Steel slag used as admixture in composite cement

Steel slag used as cement admixture in composite cement and the internal relation between microstructure and macroscopic properties of cement investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),pore structure analyzer,hydration heat analyzer and other modern analysis methods.The results showed that the water usage for standard consistence and the hydration heat of cement doped by steel slag were reduced.And the cement paste mixed steel slag had the following features,such as low linear expansion rate(less than 0.1%),non-shrinkage and excellent volume stability.A certain amount admixture in cement could reduce the porosity,improve pore distribution and increase the consistency of cement.With the admixture of 20% steel slag and 10% fly-ash,the flexural and compressive strengths of cement at 28 d could reach 8.3 MPa and 48.9 MPa respectively,and compound cement doped by steel slag and fly ash was contributed to the strength development of cement efficiently.