Considerations for High-Performance Concrete Paving: Recommendations from 20 Years of Field Experience in Texas

Presented are recommendations for high-performance concrete paving (HPCP) practice drawn from 20 years of design and monitoring of the performance of continuously reinforced concrete (CRC) pavements in Texas. Performance indicators used were crack spacing distribution, crack width, crack randomness, delamination spalling, and vertical distribution of tensile strength. Variables studied were aggregate type, aggregate blending, placement season, placement time of day, placement above 32°C (90°F), use of crack initiators, use of skewed transverse steel, evaporation rate, percent steel reinforcement, and steel bar diameter. The variables studied are ranked in the order they affected performance, to identify which are significant and can be controlled in the design and construction phases. The focus is on the most recent experimental pavements designed and built specifically to study HPCP in Texas—85 CRC test sections built at eight locations between 1986 and 1995 in the greater Houston area. Each project consisted of 8 to 22 experimental sections of slightly different design. These sections were closely controlled and monitored during construction, and periodic condition surveys continue to be conducted. The recommendations offered are especially useful under adverse conditions, such as hot weather placement of portland cement concrete using high thermal coefficient aggregates, or paving during periods of high surface evaporation. Critical temperatures and evaporation rates are specified; using weather stations, maturity meters, or other devices that indicate in situ temperatures and evaporation rates, dangerous conditions may be identified in time to take corrective measures and thus ensure adequate performance.