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The river deltas are hydrodynamic systems where high energy flux occurs due to the interaction of the river discharge, winds, water levels and wave field. This interaction triggers complex surface non-linear interactions that affect the wave parameters at the river delta, hence, non-linear analysis methods might ease the understanding of intricate surface ocean processes. Then, this research selected the Magdalena River delta to perform a novel application of a DOE-ANOVA. 2³ factorial design using winds, surface currents, and water levels as factors and surface wave parameters such as significant wave heights and peak period as responses. The factor’s data was retrieved from calibrated and validated hydrodynamic modelling of the main climate seasons (February, June, and October, respectively) in 2010, which is the year reporting the lowest and highest water levels in the river before 2015. The DOE-ANOVA results evidenced that winds modulated the surface wave parameters suggesting quadruplets wave-wave interactions, white-capping dissipation, and a surface river plume curvature due to the wind effect. The water level and currents at the river delta controlled the wave parameters, modulating the wave energy distribution between kinetic and potential. Finally, this research expanded the use of the DOE-ANOVA factorial design through factors and responses handled in time series, what eased to analyze the cause and effect within complex ocean surface interactions among wind, currents, water levels and waves. [ABSTRACT FROM AUTHOR]

This paper presents and discusses the results of an experimental study aimed at characterizing the mechanical properties of an innovative and patented concrete masonry solid block with non-conventional geometry. The measured response in the new non-conventional block is compared with a conventional solid block. The experimental program was planned to verify whether the new block complies with the minimum values prescribed by the NSR-10 Colombian Code for being used as an unreinforced structural masonry block. The verification includes tests of water absorption and compressive strength of blocks, compressive strength of prisms, and flexural bond strength of standard beams. The similitudes or differences between the two types of blocks and prisms were evaluated using ANOVA tests. The results obtained demonstrated that both types of blocks comply with the requirements prescribed by NSR-10. Moreover, the flexural bond strength of the new block is roughly two times higher than that of the conventional block. The study results confirm that the new innovative block can be used for masonry structures. [ABSTRACT FROM AUTHOR]

Concrete is one of the most commonly used construction materials in the world due to its versatility. There are different types of concrete according to the required mechanical responses, and these will depend on the composition of the elements. Therefore, additional elements have been developed to improve the properties and conditions of concrete. One of these elements is reinforcing fibers made of steel, polypropylene, glass, and so on, which, according to the base material, geometry, and dosage, improve the mechanical and workability properties and decrease and/or prevent the generation of cracks, which are some of the most common problems in industrial slabs. This study performs an analysis of the changes in the mechanical properties of concrete (compressive strength, rupture modulus, modulus of elasticity, Poisson's ratio, and residual stress) due to the addition of fiber-reinforced concrete (FRC) to determine the physical and mechanical conditions of the fibers that improve the concrete and its application in industrial concrete. Due to the large number of samples and variables, advanced statistical methods (analysis of variance and comparative index) were used in the numerical study, which allowed to analyze and compare several results at the same time. This research is divided into two stages. In the first stage, six steel fibers (with a dosage of 2.7, 6, and 11 and three of 28 kg/m3) and five polypropylene fibers (with a dosage of 0.6, 2.15, and 2.7 and two of 3 kg/m3) were used in the study, and compression and bending tests (ASTM C39 and C78, respectively) were performed on 35 cylinders and 45 beams. Improvements were identified in several fiber-reinforced concrete samples in terms of compressive strength: 67% of the steel fiber samples and 100% of the polypropylene fiber samples had values above the average value of the simple concrete; in terms of the modulus of rupture, 83% of the steel fiber samples and 80% of the polypropylene fiber samples had values above the average value of the simple concrete. In the second stage, one type of steel fiber and one type of polypropylene fiber were selected for a second mechanical analysis (64 cylinders, 72 beams, and 15 slabs) with dosages of 20, 30, and 40 kg/m3 and 2.13, 4.25, and 6.38 kg/m3, respectively. In the second stage, statistical analysis and modeling with nonlinear analysis were used to evaluate the results, where residual strength improved but Poisson's ratio decreased when the dosage of fibers was increased. [ABSTRACT FROM AUTHOR]

A compilation of structural fire statistics at the national and international levels is presented in the paper. At the national level, data were obtained from Medellín, Manizales and Pereira Cities, the National Unit for Disaster Risk Management (UNGRD), which collects relevant information reported by the National Fire Department of Colombia (DNBC) and from the DNBC. These statistics allow to identify the types of buildings in which structural fires are most frequent and the number of people injured or deceased in structural fires in Colombia. At the international level, it was possible to identify the number of structural fires reported by different countries from 1996 to 2018. These data were reported by the International Association of Fire and Rescue Services (CTIF). It was possible to establish from this information that Colombia presents values lower than 0.3 fires per thousand of inhabitants, surpassed by European countries and the United States, where this index is higher than 1. It should be clarified that the methodology for the elaboration of fire statistics includes international parameters related to the comparison of damages caused by structural fires with the population, which do not apply in Colombia in all cases. Thus, the results were analyzed with great caution, taking into account that, when comparing the results with the population of Colombia, data were presented that do not represent the current state of the country in the face of fire events. This was due to the quality of the information available in Colombia. The paper includes recommendations to be included in the next version of the Colombian Code for Earthquake-Resistant Construction (NSR). [ABSTRACT FROM AUTHOR]

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