Influence of hydrated lime on the chloride-induced reinforcement corrosion in eco-efficient concretes made with high-volume fly ash

[EN] The main objective of this study was to analyze the influence that the addition of finely ground hydrated lime has on chloride-induced reinforcement corrosion in eco-efficient concrete made with 50% cement replacement by fly ash. Six tests were carried out: mercury intrusion porosimetry, chloride migration, accelerated chloride penetration, electrical resistivity, and corrosion rate. The results show that the addition of 10¿20% of lime to fly ash concrete did not affect its resistance to chloride penetration. However, the cementitious matrix density is increased by the pozzolanic reaction between the fly ash and added lime. As a result, the porosity and the electrical resistivity improved (of the order of 10% and 40%, respectively), giving rise to a lower corrosion rate (iCORR) of the rebars and, therefore, an increase in durability. In fact, after subjecting specimens to wetting¿drying cycles in a 0.5 M sodium chloride solution for 630 days, corrosion is considered negligible in fly ash concrete with 10% or 20% lime (iCORR less than 0.2 µA/cm2), while in fly ash concrete without lime, corrosion was low (iCORR of the order of 0.3 µA/cm2) and in the reference concrete made with Portland cement, only the corrosion was high (iCORR between 2 and 3 µA/cm2).This research was funded by MINISTERIO DE ECONOMIA Y COMPETITIVIDAD, grant number MAT2012-38429-C04-04.Valcuende Payá, MO.; Calabuig Pastor, R.; Martínez-Ibernón, A.; Soto Camino, J. (2020). Influence of hydrated lime on the chloride-induced reinforcement corrosion in eco-efficient concretes made with high-volume fly ash. Materials. 13(22):1-16. https://doi.org/10.3390/ma13225135S1161322Isaia, G. C., & Gastaldini, A. L. G. (2009). Concrete sustainability with very high amount of fly ash and slag. Revista IBRACON de Estruturas e Materiais, 2(3), 244-253. doi:10.1590/s1983-41952009000300003Golewski, G. L. (2018). Green concrete composite incorporating fly ash with high strength and fracture toughness. Journal of Cleaner Production, 172, 218-226. doi:10.1016/j.jclepro.2017.10.065Hanehara, S., Tomosawa, F., Kobayakawa, M., & Hwang, K. (2001). Effects of water/powder ratio, mixing ratio of fly ash, and curing temperature on pozzolanic reaction of fly ash in cement paste. Cement and Concrete Research, 31(1), 31-39. doi:10.1016/s0008-8846(00)00441-5Deschner, F., Winnefeld, F., Lothenbach, B., Seufert, S., Schwesig, P., Dittrich, S., … Neubauer, J. (2012). Hydration of Portland cement with high replacement by siliceous fly ash. Cement and Concrete Research, 42(10), 1389-1400. doi:10.1016/j.cemconres.2012.06.009Isaia, G. ., Gastaldini, A. L. ., & Moraes, R. (2003). Physical and pozzolanic action of mineral additions on the mechanical strength of high-performance concrete. Cement and Concrete Composites, 25(1), 69-76. doi:10.1016/s0958-9465(01)00057-9Simčič, T., Pejovnik, S., De Schutter, G., & Bosiljkov, V. B. (2015). Chloride ion penetration into fly ash modified concrete during wetting–drying cycles. Construction and Building Materials, 93, 1216-1223. doi:10.1016/j.conbuildmat.2015.04.033Thomas, M. D. A., Hooton, R. D., Scott, A., & Zibara, H. (2012). The effect of supplementary cementitious materials on chloride binding in hardened cement paste. Cement and Concrete Research, 42(1), 1-7. doi:10.1016/j.cemconres.2011.01.001Delagrave, A., Marchand, J., Ollivier, J.-P., Julien, S., & Hazrati, K. (1997). Chloride binding capacity of various hydrated cement paste systems. Advanced Cement Based Materials, 6(1), 28-35. doi:10.1016/s1065-7355(97)90003-1Chalee, W., Ausapanit, P., & Jaturapitakkul, C. (2010). Utilization of fly ash concrete in marine environment for long term design life analysis. Materials & Design, 31(3), 1242-1249. doi:10.1016/j.matdes.2009.09.024Lollini, F., Redaelli, E., & Bertolini, L. (2015). Investigation on the effect of supplementary cementitious materials on the critical chloride threshold of steel in concrete. Materials and Structures, 49(10), 4147-4165. doi:10.1617/s11527-015-0778-0Baroghel-Bouny, V., Kinomura, K., Thiery, M., & Moscardelli, S. (2011). Easy assessment of durability indicators for service life