Shake-table tests of a reinforced concrete frame designed following modern codes: seismic performance and damage evaluation

This paper presents shake-table tests conducted on a two-fifths-scale reinforced concrete frame representing a conventional construction design under current building code provisions in the Mediterranean area. The structure was subjected to a sequence of dynamic tests including free vibrations and four seismic simulations in which a historical ground motion record was scaled to levels of increasing intensity until collapse. Each seismic simulation was associated with a different level of seismic hazard, representing very frequent, frequent, rare and very rare earthquakes. The structure remained basically undamaged and within the inter-story drift limits of the "immediate occupancy" performance level for the very frequent and frequent earthquakes. For the rare earthquake, the specimen sustained significant damage with chord rotations of up to 28% of its ultimate capacity and approached the upper bound limit of inter-story drift associated with "life safety". The specimen collapsed at the beginning of the "very rare" seismic simulation. Besides summarizing the experimental program, this paper evaluates the damage quantitatively at the global and local levels in terms of chord rotation and other damage indexes, together with the energy dissipation demands for each level of seismic hazard. Further, the ratios of column-to-beam moment capacity recommended by Eurocode 8 and ACI-318 to guarantee the formation of a strong column-weak beam mechanism are examined

Seismic performance and damage evaluation of a reinforced concrete frame with hysteretic dampers through shake-table tests

Passive energy dissipation devices are increasingly implemented in frame structures to improve their performance under seismic loading. Most guidelines for designing this type of system retain the requirements applicable to frames without dampers, and this hinders taking full advantage of the benefits of implementing dampers. Further, assessing the extent of damage suffered by the frame and by the dampers for different levels of seismic hazard is of paramount importance in the framework of performance-based design. This paper presents an experimental investigation whose objectives are to provide empirical data on the response of reinforced concrete (RC) frames equipped with hysteretic dampers (dynamic response and damage) and to evaluate the need for the frame to form a strong column-weak beam mechanism and dissipate large amounts of plastic strain energy. To this end, shake-table tests were conducted on a 2/5-scale RC frame with hysteretic dampers. The frame was designed only for gravitational loads. The dampers provided lateral strength and stiffness, respectively, three and 12 times greater than those of the frame. The test structure was subjected to a sequence of seismic simulations that represented different levels of seismic hazard. The RC frame showed a performance level of "immediate occupancy", with maximum rotation demands below 20% of the ultimate capacity. The dampers dissipated most of the energy input by the earthquake. It is shown that combining hysteretic dampers with flexible reinforced concrete frames leads to structures with improved seismic performance and that requirements of conventional RC frames (without dampers) can be relieved

Assessment of biochar and hydrochar as minor to major constituents of growing media for containerized tomato production

