دانلود رایگان مقاله انگلیسی بررسی دوام بتن جایگزین زباله های شیشه سنگین وزن به عنوان ریزدانه - الزویر 2018

abstract

Concrete is the most widely used construction material, and huge amounts of natural resources are required to manufacture it. With relatively recent rapid industrial development as well as the improvement of people’s living standards, the volume of domestic and industrial waste is increasing, and much of this waste is not recycled. Cathode ray tube (CRT) waste glass is an industrial waste material that has been studied by many researchers for use as fine concrete aggregate. As one example of its potential application, nuclear power plants and radioactive waste disposal sites are often located in areas vulnerable to attack by chloride and sulfate, and this may compromise the durability of the concrete structure designed to shield radiation. More durable concrete would therefore be desirable. We studied the durability of concrete mixed with waste glass through the following approach. Waste CRT glass containing heavy metals was recycled as fine aggregate for concrete; the durability of the concrete was investigated by performing freeze-thaw resistance, sulfate attack, and chloride ion penetration measurement. The test results showed that as the mixing ratio of waste glass increased, the freezing and thawing resistance, sulfate attack resistance, and chloride ion penetration resistance were all better in the concrete containing waste glass than in normal concrete. However, the compressive and the flexural strength of the concrete both decreased due to lower adhesion between cement paste and waste glass. In conclusion, it was confirmed that concrete substituted with heavyweight waste glass could be used in radiation shielding structures.

4. Conclusions In this study we evaluated the durability of concrete prepared by substituting heavyweight waste glass for fine aggregates. The following conclusions were obtained from this study.

1) Slump increased as the waste glass substitution ratio increased, but the increment decreased as the W/B ratio increased. Air content slightly increased as the waste glass substitution ratio increased, but the increase was not significantly dependent on the W/B ratio or on the waste glass substitution ratio.

2) Compressive and flexural strength of the concrete decreased as the W/B ratio and the waste glass substitution ratio increased. The decrease of the strength may have been due to decreased adhesion between the waste glass surface and the cement hydrates.

3) The freezing and thawing resistance test showed that the weight of the concrete did not significantly change due to freezing and thawing. The ratio of the relative dynamic modulus of elasticity was higher than 80% in all of the mixing conditions, indicating that concrete containing heavyweight glass waste had good freeze–thaw resistance.

4) The permeability resistance of the concrete increased as the waste glass substitution ratio increased, because of the low water absorption ratio of the waste glass. Additionally, the heavyweight waste glass content may have improved the sulfate attack resistance of the concrete. Chloride ion penetration resistance is significantly improved when heavyweight waste glass is used as fine aggregate.