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Avtorstvo: Jana ŠELIH // 1.01 Izvirni znanstveni članek
Leto: 1996
Citat: ŠELIH, Jana, SOUSA, Antonio C. M., BREMNER, Theodore W. Moisture transport in initially fully saturated concrete during drying. Transp. porous media, 1996, vol. 24, str. 81-106.
Povzetek: Moisture content changes during drying were investigated in the present work. Particular emphasis was placed on the initial stage of drying of saturated concrete, where moisture contents are high. For this stage of drying, experimental data are lacking, and no comprehensive theory exists to describe it. The present investigation was performed experimentally and numerically for drying of cylinders with one exposed end, made of normal weight and lightweight concrete with varying water to cement ratio (w/c). The gravimetric technique was employed to obtain the spatial distribution of moisture content. The experimental results obtained indicate that drying of concrete becomes diffusion controlled when the average moisture content decreases below 70 to 80 % of the initial saturation. Typical drying rates are in the order of magnitude of 0.18 kg/day/m2 and 0.02 kg/day/m2 for the first and the second stage of drying, respectively. The lightweight concrete cylinders as compared to those made of normal weight concrete exhibited higher levels of moisture content throughout the process. At high w/c ratios, the moisture profiles for both types of cylinders, as expected, show steeper changes with time. Large, constant drying rates were observed both experimentally and numerically in the beginning of the drying. The numerical model developed is based on a generalized mathematical formulation for mass and heat transfer in porous media, and its predictions are in agreement with the experimental data within the uncertainty range of the input data

V članku smo obravnavali spremembe vsebnosti vode med sušenjem polno zaščitenega betona s posebnim poudarkom na začetni fazi šušenja, ko so vsebnosti visoke. Eksperimentalnih podatkov za to fazo je v literaturi malo. Eksperimentalno in numerično preiskavo sušenja smo izvedli za betonske valje različnih dolžin. Valji so izpostavljeni sušenju na eni stranici in so narejeni iz konvencionalnega betona in betona z lahkim agregatom. Eksperimentalno smo ocenili vpliv vodocementnega faktorja ter dolžino nege betona na potek izsuševanja. Razviti numerični model temelji na posplošeni matematični formulaciji masnih in toplotnih pretokov v poroznih materialih, in njegovi rezultati se ujemajo z eksperimentalno dobljenimi vrednostmi znotraj intervala negotovosti vhodnih podatkov
Tipologija: 1.01 Izvirni znanstveni članek
COBISS ID 118375 Polni zapis iz sistema COBISS
Vpisal 2001/08/08 19:56