This paper presents the results of an investigation aimed at developing reinforced concrete beams consisting of precast\npermanent U-shaped reinforced mortar forms filled with different types of core materials to be used as a viable alternative to the\nconventional reinforced concrete beam. To accomplish this objective, an experimental program was conducted and theoretical\nmodel was adopted. The experimental program comprised casting and testing of thirty beams of total dimensions\n300 X 150 X 2,000 mm consisting of permanent precast U-shaped reinforced mortar forms of thickness 25 mm filled with the\ncore material. Three additional typical reinforced concrete beams of the same total dimensions were also cast to serve as control\nspecimens. Two types of single-layer and double-layers steel meshes were used to reinforce the permanent U-shaped forms;\nnamely welded wire mesh and X8 expanded steel mesh. Three types of core materials were investigated: conventional concrete,\nautoclaved aerated lightweight concrete brick, and recycled concrete. Two types of shear connections between the precast\npermanent reinforced mortar form and the core material were investigated namely; adhesive bonding layer between the two\nsurfaces, and mechanical shear connectors. The test specimens were tested as simple beams under three-point loadings on a span of\n1,800 mm. The behavior of the beams incorporating the permanent forms was compared to that of the control beams. The\nexperimental results showed that better crack resistance, high serviceability and ultimate loads, and good energy absorption could\nbe achieved by using the proposed beams which verifies the validity of using the proposed system. The theoretical results\ncompared well with the experimental ones.
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