Use of fiber reinforced concrete for water retaining structures

The construction of water retaining structures has been widely spreaded every where to supply individuals with water at far ends of the world. These structures need a lot of concern in controlling cracks arise due to shrinkage, ill early ages of construction, or due to loading,under service conditions, to avoid any leakage of water which causes steel rusting. This research deals with cracks due to shrinkage. A step forward to reduce the amount of steel reinforcement employed tocontrol these cracks within allowable limit is through using fiber reinforced concrete.Modifications have been introduced to the design equations to estimate for the contribunon of fibers to restrained shnnkage. An expenmental models representing ground slabs of a tank have been designed, by the developed equations, and tested WIder restramedshnnkage. Fiber aspect ratio and volume fractions have been changedto study their effects on reducmg the steel reinforcement and on theassociated crack width due to shrinkage.it has been affirmed that, not only the fibers reduced the total amount of steel reinforcement, to control lmnkage crackmg, but leads to a reduction ill the average crack WIdth if compared to that casted without fibers. In addition, the testing results show that the indirect tensile strength of plain concrete has been increased by the addition of fibers. An empirical correlation has been developed, based on the available test results, relating the splittmg tensile strength and the fiber index and the concrete ompressive strength.