bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved methodology for determining tensile strength of fibre reinforced concrete
Authors: Křístek V , Vodička J , Musil L , Hanzlová H 
Published: August 2019

Abstract
Two configurations are currently used to determine the tensile strength of fibre reinforced concrete: simply supported beams of square cross section loaded either by two forces at thirds of spans (four-point bending test) or by one force at the mid-span where the specified cross section is weakened on the tensile side by a notch (three-point bending test). Based on elementary formulas, the tensile strength of fibre reinforced concrete is then determined. Considering the unacceptability of these formulas to capture the 3D problem and, in particular, for the three-point bending test, also because of significant singularities at the notch and the degree of statistical uncertainty in determining the actual position of the weakest area of the test specimen, such a test does not respect the real stress distribution in the tensile area which is changing in the process of load increase. The proposed adjustment of the test specimen eliminates these fundamental drawbacks by removing the singular areas of the specimen and leaving only the cross-sectional areas where only uniaxial stress state may be assumed. The results obtained by this methodology are presented, statistically evaluated and compared with the currently used procedures.
The impact of various types of steel fibres on the strength parameters and blast resistance of high – performance concrete
Authors: Bibora P , Drdlová M , Prachař V , Sviták O 
Published: August 2019

Abstract
The paper describes composition proposals and subsequent optimization and testing of developed fibre-reinforced UHPC mixtures, which seem to be optimal as construction material for the blast and ballistic protective systems, such as mobile blast-resistant walls and covers, which are the expected outcomes of the presented research project. Methods of laboratory testing and optimization of developed UHPC mixtures, with the aim of achieving the best possible values of physical-mechanical parameters, are described in this paper. In connection with laboratory verification, field blast tests of UHPC board samples and consequently of the entire blast-resistant wall system were realized and resistance to dynamic stress was investigated.
Material properties of various types of fibre reinforced concrete exposed to elevated temperature
Authors: Horníková K , Foglar M 
Published: August 2019

Abstract
This paper presents experimental program focused on determination of material properties of various types of fiber reinforced concrete exposed to elevated temperatures up to 1000° C. Material properties were measured by several methods which are described and compared. The resulting changes of material properties depending on temperature are presented. The values are compared with values from literature and standards. The aim of this paper is to provide a comprehensive overview of material properties of these types of concrete depending on elevated temperature and possibility of their measurement.
Influence of internal composition of fiber reinforced cement composites on resistance to near field blast
Authors: Zíma J , Foglar M 
Published: August 2019

Abstract
This paper describes the influence of internal composition of fiber reinforced cement composites on resistance to near field blast. The influence of multiple basalt meshes and dispersed fibers on a damage induced by a near-field blast is studied and numerically evaluated. Experimental measurements performed in the Boletice military area in 2014, 2015 and 2016 are evaluated by numerical simulations. The evaluation of the results is mainly focused on the stress in the cement composite, propagation of the overpressure caused by the blast and velocity of the ejected parts from the specimen. The influence of velocity of ejected parts coming out of the specimen, originally caused by the impact of a steel plate which bears TNT charges, is examined. And last, but not least, the influence of presence and position of basalt meshes in the specimen on its damage induced by delamination is also examined.
A testing method for studying the serviceability behavior of reinforced UHPFRC tensile ties
Authors: Khorami M , Navarro-Gregori J , Serna P , Navarro-Laguarda M A 
Published: August 2019

Abstract
Structural control under the serviceability limit state is a requirement of design codes to ensure the durability of structural elements. As it is possible to consider fibers to be reinforcement in concrete, UHPFRC can be used to guarantee properly distributing cracks and limiting crack width in the serviceability limit state. This research presents an experimental testing method for direct tensile tests on UHPFRC specimens. The results obtained from the proposed method, such as the specimen’s average tensile stress-strain curve, tensile stress in concrete, number and width of cracks, can be used to consider the behavior and design requirements of UHPFRC under serviceability conditions.
Experimental analysis of crack development of an UHPC wall element under shear loading
Authors: Příbramský V , Kopálová M , Dlouhý L 
Published: August 2019

