traditional plastering + waterproof admixtures + external waterproof paint). These eight specimens were subjected to corrosion using accelerated corrosion technique, after that the four beams were tested in flexure under three point load arrangement while the four lollypops were used to calculate the total mass loss due to accelerated corrosion. The test results were used to figure out the effect of plastering layer on corrosion resistance of RC beams.


2014 ◽  
Vol 1054 ◽  
pp. 262-266 ◽  
Author(s):  
Karel Šeps ◽  
Jan Vodička

Introductory tests with insulation material STERED are mentioned in the paper. The material STERED arises from recycling of textiles from out-of-order cars. First tests showed that the material is suitable for concrete products. STERED can be used in two variants. The first one is utilisation of STERED as insulation boards in sandwich concrete element with high resistance to loading, above all blasts and fire-arms. The other variant is utilisation of crunched STERED in fibre-cement composites, possibly in a combination with other recycled materials.


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