Intumescent coatings employ the heat barrier effect of an expanded char in the fire protection of the underlying substrates. The effectiveness of an intumescent system is dependent on the strength and ability of the char to remain intact upon exposure to fire. Many approaches have been employed to measure the strength of the intumescent char, but there still remains the need for an established standard procedure. In the present study, the compressive strengths of reinforced and unreinforced intumescent chars are evaluated using the compression test for cellular materials (ASTM 1162 00). This standard procedure enabled easy evaluation of compressive strength by employing the principle of deformation force as a function of the axial displacement of char under an active load by using the common universal tensile testing machine. The force–deformation graph revealed an exponentially increasing curve with two distinct regions, an initial region of low force to high deformation representing the collapse of the cellular pores and a high-force–low-deformation region attributed to the bulk mass effect of the compressed char. The results showed that the force needed to compress a bauxite residue-reinforced char to 10% deformation increased by 59%, while the compression strength increased by 13.08% over the control char.

膨胀型涂料在底层基材的防火中采用了膨胀炭的隔热效果。膨胀系统的有效性取决于炭的强度和在火中保持完整的能力。已经采用了许多方法来测量膨胀型炭的强度，但是仍然需要建立标准的程序。在本研究中，使用多孔材料的压缩试验（ASTM 1162 00）对增强和未增强膨胀型炭的抗压强度进行了评估。通过使用通用万能拉伸试验机，通过采用变形力原理作为活性载荷下炭的轴向位移的函数，该标准程序可以轻松评估抗压强度。力-变形图显示了一个呈指数增长的曲线，具有两个不同的区域，一个低力到高变形的初始区域代表了细胞孔隙的塌陷，而一个高力-低变形区域则归因于压缩的整体质量效应字符 结果表明，将铝土矿残渣增强的炭压缩至10％变形所需的力增加了59％，而压缩强度比对照炭增加了13.08％。