This study aims to increase the economic value of silica sand originating from mud volcano of the Lapindo well burst which until now is known as a natural disaster and caused a lot of material loss by the people of Porong Sidoarjo. In addition, the replacement of the percentage of cement composition against the compressive strength of the Glass Fiber Reinforce Cement (GRC) formed will be known as the compressive strength characteristics of the concrete from the GRC made. This research was conducted using an experimental method. A mixture of cement with fiber glass and added silica sand with various compositions was used to print the research samples. The composition of cement to silica sand used has the highest ratio of 50: 50. While the lowest value of the ratio of cement and silica sand is 80:20. Next, each mixture of silica sand and cement is mixed with fiber with a fiber composition of 25% of the elements of cement and silica sand. The board molds are formed with a size of 200mm X 150 mm with a thickness of 10mm and dried in free air until the moisture content in the mold board is reduced evenly, the moisture content of each board is measured to have a uniform value to maintain the validity of the results of the compressive strength test of GRC. Test the compressive strength of GRC using a hammer test tool, and calibration is carried out for each sample. The result of study was the greater the silica sand content in the boards that have been made, the value of the compressive strength of the concrete decreases. The best value of the compressive strength of concrete is found on the cement board which is added with silica sand as much as 120 mg. while the value of the lowest concrete compressive strength is a cement board containing a mixture of silica sand of 480 mg.