Investigation of Additives on the Properties of Foamed Concrete

This paper describes how the formulation of new substances in foam cement concrete does not merely depend on the chemical composition of raw materials and C/S ratio but on the type and mode of hardening as well. Roentgenograms show that foam cement hardening at the temperature of 25 - 100 degrees centigrade does not cause the formation of crystalline calcium hydrosilicates, leading only to intense hydration of cement minerals. The inert amorphous gel of calcium hydrosilicates is formed in large amounts in the samples, which does not crystallize under normal conditions, being eventually carbonized. In autoclave foam cent concrete with crushed sand, tobermorite is formed, with no calcium hydroxide found and a decreased amount of quartz, indicating that the reaction between calcium hydroxide and quartz has taken place. According to DTA data, when samples are heated to 200 450 degrees centigrade less water is separated from calcium hydrosilicates formed under normal conditions of hardening than in steam curing. This shows that larger amounts of CSH (i) group hydrosilicates are formed in steam cured samples, thereby increasing the strength of the products obtained.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 567-674
  • Monograph Title: Role of Concrete in Sustainable Development

Subject/Index Terms

Filing Info

  • Accession Number: 01010848
  • Record Type: Publication
  • ISBN: 0727732471
  • Files: TRIS
  • Created Date: Nov 28 2005 2:48PM