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This present research mainly focused on the behaviour of monolithically and precast portal frames made with lightweight fiber reinforced concrete. The lightweight fiber reinforced concrete (LWFRC) is achieved with Palm oil shells (POS) and glass fibers (G.F). The POS is replaced with coarse aggregates and the G.F is added to the concrete to increase ductility parameters. To reduce the further density of the concrete, replaced cement with GGBS and Palm Oil Fuel Ash (POFA) individually. All these replacements are helping the reduction of solid waste and greenhouse gases from cement Industries. Portal frames are made with M30 Grade LWFRC through replacements. All the precast frames are connected with the Dowel bar connection through the grouting. All the LWFRC frames are compared with conventional concrete frames. The palm oil shells are replaced up to 50% in coarse aggregates to diminish the density of the concrete and also to decrease the greenhouse gases from the cement industry; cement is replacing with Ground Granulated Blast Furnace Slag (GGBS) and Palm Oil Fuel Ash (POFA).

Owing to its forgiving tolerances and eliminating the need for welding, grouted dowel in-conduit connections are widely used for connecting various precast concrete elements, for instance in precast wall construction and bridge bent cap systems. Current design recommendations for such a connection treat it similar to a conventional reinforcing bar-in-concrete and do not account for the restraining effect of the duct. In the present study, a series of experimental and analytical approaches have been adopted to explore the disparity between grouted dowel connections and bar-in-concrete. The experimental program consisted of testing twenty-four pull-out specimens under monotonic loads. The main parameters investigated included the embedment length, concrete compressive strength and corrugated duct. Results from the experimental and analytical procedures showed that grouted dowel in-conduit connections behave markedly different from bars in concrete. Different failure mechanisms occurred in the grouted connections due to the confinement effect of the duct. Moreover, an increase in load carrying capacity and ductility of the connections was observed at all embedment lengths, regardless of the concrete compressive strength. Based on the experimental findings, an analytical model for predicting the embedment length of the connection was derived, calibrated and proven to be more accurate than state-of-the-art design procedures.

Steel–concrete trussed composite beams are a particular types of composite girders constituted by a steel truss embedded in a concrete core. The truss is typically composed by a steel plate or a precast concrete slab working as bottom chord while coupled rebars are generally used to form the upper chord. Moreover, a system of ribbed or smooth steel rebars welded to the plate and forming the diagonals of the truss, works as web reinforcement. In the present study, the attention is focused on the evaluation of the shear resistance of the connection between bottom steel plate (the bottom chord) and concrete core through the diagonal bars of the truss developing a mechanical model able to account for the particular issues arising in this beam typology. In particular, the proposed formulation is based on the extension of existing formulations for the prediction of the resistance of steel dowels to the case of inclined steel bars loaded against concrete, accounting for the following effects: lateral and top confinement, mechanical non-linearity of materials, length of the plastic hinge arising in the steel bar and influence of moment-shear-axial force interaction effect. The accuracy of the model is verified with the available experimental data collected from the technical literature and with FE results obtained from a parametric analysis carried out by the same authors in a previous work.