Cross-laminated timber (CLT) has been widely discussed as a relevant industrialized construction solution. Numerous publications have considered CLT as a structural wood-based panel, but other documents have mentioned it as a building or even a construction system. Many authors address its application in multistory buildings, although single-family houses and lower building applications have become desirable topics as well. Given these gaps, this review study addresses a systematic method to evince the functions of cross-laminated timber in construction. The elucidation and discussion were led by technical and scientific contents through publications present in scientific websites and the Google web search engine. Intricate perceptions about the knowledge and reference of CLT functions were identified. From prospections, it was possible to state that CLT is a timber-forest product created in Europe, whose function acts as a structural composite panel of the engineered wood product category. However, CLT has been mentioned by many publications as a building or a construction system. Suggestions were raised to clarify to all readers with respect to misconceptions, and elucidate the construction systems capable of using it as the main resource. Discussions evinced the characteristics and potentials of this wood product. Even with its increasing application in tall buildings, the commercial application of CLT in low-rise buildings may be boosted by the possibility of large-scale production of industrialized houses.

Wood plays an essential role in civil construction due to its structural and sustainable properties. The longitudinal (E) and the transverse (G) modulus of elasticity are crucial for designing beams under bending, where combined deformations occur due to normal and shear stresses. However, the estimation of G for native Brazilian species still lacks standardized experimental procedures, with the simplified normative relation G = E/16 being commonly adopted. This study aims to estimate both E and G based on the Euler-Bernoulli and Timoshenko beam theories through three-point and four-point static bending tests. Four native Brazilian species and five ratios between the length and height of the cross-section (L/h) were analyzed. The results showed that, for L/h ratios below 18, the apparent modulus of elasticity was significantly affected by shear effects, exhibiting reductions of up to 18.47%. The E/G ratio ranged from 14.84 to 21.15, corresponding to a reduction of up to 7% and an increase of up to 32%, respectively, about the value proposed by ABNT NBR 7190-1 (2022). These results highlight the importance of considering specimen proportions and shear effects in the estimation of wood elasticity moduli obtained from bending tests.

In serviceability limit state, one-dimensional approaches are commonly used to estimate the bending stiffness and vertical displacement of cross-laminated timber (CLT) panels, such as the shear analogy method combined with mechanics of materials equations. Despite their simplicity, these equations disregard the orthotropic nature of wood’s elastic properties and the actual dimensions of CLT panels (treated as beams), affecting displacement predictions. In this context, a parametric study was conducted in this paper using the finite element method. Then, symbolic regression was applied to propose a correction factor for adjusting the stiffness of CLT panels obtained using the shear analogy method. The symbolic regression model for the correction factor demonstrated high accuracy (R2 = 0.9834). Adjusting the shear analogy stiffness with the proposed correction factor reduced the maximum error from 18% to 2% compared to the original method and numerical results. The model retained its accuracy in additional simulations, with percentage errors ranging from 0 to 1%.

Resumo A NBR 7190-3 (ABNT, 2022) apresenta diferentes métodos para determinar o módulo de elasticidade da madeira, permitindo a adoção de equivalência entre o módulo de elasticidade na compressão (Ec0) e na tração (Et0). Por outro lado, não apresenta uma forma de estimar o módulo de elasticidade na flexão (EM0), e tais estimativas não consideram a variação das estruturas anatômicas das espécies. Diante dessa lacuna, é necessário avaliar se essas equações são válidas para diferentes espécies. O presente artigo avaliou as propriedades elásticas de três espécies: Cumaru (Dipteryxodorata), Marupá (Simarouba amara Aubl., Simaroubaceae) e Roxinho (Peltogyne spp., Leguminosa). Para isso, realizou-se o ensaio não destrutivo de flexão, seguido de ensaios à compressão e à tração. Imagens microscópicas foram comparadas, para compreender a influência das estruturas anatômicas nas propriedades de rigidez. Os resultados confirmaram a equivalência entre Ec0 e Et0. A maior concentração de parênquimas no Cumaru e no Roxinho é responsável pelos valores estatisticamente inferiores de EM0 em relação ao Ec0 e Et0.