INFLUENCE OF ALKALI CONTENT ON CREEP AND SHRINKAGE OF CEMENT-BASED MATERIALS
Hydration products of Portland cement and in particular C-S-H nano-particles are formedin an aqueous solution. When the density of particles becomes high enough at early age asolid skeleton is built up. The nano-particles are hindered to get in close contact by thedisjoining pressure of intermediate water layers, but they are linked to each other by isolatedelectrostatic bonds and ionic correlation forces. This complex interaction between the poreliquid and the nano-particles of the hydration products is the origin of characteristic propertiesof cement-based materials such as strength, elastic modulus, creep and shrinkage. A change ofalkali ion concentration of the pore solution results in a modification of the cohesion and theequilibrium distance. Ample evidence of the influence of the modification of the micro-structure of cement-based materials by variation of alkali content on their properties has beenprovided in the past. In this contribution it will be shown that both creep and shrinkagedepend also on the alkali concentration. A colloidal model is presented, which allows us toexplain recent experimental results.
Francoise Beltzung Folker H.Wittmann Xiaomei Wan
North-West University of Applied Sciences,Institute of Civil Engineering,Switzerland Aedificat Institute,Freiburg,Germany Qingdao Technological University,Centre for Durability Studies, Qingdao Technological University,Centre for Durability Studies,Qingdao,China
国际会议
南京
英文
905-915
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）