No abstract

Due to the shortcomings of waste bricks, they cannot be used repeatedly. The brick powder can partially replace cement for construction production, which can solve the problem of cement energy consumption. This paper studies the influence of brick powder on the performance of cement-based materials. The research shows that the water absorption effect of brick powder and the friction force are the two main factors affecting concrete. Energy dispersive spectrometer, inductively coupled plasma mass spectrometry and compressive strength tests show that the addition of brick powder leads to the increase of silicon/calcium. inductively coupled plasma mass spectrometry shows that although brick powder dissolves in the early stage, the volcanic ash effect is weak. The results of mercury intrusion porosimetry and ultrasonic pulse velocity are consistent with the compressive strength. When 5 % is added, it shows excellent durability. In addition, with the increase of age, the durability will not decrease significantly. Since the brick powder only needs to be ground to avoid the related process of cement, good economic and environmental benefits can be obtained with the increase of substitution rate.

No abstract

With the rapid development of urban urbanization, a large number of old buildings that do not meet the urban construction planning have been demolished, and a large number of buildings left a lot of construction waste. The direct waste of construction waste is not only a large waste of sand and cement resources, but also increases the production cost of construction enterprises. The slump and rheology tests show that the addition of waste concrete powder is unfavorable to the working performance of concrete. The rheology shows that the waste concrete powder leads to the increase of friction force and the decrease of slump. With the increase of substitution rate, the compressive strength decreases. ICP shows that the dissolution of early concrete powder is involved in hydration. Nanoindentation shows that the hydration products change. In addition, because the waste concrete powder is rich in Si, the hydration product Si / Ca increases. In addition, MIP and UPV results show that the durability of concrete with concrete powder becomes worse. Since the concrete powder also needs to be calcined and ground, although there is still more CO2 emissions, there is still a slight decrease compared with cement. Therefore, with the increase of the substitution rate, certain economic and environmental benefits can be obtained.

No abstract