prediction or quality control of concretes with high volumes of supplementary cementitious materials. Cement and Concrete Composites, 33(8), 832-847. doi:10.1016/j.cemconcomp.2011.04.007Wongkeo, W., Thongsanitgarn, P., & Chaipanich, A. (2012). Compressive strength and drying shrinkage of fly ash-bottom ash-silica fume multi-blended cement mortars. Materials & Design (1980-2015), 36, 655-662. doi:10.1016/j.matdes.2011.11.043Poon, C. S., Lam, L., & Wong, Y. L. (2000). A study on high strength concrete prepared with large volumes of low calcium fly ash. Cement and Concrete Research, 30(3), 447-455. doi:10.1016/s0008-8846(99)00271-9Garcés, P., Andión, L. G., Zornoza, E., Bonilla, M., & Payá, J. (2010). The effect of processed fly ashes on the durability and the corrosion of steel rebars embedded in cement–modified fly ash mortars. Cement and Concrete Composites, 32(3), 204-210. doi:10.1016/j.cemconcomp.2009.11.006Ghafoori, N., Najimi, M., Diawara, H., & Islam, M. S. (2015). Effects of class F fly ash on sulfate resistance of Type V Portland cement concretes under continuous and interrupted sulfate exposures. Construction and Building Materials, 78, 85-91. doi:10.1016/j.conbuildmat.2015.01.004Han, C., Shen, W., Ji, X., Wang, Z., Ding, Q., Xu, G., … Tang, X. (2018). Behavior of high performance concrete pastes with different mineral admixtures in simulated seawater environment. Construction and Building Materials, 187, 426-438. doi:10.1016/j.conbuildmat.2018.07.196Zuquan, J., Xia, Z., Tiejun, Z., & Jianqing, L. (2018). Chloride ions transportation behavior and binding capacity of concrete exposed to different marine corrosion zones. Construction and Building Materials, 177, 170-183. doi:10.1016/j.conbuildmat.2018.05.120Cheewaket, T., Jaturapitakkul, C., & Chalee, W. (2010). Long term performance of chloride binding capacity in fly ash concrete in a marine environment. Construction and Building Materials, 24(8), 1352-1357. doi:10.1016/j.conbuildmat.2009.12.039Fanghui, H., Qiang, W., & Jingjing, F. (2015). The differences among the roles of ground fly ash in the paste, mortar and concrete. Construction and Building Materials, 93, 172-179. doi:10.1016/j.conbuildmat.2015.05.117Alaka, H. A., & Oyedele, L. O. (2016). High volume fly ash concrete: The practical impact of using superabundant dose of high range water reducer. Journal of Building Engineering, 8, 81-90. doi:10.1016/j.jobe.2016.09.008Huang, Q., Zhu, X., Liu, D., Zhao, L., & Zhao, M. (2021). Modification of water absorption and pore structure of high-volume fly ash cement pastes by incorporating nanosilica. Journal of Building Engineering, 33, 101638. doi:10.1016/j.jobe.2020.101638Anjos, M. A. S., Camões, A., Campos, P., Azeredo, G. A., & Ferreira, R. L. S. (2020). Effect of high volume fly ash and metakaolin with and without hydrated lime on the properties of self-compacting concrete. Journal of Building Engineering, 27, 100985. doi:10.1016/j.jobe.2019.100985Herath, C., Gunasekara, C., Law, D. W., & Setunge, S. (2020). Performance of high volume fly ash concrete incorporating additives: A systematic literature review. Construction and Building Materials, 258, 120606. doi:10.1016/j.conbuildmat.2020.120606Lorca, P., Calabuig, R., Benlloch, J., Soriano, L., & Payá, J. (2014). Microconcrete with partial replacement of Portland cement by fly ash and hydrated lime addition. Materials & Design, 64, 535-541. doi:10.1016/j.matdes.2014.08.022Panesar, D. K., & Zhang, R. (2020). Performance comparison of cement replacing materials in concrete: Limestone fillers and supplementary cementing materials – A review. Construction and Building Materials, 251, 118866. doi:10.1016/j.conbuildmat.2020.118866Baert, G., Poppe, A.