Types Of Infill Research Articles

Seismic Behaviour and Retrofitting of Timber Frame Walls

Half-timbered buildings are well known as one of the most efficient seismic resistant structure in the world, but their popularity is not only due to their seismic performance, but also to their low cost and the strength they offer. These structures generally consist of exterior masonry walls with timber elements embedded which tie the walls together and internal walls which have a timber frame with masonry infill and act as shear walls. Generally, different types of infill could be applied to half-timbered walls depending on the country, namely brick masonry, rubble masonry, hay, mud, etc. The focus of this paper is to study the seismic behaviour of the walls when no infill is present, i.e. considering only the timber frame, and then compare the results with those of the infill walls. Static cyclic tests have been performed on unreinforced timber frame walls and appropriate strengthening solutions have been applied in order to test the walls in a retrofitted condition, namely (1) steel plates with different configurations and (2) steel flat bars inserted with the NSM technique.

Bioaccessibility and Risk of Exposure to Metals and SVOCs in Artificial Turf Field Fill Materials and Fibers

To reduce maintenance costs, municipalities and schools are starting to replace natural grass fields with a new generation synthetic turf. Unlike Astro-Turf, which was first introduced in the 1960s, synthetic field turf provides more cushioning to athletes. Part of this cushioning comes from materials like crumb rubber infill, which is manufactured from recycled tires and may contain a variety of chemicals. The goal of this study was to evaluate potential exposures from playing on artificial turf fields and associated risks to trace metals, semi-volatile organic compounds (SVOCs), and polycyclic aromatic hydrocarbons (PAHs) by examining typical artificial turf fibers (n = 8), different types of infill (n = 8), and samples from actual fields (n = 7). Three artificial biofluids were prepared, which included: lung, sweat, and digestive fluids. Artificial biofluids were hypothesized to yield a more representative estimation of dose than the levels obtained from total extraction methods. PAHs were routinely below the limit of detection across all three biofluids, precluding completion of a meaningful risk assessment. No SVOCs were identified at quantifiable levels in any extracts based on a match of their mass spectrum to compounds that are regulated in soil. The metals were measurable but at concentrations for which human health risk was estimated to be low. The study demonstrated that for the products and fields we tested, exposure to infill and artificial turf was generally considered de minimus, with the possible exception of lead for some fields and materials.

Fiber beam model for fire response simulation of axially loaded concrete filled tubular columns

This paper presents a fiber beam model for the fire response simulation of concrete filled tubular columns of circular section under concentric axial load. The model consists of two parallel components, one with a circular tubular steel section, and the other with a solid circular concrete section. The components interact with nonlinear longitudinal and transverse links at the end nodes. The element is formulated on a system without rigid body modes and accounts for large displacement geometry through the co-rotational formulation connected both longitudinally and transversely at their nodes by link elements. The model is capable of representing different types of concrete infill of the steel tubes: plain, reinforced and steel fiber reinforced concrete of normal or high strength. It is validated against experimental data from column specimens under fire. The results are also compared against a three-dimensional finite element model characterized by its accuracy of fire response simulation.

Psychosensorial assessment of skin damage caused by a sliding on artificial turf: The development and validation of a skin damage area and severity index

Injury prevention is an important reason for the development of performance standards in football. Currently, there is no objective method available to classify sliding induced skin injuries, which includes the perceived sliding friendliness of football pitches. The purpose of this study was to develop a non-invasive method for quantification of the observed sliding induced skin damage and evaluate whether there is a correlation between the subjective perceived skin irritation and sliding friendliness. Randomized controlled trial. Previously obtained clinical images of sliding induced skin lesions where rated by a dermatologist on the degree of abrasion, erythema and type of exudation. To test the practical feasibility of a proposed Skin Damage and Severity Index (SDASI) to characterize sliding induced skin lesions, a randomized user trial with nine amateur football players was performed. The sliding friendliness of three different grades of infill materials was tested. The Skin Damage and Severity Index correlates both with the perceived skin irritation (r=-0.53, P=0.02) and sliding friendliness (r=-0.58, P=0.01). Statistical analysis of the individual clinical scores showed that perception of skin irritation and sliding friendliness correlate very well with the degree of erythema and abrasion. However, these scores are independent of the size of the lesion and type of exudation. There was no statistical significant difference found between the three evaluated types of infill and their sliding performance. This study demonstrated that the Skin Damage and Severity Index, which is a tool for quantification of a sliding induced skin lesion, correlates very well with the perceived skin irritation and the sliding friendliness.

