Experimental study on dynamic mechanical properties of fly ash and slag based alkali-activated concrete

Alkali-activated concrete (AAC) is a promising construction material. The research on AAC which about static mechanical properties have been intensively studied, while corresponding in dynamic mechanical properties are carried out in limited strain rate. In this paper, the dynamic mechanical properties of AAC with different strengths achieved by distinct precursor compositions were studied experimentally. The strain rate effects (from 10-5 s-1 to 350.4 s-1) on the compressive failure process, impact toughness, and compressive strength of AAC were investigated. Moreover, the splitting tensile tests were conducted in a strain rate range from 10-6 s-1 to 3.95 s-1. A modified SHPB was used to conduct spall experiments to investigate the tensile strength of AAC in the strain rate range from 10.54 s-1 to 156.30 s-1. The consequences demonstrated the compressive and tensile properties of AAC have significant strain rate effects, and the strength grade affects its strain rate sensitivity. The existing empirical relations describing the strain rate effect of ordinary Portland cement concrete (OPC) are not necessarily applicable to AAC. Based on the experimental results, empirical relations reflecting the strain rate effect of AAC with different strength grades were proposed.