漂珠自养护超高性能混凝土配制及性能研究

Preparation and Study on the Properties of Self-curing UHPC Containing Cenosphere

采用化学刻蚀法对粉煤灰漂珠进行预处理,形成表面具有微孔结构且具有一定储水释水功能的内养护剂,进一步饱水处理后,以轻骨料的形式部分取代河沙用于配制自养护超高性能混凝土。研究了饱水条件下漂珠对超高性能混凝土的流动性能、力学性能和自收缩性能的影响同时对其水化程度和微观形貌进一步分析。结果表明:和未掺入漂珠的超高性能混凝土相比,饱水处理后漂珠取代15%河沙情况下,超高性能混凝土扩展度提高了10%;标准养护28d后,密实的基体中水泥水化程度提高了20%;自收缩程度呈现显著下降的趋势。

A chemical etching method was used to pre-treat fly ash cenosphere in order to form an internal curing agent with a certain water storage function on its surface.The fluidity,mechanical properties and self-shrinkage of the ultra-highperformance concrete under water-saturated condition were studied in detail,and the hydration degree and the micro-morphology of the super-high-performance concrete were further analyzed.The experimental results show that,compared with the reference group,the expansion degree of the super-high concrete is increased by 10%when the water-saturated cenosphere are replaced by 15%of the river sand,and the cement water formation degree in the dense matrix for 28 days is improved by 20%,and the self-shrinkage is remarkably reduced.