"This is the peer reviewed version of the following article: Fornes, Fernando, Rosa M Belda, Pascual Fernández de Córdova, and Jaime Cebolla-Cornejo. 2017. Assessment of Biochar and Hydrochar as Minor to Major Constituents of Growing Media for Containerized Tomato Production. Journal of the Science of Food and Agriculture 97 (11). Wiley: 3675 84. doi:10.1002/jsfa.8227, which has been published in final form at https://doi.org/10.1002/jsfa.8227. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] BACKGROUND: Chars are emerging materials as constituents of growth media. However, chars of different origin differ in their characteristics and more studies are needed to ratify them for such a role. The characteristics of coir mixed with 0%, 10%, 25%, 50%, 75%, and 100% (v/v) of two biochars, from forest waste (BCH-FW) and from olive mill waste (BCH-OMW), and one hydrochar, from forest waste (HYD-FW), and their effects on growth, yield and fruit quality of two tomato cultivars (Gransol RZ and Cuarenteno) were assessed. RESULTS: Chars negatively affected plant growth and yield but not fruit quality. The effect was related to the char dose and was larger in HYD-FW and BCH-FW than in BCH-OMW, despite the high salinity of the latter, and more acute in Cuarenteno than in Gransol RZ. The results were discussed on the basis of the large particle size of BCH-FW, which could have caused low nutrient solution retention and, hence, reduced plant nutrient uptake, and the highwater-holding capacity, poor aeration and large CO2 emission of HYD-FW, which could lead to root anoxia. CONCLUSION: BCH-OMW can be used at high proportion in media for tomato cultivation. The use of BCH-FW at a high proportion might be taken into consideration after adjusting particle size, yet this needs additional assays. HYD-FW is inadequate for soilless containerized tomato cultivation. (C) 2017 Society of Chemical IndustryThis study was funded by the Universitat Politecnica de Valencia (Proyectos de nuevas Lineas de Investigacion Multidisciplinares; PAID-05-12).Fornes Sebastiá, F.; Belda Navarro, RM.; Fernández De Córdova Martínez, PJ.; Cebolla Cornejo, J. (2017). Assessment of biochar and hydrochar as minor to major constituents of growing media for containerized tomato production. Journal of the Science of Food and Agriculture. 97(11):3675-3684. https://doi.org/10.1002/jsfa.8227S367536849711Martí, R., Roselló, S., & Cebolla-Cornejo, J. (2016). Tomato as a Source of Carotenoids and Polyphenols Targeted to Cancer Prevention. Cancers, 8(6), 58. doi:10.3390/cancers8060058Dorais, M., Ehret, D. L., & Papadopoulos, A. P. (2008). Tomato (Solanum lycopersicum) health components: from the seed to the consumer. Phytochemistry Reviews, 7(2), 231-250. doi:10.1007/s11101-007-9085-xSchmilewski, G. (2009). GROWING MEDIUM CONSTITUENTS USED IN THE EU. Acta Horticulturae, (819), 33-46. doi:10.17660/actahortic.2009.819.3Graber, E. R., Meller Harel, Y., Kolton, M., Cytryn, E., Silber, A., Rav David, D., … Elad, Y. (2010). Biochar impact on development and productivity of pepper and tomato grown in fertigated soilless media. Plant and Soil, 337(1-2), 481-496. doi:10.1007/s11104-010-0544-6Dumroese, R. K., Heiskanen, J., Englund, K., & Tervahauta, A. (2011). Pelleted biochar: Chemical and physical properties show potential use as a substrate in container nurseries. Biomass and Bioenergy, 35(5), 2018-2027. doi:10.1016/j.biombioe.2011.01.053Vaughn, S. F., Kenar, J. A., Thompson, A. R., & Peterson, S. C. (2013). Comparison of biochars derived from wood pellets and pelletized wheat straw as replacements for peat in potting substrates. Industrial Crops and Products, 51, 437-443. doi:10.1016/j.indcrop.2013.10.010Steiner, C., & Harttung, T. (2014). Biochar as a growing media additive and peat substitute. Solid Earth, 5(2), 995-999. doi:10.5194/se-5-995-2014Petruccelli, R., Bonetti, A., Traversi, M. L., Faraloni, C., Valagussa, M., & Pozzi, A. (2015). Influence of biochar application on nutritional quality of tomato (Lycopersicon esculentum). Crop and Pasture Science, 66(7), 747. doi:10.1071/cp14247Libra, J. A., Ro, K. S., Kammann, C., Funke, A., Berge, N. D., Neubauer, Y., … Emmerich, K.-H. (2011). Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels, 2(1), 71-106. doi:10.4155/bfs.10.81Fornes, F., Belda, R. M., & Lidón, A. (2015). Analysis of two biochars and one hydrochar from different feedstock: focus set on environmental, nutritional and horticultural considerations. Journal of Cleaner Production, 86, 40-48. doi:10.1016/j.jclepro.2014.08.057Kuzyakov, Y., Subbotina, I., Chen, H., Bogomolova, I., & Xu, X. (2009). Black carbon decomposition and incorporation into soil microbial biomass estimated by 14C labeling. Soil Biology and Biochemistry, 41(2), 210-219. doi:10.1016/j.soilbio.2008.10.016Bargmann, I., Martens, R., Rillig, M. C., Kruse, A., & Kücke, M. (2013). Hydrochar amendment promotes microbial immobilization of mineral nitrogen. Journal of Plant Nutrition and Soil Science, 177(1), 59-67. doi:10.1002/jpln.201300154Bargmann, I., Rillig, M. C., Buss, W., Kruse, A., & Kuecke, M. (2013). Hydrochar and Biochar Effects on Germination of Spring Barley. Journal of Agronomy and Crop Science, 199(5), 360-373. doi:10.1111/jac.12024Akhtar, S. S., Li, G., Andersen, M. N., & Liu, F. (2014). Biochar enhances yield and quality of tomato under reduced irrigation. Agricultural Water Management, 138, 37-44. doi:10.1016/j.agwat.2014.02.016Vaccari, F. ., Maienza, A., Miglietta, F., Baronti, S., Di Lonardo, S., Giagnoni, L., … Genesio, L. (2015). Biochar stimulates plant growth but not fruit yield of processing tomato in a fertile soil. Agriculture, Ecosystems & Environment, 207, 163-170. doi:10.1016/j.agee.2015.04.015Cortés-Olmos, C., Valcárcel, J. V., Roselló, J., Díez, M. J., & Cebolla-Cornejo, J. (2015). Traditional Eastern Spanish varieties of tomato. Scientia Agricola, 72(5), 420-431. doi:10.1590/0103-9016-2014-0322Fornes, F., Belda, R. M., Carrión, C., Noguera, V., García-Agustín, P., & Abad, M. (2007). Pre-conditioning ornamental plants to drought by means of saline water irrigation as related to salinity tolerance. Scientia Horticulturae, 113(1), 52-59. doi:10.1016/j.scienta.2007.01.008Cebolla-Cornejo, J., Valcárcel, M., Herrero-Martínez, J. M., Roselló, S., & Nuez, F. (2012). High efficiency joint CZE determination of sugars and acids in vegetables and fruits. ELECTROPHORESIS, 33(15), 2416-2423. doi:10.1002/elps.201100640Cebolla-Cornejo, J., Roselló, S., Valcárcel, M., Serrano, E., Beltrán, J., & Nuez, F. (2011). Evaluation of Genotype and Environment Effects on Taste and Aroma Flavor Components of Spanish Fresh Tomato Varieties. Journal of Agricultural and Food Chemistry, 59(6), 2440-2450. doi:10.1021/jf1045427Dunlop, S. J., Arbestain, M. C., Bishop, P. A., & Wargent, J. J. (2015). Closing the Loop: Use of Biochar Produced from Tomato Crop Green waste as a Substrate for Soilless, Hydroponic Tomato Production. HortScience, 50(10), 1572-1581. doi:10.21273/hortsci.50.10.1572Bunt, A. C. (1988). Media and Mixes for Container-Grown Plants. doi:10.1007/978-94-011-7904-1Mukherjee, A., & Zimmerman, A. R. (2013). Organic carbon and nutrient release from a range of laboratory-produced biochars and biochar–soil mixtures. Geoderma, 193-194, 122-130. doi:10.1016/j.geoderma.2012.10.002Schulz, H., & Glaser, B. (2012). Effects of biochar compared to organic and inorganic fertilizers on soil quality and plant growth in a greenhouse experiment. Journal of Plant Nutrition and Soil Science, 175(3), 410-422. doi:10.1002/jpln.201100143Fornes, F., Carrión, C., García-de-la-Fuente, R., Puchades, R., & Abad, M. (2010). Leaching composted lignocellulosic wastes to prepare container media: Feasibility and environmental concerns. Journal of Environmental Management, 91(8), 1747-1755. doi:10.1016/j.jenvman.2010.03.01

