The Influence of Metakaolinite as the Additive on the Extent of Shrinkage Deformations in Case of Cement Concrete Intended for Airfield Pavements

摘要

The research paper presents the suggestion of using metakaolinite as concrete additive.The assessment of efficiency of using metakaolinite included the influence thereof on the modification of the registered shrinkage deformations.Cement concrete contains cement CEM I 42,5,basalt grit,fine washed aggregate,water and air entraining and plasticizing additive.The influence of the applied metakaolinite on the obtained parameters of concrete mix and hardened concrete was determined.The analyses included concretes curing in standard conditions.Analyses included the assessment of the internal structure of concrete composite in terms of changes of porosity and continuity of contact areas between aggregate grains and cement matrix.Modifications of mechanical and physical parameters and the extent of the registered shrinkage deformations were assessed.Deformation tests were conducted within the period from 1st until 28th day of curing.Reduction of cement quantity and replacement thereof with the suggested metakaolinite allows obtaining the pavement quality concrete of more favourable internal micro structure and distinguished reducing the extent of shrinkage deformations.