Fine Aggregates Size Effect on Rheological Behavior of Mortar

Abstract

Physical characteristics of aggregates affect the workability and strength of mortar and concrete, which include their fineness ratio, particle size distribution and water absorption. The workability of construction materials decreases if the incorporated fine aggregates show improper size distribution of their particles. This study shows the particle size effect on the rheological behavior of mortar and provides basic information for evaluating its workability. A mini-slump flow test was adopted to evaluate the workability of mortar. In addition, its plastic viscosity and yield stress were measured using a rheometer for building materials. The sand samples were prepared by sieving river sand and sorting out with their particle sizes. As a result, it was observed that the fines less than 0.7 mm increases the yield stress and plastic viscosity of the mortar samples. If the fines are less than 0.34 mm, the water absorption of the fines dominates change on the workability.

Rheological Method for Alpha Test Evaluation of Developing Superplasticizers’ Performance: Channel Flow Test

“…When the flow stops, the final length of the channel flow and the time to get the final length or 500 mm approach are measured. The channel guided to one-direction flow gives higher sensitivity [7,8]. More pretests using various cement paste and mortar mixes support the fact that the range of 300 mm to 700 mm is acceptable for the channel flow.…”