-M., & De Belie, N. (2008). Strength and durability of high-volume fly ash concrete. Structural Concrete, 9(2), 101-108. doi:10.1680/stco.2008.9.2.101Lammertijn, S., & De Belie, N. (2008). Porosity, gas permeability, carbonation and their interaction in high-volume fly ash concrete. Magazine of Concrete Research, 60(7), 535-545. doi:10.1680/macr.2008.60.7.535Bouzoubaâ, N., Bilodeau, A., Tamtsia, B., & Foo, S. (2010). Carbonation of fly ash concrete: laboratory and field data. Canadian Journal of Civil Engineering, 37(12), 1535-1549. doi:10.1139/l10-081Zhang, Y. M., Sun, W., & Yan, H. D. (2000). Hydration of high-volume fly ash cement pastes. Cement and Concrete Composites, 22(6), 445-452. doi:10.1016/s0958-9465(00)00044-5Zhao, Q., He, X., Zhang, J., & Jiang, J. (2016). Long-age wet curing effect on performance of carbonation resistance of fly ash concrete. Construction and Building Materials, 127, 577-587. doi:10.1016/j.conbuildmat.2016.10.065Barbhuiya, S. A., Gbagbo, J. K., Russell, M. I., & Basheer, P. A. M. (2009). Properties of fly ash concrete modified with hydrated lime and silica fume. Construction and Building Materials, 23(10), 3233-3239. doi:10.1016/j.conbuildmat.2009.06.001Filho, J. H., Medeiros, M. H. F., Pereira, E., Helene, P., & Isaia, G. C. (2013). High-Volume Fly Ash Concrete with and without Hydrated Lime: Chloride Diffusion Coefficient from Accelerated Test. Journal of Materials in Civil Engineering, 25(3), 411-418. doi:10.1061/(asce)mt.1943-5533.0000596Kumar, M., Singh, S. K., & Singh, N. P. (2012). Heat evolution during the hydration of Portland cement in the presence of fly ash, calcium hydroxide and super plasticizer. Thermochimica Acta, 548, 27-32. doi:10.1016/j.tca.2012.08.028Gunasekara, C., Sandanayake, M., Zhou, Z., Law, D. W., & Setunge, S. (2020). Effect of nano-silica addition into high volume fly ash–hydrated lime blended concrete. Construction and Building Materials, 253, 119205. doi:10.1016/j.conbuildmat.2020.119205Mohammed, M. E., Al-Shathr, B. S., & al-Attar, T. S. (2020). Effect of incorporating hydrated lime on strength gain of high-volume fly ash lightweight concrete. IOP Conference Series: Materials Science and Engineering, 737, 012058. doi:10.1088/1757-899x/737/1/012058Bentz, D. P. (2014). Activation energies of high-volume fly ash ternary blends: Hydration and setting. Cement and Concrete Composites, 53, 214-223. doi:10.1016/j.cemconcomp.2014.06.018Gandía-Romero, J. M., Ramón, J. E., Bataller, R., Palací, D. G., Valcuende, M., & Soto, J. (2016). Influence of the area and distance between electrodes on resistivity measurements of concrete. Materials and Structures, 50(1). doi:10.1617/s11527-016-0925-2Ahmad, S. (2003). Reinforcement corrosion in concrete structures, its monitoring and service life prediction––a review. Cement and Concrete Composites, 25(4-5), 459-471. doi:10.1016/s0958-9465(02)00086-0Matos, P. R. de, Sakata, R. D., & Prudêncio, L. R. (2019). Eco-efficient low binder high-performance self-compacting concretes. Construction and Building Materials, 225, 941-955. doi:10.1016/j.conbuildmat.2019.07.254Hornbostel, K., Larsen, C. K., & Geiker, M. R. (2013). Relationship between concrete resistivity and corrosion rate – A literature review. Cement and Concrete Composites, 39, 60-72. doi:10.1016/j.cemconcomp.2013.03.019Shi, C. (2004). Effect of mixing proportions of concrete on its electrical conductivity and the rapid chloride permeability test (ASTM C1202 or ASSHTO T277) results. Cement and Concrete Research, 34(3), 537-545. doi:10.1016/j.cemconres.2003.09.007Li, S., & Roy, D. M. (1986). Investigation of relations between porosity, pore structure, and C1− diffusion of fly ash and blended cement pastes. Cement and Concrete Research, 16(5), 749-759. doi:10.1016/0008-8846(86)90049-9Ngala, V., Page, C., Parrott, L., & Yu, S. (1995). Diffusion in cementitious materials: II, further investigations of chloride and oxygen diffusion in well-cured OPC and OPC/30%PFA pastes. Cement and Concrete Research, 25(4), 819-826. doi:10.1016/0008-8846(95)00072-kZhang, T., & Gjørv, O. E. (1996). Diffusion behavior of chloride ions in concrete. Cement and Concrete Research, 26(6), 907-917. doi:10.1016/0008-8846(96)00069-5Amiri, O., Aı̈t-Mokhtar, A., Dumargue, P., & Touchard, G. (2001). Electrochemical modelling of chloride migration in cement based materials. Electrochimica Acta, 46(9), 1267-1275. doi:10.1016/s0013-4686(00)00717-9Shehata, M. H., Thomas, M. D. A., & Bleszynski, R. F. (1999). The effects of fly ash composition on the chemistry of pore solution in hydrated cement pastes. Cement and Concrete Research, 29(12), 1915-1920. doi:10.1016/s0008-8846(99)00190-8Alonso, M. C., & Sanchez, M. (2009). Analysis of the variability of chloride threshold values in the literature. Materials and Corrosion, 60(8), 631-637. doi:10.1002/maco.20090529

