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Search results for: High-performance concrete
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Tuning Cu-Content La1−xSrxNi1−yCuyO3−δ with Strontium Doping as Cobalt-Free Cathode Materials for High-Performance Anode-Supported IT-SOFCs
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Effectiveness of either short-duration ischemic pre-conditioning, single-set high-resistance exercise, or their combination in potentiating bench press exercise performance
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Multifunctional nitrogen-doped nanoporous carbons derived from metal–organic frameworks for efficient CO2 storage and high-performance lithium-ion batteries
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The effect of Fe on chemical stability and oxygen evolution performance of high surface area SrTix-1FexO3-δ mixed ionic-electronic conductors in alkaline media
PublicationDevelopment of environmentally friendly, high performing oxygen evolution reaction (OER) catalysts is an important research challenge. In this work, iron doped strontium titanates with a general formula SrTi1-xFexO3-δ (x = 0.35, 0.50, 0.70, 0.90, and 1.00) denoted as STFx, were synthesized via a solid state reaction technique and characterized in terms of oxygen evolution reaction electrocatalysis in an alkaline electrolyte (0.1...
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Determination of phenylbutazone, sulfamethazine, carbendazim and linuron using a novel pine bark biosorbent for solid-phase extraction (SPE) with high-performance liquid chromatography (HPLC)
PublicationThe paper presents a novel pine bark based biosorbent for solid-phase extraction (SPE). The morphology and composition of the pine bark were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The biosorbent was used for the preparation of wastewater for the determination of phenylbutazone, sulfamethazine, carbendazim, and linuron by high performance liquid chromatography with...
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Silicon oxycarbide-tin nanocomposite derived from a UV crosslinked single source preceramic precursor as high-performance anode materials for Li-ion batteries
PublicationIn this work, we report an innovative and facile UV light-assisted synthesis of a nanocomposite based on silicon oxycarbide (SiOC) and tin nanoparticles. SiOC ceramic matrix, containing a conductive free carbon phase, participates in lithium-ion storage, and buffers the volume changes of Li-alloying/de-alloying material. The reported synthesis procedure through a polymer-derived ceramic route involves the preparation of a single-source...
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Optimal conditions of ramentaceone and plumbagin separation and isolation from carnivorous plants extracts using reverse phase-high performance liquid chromatography (RP-HPLC)
PublicationPreparatywna chromatografia cieczowa jest szczególnie przydatną techniką do rozdzielania i izolacji użytecznych ilości substancji z różnych skomplikowanych mieszanin. Praca prezentuje optymalne warunki rozdzielania i izolacji ramentaceonu i plumbaginy uwzględniając maksymalną selektywność rozdzielania naftochinonów od substancji balastowych z chloroformowych ekstraktów roślinnych D. aliciae i D. capensis z zastosowaniem techniki...
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Optimal conditions of ramentaceone and plumbagin separation and isolation from carnivorous plants extracts using normal phase-high performance liquid chromatography (NP-HPLC)
PublicationPraca prezentuje optymalne warunki rozdzielania i izolacji plumbaginy i ramentacenu z matrycy analitycznej, którą stanowią chloroformowe ekstrakty z roślin D.aliciae i D.capensis z wykorzystaiem techniki NP-HPLC. Skład eluentu dla żelu krzemionkowego jako fazy stacjonarnej był optymalizowany. Zostały przedstawione optymalne warunki powiększania skali procesu izolacji badanych metabolitów z ekstrakrów roślinnych. Określono również...
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DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL SAMPLES USING ULTRASONIC PROBE AND SALT-ASSISTED LIQUID-LIQUID EXTRACTION COUPLED WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublicationThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
PublicationThis research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting...