Abstract
UHPC (Ultra High-Performance Concrete) is an innovative material that enables design of lightweight and structurally optimized, long-lasting structures. In this paper is presented experimental analysis of precast webs of “butterfly web” box-girder bridge on scaled-down specimens. Pretensioned beam specimens were analysed in 2 variants – with continuous web and with lightened web. Based on the experimental results are both variants compared and are presented numerical and material models suitable for UHPC modelling in software SCIA Engineer. In SCIA Engineer is implemented modified Mazarz material damage model which is applicable for material with residual strength typical for FRC and UHPFRC.
Analysis of interfacial interaction in UHPFRC-strengthened reinforced concrete beams
Authors: Zanuy C , Ulzurrun G S D , Díaz I M 
Published: August 2019

Abstract
The behaviour and failure mode of reinforced concrete elements strengthened with a thin tensile layer of ultra-high performance fiber-reinforced concrete (UHPFRC) is governed by the interface interaction between the UHPFRC and conventional concrete. In order to analyze the relative displacements at the interface and its influence on the crack pattern evolution and monolithic response, digital image correlation (DIC) has been used in this contribution. With the help of DIC, the distinct stages of the behaviour of UHPFRC-strengthened beams have been correlated with the crack formation and development. Special attention has been paid to the progressive debonding due to the strain incompatibility between UHPFRC and conventional concrete when cracks develop. It is shown that the utilization of the capacity of the UHPFRC can be achieved from a certain thickness of the strengthening layer for shear-critical elements, thereby providing a gain of shear strength and ductility. In contrast, a thinner UHPFRC layer has been more beneficial for flexure-critical elements.
Macro synthetic fibre reinforced concrete: Influence of the matrix mix design on interfacial bond behavior
Authors: Del Prete C , Buratti N , Manzi S , Mazzotti C 
Published: August 2019

Abstract
Since the composite nature of Fibre Reinforced Concrete materials, their performance is strictly dependent on the mechanical properties of their components, matrix and fibres, but, above all, on their interaction. The collaboration of the two materials is directly responsible of the force transferring mechanism from concrete to fibres that reflects their contribute in the residual flexural strength performance. This paper aims at understanding how the concrete admixture components might affect the bond of polypropylene crimped fibres, and presents the preliminary results of an experimental campaign consisting of pull-out and compression tests. Four water cement ratios and three cement-sand ratios were considered. The experimental analysis is also supported by the calibration of a numerical model that simulates the pull-out behaviour of a single fibre.
Numerical modelling of failure on brick masonry strengthened with FRCM overlays
Authors: Almeida João A P P , Pereira Eduardo B , Barros Joaquim A O 
Published: August 2019

Abstract
The behaviour of masonry elements under in-plane loads can be improved by using strengthening overlays. However, the changes in stiffness of the elements after strengthening may have various effects at the level of the behaviour of the entire structure. Advanced numerical simulations can be a helpful and cost effective strategy to guide the efficient design of strengthening systems. These models should simultaneously show the ability to deal with the complexities associated with the composite behaviour of panels at a smaller scale, and allow the simulation of models that can include the entire structure. A constitutive model for a 3D interface finite element, implemented in a FEM-based computer program, was applied for the simulation of the interfaces between substrate and the Fabric Reinforced Cementitious Matrix (FRCM) overlay. The mechanical behaviour of the interfaces between the different layers of the strengthened masonry elements were obtained from direct shear tests on couplet specimens. Subsequently, these results were used to define the constitutive laws of the interface elements. Finally, the numerical model developed was used to simulate the in-plane structural response of the strengthened masonry specimens.
Utilisation of date palm fibres in cement-based composites: A feasibility study
Authors: Abdelmajeed Labib Wafa 
Published: August 2019

