CHLORIDE DIFFUSIVITY IN PARTIALLY SATURATED CEMENT-BASED MATERIALS ASSESSED BY RESISTIVITY MEASUREMENTS
Concrete is seldom saturated due to its self-desiccation.Even the submerged concrete structures may remain unsaturated for quite a long time.It has been reported the saturation level of pore solution has significant effect on species penetration.However, very little work was proposed regarding the transport properties and serviceability of concrete structures made of blended cementitious materials.This paper initiated the study of chloride ion diffusion in various blended cement-based system under non-saturated condition by resistivity measurements.Experiments have been performed on mortars made of different cement-based materials (Portland cement, fly ash, blast furnace slag, limestone powder) with different water to binding ratio (w/b=0.4, 0.5, 0.6).The mortar specimens have been curing for 200 days conditioning with 98% RH and 20℃, followed by oven drying at 50℃ until the specimens reach different saturation levels from 95% down to 18%.The resistivity measurements for different cement-based systems are performed.The results showed that saturation level has significant effect on the chloride diffusion coefficient.As to the relation between relative diffusivity and water saturation, the effect of w/b is less obvious in system with higher w/b.Compared with FA and LP system, the deepest decrease in relative diffusivity was found in BFS-blended system with the decrease of water saturation level.
blended materials relative diffusivity non-saturated chloride resistivity
Yong Zhang Guang Ye
Microlab, Civil Engineering and Geoscience, Delft University of Technology, 2628 CN Delft,The Netherlands
国际会议
The 3rd International Conference on Service Life Design for Infrastructure(2014第三届基础设施服役寿命设计国际会议)
珠海
英文
183-192
2014-10-15（万方平台首次上网日期，不代表论文的发表时间）