Dynamic properties of alkali residue-based foamed concrete under cyclic load

Abstract

Alkali residue-based foamed concrete (A-FC), consisting of cement, alkali residue, blast furnace slag, and foam, has great potential for application in subgrade engineering. A series of dynamic triaxial tests were conducted, and the influences of confining pressure, vibration frequency, and curing age on the dynamic properties of A-FC was revealed. Test results indicated that the backbone curves of A-FC exhibit a hyperbolic shape, effectively captured by the H-D model. After 7 days of curing, A-FC possessed robust dynamic bearing capacity. As the dynamic strain increases, the dynamic elastic modulus of A-FC exhibits an initial rise followed by a gradual decline. Concurrently, the damping ratio demonstrates an initial decrease and subsequent gradual increase. Elevated confining pressure, prolonged curing age, and higher vibration frequency were found to contribute to a progressive increase in the dynamic elastic modulus of A-FC. Throughout the damping ratio growth stage, the increasing curing age and confining pressure led to the decrease of damping ratio, with minimal influence from vibration frequency. A calculation model for the maximum dynamic elastic modulus of A-FC was proposed, considering confining pressure, vibration frequency, and curing age. This research underscores the capacity of A-FC to withstand cyclic loading, thereby offering valuable support for its engineering applications.