Strength Of Steel Slag Research Articles

Compound Effect of CaCO3 and CaSO4·2H2O on the Strength of Steel Slag - Cement Binding Materials

In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO3 and CaSO4·2H2O were added. This was done to study the compound effect of CaCO3 and CaSO4·2H2O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO3 and CaSO4·2H2O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO3 and CaSO4·2H2O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO3 could accelerate the hydration of C3S. In addition, CaCO3 was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO4·2H2O could increase the number of AFt. The compound effect of CaCO3 and CaSO4·2H2O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior.

Study on Desulfurized Gypsum-Steel Slag Composite Gelled Material Mechanics Properties

Using desulfurized gypsum and steel slag as raw material make desulfurized gypsum-steel slag composite gelled material, by adding cement, triethanolamine, aluminium sulfate, compound activator improve gelled material mechanics performance of materials. The experimental results show that when the proportion of desulfurized gypsum and steel slag for 85:15, mixing the compound activator that aluminum sulfate mixed quantity is 1%, cement mixed quantity is 3%, triethanolamine mixed quantity is 0.8%, sample’s 14d flexural strength can reach 5.83 MPa and compressive strength can reach 16.14 MPa. SEM analysis shows that a lot of C-S-H gel structure in hydration products is conducive to improve desulfurized gypsum-the strength of steel slag gelled material, reach the purpose of improving gelled material mechanics performance.

Experimental Study on Alkali Stimulating-Steel Slag Cementitious Materials

In order to utilize the waste steel slag effectively, three kinds of alkaline activator such as Na2SO4, Na2SiO3, Na2CO­3 were used to prepare steel slag cementitious material and measure its strength of 28 days and 60 days in the standard wet conditions. Microcosmic structure form of hydration products of cementitious material was analyzed by the test of SEM. The results indicate that: three activators on the strength of steel slag all have certain stimulation effect, and Na2SO4 has the apparent stimulation effect on the strength of steel slag, the analysis and test of SEM also shows that hydration products structure form of steel slag cementitious material added with Na2SO4 is much more than other two activators and is more helpful to improve steel slag strength.