Hamid Ahmadyar - Academia.edu (original) (raw)
Uploads
Papers by Hamid Ahmadyar
Structural applications of concrete containing fly ash have been limited mainly to high strength ... more Structural applications of concrete containing fly ash have been limited mainly to high strength concrete in the past. This trend is primarily due to the lack of information available to the resident engineer concerning curing conditions, setting times, strength characteristics and durability of normal strength fly ash concrete. This study addresses some of the major concerns of resident highway engineers on concrete containing fly ash for structural concrete in highway applications. This report summarizes the experimental observations and conclusions from a research program investigating the properties of both fresh and hardened structural concrete containing fly ash. Tests were performed to establish guidelines for the selection of materials and trial mix design procedures for producing quality concrete containing fly ash. The study investigated freeze-thaw resistance, flexural and compressive strength characteristics, mixing conditions and procedures and curing conditions such as temperature, humidity, curing methods and rate of strength gain. Types A and B fly ashes were used in this study as a replacement for 0, 15, 25, and 35% Type I portland cement by weight. In addition, Type IP cement containing 20% Type A fly ash was used. The results of this study show that concrete containing fly ash can be designed and proportioned to meet present Texas SDHPT specifications for structural applications. In addition, this study reveals that an optimum mix design for concrete containing fly ash is both technically and economically advantageous to the Texas SDHPT. This report provides the resident engineer with recommendations to ensure the production of quality concrete containing fly ash for structural applications.
Structural applications of concrete containing fly ash have been limited mainly to high strength ... more Structural applications of concrete containing fly ash have been limited mainly to high strength concrete in the past. This trend is primarily due to the lack of information available to the resident engineer concerning curing conditions, setting times, strength characteristics and durability of normal strength fly ash concrete. This study addresses some of the major concerns of resident highway engineers on concrete containing fly ash for structural concrete in highway applications. This report summarizes the experimental observations and conclusions from a research program investigating the properties of both fresh and hardened structural concrete containing fly ash. Tests were performed to establish guidelines for the selection of materials and trial mix design procedures for producing quality concrete containing fly ash. The study investigated freeze-thaw resistance, flexural and compressive strength characteristics, mixing conditions and procedures and curing conditions such as temperature, humidity, curing methods and rate of strength gain. Types A and B fly ashes were used in this study as a replacement for 0, 15, 25, and 35% Type I portland cement by weight. In addition, Type IP cement containing 20% Type A fly ash was used. The results of this study show that concrete containing fly ash can be designed and proportioned to meet present Texas SDHPT specifications for structural applications. In addition, this study reveals that an optimum mix design for concrete containing fly ash is both technically and economically advantageous to the Texas SDHPT. This report provides the resident engineer with recommendations to ensure the production of quality concrete containing fly ash for structural applications.