The influence of dynamic environmental conditions on capillary water uptake of building materials

2018 ◽  
Vol 42 (4) ◽  
pp. 506-526 ◽  
Author(s):  
Nikos Karagiannis ◽  
Maria Karoglou ◽  
Asterios Bakolas ◽  
Magdalini Krokida ◽  
Antonia Moropoulou
Keyword(s):  
Water Uptake ◽  
Environmental Conditions ◽  
Building Materials ◽  
Capillary Rise ◽  
Assessment Tools ◽  
Real Case ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Proposed Model ◽  
Capillary Water Uptake

Water capillary absorption is one of the main water uptake mechanisms in building materials, affecting their overall durability. Thus, the investigation of their capillary rise kinetics can be very useful as regards understanding buildings behavior, contributing to the increase of their durability and their service life. For this reason, a first-order mathematical model was used describing the capillary water uptake under dynamic environmental conditions (different air velocity, air temperature, and relative air humidity) for various natural and artificial building materials. This model successfully fits the experimental data. From the results, it was found that both building materials’ intrinsic characteristics and environmental conditions influence the capillary rise kinetics. In order to assess the validity of the proposed model, a comparison with a similar model was performed. The fitting of the utilized model was more accurate because of the incorporation of the environmental parameters into it. Finally, the proposed model was utilized in order to predict the capillary water uptake under hypothetical extreme weather real-case scenarios. It was found that the proposed model can successfully predict the capillary water uptake under different real-case environmental conditions. The applicability of this semi-empirical model, using parameters with physical meaning, could make it suitable for use in building simulators. This model can contribute to risk assessment tools, dealing with various challenges related to climate change and its effect upon built environment.

Mechanism of long-term capillary water uptake in cementitious materials

2020 ◽  
Vol 106 ◽  
pp. 103448 ◽  
Author(s):  
N.M. Alderete ◽  
Y.A. Villagrán Zaccardi ◽  
N. De Belie
Keyword(s):  
Water Uptake ◽  
Cementitious Materials ◽  
Capillary Water ◽  
Capillary Water Uptake

Numerical Solutions for Capillary Absorption by Cementitious Materials

2011 ◽  
Vol 94-96 ◽  
pp. 1560-1563
Author(s):  
Li Cheng Wang ◽  
Shu Hong Li
Keyword(s):  
Building Materials ◽  
Numerical Solutions ◽  
Capillary Rise ◽  
Cementitious Materials ◽  
Force Balance ◽  
Capillary Absorption ◽  
Wetting Front ◽  
Penetration Process ◽  
Mass Migration ◽  
Gravity Effects

Capillary absorption is essential to mass migration in cementitious materials. Based on previous studies, capillary rise involving gravity effects is of much greater interest in porous building materials because equilibrium is attained at the wetting front when gravitational force balance the capillary force. In this paper, two different solution forms, semi-analytical and numerical, are presented to account for the gravity effect for realistical prediction of water penetration process. The former is stable against small perturbation proved by Stepanyants [1]. The comparison of predicted results by the two methods confirms the reliability of the technique in estimating water transport.

scholarly journals Development of Building Information Modeling Template for Environmental Impact Assessment

2021 ◽  
Vol 13 (6) ◽  
pp. 3092
Author(s):  
Sungwoo Lee ◽  
Sungho Tae ◽  
Hyungjae Jang ◽  
Chang U. Chae ◽  
Youngjin Bok
Keyword(s):  
Environmental Impact ◽  
Performance Assessment ◽  
Environmental Performance ◽  
Building Materials ◽  
Building Information Modeling ◽  
Information Modeling ◽  
Assessment Tools ◽  
Building Information ◽  
Environmental Performance Assessment ◽  
Assessment Results

Eco-friendly building designs that use building information modeling (BIM) have become popular, and a variety of eco-friendly building assessment technologies that take advantage of BIM are being developed. However, existing building environmental performance assessment technologies that use BIM are linked to external assessment tools, and there exist compatibility issues among programs; it requires a considerable amount of time to address these problems, owing to the lack of experts who can operate the programs. This study aims to develop eco-friendly templates for assessing the embodied environmental impact of buildings using BIM authoring tools as part of the development of BIM-based building life cycle assessment (LCA) technologies. Therefore, an embodied environmental impact unit database was developed, for major building materials during production and operating stages, to perform embodied environmental impact assessments. Moreover, a major structural element library that uses the database was developed and a function was created to produce building environmental performance assessment results tables, making it possible to review the eco-friendliness of buildings. A case study analysis was performed to review the feasibility of the environmental performance assessment technologies. The results showed a less than 5% effective error rate in the assessment results that were obtained using the technology developed in this study compared with the assessment results based on the actual calculation and operating stage energy consumption figures, which proves the reliability of the proposed approach.

Capillary water absorption by a porous cylinder

2017 ◽  
Vol 42 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Christopher Hall
Keyword(s):  
Radial Flow ◽  
Effective Porosity ◽  
Capillary Absorption ◽  
Porous Cylinder ◽  
Capillary Water ◽  
Cylinder Axis ◽  
Flow Through ◽  
Front Model ◽  
Sharp Front ◽  
Good Agreement

Capillary absorption (imbibition) of water by a porous cylinder is described by means of a Sharp-Front model. The cumulative absorption increases as (time)1/2 at early times, but more slowly as the wet front approaches the cylinder axis. Results are given in terms of dimensionless variables. Experimental data on plaster cylinders are in good agreement with theory. Estimates of the sorptivity and effective porosity of the material can be obtained. The model may be useful in testing drilled cores and may also be applied to radial flow through the wall of a porous tube (hence to conduits and arches).

scholarly journals Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qi Gao ◽  
Zhiming Ma ◽  
Jianzhuang Xiao ◽  
Fuan Li
Keyword(s):  
Absorption Coefficient ◽  
Water Absorption ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Capillary Absorption ◽  
Capillary Water ◽  
Aggregate Concrete ◽  
Capillary Water Absorption ◽  
Freeze Thaw ◽  
Loading Level

Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.

scholarly journals TECHNOLOGY OF CREATING AND USAGE OF PROECOLOGICAL BLOCK EMPTYSEED

space&FORM ◽  
2021 ◽  
Vol 2021 (47) ◽  
pp. 31-44
Author(s):  
Jan Cudzik ◽  
◽  
Konstancja Olszewska ◽  
Keyword(s):  
Environmental Conditions ◽  
Building Materials ◽  
Environmentally Friendly ◽  
Environmental Safety ◽  
Research Process ◽  
Natural Building

Nowadays, finding natural substitutes for mass-produced materials is one of the main tasks faced by scientists and designers. There is an increasing emphasis on the theme of ecology and the need for sustainability. Variants and methods are sought which will create environmentally friendly materials in a fast, relatively inexpensive and ecological way. The aim of this paper is to present different proposals of natural building materials and to demonstrate the research process in the search for an environmentally friendly facade material, analyzing it in terms of strength, durability and aesthetics. One of the reasons for this is the steadily deteriorating environmental conditions. Thus, architects strive to improve environmental safety.

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