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Decision-making model using the Analytical Hierarchy Process for the selection of the type of concrete and the method of its maintenance in dry, hot climate conditions

Hsino Mahmoud, Jasiczak Józef

Archives of Civil Engineering

2023

Vol. 69, nr 3

385--403

The article presents selected types of phase change materials (PCM) and their properties in terms of applications in construction and concrete technology. The purpose of using PCM is to allow the technological barrier to be exceeded in hot and dry climate conditions, enabling the construction of non-cracking concrete structures. Methodology of the multi-criteria decision-making process with the use of a relatively new decision-making tool in construction - the Analytical Hierarchical Process (AHP) is presented. Theoretical aspects of the method and an example of its practical use for the selection of the best material variant and concrete care method in the dry Syrian climate are presented. The conclusions resulting from the presented article concern two areas, i.e. the advisability of using phase change materials for temperature regulation in the maturing fresh concrete in dry climate conditions and the attractiveness of the AHP method justifying the advisability of choosing the maintenance methods in such conditions.

W artykule przedstawiono wybrane rodzaje materiałów zmiennofazowych (PCM) oraz ich właściwości pod kątem zastosowań w budownictwie, w tym w technologii betonu. Celem stosowania PCM jako dodatku do świeżego betonu jest umożliwienie przekroczenia określonych barier technologicznych występujących w warunkach klimatu gorącego i suchego, gwarantując schładzanie betonu i tym samym wykonanie niezarysowanych konstrukcji betonowych. Przedstawiono metodologię wielokryterialnego procesu decyzyjnego związanego z wyborem różnych wariantów pielęgnacji betonu w warunkach ekstremalnie suchych z wykorzystaniem stosunkowo nowego narzędzia decyzyjnego w budownictwie jakim jest AHP tj. Analytic Hierarchy Process. Przedstawiono teoretyczne aspekty metody oraz przykład jej praktycznego zastosowania do wyboru najlepszego rodzaju cementu oraz betonu i metody jego pielęgnacji w suchym klimacie syryjskim. Wnioski płynące z przedstawionego artykułu dotyczą dwóch obszarów, tj. celowości stosowania materiałów PCM z przemianą fazową o stosunkowo niskiej temperaturze do regulacji temperatury w dojrzewającym świeżym betonie w suchych warunkach klimatycznych oraz atrakcyjności metody AHP uzasadniającej celowość wyboru alternatywnych metod pielęgnacji młodego betonu w takich warunkach.

Validity, reliability and certainty of PERSIANN and TRMM satellite-derived daily precipitation data in arid and semiarid climates

Khojand Keyvan, Shaghaghian Mahmood Reza, Ghadampour Zahra, Sabzevari Touraj

Acta Geophysica

2022

Vol. 70, no 4

1745--1767

Having doubts about the adequacy of reliability level of satellite-derived precipitation products, along with their application in large number of hydrological models, has led to many studies on evaluating the efficiency of such data. In this study, two new procedures were proposed to compute reliability and certainty degrees of PERSIANN and TRMM 3B42RT data sets, and six traditional indicators were used to evaluate their validation. In addition, the cumulative density function (cdf) of the above-mentioned data sets was compared with the ground-based observations in 23 synoptic stations in Fars, Iran. The Kolmogorov–Smirnov test was performed using the data sets at 5% significance level which led to the result of null hypothesis that was not being rejected, suggesting that the satellite-derived daily precipitation data (SDDPD) and ground based observations are drawn from the same distribution. Results indicated that TRMM and PERSIANN follow quite similar probability pattern of ground-based observations in arid and semiarid climate, respectively. However, data probability pattern of TRMM cannot be considered similar to ground-based observations in arid region, neither can PERSIANN in semiarid climate. Among common cross-validating attributes, the values of ME and BIAS, in addition to RMSE and MAE, led to the conclusion that in PERSIANN, the rainfall daily rates are almost underestimated while TRMM overestimates the values mainly in semiarid regions. Moreover, the PERSIANN was found to be significantly correlated with IDM (De Martonne aridity Index), and the values of underestimation increased with growth of the index. The reliability values of SDDPD over the study area, for both TRMM and PERSIANN, show the reverse trend with increasing IDM in almost all acceptable error intervals. Along with effects of climate conditions, the reliability degrees of PERSIANN seem quite more consistent at different acceptable error intervals in comparison with the corresponding values of TRMM. In addition to validity and reliability, the error entropy of SDDPD, as an index for uncertainty degree, increases as the IDM rises, which is theoretically corresponds with reliability concept. However, in comparison with PERSIANN, TRMM data set, overall, has higher degree of uncertainty. In addition, to evaluate effect of daily rainfall intensity on the uncertainty degree of SDDPD, the uncertainty degree slightly increases as daily rainfall intensifies to about 15 mm/day. But for higher daily rainfall intensities, on the other hand, the uncertainty degree seems to gradually decline as the daily rainfall increases.