Dosage Limit Determination of Superplasticizing Admixture and Effect Evaluation on Properties of Concrete

t— Superplasticizers are commonly known as High Range Water Reducers because it permits low water cement ratio as well as
the workability also affected. In very recent decades, superplasticizers creates milestone in the advancement of chemical admixtures for Portland cement concrete. The dramatic effect of superplasticizer (SP) on properties of fresh and hardened concrete has studied and the properties of concrete inspected are compressive strength and slump test. To determine the optimum dosage for the admixture, an experimental investigation conducted and the effect of over dosage of the SP admixture experimented, together with one control mixed.
The viscosity of grout and hence the workability of concrete influenced by the dosage of superplasticizer. From dosages of admixture, the difference between concrete mixes comes, which used at amounts 400 ml/100 kg, 600 ml/100 kg, 800 ml/100 kg, 1000 ml/100 kg and 1200 ml/100 kg of cement were prepared. By dosage 1.0% of SP, compressive strength is improved and after 28 days curing it is 57 N/mm2, which is higher than that of control specimen. This paper shows that, the optimum amount of admixture must be 1.0 %. Over dosage of SP found to deteriorate the properties of concrete with indication of lower compressive strength.