Abstract
The renewed interest in the preservation of non-renewable resources has made the use of plant-based natural fibres as an environmentally friendly replacement to their synthetic counterparts in construction materials a necessity. This is due to the ability of plant-based natural fibres to enhance the mechanical properties of building components, their relatively low cost, and their derivation from a renewable resource. In this paper, the feasibility of using date palm fibres in cement composites as a replacement for synthetic fibres is reported. This study has reported on the production, types, and comparison between the chemical and mechanical properties of date palm fibres and synthetic fibres.
Experimental verification of functionality of fibre-reinforced concrete submersible piers
Authors: Buchlák J , Matějka J , Ryjáček P , Bílý P , Procházka J , Pollert J , Fabel J 
Published: August 2019

Abstract
Low capacity of river banks is a problem of many world cities. Extension can be realised in many ways. One of the ways is to use a system of floating piers. Usual types of piers are filled with floating material, which supports the pier for the whole lifetime. The system of piers described in this article is innovative, because it is supported by an air bag, which can be deflated and then the whole system sinks down to the bottom of the river. This can be helpful in case of danger of floods, because there will be no need to transport the piers to a secure dock. Piers are designed for easy modular connection in various groups. The main types of groups are linear and areal. This article briefly describes the design of fibre reinforced concrete pier and other support constructions which are necessary for the right function of the system. The design of the pier was verified by hydraulic experiments on models in scale 1:10 to real pier. The article contains the description and results of the experiments that have proven the system to be feasible.
Blast resistance of multi-layered concrete slabs
Authors: Fládr J , Chylík R , Šeps K , Štoller J , Trtík T 
Published: August 2019

Abstract
This paper compares blast resistance of multi-layered and single-layered concrete panels having different thickness and reinforcement and subjected to various explosive charges. The panels were analysed by ultrasound measurements before the application of blast loading; the velocity of transfer of ultrasound waves through the panels was determined. The same measurement was conducted after exposing the panels to contact explosion and the damage was evaluated based on the determined changes. Nine panels were tested, four of them single-layered and five of them multi-layered. The weights of Pentrite explosive charges were 150 g, 300 g and 500 g. The results show that multi-layered panels are suitable for the protection of soft targets or as cladding of load-bearing structures.
Study of boundary conditions for design of new types of fibre concrete energy dissipators in hydraulic structures
Authors: Fošumpaur P , Kašpar T , Králík M , Zukal M 
Published: August 2019

Abstract
The paper describes experiments aimed at setting parameters for an efficient design of new types and shapes of energy dissipators on chutes of dam spillways. During major rainfall events, large water inflows into the reservoir induce a rise in the reservoir level, and a spillway system must be installed to spill safely the flood waters. Two key challenges during the spillway design are conveyance and energy dissipation. Energy dissipation on dam spillways can be achieved by a range of dissipator designs. One type of spillway is a block ramp. Block ramps are hydraulic structures which are often used in practical applications to assure a correct balance between hydraulic functioning and the environmental impact. One of the main peculiarities of this approach is the capacity to dissipate a larger energy amount than other traditional structures. Thus, significant efforts were spent by the scientific community around the world in order to optimize their energy dissipation efficiency. The use of fibre concrete for the design of reinforced block ramps can improve their resistance significantly. The presented experiments describe the boundary condition for the design of new fibre concrete dissipators based on the measurements performed on reinforced block ramps.
Mechanisms behind radiation-induced deterioration of concrete
Authors: Khmurovska Y , Štemberk P 
Published: August 2019

