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Abstract Date palm midribs have been used in numerous forms of traditional handicrafts and vernacular construction in Egypt since the Ancient Egyptian era. Consequently, a strong technical heritage can still be found in the rural societies in Egypt, to the present day, in the field of handmade furniture, doors, fencing and roofing, where date palm midribs are utilized as reliable materials to benefit from their abundance, high renewability rate and cost-efficiency. Bundling, ropes- fastening and simple friction-based connections were the basic techniques needed when utilizing date palm midribs in the majority of that technical heritage. Those simple techniques require no extensive preparation for midribs prior to use. This ability of direct use is due to the ability of the peripheral layer of a date palm midrib to resist humidity and direct sunlight. Thus, all those characteristics led to the widespread utilization of date palm midribs among the poor rural societies in Egypt, such as in several products for household and traditional rural housing. The know-how behind this surviving heritage still enjoys high popularity among craftsmen in Egypt, which makes it possible to build on this knowledge for further exploitation of the potential of the material. This exploitation is needed to introduce date palm midribs as a reliable material for light and versatile construction for rural communities in Egypt. Research Question Previous trials of using date palm midribs in wide-span construction varied between the inclination towards simplicity and spontaneity as tools of preserving the nature of the material, and the inclination towards depending on experimentation and machined standardization to achieve maximum productivity and facilitate mass production. However, the spread of those trials remain limited and uncompleted. Therefore, the main question raised by the thesis is: Can a fusion between traditional spontaneity and analytical experimentation unlock the structural potentials of date palm midribs while sustaining the objectives of simplicity and productivity? Hypothesis “Implementing traditional date palm midribs techniques in the design of wide-span structurally efficient component can successfully demonstrate the strength of the material, and refurbish its integrity as local, low-cost and highly productive building material for the rural communities in Egypt.” Main Objective “To design and develop a versatile wide-span date palm midribs building component, based on the renovation of traditional techniques, in order to demonstrate and evaluate the potentials of date palm midribs as a reliable and highly- productive structural material .” Procedural Objectives and Structure 1. Procedural Objective 1: To define the dominant traditional techniques of dealing with date palm midribs. Chapter 1: Heritage of Date Palm in Egypt. This chapter investigated the status of date palms in Egypt, with an emphasis on date palm midribs as a versatile and renewable date palm byproduct. Traditional handicrafts and traditional rural construction using date palm midribs were analyzed. The most wide-spread techniques were found to be rope-fastening, bundling and friction-based joinery. 2. Procedural Objective 2: To investigate the previous trials of using date palm midribs in Wide-span construction and determine the gap between those the approaches of both trials. Chapter 2: Previous Trials of Wide-Span Construction Using Date Palm Midribs The challenges facing reviving date palm midribs in construction were found to revolve around the gap between the spontaneous approach that preserves the nature of the material, yet without reaching the maximum potential; and the analytical approach that i ndustrializes the material to produce a highly- productive standardized substitute to timber. The spontaneous approach emphasized on using date palm midribs in arched bundles, clearly inspired from their traditional techniques. The analytical approach emphasized on the longitudinal transition of forces in the midribs and utilized that fact to produce moment-free trusses. A methodology was proposed to design, develop and evaluate a date palm midribs wide-span building component. 3. Procedural Objective 3: To merge between the simplicity and spontaneity of arches and the structural efficiency of trusses to introduce a wide-span component that unlocks the structural potential of date palm midribs while depending mainly on traditional techniques. Chapter 3: Design of Wide-Span Date Palm Midribs Building Components This chapter followed the proposed methodology to determine the needs the component is required to serve. This chapter also investigated the structural characteristics of arches and the structural theories that evolved based on the concept of arches. The structural concept was generated by merging the simplicity of arches with the structural efficiency of trusses led to the design of the Tri-arched space truss (TAST). Finally, the details of the design were developed by the three Vitruvius Fundamentals of Architecture and visualized by a 1:20 physical model. 4. Procedural Objective 4: To validate the structural performance of the date palm midribs tri-arched space truss. Chapter 4: Evaluation of Structural Performance of Date Palm Midribs Tri-Arched Space Truss This chapter evaluated the structural behavior of the developed systems. 1:3 specimens were built and tested under vertical loading in the Concrete laboratory in the faculty of Engineering, Ain Shams University. The specimens were built by local crate workers who reported that the building procedures were fast and easily grasped. The date palm midribs demonstrated high flexibility with gradual failure. The specimens maintained their initial form after releasing the loads and allowed for the reusability of the undamaged members. The reported behavior was used to validate the Finite Element Method (FEM) model in order to predict the actual behavior in full scale. The model showed that the 12m span design was safe under standard sheathing and wind loads. 5. Procedural Objective 5: To implement the validated system into light wide-span techniques to introduce versatile structures while satisfying the market demands and adhere to the governmental restrictions. Chapter 5: Implementing Date Palm Midribs Tri -Arched Space Truss into Wide-Span Building Arrangements The developed system was to be implemented into fully form active arrangements for maximum structural efficiency. Therefore in this chapter, the main functions that were to be hosted by those arrangements were selected according to the restrictions of the Egyptian Code of Fire Protection and the social familiarity of using the relevant techniques in the buildings of those functions. Accordingly, the TAST braced barrel vaults were proposed to host multifunction gatherings, and the TAST tensile fabric structures were proposed to host traditional markets. Both designs were analyzed structurally and were proved to be safe under standard wind loads. In addition, alternatives were derived from those basic designs to allow for more diversity. Terminology Guide Building component: the unit of a structural arrangement that is comprehensive of material, architectural and structural design. Building technique: the method used to by a builder to assemble a structure in a particular way according to the availability of the material, finance and manpower and the required structural durability within maximum material and labor efficiency. Date palm byproducts: products of date palm other than date, resultant from the annual pruning process. Productivity: the ability to sustain efficient mass production, reusability and modifiability in product desi gn. Structural arrangement: the spatial assembly of building components and structural systems to maintain architectural function. Structural element: the basic unit in structural design. Technical heritage: the comprehensive school of building and handcraft techniques inherited through generations. Validation: confirming the correspondence between actual performance and predicted analysis. |