Conference Agenda

In Honduras several empirical systems are used as shear connectors for composite steel–concrete floor slabs, such as welded steel bars and U-shaped channels. This study experimentally evaluates these connectors using the push-out test methodology established in Eurocode 4, which specifies testing three specimens for each connector type; in total, 15 specimens were tested. The aim was to assess their load-bearing capacity, stiffness, ductility, and overall shear behavior. The welded steel bar connector achieved an average maximum load of 322.88 kN, a ductility of 6.98 mm, and a stiffness of 46.26 kN/mm, while the U-shaped channel connector reached an average maximum load of 309.59 kN, a ductility of 7.65 mm, and a stiffness of 40.46 kN/mm. The results show that both connectors can develop sufficient performance to enable composite action in floor systems. Their behavior is discussed in comparison to commercial connectors such as Nelson studs and Hilti X-HVB, aiming to provide technical support for their continued use in Honduras. Practical aspects such as material availability, ease of fabrication, and cost-effectiveness further encourage their widespread application in local construction.

This article evaluates the influence of polypropylene fibres (PPF) and silica fume (SF) on the mechanical properties of concrete with a design compressive strength of 210 kg/cm² incorporating recycled coarse aggregate (RCA), as a sustainable alternative for reusing construction and demolition waste. The aggregates were characterised in accordance with ASTM standards, and the mix design was developed using the ACI 211.1 method. Nine concrete mixtures were prepared following a Taguchi L9 orthogonal array, combining three levels of RCA (20%, 50%, and 100%), PPF (0.3%, 0.5%, and 0.7%), and SF (5%, 7%, and 9%).

The workability of the nine mixtures was evaluated through slump tests, and the compressive strength at 28 days was determined using 36 cylindrical specimens. The results indicate that the slump values ranged from 3.1 to 3.8 inches, slightly below the theoretical target slump of 4 inches. Furthermore, all mixtures exceeded the design compressive strength, with values between 225.95 and 295.08 kg/cm², corresponding to increases of 7.6% to 40.5% relative to the target strength of 210 kg/cm².

In addition, the optimal mixture was identified as consisting of 50% RCA, 0.7% PPF, and 9% SF. In conclusion, the combined incorporation of RCA, PPF, and SF enables the production of concrete with a design strength of f′c = 210 kg/cm², exhibiting controlled workability and mechanical performance superior to that of conventional concrete.

This research aims to evaluate the behavior of rammed earth walls when incorporating sheets made from eucalyptus leaves, using soil samples from Chim Chim-Otuzco, Cajamarca Province. The study seeks to analyze whether the inclusion of this organic material can influence the mechanical properties of the rammed earth, contributing to the utilization of available natural resources in the area. The research will be conducted in accordance with the guidelines of technical standard E.080 – Design and Construction with Reinforced Earth, which establishes the safety and resistance criteria for earthen buildings.

The purpose of this article is to evaluate the methods and criteria used to determine seismic demand according to the Venezuelan standard COVENIN 1756-1:2019 and the Dominican Republic's R-001 regulation. The aim is to identify similarities and differences in the design approach, the level of conservatism, and how each standard represents structural behavior under design earthquakes, given that both countries are located in the Caribbean. The study includes the identification and comparison of the seismic parameters used in constructing the response spectrum, the analysis of the criteria for calculating base shear, and the evaluation of permissible lateral drift limits, establishing the implications that each standard has on seismic demand and structural performance.

The results suggest that the COVENIN 1756-1:2019 standard presents a more detailed and flexible formulation for local conditions, and more explicitly represents the inelastic behavior of structures, avoiding the overestimation of design forces. In contrast, the R-001 regulation adopts a more simplified and conservative approach, prioritizing structural safety through higher seismic demands and more restrictive drift limits. This study contributes to the comparison of standards within the regional context, strengthening the understanding of seismic design criteria among Caribbean countries.

Pervious concrete is a sustainable material for stormwater management in urban environments; however, its high porosity limits its mechanical strength. This study evaluated the combined effect of a SikaCem superplasticizer (15 % water reduction) and DRAMIX® 3D steel fibers (15 kg/m³) on pervious concrete designed for a compressive strength of f'c = 180 kg/cm², in accordance with ACI 522R-10 guidelines. An experimental methodology was adopted by comparing conventional and modified mixtures through compressive strength, flexural strength, and permeability tests conducted at 7 and 28 days.

The results showed significant improvements in mechanical performance. At 28 days, the modified mixture achieved a compressive strength of 186.31 kg/cm² (1.8 % increase) and a flexural strength of 59.73 kg/cm² (6.0 % increase) compared to the control concrete. Permeability decreased from 0.030 m/s to 0.019 m/s (approximately 36.7 % reduction), while remaining within acceptable ranges for pervious pavements. Overall, the results confirm that the combined use of a superplasticizer and steel fibers optimizes the balance between mechanical performance and infiltration capacity, constituting a viable alternative for sustainable urban pavements subjected to light to moderate traffic

The research addresses the diagnosis and review of the soil resistivity system, an instrument designed to record shallow vertical boreholes through spontaneous, normal, and lateral potential curves. This instrument has presented failures that prevent its proper functioning. The main objective of the research was to identify the causes of the poor performance of the equipment and propose a redesign that increases its accuracy without altering the measurement principle. Based on the theoretical analysis of the four-electrode resistivity system and the review of field records, it was determined that the failures are primarily due to the degradation of the power supply, contacts, and the variation of reference resistances due to aging. A proposal for updating the measurement circuit and current stabilization was developed, preserving the original architecture. This will extend the lifespan of the DR-74 and maintain its reliability in resistivity measurements applied to geotechnical and electrical studies.