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Initial performance evaluation of a high resolution Albira small animal positron emission tomography scanner with monolithic crystals and depth-of-interaction encoding from a user's perspective
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Comparison of mouse plasma and brain tissue homogenate sample pretreatment methods prior to high-performance liquid chromatography for a new 1,2,4-triazole derivative with anticonvulsant activity
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Designing high-performance quasi-symmetrical solid oxide cells with a facile chemical modification strategy for Sr2Fe2−xWxO6−δ ferrites electrodes with in situ exsolution of nanoparticles
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Optimization of a Fabric Phase Sorptive Extraction protocol for the isolation of six bisphenols from juice pouches to be analysed by high performance liquid chromatography coupled with diode array detector
PublicationFabric Phase Sorptive Extraction (FPSE) combined with high pressure liquid chromatography using to diode array detection (HPLC-DAD) was applied for the simultaneous determination of bisphenols (BPA, BPB, BPC, BPE, BPF, BPS) in juice pouches. The FPSE procedure was optimized with regards to the critical parameters that affect the performance of the method including the selection of the FPSE membrane type and size, adsorption time,...
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High-performance liquid chromatography thermodynamic study of new potential antiepileptic compounds on a cholesterol column using isocratic elution with methanol/water and acetonitrile/water eluent systems
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Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al) and its application for high-performance Zn-ion capacitor
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Preparation and evaluation of 1,3-alternate 25,27-dibenzyloxy-26,28-bis-[3-propyloxy]-calix[4]arene - bonded silica stationary phase for high performance liquid chromatography
PublicationOtrzymano nową fazę stacjonarną na bazie dibenzyloksy pochodnej kaliks[4]arenu w konformacji 1,3-naprzemianległej, chemicznie związaną z żelem krzemionkowym. Przeprowadzano badania selektywności i sprawności tej fazy w rozdzielaniu izomerów konstytucyjnych benzenu i pochodnych fenoli. Zaprezentowano wyniki badania wpływu pH fazy ruchomej oraz stężenia metanolu na zdolność rozdzielczą nowej fazy stacjonarnej.
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Na3PO4 assistant dispersion of nano-CaCO3 template to enhance electrochemical interface: N/O/P co-doped porous carbon hybrids towards high-performance flexible supercapacitors
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Preparation and evaluation of 1,3-alternate 25,27-bis-(pentafluorobenzyloxy)-26,28-bis-(3-propyloxy)-calix[4]arene-bonded silics gel high performance liquid chromatography stationary phase
PublicationA 1,3-alternate 25,27-bis-(pentafluorobenzyloxy)-26,28-bis-(3-propyloxy)-calix[4]arene-bonded silica gel stationary phase (CalixBzF10) was synthesized, structurally characterized, and used as a selector in liquid chromatography. The selectivity study of this phase was done by using fluorine-containing compounds (fluorobenzenes, fluoro-pyrimidine bases), as well as non-fluorinated analytes (non-steroidal anti-inflammatory drugs,...
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Design, engineering, and performance of nanorod-Fe2O3@rGO@LaSrFe2-Co O6 (n = 0, 1) composite architectures: The role of double oxide perovskites in reaching high solar to hydrogen efficiency
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Optical properties of phenylene–thiophene-based polyazomethine thin films
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High-performance liquid chromatography of di- and trisubstituted aromatic positional isomers on 1,3-alternate 25,27-dipropoxy-26,28-bis-[3-propyloxy]-calix[4]arene-bonded silica gel stationary phase.
PublicationOtrzymano nową fazę stacjonarną na bazie dipropyloksy pochodnej kaliks[4]arenu w konformacji 1,3-naprzemianległej chemicznie związaną z żelem krzemionkowym. Przeprowadzono badanie selektywności i sprawności tej fazy w rozdzielaniu izomerów konstytucyjnych benzenu. Zaprezentowano wyniki badania wpływu warunków chromatograficznych (pH fazy ruchomej, temperatura, stężenie modyfikatora organicznego) na zdolność rodzielczą tej nowej...
