OPTIMIZATION OF POWDER FINENESS AND WATER/POWDER RATIO TO IMPROVE SEGREGATION RESISTANCE OF SCC
The sensitivity of the coarse aggregate with regard to segregation is the main barrier for a reliable application of SCC. For this reason investigations are being conducted to increase the segregation resistance by optimizing the powder properties and paste composition of SCC.The optimization is based on the characterisation of the surface forces of the powder particles and their effect on the rheological properties of fresh mortar. Three surface forces are considered to determine the fresh properties of cement based mortars - the attractive van der Waals forces, the repulsive double layer forces and the polymer-induced steric forces.The effect of water to powder ratio and powder properties (cement fineness, surface area) on the rheological properties of fresh mortar and the segregation of concrete was investigated.Results are presented on the determination of the water layer thickness, the distance between the powder particles and the calculation of the surface forces. It is shown how the different powder properties are connected to flowability, static yield stress and segregation resistance.
D.Lowke T.Kr(a)nkei P.Schieβl
Technische Universit(a)t M(u)nchen, Centre for Building Materials (cbm), Munich, Germany
国际会议
长沙
英文
183-193
2009-06-05（万方平台首次上网日期，不代表论文的发表时间）