Hybrid polymer composites based on poly vinylidene fluoride (PVDF) matrix are fabricated by dispersion of few layered graphene (FLG) and nickel spinal ferrites (NSF) for improving EMI shielding effectiveness. The FLG loading is kept constant at 3 wt% while NSF content is varied from 15-30 wt% in PVDF using solution processing technique. The shielding effectiveness in the frequency domain of 1-12 GHz is enhanced ranging 25 dB-45 dB for PVDF/FLG composite as compared to ∼0 dB for neat PVDF. With addition of NSF up to 15 wt%, the attenuation is increased to 30 dB-53 dB, clearly indicating the effective interaction and network formation of FLG and NSF in PVDF matrix. Moreover, the shielding effectiveness trend is reduced to 12 dB-43 dB as the NSF loading is increased to 30 wt% owing to its agglomeration. Absorption is the dominant phenomena in obtaining the total shielding effectiveness of ∼53 dB for PVDF/FLG-3 wt%NSF-15 wt% hybrid polymer composites. Additionally, the I-V curves provide the electrical conductivity trend while scanning electron microscope (SEM) confirms the network formation in hybrid composite.

No abstract

No abstract

No abstract

Self-Compacting Concrete (SCC) reduces environmental noise and has more workability. This research presents an investigation of the behavior of SCC under mechanical loading (impact loading). Two types of cement have been used to produce SCC mixtures, Ordinary Portland Cement (OPC) and Portland Limestone Cement (PLC), which reduces the emission of carbon dioxide during the manufacturing process. The mixes were reinforced with Carbon Fiber Reinforced Polymer (CFRP) which is usually used to improve the seismic performance of masonry walls, to replace lost steel reinforcements, or to increase column strength and ductility. Workability tests were carried out for fresh SCC. Prepared concrete slabs of 500×500×50mm were tested for low-velocity impact loading at ages of 28, 56, and 90 days after water curing. The results were compared with the ones of non-reinforced SCC mixes and show a significant effect on the impact resistance after the SCC was reinforced with CFRP. The strongest impact resistance was recorded for reinforcing slabs made from OPC SCC, while for the reinforced concrete slabs produced from PLC the results were less, but at a close rate.

No abstract

No abstract

No abstract