In this study, the activity concentrations of 226 Ra, 232 Th and 40 K in twenty cement samples of four types (CEM, CEM II, CEM III, and CEM IV) collected from building material suppliers in Senegal were measured using a low-background digital gamma-ray spectrometer equipped with broad energy germanium detector. The activity concentrations of 226 Ra, 232 Th and 40 K varied from 7.1-150.3 Bq kg −1 , 3.7-16.1 Bq kg −1 , and 48.7-133.9 Bq kg −1 , respectively. Also, possible radiological risks from the usage of these materials were assessed by estimating external and internal index, indoor absorbed gamma dose rate and the corresponding annual effective dose, effective dose rate to different body organs and tissus, and excess lifetime cancer risk. The estimated radiological hazard indices were revised in light of the relevant national and international legislation and guidance. The values of the radiological hazard indices were found to be within relevant all limit values for structural building materials.

Recycled plastic (rHDPE) was coupled with different weight percentage of ronier palm leaf fiber (RLFs) to prepare eco‐friendly polymer biocomposites. Fourier transform infrared analysis, tensile test, dynamic rheological test, hardness test, scanning electron microscopy (SEM) analysis, and density measurement were used to determine the structural, mechanical, morphological and physical properties of the biocomposites. The modulus showed excellent improvement with the addition of RLFs. G′ and G″ were found to increase with the increment of both the filler content and the angular frequency. At low frequencies, the loss factor was increased with the frequency and decreased with the RLFs content. However, at high frequencies, it was decreased with both the angular frequency and the RLFs content. The complex viscosity η* was found to be increasing and decreasing with the RLFs content and the angular frequency, respectively. SEM micrographs of tensile fractured surfaces of biocomposites show pulled out RLFs zones and voids due to the presence of agglomeration. Finally, the experimental Young's modulus data was compared with theoretical predictions. A good fit was obtained with Einstein Model.

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