bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of different types of concrete containing waste tires rubber- a review
Authors: Ali A S , Hasan T M 
Published: August 2019

Abstract
According to Rubber Manufacturer’s Association, about 270 million waste tires are produced in United States each year. Also about 300 million scrap tires are stockpiled at the United States. Significant development in transportation and an enormous increment in the quantity of vehicles create various issues, for example, environmental contamination. Many research studies utilized scrap tires rubber in different types of concrete mixes such as normal concrete and self-compacting concrete to produce rubberized concrete and self-compacting rubberized concrete.
This review paper presents important results and conclusions that obtained from previous studies which used waste tires rubber as aggregates (fine and coarse aggregates). The results showed that the mechanical properties (compressive strength, splitting tensile strength, and flexural strength) decreased by adding rubber particles. Also the fresh properties negatively affected as rubber contain was increased but stay in the acceptable limits. The failure mode of concrete change from brittle to ductile by incorporating scrap tires rubber in concrete.
Experimental study on torsional behavior of fiberious reifoced concrete beams with different concrete strength
Authors: Waryosh Waleed A. , mohaisen Saad Khalaf , Dkhel Raed Hamed 
Published: August 2019

Abstract
This study is intended to deal with twelve reinforced concrete beams cast into three categories of Concrete type with Normal, Self Compacted and High Strength Concrete. Two beams of each category have steel fibers and the other used as reference one. Test results are presented in graphs also listed in Tables. Test results indicated that, category of High Strength Concrete beams is the strongest category depending onto the ultimate load capacity and the highest stiffness, followed by the Self Compacted Concrete beams category then the Normal Strength Concrete beams category comes later, with an increase of about (3.6-5.3%). Increasing steel fibers contained in concrete beam section will rise the ultimate load capacity of fiberious concrete beam, an increase of about 36% has been obtained. Increasing steel fiber contained with increasing concrete compressive strength of the fiberious concrete section will help increasing the ultimate load capacity of beam, an increase of about 166% has been noted. Due to continuing in rising the steel fibers contained in fiberious concrete section, the rate of development of ultimate load capacity of the fiberious concrete beam will decrease.
Evaluation of the Dynamic Behavior of Green Concrete under Impact Load by Using CEB-FIP Code
Authors: Abdulabbas Zainab H. , Sahib Jumana H. , Bashboosh Nabaa N. 
Published: August 2019

AbstractGrowing environmental pollution, rapid depletion of natural resources (virgin), need for larger areas of landfill and the increased cost of landfill are the factors that led to focus on the recycling of concrete and the demolition of waste in the new concrete. The principle of recycling for sustainable construction was adopted during the present study by recycling plastic and glass waste as an alternative to aggregates in concrete. Eight concrete mixes were tested, and production of green concrete with waste content of 35% and residual strength about 83% was achieved. The dynamic properties of green concrete under impact load were calculated. Dynamic properties are very useful in the design of civil structures exposed to impact loads such as a gas explosion, runways, etc. CEB-FIP Model code (2010) show the most inclusive forms for expecting the strain rate development of concrete. The dynamic of compressive and flexural calculated by CEB-FIP models under strain rates range 10−2and 100. This range used to predict dynamic loads in structures of civil engineering within the quasi-static strain level.
Hydraulic conductivity estimation by using groundwater modelling system program for upper zone of Iraqi aquifers
Authors: Khayyun T S , Mahdi H H 
Published: August 2019

Abstract
Estimating of soil hydraulic conductivity was so important and essential parameter for designing systems. Hydraulic conductivity measurements need many activities beginning from extract samples. Therefore it is having been found costly and time-consuming. At the present time, geo-statistical ways were used to estimate the hydraulic conductivity on the basis of restricted data. The aim of this research is to characterize hydraulic conductivity for the upper zone of Iraqi aquifers using groundwater modelling system (GMS) software and to build two dimensions geo-statistical analysis model depending on the application of 868 wells.These wells were divided into 778 wells for building the model and 90 wells for the verification. The hydraulic conductivity parameter which was obtained from the geo-statistical analysis model results indicated that the best fitted theoretical model was the inverse distance weighted (IDW) model with a coefficient of determination (R2 ) equal to 87.43% and root mean square error (RMSE) equal to 1.853. Also, by conducting many trails, it was found that the optimal distance range for estimating the hydraulic conductivity was 3800 to 5000 meters. A comparison between the kriging and IDW interpolation methods indicated that both methods could estimate the hydraulic conductivity with good accuracy and less error.
Experimental investigation for the behavior of concrete slab rests on sandy soil contains cavities
Authors: Attiya Muhammad Abed , Aziz Laith Jawad , Makki Ola Mazen 
Published: August 2019

