Workability and proportion design of pumping concrete based on Theological parameters

摘要

In this paper a method is introduced to find an optimized ratio of pumping concrete based on concrete rheology. Workability includes three aspects: fluidity, bleeding resistance and segregation resistance. We tested concrete samples with various water-to-binder ratio (W/B), fly-ash to binder ratio (FA/B), sand-to-aggregate ratio (S/A) and the dose of liquid naphthalene water reducer (FDN/B) by using a concrete rheometer. Using concrete rheometer to measure the yield stress and viscosity based on Bingham model, and then study the rheological regulation of concretes by changing the component proportions. The samples also have been tested for quantifying bleeding and segregation. We obtained the relationship between the workability aspects (the bleeding speed, segregation speed and fluidity) and the rheological parameters, thus obtained appropriate ranges of proportions for the good workability of concrete pumping.