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Nowa metoda oznaczania komponentów skomplikowanych mieszanin typu specyfiki farmaceutyczne z wykorzystaniem rozdzielania grupowego i wielowymiarowegej wysokosprawnej chromatografii cieczowej = New method of complex mixtures like pharmaceutical specifics determination using multidimensional high performance liquid chromatography and group type separation
PublicationW pracy porównano różne techniki ekstrakcji/ługowania analitów ze skomplikowanych matryc (2 specyfiki farmaceutyczne) oraz wykazano korzyści ze stosowania różnego typu układów chromatograficznych do ich rozdzielania. Wykorzystano chromatografię wykluczania bez oraz z jednoczesnymi oddziaływaniami sorpcyjnymi i chromatografię w odwróconym układzie faz. Wyniki kilku tego typu analiz były podstawą do rozwiązania układów równań linowych...
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Programming, tunning and automatic parallelization of irregular divide and conquer applications in DAMPVM/DAC.
PublicationArtykuł prezentuje nowy, obiektowo zorientowany wzorzec programowy DAMPVM/DAC, który zimplementowany został z użyciem systemu DAMPVM i umożliwia automatyczny podział nieregularnych aplikacji "Dziel i zwyciężaj" (DAC) w czasie ich działania.
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Mixed electromagnetic - circuits modeling and parallelization for rigorouscharacterization of cosite interference in wireless communication channels. W: UGC 2002 Homepage [online]. Department of Defense High Performance Com- puting Modernization Program. Users Group Conference 2002. Austin, Texas, USA. June 10-14, 2002. [Dostęp: 15 grudnia**2002]. Dostępny w World Wide Web: http://www.hpcmo.hpc.mil/Htdocs/UGC/UGC02/paper/[45 slajdów]. Modelowanie układów elektromagnetycznych i zrównoleglanie w celu określenia wzajemnych oddziaływań w bezprzewodowych kanałach komunikacyjnych.
PublicationRównoległe działanie sąsiadujące modułów nadawczo-odbiorczych typowo prowa-dzi do efektów ubocznych z powodu wzajemnych oddziaływań, które obniżają pa-rametry sieci. W celu scharakteryzowania takich efektów, zaprezentowano roz-wiązanie równań Maxwella w dziedzinie czasu z modelowaniem efektów nielinio-wych.
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Three dimensional simulations of FRC beams and panels with explicit definition of fibres-concrete interaction
PublicationHigh performance concrete (HPC) is a quite novel material which has been rapidly developed in the last few decades. It exhibits superior mechanical properties and durability comparing to normal concrete. HPC can achieve also superior tensile performance if strong fibres (steel or carbon) are implemented in the matrix. Thus, there exist the unabated interest in studying how the addition of different types of fibres modifies the...
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An experimental study of self-sensing concrete enhanced with multi-wall carbon nanotubes in wedge splitting test and DIC
PublicationConcrete is the worldwide most utilized construction material because of its very good performance, forming ability, long-term durability, and low costs. Concrete is a brittle material prone to cracking. Extensive cracking may impact durability and performance over time considerably. The addition of a small amount of carbon nanotubes (CNT) increases the concrete’s overall electrical conductivity, enabling internal structure...
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Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
PublicationThe paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical...
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Data-Driven Modeling of Mechanical Properties of Fiber-Reinforced Concrete: A Critical Review
PublicationFiber-reinforced concrete (FRC) is extensively used in diverse structural engineering applications, and its mechanical properties are crucial for designing and evaluating its performance. The compressive, flexural, splitting tensile, and shear strengths of FRCs are among the most important attributes, which have been discussed more extensively than other properties. The accurate prediction of these properties, which are required...
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Prediction of cast-in-place concrete strength of the extradosed bridge deck based on temperature monitoring and numerical simulations
PublicationThe work is devoted to the implementation of a monitoring system for high performance concrete embedded in the span of an extradosed bridge deck using a modified maturity method augmented by numerical simulations conducted by the authors’ FEM code. The paper presents all research stages of bridge construction and considers the conclusions drawn from the results of laboratory tests, field measurements, and numerical calculations....
