Experimental and numerical investigation of static and fatigue behavior of mortar with blast furnace slag sand as fine aggregates in air and water

•Static and fatigue behavior of mortar with BFS sand is investigated in air and water.•Stress-strain relationships for BFS and CS mortar are developed under static loading.•Simplified fatigue model is proposed for the assessment of plastic strain, total strain and fracture parameter.•Fatigue life of BFS and CS mortar is predicted at different stress levels using the proposed fatigue model. The experimental and analytical study are attempted to clarify the static and fatigue behavior of mortar with blast furnace slag (BFS) sand as fine aggregates in compression in air and water. The cylindrical BFS mortar specimens were used for static and fatigue compression tests in air and water and results are compared with those of mortar using crushed sand (CS). The fatigue load was applied in the form of sine signal with a constant amplitude and the frequency of 5Hz. The stress level is varied from 60%, 70% and 80% of the uniaxial compressive strength. The experimental results disclose that BFS mortar exhibits more fatigue life compared to CS mortar in air, while it is similar in water. Thereafter, the stress-strain relationships for each mortar under monotonic loading are formulated. Moreover, a simplified fatigue model for the assessment of plastic strain, total strain and fracture parameter at different number of loading cycles and for prediction of fatigue life is also proposed.