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This work is a part of an industrial waste development program. It is devoted to the study of recyclability of chips resulting from the machining of steel parts as reinforcement for concrete. We are particularly interested in this study in the rheological behavior of chips reinforced fresh concrete and its mechanical behavior at young age. The evaluation of the workability indicates that the sand over gravel optimal ratios (S/G), corresponding to the composite minimum flow time, are S/G = 0.8 and S/G = 1. The study of the chips content (W) influence on the workability of the concrete shows that the flow time and the optimal ratio S/G increase with W. Mechanical characterization tests (direct tension, compression, bending and splitting) show that mechanical properties of chips reinforced concrete are comparable to those of the two selected reference concretes (concrete reinforced with conventional fibers: EUROSTEEL fibers corrugated and DRAMIX fibers). Chips provide to control concrete a significant increase in strength and some ductility in the post-failure behavior of the composite. Recycling chips as reinforcement for concrete could be thus favorably considered.

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Aluminum can be absorbed through the digestive system from water and drinks and the food that contains natural traces and processed food or the food cooked in aluminum cookware. Some studies show that the people exposed to high levels of aluminum may develop kidney, bone and brain diseases. Aluminum foil (AlFeSi) is daily used as packaging for food and drugs stored in the refrigerator where an electric motor induces a magnetic field of a few microteslas. The purpose of this work is to study the corrosion behavior of various aluminum packaging foils and the effect of a weak magnetic field on the morphology and the corrosion kinetics in the 0.3 % and 3 % of mass fractions of NaCl solutions. The mean results for various aluminum packaging foils show that localized corrosion is controlled by the electrochemical potentials of different phases constituting the aluminum foil and the concentration of the precipitates from the other phases. The morphology and the corrosion kinetics of aluminum packaging foil in the 0.3 % and 3 % of mass fractions of NaCl solutions are different with and without an application of a weak magnetic field. Electrochemical tests applied to cheese packaging paper show that the introduction of a magnetic field decreases the polarization resistance, the potential of passivation and the value of the open-circuit potential at the beginning of the corrosion; however, its passivation-current density increases at the beginning of the corrosion. The values of the open-circuit potential with and without a weak magnetic field are the same after thirty days of corrosion. Keywords: aluminum packaging foil, weak magnetic field, aluminum alloys, corrosion, passivation Aluminij se lahko absorbira v prebavni sistem iz vode in pija~in iz hrane, ki vsebuje naravne sledi ter obdelane hrane ali hrane, kuhane v aluminijasti posodi. Nekatere {tudije ka`ejo, da ljudje izpostavljeni visokemu nivoju aluminija, lahko zbolijo na ledvicah, kosteh in mo`ganih. Aluminijeva folija (AlFeSi), ki se dnevno uporablja kot embala`a za hrano in zdravila, se hrani v hladilniku, kjer elektromotor inducira magnetno polje jakosti nekaj mikroteslov. Namen {tudije je predstavitev korozijskega obna{anja razli~nih aluminijevih embala`nih folij in vpliv {ibkega magnetnega polja na morfologijo in kinetiko korozije v 0,3 % in 3 % raztopini NaCl. Rezultati ka`ejo, da je pri razli~nih aluminijevih folijah lokalna korozija kontrolirana z elektrokemijskim potencialom razli~nih faz, ki sestavljajo aluminijevo folijo in s koncentracijo izlo~kov drugih faz. Morfologija in kinetika korozije aluminijevih embala`nih folij v 0,3 % in 3 % raztopini NaCl, sta razli~ni pri prisotnosti ali odsotnosti {ibkega magnetnega polja. Elektrokemijski preizkusi, izvr{eni na ovojni foliji za sir, so pokazali, da prisotnost magnetnega polja na za~etku korozije zmanj{a polarizacijsko odpornost, potencial pasivacije in vrednost potenciala odprtega kroga, vendar pa gostota pasivacijskega toka nara{~a. Vrednost potenciala odprtega kroga je po tridesetih dneh enaka, ob pris...

Mechanical behavior of steel fiber reinforced concrete has been studied by the direct tensile test. This fiber concrete is obtained by adding machining chips to the bare concrete. Six fiber contents were adopted (W=0.4%, 0.6%, 0.8%, 1%, 1.2% and 1.5%) for two sand over gravel ratio (S/G = 0.8 and S/G = 1). The results obtained showed that the fibers have substantially improved the stiffness and the strength of concrete and conferred a significant ductility to the material for the fiber volume fractions 0.4%, 0.6% and 0.8% (according to the S/G). The value of residual strength observed after cracking of the concrete matrix was of the same order as for the bare concrete for some of the compositions. Besides the tensile tests, compression tests have been performed. These tests showed that adding a low fiber percentage (W = 0.4%) provides a slight increase of the resistance to compression. Values of W greater than 0.8% lower this resistance. We can conclude that the presence of fibers in concrete is positive, bridging of micro cracks and recovery of the efforts through the developed macro cracks. Unfortunately, the reduction of the compactness has led to a decrease in the tensile strength and the compressive strength. The most advantageous fiber contents for compression are W = 0.4% and W = 0.6% for the two ratios .As for the tensile test, the most advantageous fiber contents are 0.6% and 0.8%.

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