On the effects of friction modelling on small punch creep test responses: a numerical investigation

This paper shows the results of finite element (FE) analyses of Small Punch Creep Testing (SPCT) of a P91 steel at 600°C using two different approaches to model the friction between the specimen and the punch. The numerical results obtained by using the “classical” Coulomb friction model (i.e. constant friction coefficient) have been compared with those obtained by a more modern formulation, which takes into account the effects of local loading conditions, i.e. the contact pressure, between the contacting bodies (the small disc specimen and the punch) on the coefficient of friction. The aim of the work is to investigate the effects of the friction formulation used for the calculations on the numerical results representing the output of the test, i.e. the variation of the punch displacement versus time and the time to rupture. The calculations, carried out for various load levels, showed that the friction coefficient is not constant at all positions on the contacting surface between the punch and the specimen during the deformation process. The maximum value for the coefficient of friction is reached at the contact edge, which is a very important region in the specimen, because this is the position at which most of the creep deformation occurs. As expected, the displacement versus time curve (that is usually the only output obtained from experimental SPCTs) is affected by friction formulation which is used, as this directly influences the stress and strain fields in the specimen

Charring rate for fire exposed X-Lam

Design of timber structures has been outlined in Eurocode 5. Notional charring rate for softwood and hardwood timber is given. For the performance of X-LAM panels in fire, only little information on charring is available and whether the fire behaviour of X-LAM is similar to homogenous timber panels has not yet been systematically analysed. This paper presents an overview of fire performance of X-LAM and evaluation of its resistance to elevated temperature as an element of structure in comparison to homogeneous timber panels. Numerical study has been carried out based on available experimental results. Charring rates for X-LAM panels obtained from experimental results are compared with those obtained from Eurocode 5 and proposed simplified model

