Influence of Types of Fillers on Workability, Bleeding, Compressive Strength, and Degree of Compaction of Hydraulic Concrete

Abstract

This study aims to determine the optimal quantity of fillers to add to hydraulic concrete and to assess the influence of these fillers on its rheological characteristics and mechanical properties. The characterization of the aggregates shows that they meet the specifications for the formulation of hydraulic concrete according to the Dreux-Gorisse method. Normalizing the formula to the cubic meter enables to define the standard concrete. The cement content is 350 kg/m3. The mineral materials added to the concrete to increase its characteristics and properties are limestone, basalt, and sandstone fillers with a weight percent of 4%, 5%, and 3% respectively. Changes in concrete properties with the addition of fillers were determined through geotechnical tests. The results obtained show a decrease in the workability measured by slump test which returned 7.8 cm for the standard concrete sample, 7.2 cm with 5% of basalt, 7.3 cm with 4% of limestone, and 6.1 cm with 3% of sandstone. Regarding the bleeding, the results show that it decreases leading to a substantial improvement in stabilization reaching 26% with 5% of basalt fillers, 29% with 4% of limestone fillers, and 31% with 3% of sandstone fillers. The compressive strengths noted Rc28 at 28 days increases compared to that of the standard concrete, which is 31.5 MPa. They increase to 34.3 MPa with 5% of basalt fillers being 8.9%, 36.2 MPa with 4% of limestone fillers being 14.9%, and 36.8 MPa with 3% of sandstone fillers being 16.8%. Finally, the addition of fillers increases the degree of compaction values to 83.62% with 5% of basalt fillers, 84.2% with 4% of limestone fillers, and 84.34% with 3% of sandstone fillers.