Influence of Redispersible Powder on Ezpansion in Self Leveling Underlayments
Self-leveling underlayments (SLUs) are principally used to produce a smooth and level floor surface when placed on an uneven or unfinished concrete. Modern and sophisticated SLUs exceed in workability, rapid hardening, and shrinkage compensation compared with ordinary mortars. In order to acquire those characteristics, SLUs are composed of complex binders, mineral and organic fillers, and most importantly admixtures. Amongst the organic fillers, redispersible powders produced by spray drying from emulsions, are added to improve flexibility, adhesion and water resistance etc. for SLUs.In this study, the influence of redispersible powders on dimensional stability (shrinkage and expansion) in SLUs at early ages has been investigated for the first 24 hours. The underlayments were based on a ternary binder containing Calcium Aluminate Cement (CAC), Ordinary Portland Cement (OPC) and Calcium Sulfate (C$). Besides mineral fillers and admixtures, different redispersible powders at varying amounts were added to the SLUs. The addition of redispersible powders showed not only the well known retardation in hydration kinetics, longer setting times and increased gel times but also changed expansion characteristics for the SLUs. The results are discussed in the light of the competing mechanisms of structure build-up by hydration and the film forming in a polymer modified, cementitious matrix as described by various researchers.
ternary binder redispersible powder ezpansion hydration kinetic
Thomas A.BIER Makoto NUKITA
Institut fuer Keramik, Glas- und Baustofftechnik, Leipziger Strasse 28, D- 09596 Freiberg, Germany Building Materials R&D Dept., Ube-Mitsubishi Cement Research Institute Corporation, 1-6 Okiniyama Ko
国际会议
6th Asian Symposium on Polymers in Concrete(第六届亚洲聚合物混凝土国际会议)
上海
英文
222-227
2009-10-29（万方平台首次上网日期，不代表论文的发表时间）