摘   要：研究了Ⅱ级粉煤灰、再生砖粉和再生混凝土微粉的基本性能，对比了再生砖粉和再生混凝土微粉替代Ⅱ级粉煤灰对混凝土工作性和力学性能的影响；并通过改性剂改善混凝土坍损过大的问题，分析了改性剂影响混凝土力学性能的机理。研究结果表明，再生砖粉和再生混凝土微粉在一定细度条件下，其性能与Ⅱ级粉煤灰相当；缓凝剂、激发剂以及部分表面活性剂组成的改性剂对工作性和力学性能具有明显的改善作用；而水化铝硅酸钙对混凝土力学性能有较大的提高作用。

Abstract: The basic properties of the fly ash, recycled brick powder and recycled concrete powder are studied. The recycled brick powder and recycled concrete powder instead of fly ash in concrete preparation are compared. The influence on the working performance and mechanical properties are investigated. And by adding the modifier to improve the large concrete slump loss. The mechanism of change influence of modifiers on mechanical properties of concrete are  analyzed. The results show that the performance of recycled brick powder and recycled concrete powder in certain fineness conditions is similar to fly ash. The retarder, activator and some surfactant composition modifier have obvious effect on the working performance and mechanical properties, the hydration calcium silicate aluminum can improve the mechanical properties of concrete obviously.