The effect of admixture rate on the mechanical andmicrostructural properties of cement mortars preparedby using sulfonate based admixtures

In the thesis study, the effects of using sulfonate based admixtures on the workability, compressive strength and microstructural properties of mortars and concretes were investigated. Using constant water / cement ratio, the workability of the fresh cement mortars prepared without admixtures and using 0.2%, 0.3%, 0.5% and 1.0% in the ratio of admixtures was measured. With the increase of the admixture rate, it was observed that the workability increased. After curing cement mortars for 7 and 28 days in water, compressive strengths were measured. X-ray diffractometer (XRD), Fourier Transformation Infrared Spectrometer (FT-IR) and Scanning Electron Microscopy (SEM) were used to evaluate the changes in microstructural properties. The most appropriate admixture amount for naphthalene sulfonate in samples aged 7 and 28 days prepared with Cement 1 was 0.5% (g / g cement), 0.2% (g / g cement) for lignosulfonate + naphthalene sulfonate and 1% (g / g cement)for melamine sulfonate. For samples aged 7 and 28 days prepared with Cement 2, the most appropriate admixture amount was 1.0% (g / g cement) for lignosulfonate + naphthalene sulfonate and 0.5% (g / g cement) for melamine sulfonate. For naphthalene sulfonate-based admixture, 0.5% (g / g cement) was determined in the sample aged 7 days and 1.0% (g / g cement) for 28 days aged sample.