J Adv Composite Mater Construction Environ Nanotechnol

Jahangir Mirza , Ghasan Fahim Huseien ,

and 2 more.

Traditional concrete is a mixture of Portland cement, aggregates, water and admixtures. The principal binder in concrete is Portland cement, the production of which consumes high energy, costly, depletes natural resources and is a major contributor to green-house gases (GHG) emission that is implicated in global warming and climate change. Every ton of Portland cement production releases about 1 ton of CO2 into the atmosphere. If the world produces 3.5 billion tons of cement per year, it emits approximately the same amount of CO2 in the atmosphere every year, just from one industry. Moreover, concrete consumes more than 8 billion tons of aggregates every year, which also depletes the natural resources, thus causing additional problems to ecology and environment. On the other hand, millions of tons of agriculture, industrial and natural waste materials (fly ash, etc.,) are abundantly available in the world and are wasted every year. Most of them may contain one or more of hazardous and toxic chemicals from trace amount to several percentages. The majority of these unused wastes are dumped in landfills, quarries, rivers and oceans, exacerbating environmental concerns like air pollution, leaching into soil and water. Studies have shown that some of these waste materials have been and are being used successfully in all kinds of existing and future concrete structures by replacing cement, sometimes up to 70%. They reduce not only ecology, environmental pollution and energy but also produce stable, more durable and economical sustainable construction materials. This paper discussed the issues and solutions related to the reduction in ecology, environment, economy and energy in concrete industry using waste materials.

MT Abedghars , H Ferdenache ,

and 3 more.

The objective of this work is to characterize two materials in order to synthesize anticorrosive coating. These materials are an oolitic iron oxide pigment containing phosphorus and a by-product of steel making that should be recycled. The characterization of these two components took place in the URASM / CRTIAnnaba laboratories. Chemical analysis showed that the pigment contains 53.18% iron and a siliceous gangue. The scale contains 73.83% iron as iron oxides (FeO, Fe3O4 and Fe2O3). Grinding tests have shown that the scale is much more suitable for grinding than pigment. A volume distribution of particles ranging in size from 0.7 to 32 microns for the scale and from 0.6 to 40 microns for the pigment; their specific areas are between 1.6 and 1.5 m2/g. TGA and DSC analyzes have shown that the pigment loses weight with phase dissolution by consuming energy as the temperature increases. The scale is gaining weight by forming a new phase with heat. At SEM, the iron pigment is in the form of an aggregate of grains surrounded by gangue. Scale showed a homogeneous structure composed of iron oxide grains of sizes and shapes ranging from 1 μm to 10 μm. X-ray diffraction analysis showed that the iron in the pigment was in the form of hematite and goethite. A tiny portion is combined with silica as Fe2SiO4. Iron in Scale is in the form of three oxides (FeO, Fe2O3 and Fe3O4). The different coating formulations used have shown that a mixture of 71.43% pigments and 28.57% scale has the best corrosion resistance, resulting in low current and low corrosion rate.

Mehmet Serkan KIRGIZ

Not applicable