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Influence of stirrups in a concrete shell on strengthening reinforced concrete column
PublicationTwelve concrete columns, with a 150x150mm square section and three columns with a circular section (d=200mm), are tested to investigate the effect of strengthening by RC jacket. Based on a confined concrete model for axial static loading, an analytical methods, reported in the literature are proposed to predict the behavior of columns with RC jacket. The results support the conception that the effect of strengthening depends...
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Evaluation of Mechanical Properties of Two-Stage Concrete and Conventional Concrete Using Nondestructive Tests
PublicationDifferent types of concrete mixtures are used as building materials. The manufacturing process of two-stage concrete (TSC) differs from that of conventional concrete. This study investigated conventional mechanical properties derive empirical relations for estimation of the mechanical parameters of TSC and conventional concrete mixtures. TSC was used to prepare 216 specimens and conventional concrete was used to prepare 108 specimens...
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Comparative study on fracture evolution in steel fibre and bar reinforced concrete beams using acoustic emission and digital image correlation techniques
PublicationIn recent decades, the demand for sustainable construction practices has increased, but raw materials such as reinforcing steel remain scarce. Therefore, steel fibres have emerged as a popular and sustainable choice in the construction industry, offering a cost-effective alternative to traditional steel bar reinforcement for both flatwork and elevated structures. The purpose of this study is therefore to compare the performance...
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Simple empirical formula to estimate the main geomechanical parameters of preplaced aggregate concrete and conventional concrete
PublicationPreplaced aggregate concrete (PAC) or two-stage concrete is a specific type of concrete successfully employed in many projects including underwater concrete structures, massive concrete structures, structures made of reinforced concrete, and improvement of concrete structures. PAC is significantly different than the conventional concrete. In this type of concrete, aggregates are initially poured into the mold, the voids between...
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Numerical simulation of hardening of concrete plate
PublicationThe paper presents a theoretical formulation of concrete curing in order to predict temperature evolution and strength development. The model of heat flow is based on a well-known Fourier equation. The numerical solution is implemented by means of the Finite Difference Method. In order to verify the model, the in situ temperature measurements at the top plate of a road bridge were carried out. A high agreement between numerical...
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Evaluation of the resistance of steel–concrete adhesive connection in reinforced concrete beams using guided wave propagation
PublicationThe development of the nondestructive diagnostic methods is of significant importance in the last decades. A special attention is paid to diagnostics of reinforced concrete structures, which are very popular in the civil engineering field. A possible use of the guided waves in the estimation of the resistance of steel–concrete adhesive connection is studied in the following paper. The relationships relating adhesive connection...
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Numerical Study on Seismic Response of a High-Rise RC Irregular Residential Building Considering Soil-Structure Interaction
PublicationThe objective of the present study is to investigate the importance of soilstructure interaction effects on the seismic response of a high-rise irregular reinforced-concrete residential building. In order to conduct this research, a detailed three-dimensional structure model was subjected to various earthquake excitations, also including a strong mining tremor. Soil-foundation flexibility was represented using the spring-based...
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Remote sensing and photogrammetry techniques in diagnostics of concrete structures
PublicationRecently laser scanning technologies become widely used in many areas of the modern economy. In the following paper authors show a potential spectrum of use Terrestrial Laser Scanning (TLS) in diagnostics of reinforced concrete elements. Based on modes of failure analysis of reinforcement concrete beam authors describe downsides and advantages of adaptation of terrestrial laser scanning to this purpose, moreover reveal under which...
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Standard and modified falling mass impact tests on preplaced aggregatefibrous concrete and slurry infiltrated fibrous concrete
PublicationAlthough several studies have been conducted to evaluate the impact response of concrete using theAmerican Concrete Institute (ACI) 544-2R falling mass impact test, the variations in test results are themain drawback of this testing method. This study aims to reduce the variations in experimental impacttest results by introducing two simple test setup modifications; (1) using coarse or fine aggregate bed-ding as an alternative...