Influence of ultra-high strength infill in slender concrete-filled steel tubular columns

This paper describes 24 tests conducted on slender circular tubular columns filled with normal, high, and ultra-high strength concrete for plain, bar reinforced and steel fiber reinforced columns. These were reinforced and subjected to both concentric and eccentric axial load. It is a continuation of a previous research paper (Portoles et al., 2011 [1]), which presented test results on eccentrically loaded plain concrete columns. The test parameters are nominal strength of concrete (30, 90 and 130MPa), eccentricity e (0, 20 and 50mm) and type of reinforcement. A comparison with the corresponding empty tubular columns is performed, as the aim of the paper is to analyze the influence of each type of infill and establish the best option for practical application. For the limited cases analyzed the results show that the addition of high or ultra-high strength infill is more useful for concentric loaded cases than for eccentric loaded ones, where it seems that the best design option is the utilization of bar reinforced concrete filling rather than steel fiber to reinforce CFST columns. The experimental ultimate load of each test was compared with the design loads from Eurocode 4, accurate for the eccentrically loaded tests.

Definition of diagonal Poisson’s ratio and elastic modulus for infill masonry walls

The prediction of the response of infilled frames through the simplified approach of substituting the infill with an equivalent pin-jointed strut is treated. In this framework the results of an experimental study for the mechanical characterization of different types of masonry infills having the aim of estimating strength, Young modulus and Poisson’s ratio are presented. Four types of masonry were investigated and subjected to ordinary compressive tests orthogonally to the mortar beds and along the directions of the mortar beds. The experimental campaign confirmed the possibility of using an orthotropic plate model for prediction of the Poisson’s ratio and Young modulus along the diagonal direction of infills (these parameters are requested by a model already known in the literature for the identification of struts equivalent to masonry infills). The experimental campaign made it possible to recognise a correlation between the Poisson’s ratios and the strengths of masonries investigated along the orthotropic axes and to obtain the diagonal Poisson’s ratio without specific experimental tests. Finally, the experimental responses of some infilled frames were used to test the reliability of the model proposed here.

Cyclic testing of single bay steel frames with various types of masonry infill

This paper presents results of a part of the Croatian project “Seismic design of infilled frames” and deals with masonry infilled steel frames. The behaviour of steel frames infilled with masonry, commonly used in Croatia, was experimentally investigated under quasi-static cyclic loading. Besides, a new structural solution is proposed. Nine one-bay, one-storey masonry-infilled steel frames with three different masonry infill types: perforated clay blocks (C), lightweight AAC blocks (A) and newly proposed combination of these materials (CA), were built and tested. Proposed combined masonry infill (CA) allowed partial separation of the masonry from the frame at certain drift levels and prevented the infill’s detrimental effects.

Fire behavior of eccentrically loaded slender high strength concrete-filled tubular columns

This paper describes a series of 24 fire tests conducted on slender circular hollow section columns filled with normal and high strength concrete, subjected to eccentric axial load. It is a continuation of a previous research paper (Romero et al., 2011 [1]), where test results on centrally loaded columns were presented. The test parameters covered in this fire testing program were the nominal strength of concrete (30 and 90MPa), the infilling type (plain, bar-reinforced and steel fiber reinforced concrete), the axial load level (20% and 40%) and the load eccentricity (20 and 50mm). The columns were tested under fixed-pinned boundary conditions, with a relative slenderness at room temperature higher than 0.5 for all the specimens. The aim of this paper is to study the influence of eccentricity in combination with the type of concrete infill. The results show that the addition of steel fibers does not improve the fire resistance of slender columns under eccentric loads, as compared to columns filled with plain concrete. However, the addition of reinforcing bars increases the fire resistance of the columns in this situation. Filling the steel hollow section columns with concrete increases their fire resistance, the increase in load bearing capacity being more noticeable for columns filled with high strength concrete. A comparison with the current simple calculation model in Eurocode 4 Part 1.2 shows that, although the method is safe for eccentrically loaded columns, it produces a high error in the predictions for columns filled with plain or steel fiber reinforced concrete.

