| Popis: |
It is well known as the presence of fine and ultra-fine particulate solids products (fillers), inside a concrete, strongly contributes to change final manufactured products characteristics. Fine carbonate fillers, in fact, complement the deficiency in fine particles of the cement's particle size distribution, which can enhance both the flowability and stability of fresh concrete. They also fill in between the relatively coarser cement grains, reducing the room available for water and consequently the water demand. In conventional concrete mixtures, slight reductions in the setting time have been often reported when carbonate fillers were used, without significant effects on the workability. However, as the use of high-performance concrete continues to rise, carbonate fillers are being added in low water/cement ratio superplasticized-mixtures. In this paper an innovative approach, based on thermal-imaging, was applied in order to establish a correlation, for the different utilized fillers, among fillers quantity and quality, concrete behaviour during ageing and final mechanical characteristics of the products at 28 days. |