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Concrete mix design using machine learning
PublicationDesigning a concrete mix is a process of synthesizing many components, it is not a simple process and requires extensive technical knowledge. The design process itself focuses on obtaining the required strength of concrete. Very often designing a concrete mix takes into account the need to maintain the proper water-demand and frost-resistance features. The parameters that influence the concrete class most significantly are the...
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Corrosion behavior of concrete produced with diatomite and zeolite exposed to chlorides
PublicationChloride induced reinforcement corrosion is widely accepted to be the most frequent mechanism causing premature degradation of reinforced concrete structures. The electrochemical impedance of reinforcing steel in diatomite- and zeolite-containing concrete exposed to sodium chloride was assessed. Chemical, physical and mineralogical properties of three concrete samples (20% diatomite, 20% zeolite, and a reference containing neither)...
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Effect of polymer fibres reinforcement on selected properties of asphalt mixtures
PublicationThe paper presents selected results of the research program concerning fibre reinforced asphalt concrete. Aramid-polyalphaolefin fibres was used in this study. Selected properties responsible for low temperature cracking and resistance to permanent deformation are presented in this paper. Low temperature cracking susceptibility was evaluated with the results obtained from bending test of rectangular beams with constant rate of...
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Lightweight structures in architecture: scenarios for the future
PublicationLightweight structures - structures with a reduced weight, which otherwise retain the qualities necessary for the building performance, ensuring a proper durability and strength, safety, indoor environmental quality and energy efficiency; stuctures which strive for the optimization of structural systems - are in tune with current trends and socio-economic, environmental and technological factors. The growing interest in the lightweight...
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A concept of heterogeneous numerical model of concrete for GPR simulations
PublicationThe Ground Penetrating Radar (GPR) method, which is increasingly being used in the non-destructive diagnostics of reinforced concrete structures, often needs more accurate interpretation tools for analysis of experimental data. Recently, there has been growing interest in developing of various numerical models for exhaustive understanding of GPR data. This paper presents the concept of a heterogeneous numerical model of concrete,...
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Machine Learning Techniques in Concrete Mix Design
PublicationConcrete mix design is a complex and multistage process in which we try to find the best composition of ingredients to create good performing concrete. In contemporary literature, as well as in state-of-the-art corporate practice, there are some methods of concrete mix design, from which the most popular are methods derived from The Three Equation Method. One of the most important features of concrete is compressive strength, which...
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The lethal effect of hydrotechnical concrete on freshwater Bivalvia
PublicationMost hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet...
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Size effect in concrete under splitting tension
PublicationThe size effect is a fundamental phenomenon in concrete materials. It denotes that both the nominal structural strength and material ductility always decrease with increasing element size under tension. In the paper splitting tensile tests on cylindrical concrete specimens with the different diameter were carried out. Two types of the loading strip (plywood board and steel cylinder) were used. The concrete strength and ductility...
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Ultrasound monitoring for evaluation of damage in reinforced concrete
PublicationThe paper deals with automated monitoring of damage evolution in concrete elements subjected to three-point bending tests. The monitoring is based on the nonlinear interactions of traveling ultrasonic waves with micro-crack zones inside the concrete specimens and surface-breaking cracks. The developed procedure assumes semi-continuous ultrasonic testing during the element full loading cycle and generation of the power spectral...
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Shear resistance of low height precast concrete lintels
PublicationThe scope of the paper is to investigate analytically and determine experimentally the shear resistance of low height reinforced precast concrete lintels. The chosen procedures included in national and international standards applied for the design of structural concrete elements to an estimation of shear behaviour of reinforced concrete elements are described. The characteristic and designed shear strength of precast concrete...