Mechanical properties of basalt fiber reinforced ambient-cured lightweight expanded polystyrene geopolymer concrete

This study investigated the mechanical properties of ambient-cured lightweight expanded polystyrene (EPS) geopolymer concrete (LEGC) specimens with densities ranging from 1321 to 1912 kg/m3 (i.e., EPS dosing of 40%, 30%, 20%, and 10%) by dosing basalt fiber (BF) with volume contents of 0.2%, 0.4%, 0.6%, and 0.8%. First, density, workability, quasistatic compression, splitting tensile, flexural and ultrasonic pulse velocity (UPV) tests were carried out with the LEGC specimens. Based on the test results, the quasistatic compressive strength enhancement rates of LEGC specimens dosed with EPS volume contents of 10%, 20%, 30% and 40% under the effect of optimal dosing of BF were 10.39%, 19.71%, 16.61%, and 15.18%; the split strength enhancement rates were 14.08%, 21.54%, 26.83% and 19.44%; the flexural strength enhancement rates were 7.35%, 17.82%, 22.56% and 17.34%; and the UPV enhancement rates were 2.82%, 1.90%, 3.12% and 2.95%, respectively. Consequently, empirical formulas were established for predicting the quasistatic compressive strengths, splitting tensile strengths, flexural strengths, and UPV values of the LEGC specimens. The prediction equations were also compared with the empirical equations proposed by previous researchers. Finally, to characterize the damage mechanisms of the LEGC specimens, computerized tomography (CT) and scanning electron microscopy (SEM) analyses were also performed on damaged LEGC specimens.