The method of mixing may affect the degree of agglomeration of particles in cement-based materials and thus the properties of the materials in their fresh, hardening, and hardened state. Paste (w/c=0.35) of white Portland cement with and without 10% silica fume and 0.65% superplasticizer were mixed by hand and in a high-speed mixer. Chemical shrinkage was measured to illustrate the effect of mixing on development of hydration. Chloride migration was measured on 28 days old pastes to illustrate the effect of mixing on the hydrated pastes. The present investigation of pastes of white Portland cement showed an effect of mixing on the development of chemical shrinkage, i.e. hydration, of pastes with superplasticizer, but without silica fume. Silica fume agglomerates were observed in thin sections of pastes with silica fume and mixed by hand; however no effect on the development of hydration was observed. The effect of mixing on development of hydration was not reflected in the resistance to migration of chloride ions in 28 days old samples.
|Title of host publication||Volume changes of hardening concrete : Testing and mitigation|
|Number of pages||410|
|Publication status||Published - 2006|
|Event||International RILEM Conference on Volume Changes of Hardening Concrete 2006: Testing and Mitigation - DTU, Kgs. Lyngby, Denmark|
Duration: 20 Aug 2006 → 23 Aug 2006
|Conference||International RILEM Conference on Volume Changes of Hardening Concrete 2006|
|Period||20/08/2006 → 23/08/2006|