Approach to digital process control with
image-based fresh concrete monitoring

Figure: Leibniz University Hannover

Fig. 1: Schematic overview of the individual steps of the developed image-based methodology for the digital determination and evaluation of (fresh) concrete properties [11]

Figure: Leibniz University Hannover

Fig. 2: Detailed view (Ø = 350 mm) of the 3D surface models of spread out fresh concretes for different water overdosages - left: Reference concrete composition (± 0 l/m³); center: + 10 l/m³; right: + 15 l/m³ [10]

Figure: Leibniz University Hannover

Fig. 3: Relative change in properties as a function of water overdosing (5-20 l/m³) - flow diameter a₁₀ and surface parameter Sku [10]

Figure: Leibniz University Hannover

Fig. 4: Schematic overview of the evaluation of a water overdose (WÜ) including the initial test using the surface parameter Sku [10]

Figure: Leibniz University Hannover

Figure: TU Hannover

Fig. 5: Schematic overview of the detection of property changes due to fluctuations in the water content through the digital determination of the surface parameter Sku during the production cycle

Figure: TU Hannover

Quality testing plays a decisive role in the reliable production of fresh concrete. In addition to consistency, other quantitative parameters are necessary for a comprehensive assessment of the properties. Some of these are discussed in the following article.

Introduction

Nowadays, the requirements for precast concrete parts or concrete products are being formulated more and more precisely. In addition to compressive strength, there are also requirements for geometric shape (e.g. geometry or dimensional accuracy), surface quality (structure, color, evenness, etc.) and other special properties. The surface quality requirements are influenced by both the production process and the concrete composition. For example, even slight fluctuations in the water content or water/cement ratio led to a visually perceptible change in the brightness of the concrete...