As buildings age some aspects will require concrete strengthening additives to prevent structural damage. This could be due to an increase in load, errors during the building process or deterioration. These composite strengthening solutions can reduce corrosion of steel reinforcements, improve the durability of the concrete and protect it from further damage.
Concrete admixtures are materials that are added to the main ingredients of cement, aggregate (sand) and water in order to modify the properties of the concrete mixture. These are often chemical or mineral products that help with various functions such as reducing shrinkage, improving workability, curing time and strengthening the concrete.
Shrinkage reducing concrete admixtures are used to control early and long-term drying shrinkage cracking in slabs, bridge decks and other structures that are susceptible to this type of cracking. They are also used to minimize the need for shrinkage joints in construction. Corrosion preventing admixtures reduce corrosion of steel reinforcement in parking garages, bridges and marine environments. They do this by reducing the amount of chloride salt that is deposited on the rebar surface.
Water reducing concrete admixtures are used when it is difficult to achieve the required slump in a particular mix design or when pouring concrete in cold weather conditions. They lower the water-cement ratio without affecting the strength development of the concrete and are often used in combination with superplasticizers to produce self-consolidating concrete (SCC).