Comportamento experimental e numérico de bioconcretos de madeira e de painéis sanduíches com faces em laminados reforçados por fibras longas de sisal

Abstract

In the current study, wood bio-concretes (WBC) beams, long sisal fibers reinforcing cementitious composites laminates (LSiFRCC) and sandwich panels made by combining WBC and laminates were developed, and their bending behavior simulated numerically. A mix design method was used to produce workable WBC with wood shavings volumetric fractions of 40, 45 and 50% from different species. Next, relationships within density, compressive strength, water-to-cement ratio, and cement consumption were established in order to propose WBC mix design diagrams. The WBC fracture behavior was also accessed to obtain their constitutive laws. Because of the sisal fiber maximum length limitation when an element of length higher than 1.5 meters is projected, fibers overlapping had been studied with lap lengths of 0, 25, 50 and 75 mm. The three-point bending test results of the laminates reinforced by unidirectional sisal fibers showed multiple cracks with deflection hardening, and revealed that the higher the lap length, better the laminate performance. Next, the flexural behavior of WBC beams and LSiFRCC laminates were simulated numerically by combining the program DOCROS with DefDOCROS and Excel. From the validation of numerical results, a sandwich panel was idealized and produced with facings of mortar, continuous sisal fibers and WBC core.