报告时间：2016.12.23（周五）下午2:30
  报告地点：土木工程楼232会议室

  报告人：Xu Chen

Abstract:

Geopolymers are being promoted as a sustainable alternative to the ordinary cements mainly because their production is associated with much less CO₂ emissions. They also show advantages including compressive strength comparable to portland cements, high temperature resistance, and stability under acid attack. However, before geopolymers can be widely used in practice, certain other behaviors must be understood and controlled, among which is setting, the transition from fluid to solid. Geopolymer setting isseen to be substantially accelerated by addition of calcium. This presentation aims to understand the setting at the nanostructural level for calcium and non-calcium geopolymers using a relatively pure aluminosilicate metakaolin precursor. In the non-calcium mix, set occurred when aluminosilicate gel connected unreacted metakaolin to form a network structure. With calcium, enhanced dissolution of metakaolin decreased Si/Al ratio for geopolymer formation and thus to further enhance geopolymer gel formation, which caused faster setting.

Bio: Xu Chen is currently a PhD candidate in the Department of Civil and Environmental Engineering at University of Illinois at Urbana-Champaign and has just defended his PhD thesis. He obtained his Bachelor of Science in Civil Engineering from Huazhong University and Science and Technology and Master of Philosophy in Materials Engineering from Hong Kong Polytechnic University.

发布人：周长东