Experimental work on seismic behavior of various types of masonry infilled RC frames

Reinforced concrete frame structures with masonry infill walls constitute the significant portion of the building stock in Turkey. Therefore it is very important to understand the behavior of masonry infill frame structures under earthquake loads. This study presents an experimental work performed on reinforced concrete (RC) frames with different types of masonry infills, namely standard and locked bricks. Earthquake effects are induced on the RC frames by quasi-static tests. Results obtained from different frames are compared with each other through various stiffness, strength, and energy related parameters. It is shown that locked bricks may prove useful in decreasing the problems related to horizontal and vertical irregularities defined in building codes. Moreover tests show that locked brick infills maintain their integrity up to very high drift levels, showing that they may have a potential in reducing injuries and fatalities related to falling hazards during severe ground shakings.

Cyclic testing of a single bay reinforced concrete frames with various types of masonry infill

ABSTRACTIn this paper, a contribution of various types of masonry infill to the behaviour of reinforced concrete frames under lateral loads is presented. As a part of the bigger project, ten one‐bay, one‐storey reinforced concrete frames were designed according to the EC8, built in a scale 1:2.5, infilled with masonry and tested under constant vertical and cyclic lateral load. The masonry wall had various strength properties, namely, high strength hollow clay brick blocks, medium strength hollow clay brick blocks and low strength lightweight autoclaved aerated concrete blocks. There were no additional shear connectors between the masonry and frame. The results showed that the composite ‘framed wall’ structure had much higher stiffness, damping and initial strength than the bare frame structure. Masonry infill filled in the load capacity gap from very low (0.05%) to drifts when the frame took over (0.75%). The structures behaved as linear monolithic elements to drifts of 0.1%, reached the maximum lateral capacities at drift of 0.3%, maintained it to drifts of 0.75% and after that their behaviour depended on the frame. Masonry infill had severe damage at drift levels of about 0.75% but contributed to the overall system resistance to drifts of about 1%. At that drift level, the frame had only minor damage and was tested to drifts of about 2% without any loss of capacity. Improvement of the ‘infill provisions’ in the codes could be sought by taking into account the contribution of a common masonry that reduces expected damages by lowering the drift levels. Copyright © 2012 John Wiley & Sons, Ltd.

Mechanical assessment of artificial turf football pitches: The consequences of no quality certification

The aim of the study is to assess a sample of twenty artificial football turf pitches (3rd Generation) of the Spanish football league. 7 regulatory tests were conducted ‘in situ’ as presented in EN 15330-1:2007 and Federation Internationale de Football Association (FIFA) rules. None of the pitches examined passed the 7 field tests of the certification protocols. Only 1 of the fields assessed passed 5 of the 7 tests in the EN protocol. The characteristics of the artificial turf system, such as the type of fibre, type of rubber infill or elastic base have an influence on the mechanical properties of the pitch. Standardization should be compulsory in new artificial turf grounds, regardless of the sporting competition that is held. Key words: Artificial turf, quality, field test, Federation Internationale de Football Association (FIFA), EN rules.

Behaviour of concrete-filled steel columns subjected to lateral cyclic loading

This paper reports the findings of an experimental study that was undertaken to investigate the cumulative damage of in-filled steel columns subjected to quasi-static loading. The parameters studied are, the diameter-to-thickness ratio of the steel tube and two types of in-fills namely Plain cement concrete and Steel fiber reinforced concrete. This paper summarizes the results of phase I testing that consisted of benchmark tests to establish the hysteresis behaviour under variable amplitude cyclic loading and phase II testing that consisted of constant amplitude cyclic loading that focused on the effects of amplitude and number of cycles on damage accumulation of in-filled columns. Findings of these studies highlight the significant increase in ductility and energy absorption capacity and decrease in the damage index of Steel fiber reinforced concrete-filled steel columns compared to plain cement concrete-filled columns. A simplified equation for cumulative damage has been proposed to predict the damage index of in-filled columns. This index can be used as a measure for predicting the safety of new and existing in-filled columns against earthquake.

