Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Coefficient of Thermal Expansion of Concrete Mixes in Hawaii: Determination and Implications for Concrete Pavement Design
AbstractThe coefficient of thermal expansion (CTE) of portland cement concrete (PCC) is a significant factor affecting the performance of concrete pavements. It is also required as a direct input in the mechanistic-empirical pavement design guide (MEPDG). The primary objective of this study was to determine CTE values of PCC mixes used in Hawaiian pavements. A secondary objective was to study the effect of curing time on the CTE. To achieve these objectives, 45 concrete specimens were prepared on-site at three Hawaiian concrete companies using local basaltic aggregates. For each site, 15 replicate test specimens (five sets of three) were cured in a 100% humidity room for 3, 7, 14, 28, and 56 days before determining their CTEs following AASHTO T 336. It was found that CTE values vary significantly with curing time. It was also observed that the CTEs at 28 days computed in this study, ranging from 6.1×10−6/°F to 6.6×10−6/°F (11.0×10−6/°C to 11.9×10−6/°C), differ significantly from the value recommended in the MEPDG manual of practice for concrete specimens with basaltic rock as a constituent (5.2×10−6/°F, 9.4×10−6/°C), which can lead to designs with overestimated performance. The variation caused by curing time is similar in magnitude to the variation caused by the use of different mixes for a given curing time. Thus, the study results support the need to establish a standard curing time when determining an appropriate CTE for design. Furthermore, use of a nonrepresentative default value can have a higher effect than that produced by differences between mixes or curing times, which highlights the importance of performing research to establish local CTE values. Based on the results, it is recommended to use the CTE obtained after 28 days of curing for design. Possible implications of the results obtained in this study are illustrated with a particular jointed plain concrete pavement (JPCP) design with the MEPDG.
Coefficient of Thermal Expansion of Concrete Mixes in Hawaii: Determination and Implications for Concrete Pavement Design
AbstractThe coefficient of thermal expansion (CTE) of portland cement concrete (PCC) is a significant factor affecting the performance of concrete pavements. It is also required as a direct input in the mechanistic-empirical pavement design guide (MEPDG). The primary objective of this study was to determine CTE values of PCC mixes used in Hawaiian pavements. A secondary objective was to study the effect of curing time on the CTE. To achieve these objectives, 45 concrete specimens were prepared on-site at three Hawaiian concrete companies using local basaltic aggregates. For each site, 15 replicate test specimens (five sets of three) were cured in a 100% humidity room for 3, 7, 14, 28, and 56 days before determining their CTEs following AASHTO T 336. It was found that CTE values vary significantly with curing time. It was also observed that the CTEs at 28 days computed in this study, ranging from 6.1×10−6/°F to 6.6×10−6/°F (11.0×10−6/°C to 11.9×10−6/°C), differ significantly from the value recommended in the MEPDG manual of practice for concrete specimens with basaltic rock as a constituent (5.2×10−6/°F, 9.4×10−6/°C), which can lead to designs with overestimated performance. The variation caused by curing time is similar in magnitude to the variation caused by the use of different mixes for a given curing time. Thus, the study results support the need to establish a standard curing time when determining an appropriate CTE for design. Furthermore, use of a nonrepresentative default value can have a higher effect than that produced by differences between mixes or curing times, which highlights the importance of performing research to establish local CTE values. Based on the results, it is recommended to use the CTE obtained after 28 days of curing for design. Possible implications of the results obtained in this study are illustrated with a particular jointed plain concrete pavement (JPCP) design with the MEPDG.
Coefficient of Thermal Expansion of Concrete Mixes in Hawaii: Determination and Implications for Concrete Pavement Design
Havel, Stephen Anthony (Autor:in) / Archilla, Adrián Ricardo / Shen, Lin
2015
Aufsatz (Zeitschrift)
Englisch
BKL:
56.45
Baustoffkunde
Lokalklassifikation TIB:
535/6520/6525/xxxx
| British Library Online Contents | 2015
Design of concrete pavement mixes
| Engineering Index Backfile | 1929
Coefficient of Thermal Expansion of Concrete for Rigid Pavement Design
| British Library Conference Proceedings | 2008