混凝土试件的强度尺寸效应是普遍现象 ,对此 ,普通混凝土已有规范可依。而对近几年发展起来的高性能混凝土 ,其试件的强度尺寸效应有待于研究。本课题对掺 30 %粉煤灰的高性能混凝土试件的强度尺寸效应进行了系统研究 ,并对研究结果进行了统计分析。研究结果表明 ,对于C70左右的粉煤灰高性能混凝土 ,其试件强度尺寸效应比普通混凝土更加明显 ,小试件对大试件的换算系数比相应普通混凝土低得多 The strength of the concrete specimen size effect is a common phenomenon, which, ordinary concrete has been standardized. In recent years, the development of high performance concrete, the strength of the specimen size effect needs to be studied. In this paper, the strength and size effect of high performance concrete specimens with 30% fly ash were systematically studied and the results were statistically analyzed. The results show that the strength-size effect of concrete with fly ash of about C70 is more obvious than that of ordinary concrete, the conversion coefficient of small specimen to large specimen is much lower than that of ordinary concrete