Effectiveness of Rectangular Spiral Shear Reinforcement on Infilled R/C Frames Under Cyclic Loading

The effect of two types of shear reinforcement, with reference to two types of masonry infills, on the seismic performance of reinforced concrete (RC) frames was experimentally investigated. Six single-story, one-bay, 1/3-scale frame specimens were tested under cyclic horizontal loading, up to a drift level of 40‰. Bare frames and infilled frames with two different infill compressive strengths were sorted into two groups based on stirrups or spirals as shear reinforcement. From the observed responses it can be deduced that rectangular spiral reinforcement is a first experience and more experiments are needed.

Masonry elements with chases: Behaviour under compression

Accommodating electrical wiring and similar installations in masonry construction often necessitates the cutting of chases in masonry. In order to investigate the influence of chases on masonry behaviour compression load tests were performed on three series of unreinforced masonry elements with chases. Three different types of chase (horizontal, vertical and inclined) were cut into the masonry elements. After placing the ducts several different types of infill were applied to fill the chases. The compressive load was applied in a deformation-controlled manner up to the failure of the specimen. A considerable reduction in the masonry compressive strength was observed. The test results are discussed in detail and recommendations for practical application are given. In addition, a simple analytical truss model for predictions of failure load is proposed and discussed.

A shear-displacement criterion for soil-infilled rock discontinuities

An infilled rock joint is likely to be the weakest plane in a rock mass. The most pronounced effect of the presence of infill material is the reduction in friction of the discontinuity boundaries (i.e. rock to rock contact of the joint walls). The thicker the infill, the smaller the shear strength of the rock joint. Once the infill reaches a critical thickness, the joint walls (rock) play no significant role in the overall shear strength. Several models have been proposed to predict the peak shear strength of infilled joints under both constant normal load and constant normal stiffness boundary conditions, taking into account the ratio of infill thickness (t) to the height of the joint wall asperity (a), that is the t/a ratio. Models based on the constant normal stiffness condition provide a much more accurate representation of the infilled joint behaviour in the field, but only a limited number of studies have focused on the more realistic constant normal stiffness stress–strain behaviour. This paper presents a critical review of some of the earlier studies and the most recent advancement of a shear-strength model developed at University of Wollongong, Australia, supplemented with laboratory data for model validation. The effect of different factors on the shear behaviour such as the t/a ratio, infill friction angle, joint wall roughness, joint stiffness and type of infill are presented.

Influence of Masonry Strength and Openings on Infilled R/C Frames Under Cycling Loading

The influence of masonry infills with openings on the seismic performance of reinforced concrete (R/C) frames that were designed in accordance with modern codes provisions is investigated. Two types of masonry infills were considered that had different compressive strength but almost identical shear strength. Infills were designed so that the lateral cracking load of the solid infill is less than the available column shear resistance. Seven 1/3 – scale, single–story, single–bay frame specimens were tested under cyclic horizontal loading up to a drift level of 40%. The parameters investigated are the opening shape and the infill compressive strength. The assessment of the behavior of the frames is presented in terms of failure modes, strength, stiffness, ductility, energy dissipation capacity, and degradation from cycling. The experimental results indicate that infills with openings can significantly improve the performance of RC frames. Further, as expected, specimens with strong infills exhibited better performance than those with weak infills. For the prediction of the lateral resistance of the studied single-bay, single-story infilled frames with openings, a special plastic analysis method has been employed.

Seismic characterization of multiple fracture sets at Rulison Field, Colorado

Conventional fracture-characterization methods assume the presence of a single set of aligned, vertical cracks in the subsur-face. We relax this assumption and demonstrate the feasibility of seismic characterization of multiple fracture sets. Our technique relies on recent numerical findings indicating that multiple, differently oriented, possibly intersecting planar cracks embedded in an otherwise isotropic host rock result in a nearly orthorhombic (or orthotropic) effective medium. Here, the governing parameters of crack-induced orthotropy are estimated from 3D, wide-azimuth, multicomponent seismic reflection data acquired over the tight-gas Rulison Field in Colorado. We translate strong azimuthal variations of the normal-moveout velocities intointerval crack densities, fracture orientations, type of fluid infill, and velocities of P- and S-waves in an unfractured rock. Our inversion procedure identifies a set of cracks aligned in approximately west northwest-east southeast direction in the western part of the study area and multiple, likely intersecting fractures in its eastern part. We validate both our underlying theoretical model and the obtained estimates by two independent measurements: (1) the estimated fluid-infill parameter indicates dry cracks as expected for the gas-producing sandstones at Rulison; and (2) the obtained crack orientations are supported by well observations. As a by-product of fracture characterization, we build an anisotropic velocity model of the Rulison reservoir which, we believe, is the first orthorhombic velocity field constructed from surface seismic data.

