Waste glass ground concrete turns waste glass into treasure?

In recent years, the use of glass products is increasing. In the process of use, a large number of waste glass is inevitably formed, and the existence of a large number of waste glass not only causes environmental pollution, but also occupies limited land resources. Rational use of waste glass can not only effectively improve the economic benefits of enterprises and society, but also solve the environmental pollution caused by waste glass, and play a positive role in environmental improvement. Waste glass powder is increasingly used in the field of concrete because of its low cost and good physical and mechanical properties. The development and application of waste glass ground concrete is conducive to reducing resource consumption, reducing the occupation of landfill and saving land resources. Waste glass ground concrete turns waste glass into treasure.

Waste glass powder concrete (WGPC) is one of the important methods to treat waste glass by grinding it into powder instead of cement. It has many advantages such as volcanic ash activity, low water absorption, good durability and good fluidity. In terms of economy, replacing cement with glass powder can save 1 93x 10* ko-h of electricity per 10* t and reduce the use of standard coal by 800t, and reduce the annual emission of CO2 to the air by 1.11×10’t.

Waste glass ground concrete first breaks the recycled waste glass to the maximum particle size below 20mm, and the proportion of fine aggregate after crushing is 0.4-0.6. After crushing, put into the heating device to soften the sharp border of the broken glass surface, the temperature is 250-500℃; After softening, it is taken out and screened into fine aggregate with a particle size below 5mm and coarse aggregate with a particle size of 5-20mm; The mixed fine aggregate comprises the fine aggregate, the mixed coarse aggregate comprises the coarse aggregate, that is, the fine aggregate with a particle size below 5mm replaces part of the sand, and the coarse aggregate with a particle size of 5-20mm replaces part of the crushed stone. A part of cement, mineral admixture and water are added to the mixer according to the original weighing ratio, and then an appropriate amount of admixture and polycarboxylic acid water reducer are added to stir for 20s to obtain a certain viscosity uniform cement slurry, the viscosity of the cement slurry is 0.4 ~ 0.6pas, and the viscosity is adjusted by the addition of polycarboxylic acid water reducer. The ratio of the cement slurry volume to the waste glass volume is 0.3 ~ 0.4, and then the treated waste glass is added to the mixer for 20 seconds and left for 1-60min. Finally, add the remaining raw materials to the mixer, and fully stir 90s, that is, the concrete prepared by waste glass is obtained.

The researchers crushed the glass waste into pieces of five different sizes: coarse, medium, fine, superfine and dusty. It is used in place of sand and gravel, which are commonly used as concrete aggregates. Because of the need to save cement and improve the strength of concrete, different particle sizes are needed to minimize the gaps between sand particles. The results show that the work performance of concrete can be improved by adding glass powder, slump is increased and water retention is good. The compressive strength of concrete mixed with glass powder is higher than that of ordinary concrete without glass powder. With the increase of glass powder content, the splitting tensile strength of concrete decreases continuously, and the tensile compression ratio decreases. The axial compressive strength of concrete with glass powder is higher than that of ordinary concrete. The elastic modulus of concrete increases with the increase of glass powder content. The elastic strength ratio of concrete increases first and then decreases with the increase of glass powder content. As a novel civil engineering material, waste glass powder admixture concrete has great potential for development. On the one hand, it can turn waste into profits and improve the environment. On the other hand, it can improve the performance indicators of concrete, the development of new concrete, will produce huge economic, environmental and social benefits.