MICROSTRUCTURE OF HIGH-VOLUME FLY ASH CONCRETE
The resistance of concrete against multiple types of deterioration is governed by gas and/or fluid transport properties of the microstructure and hence by the permeability of the capillarynetwork. The pozzolanic reaction of fly ash starts at later age and proceeds at a slower pacethan the hydration of cement. This makes high-volume fly ash concrete at young age muchmore permeable and vulnerable to the transport of gasses and fluids than traditional concrete.With time, a densification of the microstructure will take place resulting in an increasedresistance of high volume fly ash concrete against penetration of aggressive gasses and fluids.Eight concrete mixtures were made with varying fly ash-to-cementitious material ratio andwith different types of cement and fly ash. At the ages of 1 and 3 months the compressivestrength, the open porosity and the sorptivity of the concrete mixes was determined. The twolatter parameters were measured after drying at 40℃ (R.H. of 23％) and 105℃ respectively.The measured porosities were related to the compressive strength and to the sorptivitybehaviour. The C3A content and the fineness of fly ash were found to be determiningparameters for the microstructural development of concrete with these binders.
G.Baert P.Van den Heede K.Audenaert N.De Belie
Magnel Laboratory for Concrete Research,Ghent University,Ghent,Belgium
国际会议
南京
英文
207-215
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）