AbstractCavities formation into soil media is a very common problem that occurs in the gypseous soils (in which the gypsum content equals 2% and more). The gypsum dissolves by water flow leaching and leaves cavities in different shapes and sizes. In slab on grade system, the American concrete institute (ACI 360) recommends, the concrete slab transforms the load to the ground by about less than 50% of the allowable bearing capacity thereof, but when the soil contains cavities and excavation, the concrete slab behavior will change. In order to investigate the changing in behavior, twelve concrete slabs were prepared and tested on a soil media contains cavities. The investigated parameters were: cavity depth, steel wire reinforcement existence, bearing load plate shapes, and the load distributed parallel or perpendicular to the cavity. From the experimental results, it has been concluded that, the plain and reinforced concrete slab capacity decreases by (30.7%) and (7.4%) when a cylindrical continuous cavity forms at (30% mm) depth from the soil surface. However, when the cavity forms at a distance equal to (15%) from the soil surface, the plain and reinforced concrete slab capacity reduced by (70%) and (61%) respectively.
Assessment of Soil Tunnel Interaction in Sand Soil
Authors: Almashhadany Omar Yaseen , Albusoda Bushra Suhale 
Published: August 2019

Abstract
In this study, series of shaking table tests were carried out to investigate the effect of tunnel model depth and direction of ground acceleration on the ground surface settlement and the dynamic earth pressure on the tunnel wall. Box tunnel model is embedded in dry and saturated soil (Karbala Sand). It subjected to three input sinusoidal motions 0.05g, 0.1g, and 0.2g. Two relative densities were used, 30% for the upper layer and 70% for the lower layer. The results obtained indicate that the settlement of soil surface increases with an increase in ground acceleration. The increase in tunnel model depth leads to an increase in settlement especially at 0.2g earthquake loading (for saturated and dry soil). The change of direction of seismic loading leads to a small change in the settlement for dry soil. The results appear that dynamic earth pressure (DEP) was positive in dry soil and negative in saturated soil in all test. In saturated soil, the effect of direction of ground acceleration and depth of tunnel model on DEP in 0.2g is quite little.
Effect of Partial Replacement with Crushed Concrete on Settlement and Bearing Capacity of Soft clay
Authors: Mohammed Al-Waily Maki Jafar 
Published: August 2019

Abstract
This paper aims to examine the effect of partial replacement with crushed concrete as a recycled material to enhance the bearing capacity and to decrease the settlement of soft clay. To clarify the effect of scale factor, four cubic steel soil tank with four dimensions of (250 x 250 x 250) mm; (300 x 300 x 300) mm;(400 x 400 x 400) mm; and (500 x 500 x 500) mm are used to carry out the experimental works, by using a foursizes for each square and strip footings with varying the depth of replacement (0.2, 0.4 and 0.6 width of square footing) and (0.33, 0.67 and 1 width of strip footing).The effect of replacement wasevaluated with regard to settlement control and bearing capacity. It is found from results of experimental works that a significant decreasing in settlement and increasing in bearing capacity of treated soil with increasing the depth of the partial replacement layer for both square and strip footing compared to untreated soil. The study also shows that the use of partial replacement layer with a depth of 0.4 B for strip footings results in reducing the settlements by an averaged percentage of 72 % and increasing the bearing capacity with an average of 96%. Also the results demonstrates that clear increasing in bearing capacity for all depth of replacement under square footing with indistinct in settlement
Application of the design code for steel fibre reinforced concrete into finite element software
Authors: Dlouhý L , Pouillon S 
Published: August 2019

Abstract
Steel fibre reinforced concrete (SFRC) is more and more used as construction material. Well-known are applications for industrial floors. Nevertheless, this material is also widely used in structural concrete elements where it is especially effective to cover crack widths in combination with standard conventional reinforcement. Currently there is no general part in Eurocode 2 [1] for buildings regarding steel fibre concrete. There are various standards and recommendations for the calculation of the steel fibre contribution. One of the most applied publications is the German guideline DAfStb [2] which was used as a basis for the numerical analysis outlined in this paper. Thus, company SCIA N.V. together with Bekaert N.V. as producer of DRAMIX® fibres developed a special tool for designing and checking SFRC structures. This tool was built in into finite element software SCIA Engineer and based on the German guideline. To gain a fundamental understanding of the structural behaviour, we have also developed non-linear FEM models, which contain a built-in module for SFRC structures. Numerical simulation results are compared to experimental performance of SFRC slab on piles of the Nanhui project in Shanghai in terms of ultimate load and crack pattern.
Properties of cement-lime render containing perlite as lightweight aggregate
Authors: Pokorný J , Pavlíková M , Pavlík Z 
Published: August 2019

