Use of lignocellulosic materials in particleboard has turned into an alternative for the reuse of such materials, which are abundant and may have precarious disposal techniques. The present study fabricated particleboards using industrial sawmill waste from tropical hardwoods (a mix of species) and sugarcane bagasse with castor oil-based bicomponent polyurethane resin and evaluated the influence of the incorporation of sugarcane bagasse (0, 10, 20, 30, 40, and 50%) on the physical and mechanical properties of the composites. The particleboards were produced according to the Brazilian Standard ABNT NBR 14810 (2018), and performance requirements were assessed using Brazilian and international standards. Some of the particleboards met standardized requirements, with Treatment 5 (50% sawdust and 50% bagasse) showing better performance, indicating the possibility for use indoors in dry conditions. The addition of sugarcane bagasse increased dimensional stability of particleboards when compared with panels manufactured with timber residue. Statistical analysis indicated the percentage of bagasse was significant, increasing physical and mechanical properties when compared with the reference treatment.

Four-pile caps made from concrete are essential elements for the force transfer from the superstructure to piles or pipes. Due to the difficulties in carrying out full-scale tests and all the instrumentation involved, the use of numerical models as a way to study the mechanical behavior of these elements presents itself as a good alternative. Such numerical studies usually provide useful information for the update and improvement of normative standards and codes. The concrete damaged plasticity (CDP) constitutive model, which combines damage and plasticity with smeared-crack propagation, stands out in the simulation of reinforced concrete. This model is composed of five parameters: dilatation angle (ψ), eccentricity (ϵ), ratio between biaxial and uniaxial compressive strength (σ_bo/σ_co), failure surface in the deviator plane normal to the hydrostatic axis (K_c), and viscosity (μ). For unidimensional elements, the values of the CDP parameters are well defined, but for volumetric elements, such as concrete pile caps, there is a gap in the literature regarding the definition of these values. This fact ends up limiting the use of the CDP on these structural elements due to the uncertainties involved. Therefore, the aim of this research was to calibrate two numerical models of concrete four-pile caps with different failure modes for the evaluation of the sensitivity of the CDP parameters, except for ϵ, which remained constant. As a result, the parameters σ_bo/σ_co and K_c did not significantly influence the calibration of the force × displacement curves of the simulated structures. Values of ψ and μ equal to 36° and 1 × 10⁻⁴, respectively, are recommended for “static” analysis, while for “quasi-static” analysis, ψ values ranging between 45° and 50° are suggested according to the failure mode. The results also showed to be sensitive to the constitutive relation of concrete tensile behavior in both modes of analysis. For geometric parameterization, the “static” analysis is recommended due to the lower coefficient of variation (3.29%) compared to the “quasi-static” analysis (19.18%). This conclusion is supported by the evaluation of the ultimate load of the numerical models from the geometrically parametric study compared to the results estimated by an analytical model.

As wood is an orthotropic and natural material, there are several properties required for its use in civil construction. The apparent density has been used to estimate physical and mechanical properties of wood, as it is easy to determine experimentally, unlike other determinations, which involve the use of equipment available only in large research centers. Using the Brazilian standard ABNT NBR 7190 and linear and non-linear regression models, this research aimed to evaluate their accuracy in estimating the compressive strength parallel to the fibers (fc0) as well as their characteristic value (fc0,k). This study considered 72 tropical wood species from native forests that were divided into the 4 strength classes of this standard. For the set formed by all species, the linear polynomial model was the best fit, resulting in a determination coefficient of just over 70%.

Mercury intrusion porosimetry (MIP) is a technique used to characterize the pore size distribution and resin penetration in lignocellulosic materials, such as oriented strand board specimens (OSB), a multilayer panel utilized in structural applications. The method is based on the isostatic injection, under very high pressure, of a non-wetting fluid (mercury) into the porous material to determine parameters such as pore size distribution and percentage of porosity of the specimens. In this study, five different OSB were analyzed; they contained different wood species, resin type, and resin content. The panels manufactured with castor oil polyurethane resin showed porosity values in the range of 54.7 and 27.8%. This was a promising result compared with those obtained for panels made with phenolic resins, which are currently commercialized in Brazil.