Strength and Durability Evaluation by DEM Approach of Green Concrete Based on Gap-Graded Cement Blending

Abstract:

This paper discusses the particle packing background of cementitious materials. On micro-level the Portland cement and eventually the mineral admixture grains can be considered packed in the watery environment. Particularly for (super) high performance materials, the packing density can be quite significant. An economic and due to fast computer developments reliable way to study packing of the binder, is by modern discrete element modeling (DEM) approach. In this paper use is made of a concurrent algorithm-based dynamic system, HADES. Hydration is simulated based on spherical grains. Thereupon strength can be studied on the basis of packing density. For durability issues, the complex and tortuous 3D pore structure has to be investigated. This paper uses for the assessment of pore characteristics the robotics-inspired DraMuTS system. Hydrated Portland cement is compared with gap-graded rice husk ash-(RHA)-blended (green) Portland cement. Experiments on gap-graded RHA-blended PC concrete are used as reference. Packing density is shown improved by gap-graded packing. What is more spectacular are the effects of gap-grading with RHA on the pore characteristics obtained on the DEM-produced virtual materials. This paper discusses the expected positive effects on transport-based durability issues due to gap-graded packing-induced changes in the pore system

• Periodical: Advanced Materials Research (Volumes 450-451)
• Pages: 631-640
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.450-451.631
• Online since: January 2012
• Authors: L.B Nghi Le, Piet Stroeven
• Keywords: Cement, Concrete, Durability, Gap-Grading, Particle Packing, Porosimetry, Strength

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