Expected compressive strength in precast, prestressed concrete design: A methodology to analyze regional strength results

Accurate predictions of concrete compressive strength are critical for designers to effectively estimate the camber, deflections, and prestress losses of precast, prestressed concrete elements. A methodology that relies on regional concrete bridge girder strength test results is proposed for predicting expected concrete compres­sive strength. Strength data collected from precast, prestressed concrete plants were manipulated by the use of a strength-difference approach to facilitate American Concrete Institute 214R-11 analysis methods. The data set was used to evaluate five other empirical prediction model forms. When implemented using an Alabama regional data set, the methodology resulted in markedly more accurate predictions of expected concrete strength at prestress transfer and at 28 days compared with cur­rent practice.