To study the durability of shield tunnel concrete segment under coupling multi-factors, the durability and degradation law of reinforced concrete segments under the joint action of carbonation, sulfate, chloride salt and stray current was studied by accelerated environmental and direct current (DC) power simulation test. The results show that the presence of the stray current not only accelerat...

Concrete is an essential material in all constructions throughout the world. It has lot of uses our daily routine life. Every to deteriorate and damage due many factors same way concrete also deteriorates. The carbonation process identified as a main reason for corrosion reinforcement structure. mechanism which includes entrance carbon dioxide (CO2) into solid permeable framework shape situatio...

Growing urbanization around the world is leading to increased consumption of concrete, which poses serious environmental problems. The cement industry has very issues and causes various sustainability issues; Carbon dioxide a greenhouse gas that many negative effects on environment. An effective way overcome this impact environment use another material instead in concrete. In study, aim rice hu...

The development of new or modified cementitious materials is an important part of existing strategies to improve performance and minimize life-cycle costs and to eliminate the CO2’s impact on durability. The high anion exchange capacity of layered double hydroxides (LDHs) materials makes their interlayer ion exchange by organic and inorganic anions versatile and easily achieved. LDH-like materi...

One of the primary problems related to reinforced concrete structures is carbonation concrete. In many cases, depth on used evaluate service life. Factors that can substantially affect resistance are temperature, relative humidity, cement composition, concentration external aggressive agents, quality concrete, and cover. This paper investigates effect varying proportions blended Portland (ordin...

s and Publications: Johnson, N. C., Thomas B. Maher, K., Bird, D. K., Rosenbauer, R. Brown, G. E. Jr. (2011) Adsorption of organic ligands on silicate mineral surfaces in the presence of CO2 and water: Insight into olivine dissolution rates. Goldschmidt Conference, Prague, Czech Republic. Johnson N. C., Thomas B., Maher K., Bird D. K., Rosenbauer R. J., Brown G. E. Jr. (2011) Kinetics of olivin...

This study proposes a simple and novel synthesis route for rhombohedral single crystals (<2µm) of magnesite. This synthesis can be summarized by two main sequential reactions: (1) aqueous carbonation of synthetic brucite (Mg(OH) 2) by injection of CO 2 in a highly alkaline medium (2Molal of NaOH) at ambient temperature (∼20°C), leading to precipitation of platy-compacted aggregates of dypingite...

Precipitated calcium carbonate (PCC) was prepared by means of semicontinuous carbonation of Ca(OH)2 suspension, at 35 and 45 °C and in the presence of non-ionic dextran and dextran sulfate. The carbonation process was regulated at different predetermined values of electrical conductivity, that corresponded to different concentrations of dissolved Ca(OH)2: 0.5 mS cm < κ25 < 5.0 mS cm. The result...

1 2 The hydrothermal carbonation of calcium hydroxide (Ca(OH) 2) at high pressure of CO 2 3 (initial P CO2 = 55 bar) and moderate to high temperature (30 and 90°C) was used to synthesize 4 fine particles of calcite. This method allows a high carbonation efficiency (about 95% of 5 Ca(OH) 2-CaCO 3 conversion), a significant production rate (48 kg/m 3 h) and high purity of 6 product (about 96%). H...