High-strength concrete resists loads that cannot be resisted by normal-strength concrete. Not only does high strength concrete allow for more applications, it also increases the strength per unit cost, per unit weight, and per unit volume as well. These concrete mixes typically have an increased modulus of elasticity, which increases stability and reduces deflections.
Along with the inherent advantages of high-strength concrete, several less clearly defined disadvantages can materialize. Most of these disadvantages are due to a lack of adequate research under field conditions, although many of the issues are currently being alleviated though the use of improved admixtures. First, increased quality control is needed in order to maintain the special properties desired. High-strength concrete must meet high-performance standards consistently in order for it to be effective. Second, careful materials selection is necessary. High quality materials must be used. These materials may cost more than materials of lower quality. Third, allowable stress design discourages the use of high-strength concrete. One solution is to use load factor and resistance design when using high-strength concrete. Fourth, minimum cover over reinforcement or minimum thickness of members may restrict the realization of maximum benefits. Fifth, available prestress force in a member may be inadequate to achieve maximum strength. Sixth, low water to cementitious materials ratios require special curing requirements. Finally, since serviceabilty conditions such as deflection can control design, increased capacity may not be fully utilized (Peterman).