This research aimed to study the impact response of topology optimized hammerhead pier beam (HPB) based on the density approach. The HPB is prepared with the concept of preplaced aggregate fibrous concrete (PAFC) comprising two primary approaches; first, the coarse aggregate and fiber are prepacked into the designed formwork. Second, the gaps between the aggregate and fiber are filled with cement grout. In this work, an attempt has been made to study an impact response of HPB made with PAFC. Five HPBs were prepared and strengthened with steel fibers with two different schemes, Firstly, the HPB was reinforced with a full cross-section at 2 and 4% of steel fiber, while another set of beams were only reinforced in the tension zone with the same amount of fibers. The study parameters included compressive strength, impact strength, impact ductility index, number of main and secondary cracks, and failure pattern. It was observed that the PAFC had an increase in compressive strength up to 56.9%, compared with nonfibred concrete. A fully fibered concrete beam with 4% fiber addition was the best at taking impact, and the initial crack and failures were observed at 2725.1 J and 3009.8 J, respectively, compared with non-fibered and tension zone fibered concrete beams. Compressive local damage and transverse flexural cracks were observed, which had caused initial cracks and final failure. The HPB with a full reinforced scheme at 4% dosage exhibited higher impact strength than the normal concrete and beam reinforced only in the tension zone.

A novel sorbent, Lanthanum-Impregnated Bauxite (LIB), was prepared to remove fluoride from water. To understand the surface chemical composition and morphology, LIB was characterized using X-ray diffraction and scanning electron microscopy techniques. Experiments were performed to evaluate the sorption potential, dose of sorbent, kinetics, equilibrium sorption capacity, pH and influence of anions for defluoridation by LIB. Equilibrium isothermal studies were conducted to model the sorption and regeneration studies were carried out to evaluate the reusability of LIB. The results showed that LIB, at a dose of 2 g/L could remove 99 % of fluoride from an initial concentration of 20 mgF/L. Kinetic studies revealed the best fit of pseudo second order model. The sorption followed Langmuir isotherm model and the maximum sorption capacity of LIB for removal of fluoride was found to be 18.18 mg/g. Naturally occurring pH of water was found to be favorable for sorption. Usually occurring anions in water except nitrates influenced sorption of fluoride by LIB.

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