Experimental Analysis of Mechanical Anisotropy of Selected Roofing Felts

Abstract

In this work, four representatives of roofing felts are under consideration. Special attention is paid to the mechanical behaviour under the tensile load of the samples. The results of strength tests for the entire range of material work, from the first load to sample breaking, are shown with respect to a specific direction of sample cutting. Moreover, a unique study of the microstructure obtained with the scanning electron microscope and chemical composition determined by energy dispersive spectroscopy of the tested materials is presented. The significant mechanical material anisotropy is reported and moreover argued by microstructure characteristics. In perspective, the outcomes can give comprehensive knowledge on optimal usage of roofing felt and proper mathematical modelling.

Self-Healing Mechanical Properties of Selected Roofing Felts

“…This article is a continuation of the work started in [ 62 ]. However, in this article, an attempt is made to assess the possibility of connecting damaged, not modified in any way, roofing felt and to evaluate the strength of the joint resulting from material self-healing as a result of exposing the damaged material to an elevated temperature.…”

“…Another conclusion could be that because the reinforcement matrix in both cases was discontinued, this may indicate that, in the test, the strength of the base material itself was determined without the influence of the reinforcement layer—the strength of healthy, undamaged material is described in detail in the previous work [ 62 ]. The lack of a reinforcement matrix also results in a less significant difference in strength, depending on the direction in which the samples were cut—the effect of the reinforcement matrix on the anisotropy of the material is described in [ 62 ], which indicates the possibility of examining the impact of modifiers used in the production of the base material of roofing felt. In both cases, there are big differences in the strength for each material.…”

“…This research focused on exploring the possibility of creating a force-transmitting connection by heating two series of samples. In the first series, samples were prepared for tensile strength tests according to the method and dimensions presented in [ 62 ]. As a result, specimens of three types were cut from a sheet of roofing material at an angle of 0°, 45°, 90° to the reinforcement direction of the material for each one of four materials (M1–M4) obtained.…”

“…The second series of samples were prepared in the same way as previously described, except for cutting, and were subjected to a tensile test until tearing was caused according to the procedure presented in [ 62 ]. Therefore, a random and nonuniform connection area was created between the sample halves.…”

“…The thickness given for all samples was within the tolerance declared by the manufacturer for materials M1 and M3, ±0.5 mm, and for materials M2 and M4, it was ±0.4 mm. Detailed information on the selected materials, their chemical composition, microscopic structure, and mechanical properties are presented in previous work [ 62 ].…”