Figure 3
The illustration contains two distinct photographs, labeled “a” and “b,” arranged side-by-side. Photo “a,” positioned on the left, shows a stack of three rectangular, light-colored concrete specimens. They are roughly cuboid in shape, with visible aggregates and some surface irregularities. The specimens are horizontally oriented and positioned side by side. One of the visible specimens has the number “20” handwritten on its front surface. Photo “b,” positioned on the right, depicts a single, light-colored concrete specimen placed within a testing apparatus. The specimen itself is a flat, rectangular block positioned horizontally on a red-colored base. Above the specimen, a large, cylindrical component of the testing machine is visible, applying pressure from the top. Two dimensions are indicated with black arrows and labels: a horizontal double-headed arrow below the specimen points to “222 millimeters,” indicating its approximate length, and a vertical double-headed arrow on the right side of the specimen points to “73 millimeters.” The specimen is centrally positioned between the loading plates of the machine.Compressive strength test setup: (a) carefully dismantled SCBs with 20% CR and (b) a 2 MN instron actuator machine. Authors’ own work