Dynamic compression study of seawater sea sand concrete incorporated with expansive agents and glass fibre

Seawater sea sand concrete (SSSC) is an eco-friendly protection material with better development prospects than other cementitious composites. There are many projects facing dynamic compressive load during construction and operation. Therefore, it is important to explore an SSSC with excellent dynamic compression performance. In this study, alkali-resistant glass fibre (GF) was used to enhance the performance of SSSC and expansion agent (EA) was introduced to improve the interface of cement slurry. The results show that the slopes of the relationship between DIF and strain rate of F1EA6, F1EA0 and F0EA6 are 12.6%, 8.4% and 6.7% higher than that of F0EA0, respectively, which indicates that GF and EA have a more significant strain rate effect on the dynamic compression performance of SSSC. In addition, through introducing the fineness modulus of residue (MR) and scanning electron microscopy (SEM) observation to analyse the failure mode of the specimen, it further proves that GF and EA have a synergistic effect on dynamic compressive strength. This study put forward some guidelines for the future research direction of impact resistance of SSSC structure. •Dynamic compression performance study of SSSC based on SHPB.•GF or EA causes dynamic compressive strength and peak toughness to have more obvious strain rate effects.•Combining the fineness modulus of residue and scanning electron microscopy to analyse the failure modes of SSSC mixture.•EA causes GF adhere more tightly to the cement interface and thus improve the dynamic compression performance greatly.