Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model

Recycled aggregate concrete (RAC) has emerged as a viable solution for solving some of the environmental problems of concrete production. However, design guidelines for deflection control of reinforced RAC members have not yet been proposed. This study presents a comprehensive analysis of the applicability of the fib Model Code 2010 (MC2010) deflection control model to reinforced RAC beams. Three databases of long-term studies on natural aggregate concrete (NAC) and RAC beams were compiled and meta-analyses of deflection predictions by MC2010 were performed. First, the MC2010 deflection control model was tested against a large database of long-term tests on NAC beams. Second, a database of RAC and companion NAC beams was compiled and initial and long-term deflections were calculated using the MC2010 model. It was shown that deflections of RAC beams are significantly underestimated relative to NAC beams. Previously proposed modifications for MC2010 equations for shrinkage strain and creep coefficient were used, and new modifications for the modulus of elasticity and empirical coefficient β were proposed. The improved MC2010 deflection control model on RAC beams was shown to have equal performance to that on companion NAC beams. The proposals presented in this paper can help engineers to more reliably perform deflection control of reinforced RAC members.This is the peer-reviewed version of the article: N. Tošić, S. Marinković, and J. de Brito, ‘Deflection control for reinforced recycled aggregate concrete beams: Experimental database and extension of the fib Model Code 2010 model’, Structural Concrete, vol. 20, no. 6, pp. 2015–2029, 2019 [https://doi.org/10.1002/suco.201900035

Extension of the ζ‐method for calculating deflections of two‐way slabs based on linear elastic finite element analysis

This is the peer reviewed version of the following article: [Tošić, N, Pecić, N, Poliotti, M, Marí, A, Torres, L, Dragaš, J. Extension of the ζ‐method for calculating deflections of two‐way slabs based on linear elastic finite element analysis. Structural Concrete. 2021; 1– 19], which has been published in final form at https://doi.org/10.1002/suco.202000558. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Deflections are among the most complex aspects of reinforced concrete behavior. Furthermore, deflection control is increasingly a governing criterion in design, especially in the case of two‐way members such as flat slabs or edge‐supported slabs. However, simple and theoretically sound and adequately verified methods for calculating deflections of two‐way reinforced concrete members have been lacking. Therefore, in this study, a novel method is proposed for deflection control of two‐way slabs. The method is an extension of the ζ‐method (as defined by Eurocode 2 and the fib Model Code 2010) of interpolating deflections between the uncracked and fully cracked state. As a basis, the method uses elastic deflections that are obtained through linear elastic analyses in finite element software. The elastic deflection is then adequately transformed based on the properties of a representative section, to account for cracking, shrinkage and creep according to a modified version of the ζ‐method. Finally, the method is validated against available experimental results from literature, obtaining satisfactory precision and accuracy. The method proposed in this study aims at providing an easy‐to‐use tool for designers carrying out deflection control of two‐way reinforced concrete slabs.Peer ReviewedPostprint (author's final draft

Effect of maturation conditions on sensory and antioxidant properties of old Serbian plum brandies

ljivovica and Prepeenica are traditional Serbian distillated beverages made from varieties of plum, of the genus Prunus. The ageing in wooden casks not only improves the sensory characteristics, but also changes the content of total polyphenols and contributes to the other important health properties, such as the increase of their antioxidant capacity. In this study, home-made brandy (ljivovica and Prepeenica) samples were used, which matured in casks during the time period from 10 to 47 years. The aim of this investigation was to examine the influence of the ageing parameters (time period and type of wooden casks) and raw material (plum cultivars) on the total polyphenol content, amount of certain phenol compounds, sensory properties, colour and antioxidant properties in matured brandies. The individual phenol components were determinated using HPLC system equipped with diode array detector, while the total phenol content and antioxidant activity was estimated using spectrophotometric methods (Folin-Ciocalteu, DPPH, FRAP and TEAC). Total polyphenol content (TPC) of aged Prepeenica samples was ranged from 230.26 to 890.26 mg/L gallic acid equivalents (GAE mg/L), whereas the TPC of ljivovica sample was 110.38 mg/L. Antioxidant capacity of analysed Prepeenica samples and ljivovica sample was in strong correlation with TPC. Total sensory score of all samples was very high and varied between 18.2 and 19.8. The obtained results have shown that the benefit of longer maturation on sensory characteristics is well recognized, but the improvement has some limitation

Chemical composition, antiproliferative and antioxidant activity of differently processed Ganoderma lucidum ethanol extracts

The content of phenolic compounds (TPC) and glucans, as well as the effectiveness of antiproliferative and antioxidant activity of differently processed Ganoderma lucidum ethanol extracts were determined and compared. The content of glucans (total, α- and β-) strongly depended on the extraction time and particle size, but only interaction of these parameters influenced the TPC. Gallic acid, quercetin, trans-cinnamic acid, kaempferol, hesperetin and naringenin were detected in extracts by HPLC–DAD. The most abundant phenols were hesperetin (1.875–3.222 µg/g) and naringenin (1.235–2.856 µg/g). The ethanol extracts exhibited noteworthy antioxidant activity, but the significant amount of phenolic compounds was strongly linked to polysaccharides, and hence reduced their antioxidant capacity. The results of the antiproliferative activity in vitro showed that the analyzed extracts were the most effective against HeLa cells. Significant correlations were observed between the antiproliferative effect and the TPC/glucan content of extracts

Physicochemical, Antioxidant and Sensory Properties of Peach Wine Made from Redhaven Cultivar

Physicochemical, sensory, and health-related characteristics of peach wine produced from Redhaven variety and selected white wines produced from various grape varieties were determined and compared. The alcohol content, titratable acidity, and total extract of peach wine was significantly lower compared with that of white wines, while its pH value was higher. The content of total phenolics (TPC) and flavonoids (TFC) of peach wine (402.53 mg/L GAE and 332.67 mg CAE/L, respectively) have been found significantly higher in comparison with that of white wines (TPC range 243.67-319.00 mg/L GAE, TFC range 129.67-175.17 mg CAE/L). The main phenolic compounds found in peach wine were chlorogenic acid, caffeic acid, and catechin (3.59, 0.87, and 0.60 mg/L, respectively). Antioxidant capacities were strongly correlated with total phenolics with correlation coefficients over 0.99. The highest antioxidant capacity was ascribed to peach wine. The results of sensory analysis indicated that the peach wine was very well accepted by the regular consumers of wine and can be a very interesting product in the market