OC, HPC, UHPC and UHPFRC Corrosion Performance in the Marine Environment

[EN] This work aims to study the corrosion performance of six concretes in the marine environment: three ordinary concretes (C30, C40 and C50); one high-performance concrete (C90); two ultra high-performance concretes, one without fibres (C150-NF) and another one with steel fibres (C150-F). To this end, porosity and chloride ingress resistance were analysed at different ages. Resistivity was also evaluated and the corrosion rate in the embedded rebars was monitored. The results showed that C30, C40 and C50 had porosity accessible to water percentages and capillary absorption values between six- and eight-fold higher than C90 and C150-NF and C150-F, respectively. Similar differences were obtained when oxygen permeability was analysed. Chloride ingress resistance in the ordinary concretes was estimated to be one-fold lower than in C90 and two-fold lower than in C150-NF and C150-F. Presence of fibres in C150-F increased the diffusion coefficient between 5% and 50% compared to C150-NF. Fibres also affected resistivity: C150-NF had values above 5500 ohm m, but the C150-F and C90 values were between 700 and 1000 ohm m and were one-fold higher than the ordinary concretes. After 3 years, the corrosion damage in the embedded rebars exposed to a marine environment was negligible in C90, C150-NF and C150-F (9.5, 6.2 and 3.5 mg mass loss), but with higher values (between 170.4 and 328.9 mg) for C3, C40 and C50. The results allow a framework to be established to make comparisons in future studies.This research was funded by the Spanish Government, grant number PID2020-119744RB-C21 funded by MCIN/AEI/10.13039/501100011033Lliso-Ferrando, JR.; Gandía-Romero, JM.; Soto Camino, J.; Valcuende Payá, MO. (2023). OC, HPC, UHPC and UHPFRC Corrosion Performance in the Marine Environment. Buildings. 13(10):1-27. https://doi.org/10.3390/buildings13102439127131

