机制砂石骨料与减水剂适应性的试验研究

选用两种具有代表性的机制砂石骨料——钙质骨料与硅铝质骨料,经扫描电镜分析发现,前者主要化学成分为碳酸钙,呈岛状结构,后者为硅铝质岩,呈层状结构;通过与不同品种减水剂配制混凝土后进行浆体流动性、ζ电位及混凝土性能等试验发现,钙质骨料吸水性小,与不同减水剂的适应性良好,采用聚羧酸系减水剂配制的混凝土工作性极好,强度较高,而硅铝质骨料吸水性大,ζ电位高,与不同减水剂的适应性差,掺高性能聚羧酸系减水剂的优势也不明显.

Experimental Study on Adaptability of Machine-Made Aggregate with Water-Reducers

Two kinds of representative machine-made aggregates,namely the calcium-base and silialuminate-base,were chosen in the experimental study.Through analysis of SEM,it was found that the former's main chemical component was calcium carbonate with an island like structure,the latter might be a rock of silialuminate-base in a state of sandwich.Through experiments of the paste fluidity,Zeta potential and concrete test with different water-reducers it is shown that the calcium-base aggregate,which could be easily used to prepare high workability and high strength concrete with polycarboxylate water-reducer,has lower water absorption ability and good adaptability with any water-reducer,whereas the silialuminate-base aggregate has higher water absorption ability,higher zeta potential value and poor adaptability so that there might be a problem to produce HPC by using high performance polycarboxylate water-reducer.