Fig. 10: Relationship between SO₃ content and material hardness. | npj Heritage Science

Fig. 10: Relationship between SO₃ content and material hardness.

From: A lightweight integrated diagnostic approach for Macao Architectural Heritage using 3D laser scanning and NDT

Fig. 10: Relationship between SO₃ content and material hardness.The alternative text for this image may have been generated using AI.

This scatter plot illustrates the quantitative relationship between sulfur trioxide (SO₃) content and Leeb hardness (HL) measured on the rammed earth walls. Each data point represents a paired measurement from a specific location. The blue curve represents the fitted trend, revealing a strong negative correlation between the two variables. The goodness of this fit is indicated by a coefficient of determination (R²) of 0.76, statistically confirming that increasing SO₃ accumulation is a key factor in the mechanical degradation of the wall material under the studied environmental conditions.

Back to article page