Corrosion resistance of ultra-high performance fibre- reinforced concrete

[EN] The corrosion resistance of ultra-high performance concrete (UH) made with different fibre contents and under distinct curing conditions was studied. No signs of carbonation were observed after 1 year of accelerated carbonation testing (3% CO2). The fibreless UHs¿ electrical resistivity was above 5000 ¿·m, although these values were 2-fold higher than a UH with 1% fibres and approximately 5-fold higher than a UH with 2% fibres. Concrete resistance to chloride penetration was also extremely high (the diffusion coefficient equalled 1.3·10¿13 m2/s) and curing temperatures of 60 °C or 90 °C improved even more these properties, while lack of curing made them slightly worse. Given these excellent properties, the corrosion rate in specimens submerged in chloride solution for 1 year was negligible (iCORR from 0.007 to 0.025 µA/cm2). These values remained stable with time, unlike the 50 MPa concrete at 2 months when iCORR starting to increase and was 12-fold higher after 1 year. The time estimated for corrosion onset in UH is on average about 150-fold higher than that of 50 MPa.Authors thank to the Spanish Government the financial support of project BIA2016-78460-C3-3-R and to the European Union¿s Horizon 2020 the financial support of ReSHEALience project (Grant Agreement No. 760824). Furthermore, authors would like to express their gratitude for the support of the Universitat Politecnica de Valencia. Funding for open access charge: CRUE-Universitat Politecnica de Valencia. The predoctoral scholarship granted to Josep Ramon Lliso Ferrando within the program ¿Formacion de Personal Investigador¿ from the Universitat Politecnica de Valencia (FPI-UPV-2018) is also gratefully acknowledged.Valcuende Payá, MO.; Lliso-Ferrando, JR.; Ramón Zamora, JE.; Soto Camino, J. (2021). Corrosion resistance of ultra-high performance fibre- reinforced concrete. Construction and Building Materials. 306:1-10. https://doi.org/10.1016/j.conbuildmat.2021.124914S11030

Full Counting Statistics of Multiple Andreev Reflections in incoherent diffusive superconducting junctions

We present a theory for the full distribution of current fluctuations in incoherent diffusive superconducting junctions, subjected to a voltage bias. This theory of full counting statistics of incoherent multiple Andreev reflections is valid for arbitrary applied voltage. We present a detailed discussion of the properties of the first four cumulants as well as the low and high voltage regimes of the full counting statistics. The work is an extension of the results of Pilgram and the author, Phys. Rev. Lett. 94, 086806 (2005).Comment: Included in special issue Spin Physics of Superconducting heterostructures of Applied Physics A: Materials Science & Processin

