VARIATION OF SUPERPLASTICIZER AND CEMENT REDUCER ADDITIONS ON SLUMP VALUE AND COMPRESSIVE STRENGHT OF CONCRETE MIX WITH f’c 25 MPa

Abstract

Concrete is the most commonly used construction material due to its strength, durability, and ease of shaping. However, to achieve good quality concrete, proper mix design and the use of appropriate admixtures are essential. This study aims to investigate how variations in the addition of superplasticizer and cement reducer affect the slump value and compressive strength of concrete with a target strength of fc’ 25 MPa. Superplasticizer functions to improve the workability of concrete by reducing water usage, while the cement reducer serves to decrease the amount of cement in the mix without reducing the concrete's strength. Using cylindrical specimens of 150 mm × 300 mm, the research was conducted experimentally in a laboratory setting. The variations used were superplasticizer at 0%, 0.4%, 0.6%, and 0.8%, and cement reducer at 0.8% of the cement weight. To evaluate the workability of fresh concrete, a slump test was conducted, and compressive strength was tested at 3, 7, 14, and 28 days of curing. The test results showed that the gradual addition of superplasticizer increased the slump value, thus facilitating concrete workability. Meanwhile, the combination of superplasticizer and cement reducer enhanced the compressive strength, with the optimum result achieved at 0.8% superplasticizer and 0.8% cement reducer. Therefore, the use of these admixtures is effective in improving concrete performance while also conserving water and cement usage