White cement mortar suffers from the appearance of cracks when it is used in the facades of buildings, and these cracks affect its durability and shelf life. Therefore, three additives were suggested to be used with white cement mortar to reduce shrinkage, taking into consideration that they do not negatively affect other cement properties. A type of water-soluble polymer, Polyvinylpyrrolidone (PVP), as well as two types of steel fibers (hooked fibers and straight fibers) and they were all used in proportions 0 %, 1 %, 2 %, and 3 % of the weight of cement. A set of physical and mechanical tests were carried out in addition to dry shrinkage test such as setting time, compressive strength, flexural strength, and water absorption. It was found through these tests that all the additives reduced the dry shrinkage and the best results were obtained when using steel fibers with hooked ends by 3 % where the dry shrinkage was decreased by 75 %. The same type of fiber gave the highest flexural strength, with an increase of 16 % by using the same ratio. As for the use of 1 % straight steel fibers, it achieved the highest value in the compressive strength test, with an increase of 5 %. As for PVP, it reduced the water absorption by 6 % when it was used by 3 %.
Abdulrehman et al. (Wed,) studied this question.