Mechanical behavior of sandwich panels with curauá fiber reinforced composite skins and autoclaved aerated concrete core

Resumo

A curauá fiber-reinforced aerated concrete sandwich panel was developed as a sustainable, lightweight,
and low-cost alternative construction material. Each composite skin consisted of long unidirectional aligned curauá
fibers, applied by a cast hand layup technique, and a cementitious matrix with 50% of Portland cement replacement
by pozzolanic materials. The mechanical properties of the sandwich panels and their components were
investigated. The skins displayed a strain-hardening response and multiple cracking behavior. Strength,
deformation capacity, and cracking mechanisms of the composite laminates are presented. The sandwich panels'
monotonic and cyclic four-point bending responses were evaluated. The bonding between the composite layers
and the autoclaved aerated concrete (AAC) core was assessed through pull-off tests and microscopic imaging. The
results revealed the efficiency of the cementitious layers in providing a more ductile behavior and a higher flexural
strength to the material. The ductility properties of the AAC core were improved when assisted by the skin layers
in the sandwich structure. A deflection-softening behavior and a satisfactory post-peak ductility were observed in
the cyclic bending tests. Failure mechanisms, strength, and toughness are reported.