Dynamic mechanical properties and constitutive model of red sandstone under different loading rates and high temperatures

• Elevated treatment temperature reduces red sandstone mass and enhances deformability under impact loading. • Higher impact velocity increases strain rate and dynamic compressive strength, confirming a strain rate hardening effect. • Damage features and ultimate failure modes are intensified by both higher strain rates and higher temperatures. • A dynamic damage constitutive model incorporating strain-rate and temperature effects was proposed for engineering design.