Esteema 501 is a retarding type high range water reducing admixture based on modified polycarboxylic ether. The product has been specially developed for applications in ready mix and site-batched concrete, where long retention is needed. Esteema 501 allows considerable reduction of mixing water while maintaining control on extend of set retardation thus improve the compressive strength of concrete and mortar without increasing the cement content. It makes concrete more impermeable and durable.