Abstract: This study is devoted to evaluate the performance of low pH cement for the use in soil improvement. Soil samples were collected from a depth at 0.7 m below the ground level. A phosphate binder was used in this study. The soil treated with four different percentages of the binder. These percentages were 0, 3, 5 and 7% by the dry mass of the treated soil. The performance evaluation of the binder used was dependent on the results obtained from the compressive strength and microstructure tests of the base and treated soil samples. The obtained results indicated a considerable evolution in the soil compressive strength. Additionally, coherent and compacted microstructures were observed along with the formation of the cementitious products of phosphate cement. A reduction in pore voids of the samples of the treated soil was detected as well.