Rheological and mechanical properties of fiber-reinforced alkali-activated composite

• We presented strain-hardening fiber reinforced alkali-activated slag composite with low viscosity.
• The composite has one order of magnitude lower rheological values than those of normal concrete in the fresh state.
• The tensile strain capacities of the composite ranged from 1.02% to 2.38%.
• The micromechanical test and analysis support the uniaxial tension test result.

The purpose of this study is to investigate the rheological and mechanical properties of fiber-reinforced alkali-activated slag based cementless composite. The type of binder and fiber and mixture proportions were determined through preliminary tests. Then, a series of experiments, including rheology, compression, and uniaxial tension tests were performed to characterize the rheological and mechanical properties of the composite, followed by single fiber pullout tests and matrix fracture tests to characterize the micromechanical behavior of the composite. The test results show that low plastic viscosity, low yield stress, and high ductility can be attained by employing an alkali-activated slag based binder with water to binder ratio of 40% and PVA fibers of 1.3 vol.% in composites.