Novel ultra high performance concrete mixing technology with preliminary dry forced packing

摘要

It is a universally recognized fact that the production of ultra high performance concrete (UHPC) requires mixing technologies that go beyond what is typically used for ordinary concrete. A generally accepted approach is to adapt and repurpose unique mixers from other industries to mix UHPC. However, in some cases these tools have intrinsic limitations that preclude the production of UHPC that exhibits uniform dispersal of all constituents. This study discusses a method of mixing that utilizes preliminary forced packing of dry multi-component mixtures, and studies the effect of such forced packing on the physicochemical properties of the composition, microstructure, homogeneity, and mechanical properties of the resultant UHPC. The methodology achieved complete de-agglomeration of ultra-fine particles in the mixture and facilitated their uniform distribution within the cementitious matrix, leading to increased homogeneity, density and strength of the concrete. The study discusses methods of direct measurement of uniformity of the hardened cementitious matrix. (C) 2020 Elsevier Ltd. All rights reserved.