Compressive strength development of unloaded specimens and creep specimens (after 1 month of sustained load applied at ages of 1 month and 3 months) vs. concrete age (Mix nos. 1, 2, and 3 were generated to investigate the effect of quasi-instantaneous compressive preloading (at levels of 80%, 90%, and 95%, respectively) on tensile strength. Mix no. 6 was produced to study the impact of compressive creep on tensile strength. The influence of compressive creep on compressive strength was assessed by casting mix nos. 4 and 5 for a 1-month loading age (levels of 50% and 65%, respectively) and by introducing mix no. 7, with the load being placed at an age of 3 months (for both, 50% and 80% loading levels)).