Influence of Plasticizer on the and Workability of Concrete

Abstract

The concrete performance is very reliant on finding an optimum balance between workability and strength, which can be affected by the water-cement ratio and the aggregate composition. This paper examined how plasticizer influences the mechanical properties and the workability of concrete when it is combined with partial substitution of traditional coarse aggregate by 6 mm aggregate. The dosage of plasticizer was 0.5 percent by weight of cement in order to reduce the water content by about 15 percent. Concrete blends were made with 0, 15, 20, 25, and 30 replacement levels, and tests were done to check the slump, flow behavior, setting time, compressive strength, and split tensile strength. The findings showed that there was a steady rise in the workability, whereby the slump and flow value rise with the proportion of replacement, largely because of better packing of particles and better dispersion of cement particles. The setting time was found to be rising, i.e., there was a delay in the hydration. The compressive strength was increasing up to 20 percent replacement, after which the strength started declining, as there was too much fine aggregate content and less bonding power. Correlation analysis also indicated that the workability parameters and replacement levels showed a strong positive relationship, and strength showed a slight negative relationship at higher replacements. The research draws a conclusion that using a mixture of plasticizer and partial aggregate modification has a significant positive effect on concrete performance under the condition of its optimal use. The optimal value of 20 was found as a replacement level, which offered the most suitable balance between workability and strength and as such is appropriate in real-world construction projects that need both convenience in the location of a product and structural competence.