PLS multivariate analysis applied to corrosion studies on reinforced concrete

[EN] There are few techniques available to calculate the corrosion rate (i(corr)) of reinforcing steel in concrete structures. This is due not only to a lack of instrumentation but also because it is necessary to take into account that polarization can irreversibly modify the metal surface and can affect the results or the future state of the metal. This is the reason some researchers prefer to test reinforcing steel with reversible techniques. The main objective of this study is to predict the corrosion rate of reinforced concrete using electrochemical methods combined with statistical tools such as multivariate analysis. Using reinforcements embedded in mortar samples, the corrosion rates were determined at different ages using the Tafel method, and values obtained were compared with other techniques: linear polarization resistance (LPR), potentiostatic pulse testing (PPT), and AC electrochemical impedance spectroscopy (EIS). In addition, these values were compared to those obtained using a mixed technique based on partial least squares (PLS). With this technique, we were able to automatically analyze the current data obtained from LPR, PPT, and EIS and to predict the i(corr) value. The study allows us to conclude that it is possible to obtain reliable i(corr) values, very close to those obtained with the Tafel method by using PLS combined with PPT or LPR. Furthermore, it presents several advantages, such as being able to directly treat data without requiring an established Stern-Geary constant (B) for LPR and not having to use an equivalent circuit (EC) in EIS to calculate i(corr) because only the impedance spectra are necessary.Spanish Ministry of Economy and Competitiveness, Grant/Award Number: BIA2016-78460-C3-3-R; Spanish Ministry of Science and Innovation, Grant/Award Number: FPU 13/00911 and FPU16/00723Monzón, P.; Ramón Zamora, JE.; Gandía-Romero, JM.; Valcuende Payá, MO.; Soto Camino, J.; Palací-López, D. (2019). PLS multivariate analysis applied to corrosion studies on reinforced concrete. Journal of Chemometrics. 33(2):1-12. https://doi.org/10.1002/cem.3096S112332Chang, Z.-T., Cherry, B., & Marosszeky, M. (2008). Polarisation behaviour of steel bar samples in concrete in seawater. Part 1: Experimental measurement of polarisation curves of steel in concrete. Corrosion Science, 50(2), 357-364. doi:10.1016/j.corsci.2007.08.009Law, D. W., Millard, S. G., & Bungey, J. H. (2000). Linear polarisation resistance measurements using a potentiostatically controlled guard ring. NDT & E International, 33(1), 15-21. doi:10.1016/s0963-8695(99)00015-8Andrade, C., & Alonso, C. (1996). Corrosion rate monitoring in the laboratory and on-site. Construction and Building Materials, 10(5), 315-328. doi:10.1016/0950-0618(95)00044-5Glass, G. K., Page, C. L., Short, N. R., & Zhang, J.-Z. (1997). The analysis of potentiostatic transients applied to the corrosion of steel in concrete. Corrosion Science, 39(9), 1657-1663. doi:10.1016/s0010-938x(97)00071-1Poursaee, A. (2010). Potentiostatic transient technique, a simple approach to estimate the corrosion current density and Stern–Geary constant of reinforcing steel in concrete. Cement and Concrete Research, 40(9), 1451-1458. doi:10.1016/j.cemconres.2010.04.006Bastidas, D. M., González, J. A., Feliu, S., Cobo, A., & Miranda, J. M. (2007). A Quantitative Study of Concrete-Embedded Steel Corrosion Using Potentiostatic Pulses. CORROSION, 63(12), 1094-1100. doi:10.5006/1.3278327Saricimen, H., Mohammad, M., Quddus, A., Shameem, M., & Barry, M. . (2002). Effectiveness of concrete inhibitors in retarding rebar corrosion. Cement and Concrete Composites, 24(1), 89-100. doi:10.1016/s0958-9465(01)00030-0Lee JLS Gilmore IS Seah MP Extract of multivariate analysis terminology from ISO 18115-1 Surface Chemical Analysis - Vocabulary - Part 1: general terms and terms for the spectroscopies National Physical Laboratory. Teddington. Middlesex UK 2010UNE 112072: Determinación de la velocidad de corrosión de armaduras en laboratorio mediante medidas de la resistencia de polarización 2001ASTM G 102-89: Standard pratice for calculation of corrosion rates and related information from electrochemical measurements 2010Trabanelli, G., Monticelli, C., Grassi, V., & Frignani, A. (2005). Electrochemical study on inhibitors of rebar corrosion in carbonated concrete. Cement and Concrete Research, 35(9), 1804-1813. doi:10.1016/j.cemconres.2004.12.010Koleva, D. A., de Wit, J. H. W., van Breugel, K., Lodhi, Z. F., & van Westing, E. (2007). Investigation of Corrosion and Cathodic Protection in Reinforced Concrete. Journal of The Electrochemical Society, 154(4), P52. doi:10.1149/1.2436609Chang, Z.-T., Cherry, B., & Marosszeky, M. (2008). Polarisation behaviour of steel bar samples in concrete in seawater. Part 1: Experimental measurement of polarisation curves of steel in concrete. Corrosion Science, 50(2), 357-364. doi:10.1016/j.corsci.2007.08.009Stern, M., & Geaby, A. L. (1957). Electrochemical Polarization. Journal of The Electrochemical Society, 104(1), 56. doi:10.1149/1.2428496McCafferty, E. (2005). Validation of corrosion rates measured by the Tafel extrapolation method. Corrosion Science, 47(12), 3202-3215. doi:10.1016/j.corsci.2005.05.046Poorqasemi, E., Abootalebi, O., Peikari, M., & Haqdar, F. (2009). Investigating accuracy of the Tafel extrapolation method in HCl solutions. Corrosion Science, 51(5), 1043-1054. doi:10.1016/j.corsci.2009.03.00

Analysis of business incubators in Galicia through the «Integral Model of economic profitability»

Una de las políticas económicas utilizadas por los diversos gobier - nos para el desarrollo local y regional es el fomento del emprendimiento a tra - vés de los viveros de empresas, que contribuyen a la creación de empresas, de puestos de trabajo, incrementar las tasas de supervivencia empresarial y el pago de impuestos y cotizaciones sociales a las administraciones públicas. Pero como contrapartida son consumidores de recursos ajenos, con gran dependencia del sector público. En este estudio se pretende analizar la contribución neta de estos centros de iniciativas empresariales en Galicia (España), mediante la utilización del «Modelo integral de la rentabilidad de los viveros de empresas» basado en ecuaciones estructurales

