This article presents the individual and simultaneous effects of metakaolin reactive silica and plastic fiber straw on the mechanical properties and impact behavior of concrete made from natural aggregates and those of recycled aggregates containing 50% replacement. The addition of metakaolin alone or with the plastic fibers only improved the mechanical performance of all the mixtures at a later age (90 days). However, the addition of plastic fibers slightly increased the compressive and tensile strengths of natural aggregate concretes with a decrease in those of recycled aggregate concretes. This deficiency was compensated for by the reactive effect of the silica provided by metakaolin. An optimum of 1% has been specified in plastic fibers for compressive strength for all composites. Natural concretes and those recycled without metakaolin and plastic fibers present a fragile behavior, the energy absorbed at the first crack is substantially equal to that at failure. When these components are used simultaneously, their behavior becomes ductile and the fracture energy is significantly higher than the control concrete and that of the first crack.

In this study, we synthesized new substituted coumarins, with the structure confirmed using 1H nuclear magnetic resonance. Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscope (POM) analysis were used to monitor the thermal behavior of the coumarin and its mixtures. DSC revealed a unique glass transition temperature for the first two products, the glass transition temperature of the third could not be determined.The variation in molecule density increases or decreases with increasing temperature, this was detected by the MOP. We see for instance small aggregates with a phase change that occurs between 25°C and 40°C, this phenomenon results in the formation of (micelles).This study is different from the others available because telomers using heterocycles are the speciality of our laboratory, several routes have been set to improve their synthesis and in particular the coumarin series.The latter are analogues of active substances. For example, thiophene series analogues of paullones have been evaluated on MCF-7 breast cancer cells.For Alzheimer's disease, the synthesis of numerous analogues of Tacrine, used as a treatment, have been carried out and the activities have been tested. Similarly, coumarin analogues have been evaluated for ROS (reactive oxygen species) reduction and phosphatase inhibition.