Figure 15
The illustration consists of two main sections labeled “a” and “b,” each containing six line graphs arranged in a 3 by 2 grid layout from left to right and top to bottom. Each graph presents the temperature variation over time in concrete samples exposed to elevated temperatures, specifically the C R and R 8 series samples. In each graph, the vertical axis is labeled “Temperature (degrees Celsius)” and ranges from 0 to 1200 with an interval of 200. The horizontal axis is labeled “Time (minutes)” and ranges from 0 to 120 with an interval of 30. The legend in both sections explains six line styles representing different depths: a red dashed line for “Exp.,” green for “20 millimeters,” purple for “40 millimeters,” light green for “60 millimeters,” magenta for “80 millimeters,” and black for “Unexp.” In section “a,” the six graphs are titled from top-left to bottom-right as “C R-05,” “C R-10,” “C R-20,” “C R-30,” “C R-40,” and “C R-50.” C R-05 (Top-left graph): All the curves start from the origin. The red curve lies at the top and rises with a concave-down shape, which ends just above 1000 degrees Celsius. The green curve follows the same profile, which ends above 600; the purple and light blue curves end above the temperatures of 400 and 200, respectively. The red and black curves are positioned at the bottom, which ends below the temperature of 200. The bottom curves are almost linear. C R-10 (Top-center graph): Similar to C R-05, the red line rapidly climbs initially and shows a slightly more curved pattern, and the other curves are similar to C R-05. C R-20 (Top-right graph): Similar to C R-10, the red line rapidly climbs initially and shows a slightly more curved pattern, and the other curves are similar to C R-10. C R-30 (Bottom-left graph): Similar to C R-05, the red curve shows the smooth change initially than C R-05 and the other curves follow a similar profile. C R-40 (Bottom-center graph): Similar to C R-30, the red curve shows the smooth change initially than C R-30 which becomes a smooth curved profile, and the other curves follow a similar profile. C R-50 (Bottom-right graph): Similar to C R-40, the red curve shows the smooth change initially than C R-40 becomes a smooth curved profile, and the other curves follow a similar profile. In section “b,” the layout mirrors section “a” and includes six graphs labeled “R 8-05,” “R 8-10,” “R 8-20,” “R 8-30,” “R 8-40,” and “R 8-50.” These also share the same axis labels and scales as the C R series. The same six line styles appear in the same order, showing temperature rise profiles at varying depths. As with section “a,” the red line consistently reaches the highest temperature, near 1000 degrees Celsius, quickly, whereas the other lines lag significantly, especially the black dashed line for the unexposed face, which remains below 200 degrees Celsius throughout the test duration.Temperature readings during the fire-resistance test of walls constructed with SCB incorporating (a) CR and (b) R8. Authors’ own work