The dead load and consequently the burden imposed on the structures due to earthquake can be reduced using Lightweight Aggregate Concrete (LWAC). In this study the cyclic flexural performance of LWAC beams is experimentally investigated to assess the influence of nano-SiO2 and steel fibers on the reversal flexural behavior. Tests were carried out on the reinforced LWAC beams with dimensions of 150 × 200 × 1200 mm under alternative cycles of variable displacement amplitudes. The cyclic behavior of these members including hysteresis response, load bearing capacity, envelope curve, stiffness, energy dissipation capacity and crack pattern are discussed and compared. The results showed that the addition of steel fiber significantly enhanced maximum flexural strength, cumulative dissipated energy, post-cracking stiffness and damage tolerance ability of LWAC beam. Adding nano-silica alone had slight effect on improving the reversal cyclic flexural behavior of LWAC. Furthermore the use of nano-silica increased the effectiveness of steel fiber on enhancement the cyclic flexural performance, especially at higher levels of displacement.
