Normally, rust or corrosion of reinforcing steel in concrete is restricted by high alkaline environment (pH > 12). The passive film on the steel surface is the key for corrosion control in concrete. However, the passive film of reinforcing steel will become unstable or be destroyed in the presence of chloride or carbon dioxide. Concrete is permeable and allows the ingress of chloride and carbon dioxide. The carbon dioxide will react with alkali and form carbonate. Carbonation will reduce the pH value of concrete to about 8. If the carbon dioxide penetrates deeply into concrete and reaches the reinforcing steel, the passive film is destroyed and steel begins to corrode.
The corrosion of reinforcing steel due to ingress of chloride is more common than that of carbon dioxide. The cracking and spalling of reinforced concrete can be frequently founded in seawater, blackish water, seacoast, salty ground water and etc. The rust is larger than steel. Thus, the internal pressure or expansion within the concrete is the cause of cracking and spalling.
●Refer attachment for specific volume of the corrosion product of iron
Thai Marine Protection Co., Ltd. (TMP)was found by a group of experienced engineers on June 18, 2008. TMP was started by commercialization of the successful research in aluminium anode. We are the first company which can manufacture the aluminium anode for cathodic protection in Thailand. TMP also specializes in corrosion protection and failure analysis of metal structure.
MP is the leading sacrificial anodes (galvanic anodes) manufacturer in Thailand. Now, we are expanding our business from cathodic protection alone to corrosion control business to fulfill the customer's need in the future.
Thai Marine Protection Co., Ltd. (TMP) specialize in corrosion protection and failure analysis of metal structure. TMP aims to be a leading company regarding corrosion control in South East Asia. TMP therefore will continually develop our products and create new products to fulfill the needs of customers with competitive price.