Aim of research
The aim is to determine interactions between concrete admixtures that accelerate strength development and cements with several main constituents. By systematically varying cement-technical parameters in conjunction with the targeted use of different accelerating agents, it is investigated how the reaction of the various main constituents in cement can be stimulated earlier and thus the early strength development can be increased without significantly affecting the late strength and durability of concrete. It is also determined to what extent the latent hydraulic or pozzolanic reaction of the further main constituents besides clinker can partially compensate for this. The influence of reduced w/c ratios and partially retarding superplasticizers, which are necessary to process such water-reduced systems, on the strength development of accelerated systems is determined. The influence of more intensive, two-stage mixing processes on the early strength will also be comparatively investigated in tactile tests.
Methods and benefits for small and medium-sized companies
In addition to strength tests, hydration reactions and microstructure formation are determined by heat flow calorimetry and differential scanning calorimetry, X-ray analysis, electron microscopy, ultrasonic transmision measurements and porosity measurements. The results are verified by strength and durability tests on concrete. The results will primarily support SMEs in the development and marketing of innovative, clinker-efficient cements and the resulting sustainable concretes with improved strength development. This maintains and strengthens the competitiveness of SMEs in the decarbonisation of concrete construction.