Engineering properties of concrete made with crushed aggregates of diorite, Jeddah, Saudi Arabia

The aggregate characteristics play an effective role in both fresh and hardened concrete properties. The western parts of Saudi Arabia characterized by rareness of natural aggregates resources so that the Precambrian rocks of the Arabian Shield considered as very important source of crushed aggregates. The studied Precambrian diorite is a hard and dense coarse-grained plutonic igneous rock that represents a local source of crushed aggregates of concrete, mortar and pavement materials. It composes mainly of plagioclase feldspar (andesine), biotite, hornblende and pyroxene. Sometimes, diorite contains small amounts of quartz. The studied samples were plotted in the field of diorite and quartz diorite of discrimination diagram. Its absorption values indicated that the studied crushed diorite aggregates have standard limits for aggregates absorption in the specified standards. The studied crushed aggregates are consisting mainly of equi-dimensional or cubical grains, that means these crushed grains are enough resist shear strength. The studied crushed aggregates have standard limits for aggregates absorption. The Los Angles abrasion values indicate relatively high resistance to wear. The compressive strength values of the studied concrete mix were ranging from 34.43 MPa to 38.32 MPa and having a strong direct proportional relationship with very angular grains content of coarse aggregates (R-2 value = 0.96).