WANG Shuangfei¹, KE Guojun¹, PENG Bo², LI Jun², QIU Haoqun²

(1.School of Civil Engineering; China Nuclear Construction Key Laboratory of High Performance Concrete, University of South China,Hengyang 421001, China; 2.Hunan Goodbond Construction Technic Development Co., Ltd., Changsha 410205, China)

Abstract：By using of design of the mix proportion of the cementitious materials and fine aggregate based on close packing theory, the influence of different water-binder ratio(0.135～0.165, mass fraction)on the workability and compressive strength of ultra-high performance concrete(UHPC)were studied.The air content(volume fraction)of UHPC mixture with different water binder ratio were tested.The pore structure and micro morphology of UHPC specimens were studied by low field magnetic resonance analysis and scanning electron microscopy.The results show that with the increasing of water-binder ratio, the expansion of UHPC mixture increases and presentes a linear relationship.The compressive strength of UHPC increases first and then decreases with the increasing of water-binder ratio, and reaches the maximum when the water-binder ratio is 0.15.When the water-binder ratio is 0.15, the air content is the minimum, and there is a good linear relationship between the compressive strength and the air content.When the water binder ratio is 0.15, the pore structure is the best and the matrix is the densest.

Keywords：ultra-high performance concrete; water-binder ratio; compressive strength; expansibility; pore structure; air content

Received：2022-09-25，Revised：2022-10-21,Online：2023-03-02 09:25。

Funding Project：湖南省自然科学基金衡阳联合项目，编号：2019JJ60003。

First Author:王双飞(1998—)，男，硕士研究生，研究方向为高性能与超高性能混凝土及固体废渣利用。E-mail：1542683896@qq.com。

Corresponding Author:柯国军(1964—)，男，教授，硕士，硕士生导师，研究方向为高性能与超高性能混凝土及固体废渣利用。E-mail：1132980799@qq.com。