No abstract

In this paper, the effects of different stone powder content (5%, 10%, 15%, 20%, 25%) of iron tailings manufactured sand on the workability and mechanical properties of cement were studied. The results show that the strength of hardened paste can be improved by adding appropriate amount of stone powder. When the content of stone powder is 5%, The compressive strength reached 34.4MPa. The results of XRD show that the hydration products of cementitious materials mixed with stone powder are mainly ettringite, Ca(OH)2, hydro calcium, calcium silicate hydrate and quartz. The results of SEM show that proper amount of stone powder can effectively improve the porosity of composite cementitious materials, but the content of stone powder increases, the bond between stone powder and hydration products is not close enough, and the paste structure becomes loose.

In this paper, the effects of different stone powder content (5%, 10%, 15%, 20%, 25%) of dolomite manufactured sand on the workability and mechanical properties of cement were studied. The influence of stone powder content on the hydration products and microstructure of cement were studied by XRD, SEM. The results show that the workability and mechanical properties of cement can be improved obviously when the content of stone powder is less than 10%, and the influence of stone powder on hydration products and Microstructure of cement is small.

Using Aeolian sand as fine aggregate, adopt fixed lime sand ratio(1:2, Under the same consistency of mortar, the effect of single and compound doping of VAE and Water retaining agent(BS-W) on the working and physical properties of mortar was studied. Through the coMparison of its properties with blank mortar, to get the best content of admixture and the best proportion of compound admixture, to provide ideas for the development and research of high proportion or total replacement of aeolian sand mortar. The results show that: VAE and water retaining agent can obviously improve the workability, construction and water retaining performance of the slurry, but the physical and mechanical properties of mortar are reduced. When VAE content is 0.7%, BS-W content is 0.15%, the overall performance of mortar mixed with them is better, the flexural strength and compressive strength of mortar reached 4.78Mpa and 15.3Mpa respectively in 28d.