This document discusses the effects of the admixture Rapidite on the strength of concrete. It presents results from an experimental investigation where concrete mixtures with varying percentages of Rapidite by weight of cement (0.8-1.6%) were tested. Tests on fresh concrete included slump tests to measure workability. Hardened concrete was tested at 7 and 28 days through compression, splitting tensile, and flexural strength tests. Results showed that 7-day compressive strength decreased with Rapidite while 7-day tensile strength increased up to 1.2% dosage. Graphs and analyses indicate 28-day strengths generally increased with Rapidite percentage up to certain levels before decreasing. The study aims to evaluate Rapidite's suit