In recent years, the use of corrosion inhibitors in producing high-performance steel reinforced concrete structures has increased significantly to minimize the chloride and sulfate attacks. However, most inhibitors available in the market are toxic to the environment. Hence, one objective of the present investigation was to test a novel, eco-friendly, so-called green inhibitor extracted from a fruit waste (orange peel), and its effects were studied on the compression strength of the XD3 type concrete samples. The inhibitor was added to the concrete mix in concentrations of 1% and 3% by weight of cement in addition to two different superplasticizers (Mapei Dynamon SR 31, Budapest, Hungary and Oxydtron, Hungary). The test results on steel reinforced samples immersed in 3.5 wt% NaCl aqueous solutions at room temperature showed promising corrosion mitigating effects just after 6 months testing period. The lower corrosion currents (i.e., better corrosion resistance) after 6 months immersion were observed when the samples contained both green inhibitor and Oxydtron superplasticizer, especially with sample C2 (in this case 3% green inhibitor was added to the mixture of cement + Oxydtron superplasticizer). K E Y W O R D Scorrosion rate, electrochemical polarisation, green inhibitor, reinforced concrete, superplasticizers

Carbon steel, the most widely used engineering material, despite its relatively limited corrosion resistance used in large tonnages in marine applications, nuclear power transportation, chemical processing , petroleum production and refining, pipelines, mining, construction and metal-processing equipment. The main objective of the present work involved the study of the inhibitive properties of natural product as spearmint plant extract as a safety and an environmentally friendly corrosion inhibitor for low carbon steel in (3.5% NaCl) solution. Results showed when the immersion model in (3.5% NaCl) solution that contains the inhibitor with concentration of (15% in volume), it's getting decrease in lost weight , indicating a layer of adequate oxide on the surface of steel, indicating that the amount of loss weight decrease with increasing concentration of inhibitor and this shows the damper on his ability to form a protective layer .

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SHayMaa abbaSAbstract the applicability of a new organic inhibitor extracted from a cheap organic waste of orange peel (so-called "green" inhibitor) was studied in a laboratory system where the steel rebar samples obtained from a steel mill operating in Hungary were investigated in several sets of experiments to reveal their major corrosion properties in aqueous solutions containing sodium chloride salt. the initial corrosion rates were determined by a standard electrochemical polarisation technique on active (scale and rust free) steel specimen while being immersed in 3.5% nacl aqueous solutions containing the methanol extract of the chosen green inhibitor in a preliminary test run of 24 hours. Due to the inhibitor's active groups identified by Ftir spectroscopy, this new green inhibitor (with concentrations tested at 1 and 3%) showed promising surface adsorptive and corrosion mitigating effects examined also by scanning electron microscopy (sem) combined with eDs surface analysis. these sem-eDs surface analyses were performed on the given rebar samples after an immersion (i.e. corroding) period of one month.

In this article, particles of date seeds as a natural strengthening of the polyester resin and reinforcing percentages (1, 2, 3) wt% were used. For the purpose of comparison with the properties that were obtained in these composite materials reinforced by date seeds, particles have been manufacturing a composite material of the same resin reinforced particles calcium carbonate industrial, the same reinforcing percentages above. Results showed the samples that contain date seeds have a high resistance strain compared to models that contain calcium carbonate and this increase in tensile strength increases with the amount of particles date seeds, plus a big improvement in impact resistance samples have particles date seeds and increases with increasing reinforcement ratio compared with sample have calcium carbonate particles.

In this article, novolac nanoparticles with different weight fraction (0-40) wt.% were added to NBR/CR blends and investigate the effect of these additions on the specific gravity of rubber blend. The results obtained shown that the novolac nanoparticles works on increasing the specific gravity of NBR/CR blends, and specific gravity ratio increases with increased novolac nanoparticles percentage.

The breakthrough and diffusion of chloride ions into reinforced concrete structures is the major contributing factor for inducing corrosion of the steel reinforcement. This work presents a study of the total chloride contents in concrete and the corrosion process by testing electrical resistivity and half-cell potential of concrete samples. The novelty of this work in the use of a green inhibitor-orange peel extract. The analysis was based on an experimental investigation of the samples with time of immersion in 3.5 wt% NaCl aqueous solutions at room temperature according to European Standards. For this study, different mixtures of concrete were prepared by adding two types of superplastisizers and green inhibitors in different concentrations. The results of the Cl − ions test showed that all the samples (except sample C2) after an immersion testing period of 6 months contained Cl − ions in high concentrations, indicating a greater risk of corrosion. Sample C2 (with green inhibitor and Oxydtron superplasticizer) showed the highest resistance against the chloride ion ingress measured by following the Cl − concentration changes up to the end of the 6 months testing period. This samples' good resistance to corrosion in the tested environment was also proved by the results of several sets of measurements of the electrical resistivity and half-cell potentials carried on the concrete test samples.

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