LONG-TERM STRENGTH DEVELOPMENT OF PAVEMENT CONCRETES

Development of pavement concrete compressive strength, flexural strength. and splitting tensile strength as a function of time is discussed. Eighteen sets of post-1985 exerimental data from academic and industrial sources were selected to form a database of strength data for ''modern'' pavement concrete. Specimens were categorized as high or normal strength, use of fly ash was identified, and curing conditions were noted. Significant gains beyond 28-day strength are observed in compressive, flexural, and tensile strength of modern pavement concretes. This general observation holds true for high- and normal-strength concrete, concretes with and without fly ash, and concretes cured in air and moist conditions. Modern concretes have higher early compressive strength gains than concretes produced in 1940-56. However, both modern and 1940-56 concretes exhibit similar long-term trends in strength development when normalized to their 28-day strengths.