• Mohammad Zakir
• Shaief Manzoor
• Sumair Javeed

For fresh concrete increase in temperature results in increased water demand, lesser setting time, more slump loss and less strength.When the time gap between mixing and casting is large Superplasticizers (SP) and retarders are used to enhance the workability and setting time of concrete to overcome limitations faced.By using superplasticizers it is possible to make concrete at the lowest possible water/cement ratio while maintaining a high workability. They have indeed added a new dimension to the application of admixtures with regards to production of high strength and flowing concretes. In this study the optimum quantity of admixtures was determined up to limit the desired parameters are improved without having any undesirable effects on mechanical properties (such as Compressive strength, flexural strength and tensile strength) of concrete. Hence an experimental investigation is to be conducted to determine the optimum dosage for the admixtures and to study the effect of over dosage of super plasticizer and retarder. After casting, normal curing is to be carried out on the concrete samples until the 28th day. The quantity of SP and retarder dosages of 0.3%, 0.5%, 0.8%,1%, and 1.5% by weight of cement were used, together with control mix (w/c ratio = 0.40). After casting, normal curing was carried out on the concrete samples till the 28th day. Properties such as compressive strength, tensile strength and flexural strength was determined on 3rd, 7th, and 28th days of curing, besides determining the workability of the fresh concrete by slump and compaction factor tests.In this study also the comparison was made between the properties of control mix and the varying percentage of admixture mixes and optimum dosage of the admixture is determined for constant w/c ratio. The comparison was then made with the properties of concrete of lower water cement ratio of 0.38,0.35 and 0.33 and quantity of the admixture is determined which can offset the decrease in workability of concrete due to lower w/c ratio

Properties of Concrete,M25 Grade, Superplasticizer

"Effects on Properties of M25 grade concrete mix using retarding super plasticizer", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 5, page no.196-209, MAY-2018, Available :http://www.jetir.org/papers/JETIR1805634.pdf

"Effects on Properties of M25 grade concrete mix using retarding super plasticizer", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 5, page no. pp196-209, MAY-2018, Available at : http://www.jetir.org/papers/JETIR1805634.pdf