Abstract
This paper describes the mechanism of radiation-induced deterioration of concrete and its components based on the literature review. The deterioration mechanism in different levels starting from the interaction between neutron and nucleus through the mineral metamictization and cement paste shrinkage up to the reduction of mechanical properties of concrete is explained in detail. All basic dependencies and patterns of volumetric change of minerals, aggregates, cement paste and finally concrete are also described in order to create a base for the future development of numerical models. Finally, the reduction of concrete mechanical properties is in correlation with its volumetric expansion. The radiation-induced volumetric expansion of concrete is affected by irradiation conditions (neutron fluence, neutron spectrum and temperature) and concrete composition (the amount, the proportion, the type and the structure of the minerals in the aggregate composition and the amount, the composition, the age and the structure of the cement paste).
Mechanical properties of concrete with small fibre for numerical modelling
Authors: Marcalikova Z , Prochazka L , Pesata M , Bilek V , Cajka R 
Published: August 2019

Abstract
The study specializes in the area of mechanical properties of select fibre reinforcement concrete. For the research fibre concrete reinforced with short steel fibres was used without bending. Fibre concrete is produced in the dosing 40 and 75 kg/m3. Laboratory program includes a complete group of tests, i.e. concrete compressive strength in cubes, three-point bending test, and split tension strength perpendicular and parallel to filling direction. Results are processed in summary, and they also include fracture-mechanical parameters needed for structural modelling. The research carried out found the positive influence of fibre on tensile strength and fracture energy. However, with more fibre, only fracture energy increases. It has also been found that the effect on compressive strength is small. For numerical modelling, the suitability of using a 3D computational model in combination with the fracture-plastic material model for fibre reinforcement concrete was verified.
Evaluation of the size effect of waste tyre rubber particles on properties of lightweight rubber concrete
Authors: Záleská M , Pavlíková M , Čítek D , Pavlík Z 
Published: August 2019

Abstract
Due to the increasing amount of waste tyres and also to their properties, it is necessary to look for suitable ways for their recycling. For production of rubber concrete, the crushed tyre rubber of fraction 0/4 and 4/8 was used for partial substitution of silica sand at the rate of 10 % by mass. For comparison, a reference concrete without rubber aggregate was also studied. Both natural and rubber aggregate were first assessed in terms of their physical parameters and thermal transport and storage properties. Evaluation of produced lightweight rubber concrete included measurement of basic physical properties, strength tests, and microstructural analysis. Thermal properties were studied from dry to fully water saturated state. The experimental results showed that concrete with a small amount of rubber aggregate had improved thermal insulation performance and can serve as an eco-friendly material for structural applications in civil engineering.
Using of TRC for research of crack evolution and the effect of autogenous healing
Authors: Žáková H , Žák J 
Published: August 2019

Abstract
Cracks in the concrete part of substructure are a problem in terms of penetration of water into the building. The best way is to prevent their development or support autogenous healing of concrete as much as possible. It is suitable to create many small specimens for research of crack evolution in various boundary conditions. TRC is applicable material for this research due to its compact dimensions and the ability to create a lot of cracks in relatively small area of the specimen. There are two basic methods how to create cracks in this material, tensile and bending loading. Each method provides different crack shapes.
At wavelength coherent scatterometry microscope using high-order harmonics for EUV mask inspection
Authors: Nagata Yutaka , Harada Tetsuo , Watanabe Takeo , Kinoshita Hiroo , Midorikawa Katsumi 
Published: August 2019

