Abstract :
Concrete is the main choice in the construction industry because of its strength which is able to withstand fiber loads and is resistant to weather and extreme environmental conditions. In this research, concrete uses type F addictive
substances, namely (High Range Water Reducing, High Range Admixtures). Thismaterial functions to increase workability so that it can increase the slump value of the concrete and increase the compressive strength of the concrete at its initial age. The method used in this test is to make a concrete mixture using the Grolen HP19R additive with additional doses of 0.2%, 0.4%, 0.6%, 0.8% and 1%. Concrete that is treated by soaking for 3 days and 28 days is then tested to obtain the compressive strength and weight of the concrete. What this research wants to achieve is the slump value, unit weight and compressive strength of concrete.The effect of adding the Grolen HP19R additive is that it can increase the slump value. Apart from the slump value, the density of concrete at the age of 3 days with variations in the addition of Grolen HP19R 0.2%, 0.4% 0.6% and 1% has a greater value compared to normal concrete and for the 0.8% variation it has a value which is smaller than normal concrete. For the results of testing the compressive strength of concrete at 3 days and 28 days for variations in the addition of the Grolen HP19R additive, the compressive strength value is small compared to normal concrete,however, for variations of 0.6% and 0.8%, the compressive strength value is close to normal concrete.