The effect of cement particle size distribution on the optimization of cement use

• Grant number: 10/08910-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2010
• End date: July 31, 2011
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Vanderley Moacyr John
• Grantee: Gustavo Sandalo Jacomini
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Cement's manufacture process is responsible for about 5% of global CO2 emissions. This share of emissions is expected to grow, since there is a forecast of a sharp increase in the global demand for cement-based products within next 40 years and the current mitigation strategies industry do have limits. The optimization of cement use in concrete mixtures - its major consumer - is an unexplored strategy with great potential for mitigation. This optimization seems to depend, among others, on the increasing of cement grains fineness, which allows higher hydration rates by enlarging available reactive. This project intends to evaluate the influence of changes in granulometric distribution of cement particles over cement pastes' rheology, mechanical properties, microstructure and degree of hydration over time. The particle size distribution of clinker with 4% of calcium sulfate dehydrate will be adjusted by progressive grinding process, resulting in cement with different average diameter. Cement pastes will be produced using a fixed w/c ratio. The influence of grinding on Rheological properties, microstructure and hydration degree over time will be evaluated. Results will be compared with available models of cement hydration. It's expected to obtain results that allow us to demonstrate that changes in cement grain sizes allows users to reduce the volume of cement in concrete and other applications, helping to reduce CO2 emissions from cement supply chain. (AU)