The Results of Making a City More Compact: Neighbours' Interpretation of Urban Infill

The quest for more sustainable urban forms has added renewed vigour to urban planning, with various types of urban infill and intensification becoming increasingly popular with local authorities. These approaches seek to achieve environmental and social objectives but, despite the supposed advantages of a more consolidated urban form, infill housing as a strategy for growth management is not always well received by local residents and it remains a contentious issue. In this paper the authors report on an enquiry into neighbours' interpretations of, and responses to, infill housing in Christchurch, New Zealand.

Penny-shaped fractures revisited

All methods of seismic characterization of fractured reservoirs are based on effective media theories that relate geometrical and material properties of fractures and surrounding rock to the effective stiffnesses. In exploration seismology, the first-order theory of Hudson is the most popular. It describes the effective model caused by the presence of a single set of thin, aligned vertical fractures in otherwise isotropic rock. This model is known to be transversely isotropic with a horizontal symmetry axis (HTI). Following the theory, one can invert the effective anisotropy for the crack density and type of fluid infill of fractures, the quantities of great importance for reservoir appraisal and management.

A Bow-form Burrow and its Sedimentological and Paleoecological Significance

Other| December 01, 2002 A Bow-form Burrow and its Sedimentological and Paleoecological Significance ROLAND GOLDRING; ROLAND GOLDRING 1Postgraduate Research Institute for Sedimentology, University of Reading, P.O. Box 227, Whiteknights, Reading RG6 6AB, UK Search for other works by this author on: GSW Google Scholar MICHAL GRUSZCZYNSKI; MICHAL GRUSZCZYNSKI 2Instytut Paleobiologii, Polska Akademia Nauk, ul. Twarda 51/55, PL-00-818 Warszawa, Poland Search for other works by this author on: GSW Google Scholar PETER A. GATT PETER A. GATT 3327 Manwel Dimech Street, Sliema SLM02, Malta Search for other works by this author on: GSW Google Scholar Author and Article Information ROLAND GOLDRING 1Postgraduate Research Institute for Sedimentology, University of Reading, P.O. Box 227, Whiteknights, Reading RG6 6AB, UK MICHAL GRUSZCZYNSKI 2Instytut Paleobiologii, Polska Akademia Nauk, ul. Twarda 51/55, PL-00-818 Warszawa, Poland PETER A. GATT 3327 Manwel Dimech Street, Sliema SLM02, Malta Publisher: SEPM Society for Sedimentary Geology Accepted: 12 Apr 2002 First Online: 03 Mar 2017 Online ISSN: 1938-5323 Print ISSN: 0883-1351 Society for Sedimentary Geology PALAIOS (2002) 17 (6): 622–630. https://doi.org/10.1669/0883-1351(2002)017<0622:ABFBAI>2.0.CO;2 Article history Accepted: 12 Apr 2002 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation ROLAND GOLDRING, MICHAL GRUSZCZYNSKI, PETER A. GATT; A Bow-form Burrow and its Sedimentological and Paleoecological Significance. PALAIOS 2002;; 17 (6): 622–630. doi: https://doi.org/10.1669/0883-1351(2002)017<0622:ABFBAI>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract A deep-tier, bow-form burrow with a long apertural neck, and several different types of infill is described from Upper Jurassic shelfal carbonates of Saudi Arabia, Miocene pelagic packstones and wackestones of Malta, and Lower Cretaceous shoreface sands and mudrocks of southern England. The two most commonly observed types of infill are a coarse-grained infill, referred to as Glyphichnus-mode (formed by sediment entering the burrow following breakage of the apertural neck), and a laminated, muddy infill, referred to as Cylindrichnus-mode, which is considered to represent passive, draught filling through a complete burrow. The type of infill and aspects of preservation show that these burrows can be used to assess the style of sedimentation, particularly steady aggradation versus periodic erosion. At present the bow-form burrow is not assigned to a specific ichnotaxon. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.