study on slump retention of superplasticized concrete.

The slump loss with the lapse of time is one of the most significant disadvantages of superplasticized concrete. Recently, the slump retentive superplasticizer was developed to reduce the slump loss after flowing. The present paper describes the experimental results of the properties of concrete with such slump retentive superplasticizer.Four types of slump retentive superplasticizer were used in this experiment. The slump, air content, rheological properties and compressive strength of superplasticized concrete under various conditions were measured. The effects of the timing of superplasticizing, the amount of dosage of superplasticizer and the sand/aggregate ratio of the base concrete on the properties of superplasticized concrete were experimentally investigated.It has been proved that the slump retentive superplasticizer can be effectively used to prevent the rapid slump loss after flowing under the condition of proper adding time of superplasticizer and a suitable sand/aggregate ratio of concrete.