Análisis de los viveros de empresas en Galicia a través del «Modelo integral de rentabilidad económica»

One of the economic policies used by governments for local and regional development is the encouragement of entrepreneurship through business incubators, which contribute to the creation of companies and employment, increase business survival rates and the payment of taxes and social contributions to public administration. However, they are consumers of external resources and have a high dependence on the Public Sector. In this study we analyse the net contribution of these business initiative centres in Galicia (Spain) through the use of the "Integral Model of profitability of business incubators" based on structural equations.Una de las políticas económicas utilizadas por los diversos gobiernos para el desarrollo local y regional es el fomento del emprendimiento a través de los viveros de empresas, que contribuyen a la creación de empresas, de puestos de trabajo, incrementar las tasas de supervivencia empresarial y el pago de impuestos y cotizaciones sociales a las administraciones públicas. Pero como contrapartida son consumidores de recursos ajenos, con gran dependencia del sector público. En este estudio se pretende analizar la contribución neta de estos centros de iniciativas empresariales en Galicia (España), mediante la utilización del "Modelo integral de la rentabilidad de los viveros de empresas" basado en ecuaciones estructurales

Análisis financiero-presupuestario en la provisión pública local, un caso práctico: Cercedo y Cotobade

La Administración Local, al ser la más próxima al ciudadano, es la que mejor conoce sus necesidades por lo que su eficiencia al prestar servicios básicos colectivos es alta. Sin embargo, para garantizar una óptima provisión de esos servicios requiere de una suficiencia financiera. Por ello, el estudio del estado financiero de nuestras Corporaciones Locales es prioritario, tarea donde además de las cuestiones financieras inciden otros múltiples aspectos. Este trabajo aborda la cuestión financiera a partir de los estados contables y ratios financieros aplicados a las entidades locales, midiendo así la capacidad evaluadora de estos indicadores financieros en relación a la situación económico-financiera de las entidades locales. El estudio, se basa en un análisis comparado acerca de la centralidad y dispersión de esos instrumentos, siendo las referencias utilizadas tanto las establecidas a partir de reglas empíricas como en los valores alcanzados por los indicadores de otras Corporaciones Locales de similar tamaño a nivel provincial y autonómico. Concluyendo con la proyección de los ratios del municipio investigado sobre las distintas referencias espaciales disponibles, obteniendo así una información relevante de la dirección a seguir para garantizar la provisión local.

La formación y la gestión del talento en las empresas más valoradas en recursos humanos en España

The objective of this article is to know the profile of the most attractive companies for professional development in Spain through the Training and Talent Management variables, in relation to other objective variables such as: economic activity, nationality, geographical location, size, and stock market listing. The statistical analysis techniques used are multiple linear regressions through ordinary least squares, Pearson correlations, unifactorial variance with Levene’s test, averages, and weightings. A unique profile is not obtained for both variables. On the one hand, Training obtains greater values in sanitary activities in companies from the Mediterranean located in the area north of Spain, and they are also large organization listed in the stock market; it is these two variables that are statistically relevant. On the other hand, Talent Management has greater values in the professional, scientific, and technical sector, in Anglo-Saxon companies located in the center of Spain, with large companies listed in the stock market predominating; it is this last variable that is statistically relevant.Este artículo pretende conocer el perfil de las empresas más atractivas para el desempeño profesional en España a través de las variables Formación y Gestión del Talento, en relación con otras variables objetivas como: actividad económica; nacionalidad; ubicación geográfica; tamaño y cotización en bolsa. Las técnicas de análisis estadístico empleadas han sido: regresiones lineales múltiples mediante mínimos cuadrados ordinarios, correlaciones de Pearson, varianzas unifactoriales con el test de Levene, promedios y ponderaciones. No se obtiene un perfil único para ambas variables. Por un lado, la Formación alcanza mayores valores en actividades sanitarias en las empresas del área mediterránea ubicadas en la zona norte de España; y son grandes organizaciones que cotizan en el mercado bursátil; son estas dos últimas variables relevantes estadísticamente. En cambio, en la Gestión del Talento los mayores valores se encuentran en el sector profesional, científico y técnico, en las empresas anglosajonas ubicadas en el centro de España, en la que predominan las grandes compañías que cotizan en bolsa; esta última variable es relevante estadísticamente