Procházení Ústav fyziky dle data publikování
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NDT of Mechanical Damaged Concrete Specimens by Nonlinear Acoustic Spectroscopy Method
(Ministry of Transport, 2010-04-14)Current research and development of non-linear ultrasonic spectroscopy methods shows these methods to be very promising for material testing and defectoscopy in the near future. Our experiments focused on the testing of ... -
Nondestructive Testing of Advanced Concrete Structure during Lifetime
(Hindawi Publishing Corporation, 2015-07-08)The paper reports on measurements and analysis of the measurements during hardening and drying of specimens using selected acoustic nondestructive testing techniques. An integrated approach was created for better understanding ... -
Low-frequency noise measurements used for quality assessment of GaSb based laser diodes prepared by molecular beam epitaxy
(Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology, 2015-08-01)The paper reports on a non-destructive method of reliability prediction for semiconductor lasers diodes GaSb based VCSE. Transport and noise characteristic of forward biased were measured in order to evaluate the new MBE ... -
Methods for topography artifacts compensation in scanning thermal microscopy
(Elsevier, 2015-08-01)Thermal conductivity contrast images in scanning thermal microscopy (SThM) are often distorted by artifacts related to local sample topography. Three methods for numerically estimating and compensating for topographic ... -
Computer Evaluation of Asperity Topology of Rock Joints
(Elsevier, 2015-09-07)Grounds beneath large civil engineering structures (bridges, dams, tunnels) that are established in the terrain of rock discontinuities represent a risk of mechanical failure. The surface topology of joint surfaces strongly ... -
Nonlinear Elastic Wave Spectroscopy with MLS Perturbation Signal
(Výzkumný ústav stavebních hmot,a.s., 2016-05-31)The article describes a test procedure based on the fundamental principle of Nonlinear Elastic Wave Spectroscopy. Without integration of all test stages into one automated measurement station and without Maximum Length ... -
Effect of carbon nanotubes on the mechanical fracture properties of fly ash geopolymer
(Elsevier, 2016-06-01)Fly ash geopolymer is amorphous aluminosilicate material which is considered as alternative to Portland cement concrete. One of the limiting factors of its utilization is an increased shrinkage and related deterioration ... -
Database 3D Surfaces for Evaluation of Joint Rock Coefficients
(Elsevier, 2016-06-13)Surfaces of rock joints were classified by means of the computerized procedure utilizing three-dimensional reliefs. These standard reliefs were formed as fractal objects using scaling properties of rock joints. Applicability ... -
Comparison of results of impedance spectroscopy methods with results of impact-echo method in investigation of high-temperaturedegraded concrete
(Elsevier, 2016-08-01)The growth in the transport industry results in more accidents, which often include fire in locations with the concrete structures, which also effects its lifetime and its functionality. After any case of fire loading it ... -
Monitoring of concrete hydration by electrical measurement methods
(Elsevier, 2016-08-01)Analysis of impedance spectra of inhomogeneous materials is a part of the impedance spectroscopy which is still waiting for its development. Materials having higher electric resistance values (over 500 kohm) can be considered ... -
Electric conductivity changes in geopolymer samples with added carbon nanotubes
(Elsevier, 2016-08-01)By incorporation of nanotubes to the current composite materials, their properties can be significantly improved. Carbon nanotubes can act as filler, which minimizes the air gaps content in the matrix. The denser structure ... -
Carbon admixtures influence on the electrical properties of slag mortars focusing on alternating conductivity and permittivity
(Elsevier, 2016-08-01)New materials based on alkali-activated slag mortars may be an important contribution of applied research, which strives to offer the use of waste materials as a full replacement for the currently used binders and explores ... -
Comprehensive Testing Techniques for the Measurement of Shrinkage and Structural Changes of Fine-Grained Cement-Based Composites during Ageing
(Hindawi Publishing Corporation, 2017-01-15)The paper deals with an experimental analysis focusing on the utilization of a specific measurement technique for determining the development of shrinkage and for monitoring structural changes in fine-grained cement-based ... -
Using acoustic emission methods to monitor cement composites during setting and hardening
(MDPI AG, 2017-04-28)Cement-based composites belong among the basic building materials used in civil engineering. Their properties are given not only by their composition but also by their behaviour after mixing as well as by the methods of ... -
The use of the acoustic emission method for the monitoring of changes in the internal structure of polymer-cement mortars when testing the static compressive modulus of elasticity
(EDP Sciences – Web of Conferences, 2017-05-24)The paper focuses on the experimental determination of the dynamic and static compressive modulus of elasticity of selected polymer-cement mortars and their comparison. The dynamic modulus of elasticity was determined by ... -
Experimental assessment of the influence of multiple cyclic loading on the dynamic modulus of elasticity of concrete
(EDP Sciences – Web of Conferences, 2017-05-24)The goal of the experiment was to determine the influence that cyclic loading has on concrete dynamic modulus of elasticity and compressive strength. Each test specimen was subjected to cyclic loading with the loading force ... -
Flexure response of thermal loaded concrete specimens by acoustic emission method
(EDP Sciences – Web of Conferences, 2017-05-24)The response to fire of concrete structural members depends on the thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature depending on the composition and ... -
Effect of steel fibres dosage in alkali-activated slag mortars on acoustic emission obtained during three-point bending tests
(EDP Sciences – Web of Conferences, 2017-05-24)The acoustic emission phenomenon is directly associated with nucleation of cracks in structural materials during loading. This paper analyses acoustic emission signals captured during three-point bending fracture tests of ... -
Impact of graphite admixture on electrical properties of alkali-activated slag mortars
(EDP Sciences, 2017-05-24)One of the objectives of the applied research's striving consists in providing the users with new slag-mortar-based materials. Basic research, in its turn, aims at examining the newly created materials from the viewpoint ... -
The Acoustic Emission Parameters Obtained during Three-point Bending Test on Thermal-stressed Concrete Specimens
(Elsevier, 2017-06-02)Fire response of concrete structural members depends on thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature and also depend on the composition and characteristics ...