大掺量粉煤灰碾压混凝土浆体体系的优化研究

Research on the Optimization of RCC-paste System Incorporating High-volume Fly Ash

优质粉煤灰是一种有价值的资源,但在富胶凝材料碾压混凝土中高掺粉煤灰已显得不够经济。为此,结合龙滩工程大坝碾压混凝土的特点,研究了石灰岩石粉的颗粒特性以及石粉含量对碾压混凝土性能的影响,发现用石粉取代部分粉煤灰不影响碾压混凝土的工作性,仅会使碾压混凝土抗压强度轻微下降。所以,在富胶凝材料碾压混凝土中可以用石粉取代部分粉煤灰,但人工砂中的石粉含量不宜超过20%。通过试验验证,与给定的基准混凝土相比,用石粉取代部分粉煤灰得到的碾压混凝土配合比的各项性能均没有降低,且每m3混凝土可节省粉煤灰28kg,经济性较优。

The high quality fly ash is a valuable resource, and the high-volume fly ash used in RCC with rich cementitious material seems to be uneconomical. In this paper, the granule characteristics of limestone powder and the influence of stone powder content on the properties of RCC in Longtan Hydropower Station were studied, it was found that the workability of RCC would not be affected if replacing a part of fly ash with stone powder ,but the compressive strength of RCC would decreased slightly.A part of fly ash might be replaced with stone powder in high-paste RCC.but the content of stone powder in crushed sand should be not more than 20%.Under the testing conditions,the propeties of RCC with stone powder replacing part of fly ash didn＇t decreased compared with the given reference RCC mix ,and 28kg fly ash per one cubic mether RCC was saved.