1.1 BACKGROUND OF STUDIES In Malaysia, steel corrosion in reinforced steel due to chloride ingress is one of the most common environmental attacks leading to deterioration of concrete structures. Corrosion damage to bridge decks, parking lots, marine structures and industrial facilities results in large annual repair and maintenance expenses. This durability issue has received widespread attention in recent years due to its frequent occurrence associated with high repair costs. This study will focus on the penetration of chloride into concrete at various concrete strengths and days. This study examines the effect of chloride on the strength and durability of concrete at various types of concrete mix proportions. Different types of concrete proportion mixes will give different results of the experiment.1.2 PROBLEM STATEMENTThe famous problem in our country is that the main forms of environmental attack are chloride ingress leading to corrosion of reinforcing steel and a consequent reduction in the resistance, functionality and aesthetic values ​​of the structure. This may lead to preliminary repair or replacement of the structure. Previous studies on ordinary Portland cement (OPC), high performance concrete (HPC) and ultra high performance concrete (UHPC) revealed different results on the penetration of chloride ions into the sample. This is because reinforced concrete is exposed to harsh environments but is often expected to last with little or no maintenance for long periods of time. Failure to maintain the concrete can cause this problem to worsen and the concrete may be unfit for use. To overcome this problem, ...... middle of the paper ...... reddish the cell. The negative terminal is connected to the electrode in the tank with the NaCl solution, and the positive terminal is connected to the electrode in the NaOH solution. The negatively charged chloride ions will migrate towards the positive terminal. The more permeable the concrete, the more chloride ions will migrate through the sample and a higher current will be measured. The current is measured for 6 hours. The area under the current versus time curve, which represents the total charge or Coulombs passed through the sample, is determined. Coulomb values ​​are used to classify concrete as follows. While for Ultra Pulse Velocity (UPV) test, after the sample is subjected to RCPT test, UPV test will be started. Each sample is tested by repeating the reading three times. The readings are recorded and will be analyzed using the formula.