Abstract
Lightweight renders with improved thermal performance, resistant against moisture and respecting specific behaviour of original plasters and substrates became attractive materials for surface finishing of both historical and old wall structures. In this respect, structural, mechanical and thermal properties of cement-lime based renders containing a different amount of perlite as fine silica sand substitution are researched in the presented paper. Experimental tests conducted for 28 days samples showed significant lightening of hardened renders with increased perlite content in their fresh mix. Gained strength parameters were, because of higher total open porosity of perlite enriched samples, lower compared with reference material. On the other hand, newly developed lightweight renders exhibited improved thermal insulation performance due to the highly porous perlite particles. In summary, cement-lime renders with incorporated lightweight aggregate based on expanded perlite were considered as alternative and promising materials for application in repair and restoration of historical masonry.
Behaviour of recycled aggregates RC columns strengthened with CFRP under uniaxial compressive loadings
Authors: Khan A R , Fareed S 
Published: August 2019

Abstract
The recent development in the construction industry has significantly influenced the socio-economic growth and the built environment of the mega cities around the globe. However, these developments have also resulted in millions of tonnes of construction demolition waste, which is mainly dumped, in the already populated landfills. As a result, the construction waste is not only causing a threat to the natural resources but also to the already deteriorating environment. Over recent past, studies have been conducted which investigated the use of concrete based construction waste as recycled coarse aggregates in preparing concrete for structural purposes. Based on these studies, in general it was found that the concrete compressive strength decreases with the increase in the percentage of recycled aggregates. Furthermore, studies have also been carried out in which use of Carbon Fiber Polymers wrapped along the outer surfaces of the structural elements resulted in significant increase of load carrying capacity. Therefore, in this study, investigation aims at the behaviour of reinforced concrete columns made with recycled aggregates and wrapped with Carbon Fiber Reinforced Polymers under uniaxial static compressive loading. For this purpose, 12 rectangular specimens having cross section dimensions of 150mm x 300mm and height of 600mm reinforced both longitudinally and transversely were used. The specimens were made with three different mixes of concrete having 0%, 30% and 50% of recycled aggregates. It was found that the recycled aggregates reinforced concrete specimens wrapped with CFRP exhibited higher compressive loads as compared to their corresponding specimens made with natural aggregates.
Utilization of recycled plastic for plastic-based concrete
Authors: Horáková A , Novák J 
Published: August 2019

Abstract
The environmental aspects of sustainable development in the construction industry consist in the utilization of secondary raw materials in a design and construction of new structures. The fact that China significantly reduced the import of plastic waste in 2017 raises the question of dealing with this waste in other states. A complicated recycling process of waste plastics puts pressure on scientific community to find new, more efficient ways of using this waste. The paper deals with the behaviour and mechanical properties of a completely innovative material called waste plastic-based concrete composed of natural aggregate and plastic waste which replaces cement as a binder. The completely unique composition of this concrete required to firstly test production technology and subsequently to conduct standard quasi-static experimental tests to obtain basic knowledge about the behaviour and mechanical properties of this composite. The obtained knowledge show that special attention must be paid to the production of the material which takes place under elevated temperature. The investigated composite has a relatively high tensile strength compared to conventional concrete and brittle fracture behaviour. In the next phases of the research the optimization of the production technologies and the composition of the composite will be provided.
Visualization and analysis of concrete specimens damage after fire and blast experiments
Authors: Štefan R , Foglar M 
Published: August 2019

Abstract
The paper is focused on visualization and analysis of concrete specimen damage after fire and blast experiments. A data visualization tool, based on an in-house MATLAB code, is described and its applicability and versatility are illustrated. In the first illustrative example, concrete spalling of fire exposed floor slab panels made of various types of concrete (without fibres, with polypropylene fibres, with steel fibres) is analysed. In the second example, the results of ultrasonic pulse velocity measurements of concrete bridge decks before and after blast experiments are shown in order to investigate the blast resistance of the decks made of different types of materials and to illustrate the damage of the decks in the form of the material degradation, surface spalling and puncture. The developed data visualization tool has been included in a freely available scientific computer program with a graphical user interface.
Classical general relativity effects to second order in mass, spin, and quadrupole moment
Authors: Arce-Gamboa J R , Frutos-Alfaro F 
Published: August 2019

Abstract
In this contribution, we calculate the light deflection, perihelion shift, time delay and gravitational redshift using an approximate metric that contains the Kerr metric and an approximation of the Erez-Rosen spacetime. The results were obtained directly using (Mathematica 2018 Wolfram Research, Inc., Version 11.3, Champaign). The results agree with the ones presented in the literature, but they are extended until second order terms of mass, angular momentum and mass quadrupole. The inclusion of the mass quadrupole is done by means of the metric; no expansion of the gravitational potential as in the parameterized post-Newtonian is required.
Excess phosphorus from compost applications in urban gardens creates potential pollution hotspots
Authors: Small Gaston , Shrestha Paliza , Metson Geneviève Suzanne , Polsky Katherine , Jimenez Ivan , Kay Adam 
Published: August 2019

