Date Palm Rachis as a Local and Renewable Structural Material for Rural Communities in Egypt

Abstract

Date Palm Rachis has been widely used in sheathing of houses in the rural communities in Egypt and the Middle East, as a local and cheap material that naturally resists direct solar radiation and humidity. Lately, researchers around the world began to build complete structures using Date Palm Rachis to take advantage of its abundance and natural resistance. However, due to the lack of the required mechanical properties for structural analytical modeling, mock ups are used to assess the structural properties of Date Palm Rachis. This tool of assessment is insufficient in the consideration of wind or temporary and unforeseen loads. This paper introduces the closest estimations of the complicated mechanical properties required for structural analytical modeling, according to the available equipment and the variable nature of Date Palm Rachis. The results showed that Date Palm Rachis is a promising structural material with structural properties that are competitive to that of imported timbers in Egypt. This paper invites researches and builders to exploit the potentials of Palm Rachis as a structural material for rural communities.

Structural Performance of Arched Space Trusses Using Date Palm Midribs for Light and Cost-Effective Construction in Egypt

“…The failure demonstrated at the overlapping area showed breakage at the middle bundles right above the end of the overlap. This breakage type of failure was reported previously as the failure pattern in the bending testing of date palm midribs, as shown in Figure 21b [16]. The vertical loading at the top of the middle bundles gradually reduced the arched shape of the bundles.…”

“…In summary, this type of failure in the specimens required extremely careful inspection to detect and showed gradual and slow progress. The failure at the middle bundles was found to take the form of few narrow longitudinal cracks that resembled the failure patterns reported in the tension testing of date palm midribs previously as shown in Figure 21a [16,20]. Such type of failure occurs because of the tensile overstressing on the peripheral cover of the date palm midribs.…”

“…On the other hand, the firmness of bottom bundles was growing along the increasing compression that was generated from the resistance of the natural parabolic shaping to the vertical loading and the solid fixation into the base. Subsequently, the resistance of the bottom bundles to bend enough to accommodate the increasing The failure at the middle bundles was found to take the form of few narrow longitudinal cracks that resembled the failure patterns reported in the tension testing of date palm midribs previously as shown in Figure 21a [16,20]. Such type of failure occurs because of the tensile overstressing on the peripheral cover of the date palm midribs.…”

“…The mechanical properties of a date palm midrib, as discussed earlier in the Introduction, vary according to the relationship with the direction of the fibers in the midrib, in addition to the type of joinery used in testing in the case of the tensile properties. The chosen mechanical properties, including the orthotropic moduli of elasticity, shear moduli and Poisson ratios, were the properties taken from the compression tests, as the parabolic arched chords were to mainly carry axial compression in normal cases [8,16]. However, from the observation of the structural behavior in the experimental testing, it was noted that the most critical part in the structure was in the middle bundles above the overlap where the failures occurred.…”

“…However, as the date palm midribs bundles were relatively heavier than their reed counterpart, the available manpower led to the decrease of the diameter to only 250 mm instead of the 700 mm diameter of the reed bundles in the Mudhif [15]. This decrease caused high deformations in the arches, which led to the addition of intermediate palm trunks columns, which subsequently reduced the span from the intended 13 m to 3.25 m between the columns [8,15,16]. Nevertheless, the main gain of this trial was maintaining the simplicity of the system where the used date palm midribs were in their original shape without any processing.…”