Abstract
In this review, we describe our research on the development of the 13.5 nm coherent microscope using high-order harmonics for the mask inspection of extreme ultraviolet (EUV) lithography. EUV lithography is a game-changing piece of technology for high-volume manufacturing of commercial semiconductors. Many top manufacturers apply EUV technology for fabricating the most critical layers of 7 nm chips. Fabrication and inspection of defect-free masks, however, still remain critical issues in EUV technology. Thus, in our pursuit for a resolution, we have developed the coherent EUV scatterometry microscope (CSM) system with a synchrotron radiation (SR) source to establish the actinic metrology, along with inspection algorithms. The intensity and phase images of patterned EUV masks were reconstructed from diffraction patterns using ptychography algorithms. To expedite the practical application of the CSM, we have also developed a standalone CSM, based on high-order harmonic generation, as an alternative to the SR-CSM. Since the application of a coherent 13.5 nm harmonic enabled the production of a high contrast diffraction pattern, diffraction patterns of sub-100 ns size defects in a 2D periodic pattern mask could be observed. Reconstruction of intensity and phase images from diffraction patterns were also performed for a periodic line-and-space structure, an aperiodic angle edge structure, as well as a cross pattern in an EUV mask.
Psychological correlates of multimorbidity and disability accumulation in older adults
Authors: Calderón-Larrañaga Amaia , Vetrano Davide Liborio , Welmer Anna-Karin , Grande Giulia , Fratiglioni Laura , Dekhtyar Serhiy 
Published: August 2019

Abstract

Background/Objectives
attitudes toward life and health are emerging as important psychological contributors to health heterogeneity in ageing. We aimed to explore whether different psychological factors were associated with the rate of chronic disease and disability accumulation over time.

Design
population-based cohort study between 2001 and 2010.

Setting
Swedish National study on aging and care in Kungsholmen.

Subjects
adults aged 60 and older (N = 2293).

Methods
linear mixed models were employed to study the association of life satisfaction, health outlook, resistance to illness, sickness orientation, and health worry with the rate of accumulation of chronic diseases and impaired basic and instrumental activities of daily living. Models were adjusted for demographic, clinical, social, personality and lifestyle factors. Analyses were repeated after excluding individuals with multimorbidity or disability at baseline.

Results
high life satisfaction and positive health outlook were consistently associated with a lower rate of accumulation and progression of multimorbidity (β −0.064 95% confidence interval [CI] −0.116, −0.011; β −0.065 95% CI −0.121, −0.008, respectively) and disability (β −0.063 95% CI −0.098, −0.028; β −0.042 95% CI −0.079, −0.004, respectively) over time. This was true even for people without multimorbidity or disability at baseline and after adjusting for all covariates.

Conclusions
positive attitudes toward life in general and health in particular may be especially important in old age, when the cumulative effects of biological and environmental deficits lead to accelerated health decline. These findings should encourage researchers to use measures of psychological well-being to better understand the multifactorial and diverse process of ageing.
Human Papillomavirus (HPV) 16 and 18/45 Genotyping-Directed Follow-up of Women With Messenger RNA HPV-Positive, Cytology-Negative Cervical Screening Test Results
Authors: Han Min , Li Juan , Austin Marshall , Varma Kavita R , Zhang Huina , Zhao Chengquan 
Published: August 2019

Abstract

Objectives
In this study, we sought to correlate genotype test results for human papillomavirus (HPV) types 16, 18, and 45 with histopathologic follow-up diagnoses in patients with messenger RNA (mRNA) high-risk HPV-positive, cytology-negative results.

Methods
We identified 1,157 patients with mRNA HPV-positive, cytology-negative cervical screening test results between June 2015 and June 2018. Reflex HPV 16/18/45 genotype results were documented in 1,018 women aged 30 years or older, 318 of whom had follow-up within 18 months.

Results
Histopathologic findings of cervical intraepithelial neoplasia 2 or worse (CIN2+) were diagnosed in 14 of 122 (11.5%) patients positive for HPV 16/18/45 vs in seven of 196 (3.6%) HPV 16/18/45–negative patients. Three patients with high-risk HPV–positive, cytology-negative cervical screening test results were diagnosed with stage I cervical adenocarcinomas following early colposcopic referral and biopsy after HPV 16/18/45–positive genotype results.

Conclusions
Immediate reflex HPV 16/18/45 genotyping of mRNA HPV-positive, cytology-negative patients led to early colposcopic referral and histopathologic diagnoses of three difficult-to-detect, low-stage, cervical adenocarcinomas and significantly increased overall early detection of CIN2+ lesions.