Study On Effect Of Recycled Powder On Properties And Microstructure Of Cementitious Materials

The increasing population and the urbanization process have led to the demolition of existing ground floor buildings and the construction of more high-rise buildings so they didn’t use the demolition materials strictly.This phenomenon has become a catalyst for aggravating the use of natural resources,and has gradually become a concern for sustainability.To solve this problem,the use of recycled powder(RPs)from construction waste can be considered during the construction process.This article discusses the possibility of using recycled powder to improve the performance and microstructure of cementitious materials to increase the consumption rate of building materials.In order to study the application of recycled powder in cement cementing materials,a study was conducted on the effect of partial replacement of cement by recycled powder on the chemical binding water,mechanical properties and microscopic properties of the samples,and different amounts of recycled concrete powder and recycled brick powder were used as Variables are designed for mix ratio,through the use of compression and flexural testing machine,scanning electron microscope(SEM)and nano-indentation instrument,to explore the impact of regenerated powder on cement cementing materials from the macro and micro angles.The main conclusions obtained in this article are as follows:In this study,recycled concrete powder or recycled brick powder was used to partially replace the cement in the cement-based material.When the replacement rate of recycled concrete powder was 10%,the compressive strength and flexural strength reached 90% of the cement mortar of the control group after 28 days of curing.Recycled concrete powder and recycled brick powder have a positive effect on the mechanical properties of the late mortar.SEM image analysis shows that due to the volcanic ash reaction and micro-filling effect,the regenerated powder content of 10% can effectively improve the internal structure of the sample at 90 days of age.Nanoindentation studies have shown that increasing the content of high density(HD)C-S-H and increasing the proportion of HD C-S-H in C-S-H effectively improve the performance of the sample.