Influence of Fly Ash on the Strength Development of Ready-Mixed Soil Materials

• Main Authors: Zhun-rong Zhang, 張純榮
• Other Authors: Yeong-Nain Sheen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/95848699955599636900

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 99 === In this study, the feasibility of using Ready-Mixed Soil Materials (RMSM) in substitution for Controlled Low Strength Materials (CLSM) as backfill materials in pipe construction was discussed. The relationship between the non-destructive investigation of ultrasonic test, rebound hammer test and compressive strength was established. Fly ash was added to help the strength development of RMSM. There only 100kg cement used in every cubic meter mix design proportion, and fly ash replaced the cement by 0%, 15%, 30%, and 45% respectively among with or without 2% accelerating agent. Three types of water/cement ratio, 3.0, 3.2, and 3.4 were used in each mix proportion. Therefore, total 24 sets of specimens were tested in 1, 7, 28, 56, and 91-days strength. Experiment results showed that the workability of RMSM is well according to the requirement from CPAMI for CLSM: slump>20cm, slump flow>40cm, and modified slump>15cm. All compressive strength test results in the age of 28, 56, and 91days were smaller than 50 kgf/cm2, which satisfied ASTM D4832 specification for CLSM. At 1-day compressive strength test, there were 15 sets of specimen satisfied the RMSM specification of Japan Ministry of Construction that of RMSM should large than 1.3 kgf/cm2 then it is open to traffic. In conservative consideration, 8 sets of specimen with 1.5 kgf/cm2 of 1-day compressive strength were chose to make imitation field loading test and ball drop test to evaluate the hardness property of RMSM. Ball drop test value was situated between 8~10 cm larger than the 7.6 cm, ASTM d6024-96 specification for CLSM, although that 1-day compressive strength of CLSM were required to reach 3.5 kgf/cm2. This result showed that the requirement of ball drop test value can be further discuss. Imitation field loading test result showed that 35 ton trucks can be supported by RMSM with water/cement ratio and 15% fly ash replacement.