Effects of a two-stage mixing process on the characteristics of concrete: Part I - Hardened concrete characteristics

Abstract

Mixing is an often overlooked aspect in the concrete production process, yet, it has a major impact on the concrete characteristics. This research investigates how different mixing methods affect the hardened concrete characteristics across four distinct mix designs. A primary objective of the study is to assess the compressive strength of concrete, which serves as a crucial indicator of its structural integrity. This is evaluated at 7, 28, and 56 days of curing. Three distinct experimental testing series were conducted to comprehensively assess the impact of various mixing methods on concrete performance. The findings indicate that higher shear rates during mixing can elevate the development of strength, depending on the type of additives utilized and the specific curing period. Limitations to such improvements were briefly discussed as well. Of particular note is the finding that selecting the optimal mixing method could potentially result in a reduction in cement clinker content while maintaining concrete performance.