Abstract
Urban sustainability initiatives often encompass such goals as increasing local food production, closing nutrient loops through recycling organic waste, and reducing water pollution. However, there are potential tradeoffs among these desired outcomes that may constrain progress. For example, expansion of urban agriculture for food production may create hotspots of nutrient pollution if nutrient recycling is inefficient. We used gardener and urban farmer survey data from the Twin Cities Metropolitan Area (Minnesota, USA) to characterize phosphorus (P) and nitrogen (N) inputs and harvest in order to determine nutrient use efficiencies, and measured soil P concentrations at a subset of these sites to test whether excess soil P was common. All survey respondents (n = 142) reported using some form of soil amendment, with plant-based composts being the most common. Median application rates were 300 kg P/ha and 1400 kg N/ha. Median nutrient use efficiencies were low (2.5% for P, 5.0% for N) and there was only a weak positive relationship between P and N inputs and P and N harvested in crop biomass. Garden soils had a median Bray P value of 80 ppm, showing a buildup of plant-available P far exceeding recommended levels. Our results show that urban gardens are characterized by high nutrient inputs and inefficient conversion of these nutrients into crops, leading to buildup and potential loss of P and N from garden soils. Although urban gardens make up only 0.1% of land area in the Twin Cities, compost application to these urban gardens still constitutes one of the largest inputs of P to the watershed. In order to maximize desired outcomes from the expansion of urban agriculture (UA), it will be necessary to target soil amendments based on soil nutrient levels and crop nutrient demand.
Probing magnetism via spin dynamics in graphene/2D-ferromagnet heterostructures
Authors: Cummings Aron W 
Published: August 2019

Abstract
The recent discovery of two-dimensional magnetic insulators has generated a great deal of excitement over their potential for nanoscale manipulation of spin or magnetism. One intriguing use for these materials is to put them in contact with graphene, with the goal of making graphene magnetic while maintaining its unique electronic properties. Such a system could prove useful in applications such as magnetic memories, or could serve as a host for exotic states of matter. Proximity to a magnetic insulator will alter the spin transport properties of graphene, and the strength of this interaction can be probed with Hanle spin precession experiments. To aid in the analysis of such experiments, in this work we derive an explicit expression for Hanle spin precession in graphene interfaced with a ferromagnetic insulator whose magnetization points perpendicular to the graphene plane. We find that this interface results in a shifted and asymmetric Hanle response, and we discuss how this behavior can be used to interpret measurements of spin transport in these systems.
Intracranial Atherosclerosis and Stage 1 Hypertension Defined by the 2017 ACC/AHA Guideline
Authors: Nam Ki-Woong , Kwon Hyung-Min , Jeong Han-Yeong , Park Jin-Ho , Kwon Hyuktae , Jeong Su-Min 
Published: August 2019

Abstract

Background
In 2017, the American College of Cardiology (ACC)/American Heart Association (AHA) released a new, stricter definition of stage 1 hypertension which was previously considered prehypertension. However, impacts of the novel stage 1 hypertension on deleterious target-organ outcomes are still controversial. In this study, we evaluated the relationship between this newly defined stage 1 hypertension and the presence of intracranial atherosclerosis (ICAS) lesions in neurologically healthy participants.

Methods
We assessed consecutive participants in routine health checkups between January 2006 and December 2013. Blood pressure (BP) was classified according to the 2017 ACC/AHA hypertension guideline, and ICAS was defined as occlusion or ≥50% stenosis of intracranial vessels on flight magnetic resonance angiography.

Results
Among 3,111 healthy participants (mean age: 56 years, sex: 54% men), 85 (3%) had ICAS lesions. In multivariate analysis, stage 1 hypertension (adjusted odds ratio: 2.46, 95% confidence interval: 1.10–5.51, P = 0.029) remained an independent predictor of ICAS after adjustment for confounders. Stage 2 hypertension showed a higher odds ratio and a lower P value, indicating a dose–response effect. Age and HbA1c level were also significantly associated with ICAS, independent of the BP categories. The ICAS lesion burden showed a dose–response effect across the BP categories (P for trend &lt;0.001), whereas ICAS lesion location did not (P for trend = 0.699).

Conclusions
We demonstrated that stage 1 hypertension, defined according to the 2017 ACC/AHA guideline, was associated with a higher prevalence and burden of ICAS lesions in a neurologically healthy population.