Accurate and easy-to-use nondestructive tests (NDTs) are strongly required to detect damage and defects in concrete structures. In the Sonic-IR method, the IR radiation due to ultrasonic vibration at the object surface is visualized using a thermography camera. A temperature rise occurs with frictional heat generation due to the rubbing action of crack interfaces. Meanwhile, it is known that the technique is usually introduced for steel and composite materials, which have much higher thermal conductivity than a cement-hardened body. In this study, we applied the Sonic-IR method to identify crack propagation in cementitious materials. We found that the Sonic-IR method can be utilized for detecting the cracks in mortar under compressive stress failure. The resolution for detecting cracks in the targeted specimens was compared between the Sonic-IR method and cross-sectional imaging by X-ray computed tomography (CT) as NDTs. The effective test conditions for evaluating the internal/surface crack by the Sonic-IR method were clarified by changing the ultrasonic vibration frequency and the external force applied to mortar specimens to induce crack formation by compression loading. Varying the testing conditions in the Sonic-IR method, such as stress constraint and ultrasonic frequency, also enabled us to quantitatively observe the fracture progress upon the application of stepwise loading, which causes the evolution of compression failure.