scholarly journals Fundamental Studies on the Use of Distributed Fibre Optical Sensing on Concrete and Reinforcing Bars

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7643
Author(s):  
Tena Galkovski ◽  
Yasmin Lemcherreq ◽  
Jaime Mata-Falcón ◽  
Walter Kaufmann
Keyword(s):  
Best Practice ◽  
Optical Sensing ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Compression Tests ◽  
Reinforcing Bars ◽  
Structural Concrete ◽  
Structural Relevance ◽  
Optical Frequency Domain Reflectometry ◽  
Frequency Domain Reflectometry

Distributed fibre optical sensing (DFOS) allows for quasi-continuous strain measurement in a broad range of gauge lengths and measurement frequencies. In particular, Rayleigh backscatter-based coherent optical frequency domain reflectometry has recently registered a significant application increase in structural concrete research and monitoring thanks to its numerous merits, such as high resolution and low invasiveness. However, it is not a plug-and-play technique. The quality of the acquired data depends highly on the choice of the fibre optical sensor and the methods of instrumentation and post-processing. Furthermore, its unprecedented resolution and sensitivity allow capturing local effects not well documented so far. This paper analyses the suitability of DFOS based on Rayleigh backscatter for reliably measuring strains and discusses the origin and structural relevance of local variations in the results. A series of experimental investigations are presented, comprising tensile tests on bare reinforcing bars and concrete compression tests. A critical analysis of the results leads to a best practice for applying DFOS to reinforcing bars and concrete, which establishes a basis for reliable, accurate measurements in structural concrete applications with bonded reinforcement.

Experimental Investigations on the Residual Strength of Corroded Steel-Stiffened Plates

2020 ◽  
Author(s):  
Sang-Hyun Park ◽  
Hyun Kyoung Shin ◽  
Jae-Shin Kim ◽  
Sang-Rai Cho ◽  
Yong-Su Jang ◽  
...  
Keyword(s):  
Corrosion Damage ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Stiffened Plates ◽  
Thickness Gauge ◽  
Test Results ◽  
Compression Tests ◽  
Fe Modelling ◽  
Initial Shape ◽  
Numerical Predictions

Abstract In this study, the tensile and compressive behaviours of corroded steel-stiffened plates were experimentally investigated, and the effects of pitting- and grooving-corrosion damage on the residual strengths of corroded stiffened plates were evaluated. Two series of tests were conducted for this study: one involved tensile test on specimens having natural corrosions and artificially machined corrosions, and the other involved compression tests on damaged stiffened plates having artificially machined corrosions. Naturally corroded tensile specimens were obtained from an aged ship. The profiles of the naturally corroded tensile specimens were measured using a three-dimensional (3-D) scanner and a dial thickness gauge. Tensile tests were conducted on nine naturally corroded and fifteen artificially machined specimens. Compression tests were performed on seven stiffened plates having artificially machined corrosion damage. Pitting- and grooving-corrosions were considered in the compression tests. Before these tests, the initial shape imperfections of the stiffened plate models were measured using a 3-D scanning machine. Test results including load-displacement relationship and the ultimate strength under compressive loads were analysed. Finite element (FE) modelling and analyses were performed in this study using commercial software CATIA and ABAQUS. The outputs of numerical analyses were compared with the corresponding test results, and a reasonable agreement between the test results and numerical predictions is shown.

scholarly journals Design and characterization of concrete masonry parts and structural concrete using repurposed plastics as aggregate

2019 ◽  
Vol 28 (1) ◽  
pp. 81-88
Author(s):  
Miguel A. González-Montijo ◽  
Hildélix Soto-Toro ◽  
Cristian Rivera-Pérez ◽  
Silvia Esteves-Klomsingh ◽  
Oscar Marcelo Suárez
Keyword(s):  
Structural Strength ◽  
Construction Materials ◽  
Tensile Tests ◽  
Compression Tests ◽  
Conventional Concrete ◽  
Structural Capacity ◽  
Plastic Type ◽  
Concrete Mix ◽  
Scientists And Engineers

AbstractHistorically known for being one of the major pollutants in the world, the construction industry, always in constant advancement and development, is currently evolving towards more environmentally friendly technologies and methods. Scientists and engineers seek to develop and implement green alternatives to conventional construction materials. One of these alternatives is to introduce an abundant, hard to recycle, material that could serve as a partial aggregate replacement in masonry bricks or even in a more conventional concrete mixture. The present work studied the use of 3 different types of repurposed plastics with different constitutions and particle size distribution. Accordingly, several brick and concrete mix designs were developed to determine the practicality of using these plastics as partial aggregate replacements. After establishing proper working material ratios for each brick and concrete mix, compression tests as well as tensile tests for the concrete mixes helped determine the structural capacity of both applications. Presented results proved that structural strength can indeed be reached in a masonry unit, using up to a 43% in volume of plastic. Furthermore, a workable structural strength for concrete can be achieved at fourteen days of curing, using up to a 50% aggregate replacement. A straightforward cost assessment for brick production was produced as well as various empirical observations and recommendations concerning the feasibility of each repurposed plastic type examined.

scholarly journals Parametric study on the behaviour of bagasse ash-calcium carbide residue stabilized soil

2018 ◽  
Vol 195 ◽  
pp. 03015
Author(s):  
John Tri Hatmoko ◽  
Hendra Suryadharma
Keyword(s):  
Calcium Carbide ◽  
Friction Angle ◽  
Tensile Tests ◽  
Peak Strength ◽  
Compression Tests ◽  
Exchange Reactions ◽  
Short Term ◽  
Calcium Carbide Residue ◽  
Stabilized Soil ◽  
Strength And Stiffness

A series of experiments including unconfined compression tests, three-axial tests, compaction tests, and split tensile tests were undertaken to investigate the influence of compaction parameters on the behaviour of bagasse ash-calcium carbide residue stabilized soil. A preliminary study on soil with the addition of 4%, 6%, 8%, 10%, and 12% calcium carbide residue established that the lime fixation point (LFP) was 4%. Then 9% bagasse ash was added to soil with 4% calcium carbide residue, and the cation exchanges and pozzolanic reactions were investigated. The addition of calcium carbide residue to bagasse ash stabilized soil caused short-term changes due to cation exchange reactions, including an increase in the friction angle and cohesion in the stabilized soil. In addition, due to the short-term reaction, the maximum stiffness in three-axial tests occurred in the samples moulded with less than their optimum moisture content (OMC), whereas the peak strength occurred in the samples moulded at their OMC. After a 28-day curing period, pozzolanic reactions improved significantly the three-axial peak strength and stiffness of the stabilized soil, and the maximum three-axial shear strength and stiffness occurred in the samples prepared below their OMC.

Sign in / Sign up

Export Citation Format

Share Document