Engineering Properties of Sand Derived from Kawkaban Member (Tawilah Group) NE Sana'a, Yemen

Abstract The purpose of this study is to assess the engineering properties of crushed sandstone sand from the Kawkaban Member (Tawilah Group) exposed in the area NE Sana'a city. This was achieved by conducting several laboratory techniques on the sand samples to determine their grain size, water absorption, water content, specific gravity, unit weight, and nature of deleterious materials. The results satisfied the ASTM and AASHTO requirements. For mortar mixes, the component materials were grouped by weight and 1:2:4 mix ratio was designated. The mortar specimens were immersed in water for 2, 7, 28, 56, 70 and 90 days. The standard sand (SS) mortar revealed good results and higher values of flexural strength (FS) and compressive strength (CS) than those for Zigan sand (ZS) mortar for all immersed periods. The CS values of SS mortar are higher than the required values by 9.65%, while those of the ZS mortar were less than the limit of CS by 20.59% at 28th day curing time. The CS values for SS and ZS mortars at the 7th day of curing were 70 and 80% of those for the CS at the 28th day of curing, respectively. The FS values for ZS mortar at 28th day of curing was less than that of the SS mortar by 8.70%. For the designated water to cement and mix percentages the ZS mortar was found to be appropriate for structural applications wherever high strength is a requirement.