Nanotechnology-Based Performance Improvements For Portland Cement Concrete - Phase I

A fundamental understanding of the nano-structure of Portland cement concrete (PCC) is the key to realizing significant breakthroughs regarding high performance and sustainability. MBTC-sponsored research (MBTC 2095/3004) using molecular dynamics (MD) provided new understanding of Calcium Silicate Hydrate (CSH) structure (the main component giving strength and durability to PCC); however, the study was limited, particularly regarding nano-level mechanical properties in the PCC due to number of atoms that could be considered in the MD approach. In this work discrete element method (DEM) for considering the CSH gel structure is proposed. The progress made in phase I out of three phases is reported. The review of DEM application in engineering and specifically for CSH study is reported. Existing free ware and commercial code available for DEM study is presented. An in house DEM code is developed to apply an indentor type load to a cohesive material. Sample model calculation reasonably illustrated the development and application of the DEM code.