A numerical investigation on the fire response of a steel girder bridge

The response of bridges subject to fire is an under researched topic despite the number of bridge failures caused by fire. Since available data shows that steel girder bridges are especially vulnerable to fire, this paper delves into their fire response by analyzing with a 3D numerical model the response of a typical bridge of 12.20 m span length. A parametric study is performed considering: (1) two possibilities for the axial restraint of the bridge deck, (2) four types of structural steel for the girders (carbon steel and stainless steel grades 1.4301, 1.4401, and 1.4462), (3) three different constitutive models for carbon steel, (4) four live loads, and (5) two alternative fire loads (the hydrocarbon fire defined by Eurocode 1 and a fire corresponding to a real fire event). Results show that restraint to deck expansion coming from an adjacent span or abutment should be considered in the numerical model. In addition, times to collapse are very small when the bridge girders are built with carbon steel (between 8.5 and 18 min) but they can almost double if stainless steel is used for the girders. Therefore, stainless steel is a material to consider for steel girder bridges in a high fire risk situation, especially if the bridge is located in a corrosive environment and its aesthetics deserves special attention. The methodology developed in this paper and the results obtained are useful for researchers and practitioners interested in developing and applying a performance-based approach for the design of bridges against fire. © 2012 Elsevier Ltd. All rights reserved.Funding for this research has been provided to Dr. Paya-Zaforteza by the Spanish Ministry of Education (contract number EX-2008-0669 of the Program for Postdoctoral Stays), the Spanish Ministry of Economy and Competitiveness (research project BIA 2011-27104) and the Universitat Politecnica de Valencia (Research and Development Support Program PAID-06-11). Funding has also been provided to Dr. Maria Garlock by the National Science Foundation (NSF) under award number CMMI-1068252. All opinions expressed in this paper are the authors' and do not necessarily reflect the policies and views of the sponsors.Paya-Zaforteza, I.; Garlock, ME. (2012). A numerical investigation on the fire response of a steel girder bridge. Journal of Constructional Steel Research. 75:93-103. https://doi.org/10.1016/j.jcsr.2012.03.012S931037

Influence of adding phase change materials on the physical and mechanical properties of cement mortars

During the last years several studies of construction materials with incorporation of encapsulated phase change material (PCM) have been published. However, the utilization of non-encapsulated PCM is one of the main gaps. The main objective of this work was the study of physical and mechanical properties of cement mortars with incorporation of non-encapsulated PCM. It was possible to conclude that the utilization of non-encapsulated phase change materials can be seen as a good and more economical solution for the energy efficiency of the buildings, without prejudice of the properties.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for the financial support of PhD scholarship SFRH/BD/95611/2013

Applicability of the ISO Reference Terminology Model for Nursing to the Detailed Clinical Models of Perinatal Care Nursing Assessments

Objectives: The purpose of this study was to examine the applicability of the International Organization for Standardization (ISO) reference terminology model for nursing to describe the terminological value domain content regarding the entities and attributes of the detailed clinical models (DCMs) used for nursing assessments. Methods: The first author mapped 52 DCM entities and 45 DCM attributes used for perinatal care nursing assessments to semantic domains and their qualifiers to the ISO model. The mapping results of the entity and attribute concepts were classified into four categories: mapped to a semantic domain qualifier, mapped to a semantic domain, mapped to a broader semantic domain concept, and not mapped. The DCM mapping results were classified into three categories: fully mapped, partially mapped, and not mapped. The second author verified the mapping. Results: All of the entities and 53.3 % of the attribute concepts of the DCMs were mapped to semantic domains or semantic domain qualifiers of the ISO model, 37.8 % of the attributes were mapped to the broader semantic domain concept, and 8.9 % of the attributes were not mapped. At the model level, 48.1 % of the DCMs were fully mapped to semantic domains or semantic domain qualifiers of the ISO model, and 51.9 % of the DCMs were partially mapped. Conclusions: The findings of this study demonstrate that the ISO reference terminology model for nursing is applicable in representing the DCM structure for perinatal care nursing assessment. However, more qualifiers of the Judgment semantic domain are required in orde

Dynamic Effects of Turbulent Crosswind on the Serviceability State of Vibrations of a Slender Arch Bridge Including Wind-Vehicle-Bridge Interaction

The use of high-performance materials in bridges is leading to structures that are more susceptible to wind- and traffic-induced vibrations due to the reduction in the weight and the increment of the slenderness in the deck. Bridges can experience considerable vibration due to both moving vehicles and wind actions that affect the comfort of the bridge users and the driving safety. This work explored the driving safety and comfort in a very slender arch bridge under turbulent wind and vehicle actions, as well as the comfort of pedestrians. A fully coupled wind–vehicle–bridge interaction model based on the direct integration of the system of dynamics was developed. In this model, the turbulent crosswind is represented by means of aerodynamic forces acting on the vehicle and the bridge. The vehicle is modeled as a multibody system that interacts with the bridge by means of moving contacts that also simulate road-surface irregularities. A user element is presented with generality and implemented using a general-purpose finite-element software package to incorporate the aeroelastic components of the wind forces, which allows modeling and solving of the wind–vehicle–bridge interaction in the time domain without the need for using the modal superposition technique. An extensive computational analysis program is performed on the basis of a wide range of turbulent crosswind speeds. The results show that bridge vibration is significantly affected by the crosswind in terms of peak acceleration and frequency content when the crosswind intensity is significant. The crosswind has more effect on the ride comfort of the vehicle in the lateral direction and, consequently, on its safety in terms of overturning accidents