Knee Point Detection in Water Absorption Curves: Hygric Resistance in Multilayer Building Materials

Author(s):  
A. C. Azevedo ◽  
J. M. P. Q. Delgado ◽  
A. S. Guimarães ◽  
I. Ribeiro ◽  
R. Sousa
Author(s):  
Herinjaka Haga Ratsimbazafy ◽  
Aurélie Laborel-Préneron ◽  
Camille Magniont ◽  
Philippe Evon

The valorization of available agricultural by-products is important for the development of bio-aggregate based concretes as eco-friendly solutions for building materials. However, their diversity requires to assess their potential of use in vegetal concretes. This study aims to propose simple and relevant multi-physical characterization methods for plant aggregates. Basic and complementary characterizations were carried out on hemp shiv as a reference plant aggregate, and nine by-products available in the South-West part of France, i.e., oleaginous flax shiv, sunflower pith and bark, coriander straw, wheat straw, wheat chaff, corn shuck, miscanthus stem and vine shoot. The basic characterizations performed were those recommended by the TC-RILEM 236 BBM, i.e., particle size distribution, bulk density, water absorption and thermal conductivity. Complementary characterizations have also been proposed, taking into account the possible environment of the binder and the vegetal concrete manufacturing method. The additional tests developed or adapted from previous research assess the following properties: the content of water-soluble compounds at pH 7 and 12, the dry density of plant aggregates compacted in wet state, the real water absorption after compaction and the compression behavior of these compacted aggregates. This complete characterization highlights the distinct behavior of the different agroresources and allows to correlate these characteristics to the use properties of hardened composites.


1970 ◽  
Vol 43 (2) ◽  
pp. 197-206
Author(s):  
MK Alam ◽  
MN Islam ◽  
MA Zaman

Neutron radiography (NR) technique has been adopted to study homogeneity and water absorption behavior of building materials, like double layer silver gray tiles obtained from Concord Real Estate & Building Products, Unit II, Salna, Gazipur, Dhaka, Bangladesh. Measurements of optical density differences between the film background and radiographic images of the dry/wet samples were used for investigation of the present work. The optical density was measured by using the digital optical densitometer (Model 07-424, S-23285, Victoreen Inc. USA). Large variation in optical density values of the radiographic image was observed. From this observation it shows that the rate of water absorption of the tiles increases with increase of immersion time. Through the investigation of radiographic image and subsequently analyzing the optical density we observed that distribution of the elements in the tiles are inhomogeneous. Key words: Homogeneity, Water absorption, Silver gray, Neturon radiography.DOI: 10.3329/bjsir.v43i2.963 Bangladesh J. Sci. Ind. Res. 43(2), 197-206, 2008


Cerâmica ◽  
2019 ◽  
Vol 65 (373) ◽  
pp. 153-161 ◽  
Author(s):  
H. M. Khater

Abstract Production of lightweight building materials attract the attention of the scientists worldwide with the need for reducing the structure deadweight, provide better thermal insulation for buildings, and cost less to transport. The current work focused on the production of lightweight geopolymer composites by the incorporation of aluminum powder and aluminum slag in various ratios for water-cooled slag/kaolinite sand composite; the activators used were 6% of equal ratio from sodium hydroxide and sodium silicate. The properties of the produced lightweight geopolymer composites were studied by measurement of compressive strength, bulk density, water absorption, FTIR, XRD and SEM imaging. Results showed the enhancement for both physicomechanical and microstructural characteristics with using aluminum powder and aluminum slag forming lightweight composites with densities below 2.15 g/cm3 depending on the studied mix composition.


1997 ◽  
Vol 3 (3) ◽  
pp. 219-234
Author(s):  
M. Krus ◽  
A. Holm ◽  
Th. Schmidt

Abstract Computer calculations are of increasing importance for the assessment of moisture balance in building components, since modern calculation methods achieve good agreement with measurements. A broader application of these methods is hampered, however, by the laborious measurements needed to determine the capillary transport coefficients essential for the calculations. A new method is therefore presented which allows to estimate the coefficients from wellknown standard material properties (free capillary saturation, practical moisture content and water absorption coefficient). These coefficients are sufficient for estimative assessment of the moisture balance of many materials, as is demonstrated by comparison of suction profiles calculated in this way and measured profiles.


2017 ◽  
Vol 13 ◽  
pp. 85
Author(s):  
Barbora Mužíková ◽  
Tereza Otcovská ◽  
Pavel Padevět

This article presents the development of mass moisture of rammed earth material and determines the water absorption capacity coefficient for rammed earth with illite-kaoline clay. Specimens of two prescriptions were rammed in the moulds. They were settled in the box with soft foam that was moistened. The level of moistening was kept constant. The specimens were regularly measured and weighted. Two measuerements were carried out – one of montmorillonite clay during 13 days and one of illite-kaoline clay during three hours. The development of moisture increase was captured and the water absorption capacity coefficient for illite-kaoline clay was determined and compared to coefficients of common building materials.


2020 ◽  
Vol 857 ◽  
pp. 48-55
Author(s):  
Asaad Al-Omari ◽  
Suhail I.A. Khattab

Al-Hadba minaret is one of the ultimate minarets in beauty and excellence that belonged to the constructions of Zankid dynasties in Syria and upper Mesopotamia. The minaret was built during the 12th entury, it is located in the center of old Mosul city-Northern Iraq. This minaret is the most famous in the Middle East, since it has a significant curvature (banana shape) that threatens its integrity. Unfortunately, the main parts of this monument were destroyed during the last military operations in 2017. Nowadays, there are serious attempts to reconstruct the minaret. The objective of this study is to characterize the original bricks, one of the main building materials of the minaret, in an attempt to complete planning preparations for returning to Mosul its historic value. In this research, the ancient bricks were characterized under different laboratory tests including the determination of skeletal density, porosity, free water absorption, forced water absorption, water retention capacity, capillarity parameters and uniaxial compressive strength. It is expected that the information obtained from this study can be helpful in providing the important knowledge for selecting the suitable and compatible material for the future reconstruction and maintenance works.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Valdir M. Pereira ◽  
Gladis Camarini

Self-leveling mortar (SLM) has several advantages when compared to the conventional mortar used in subfloors, especially when productivity is desired. In Brazil, the use of SLM is not still widespread related to conventional mortar. Few builders are using it in constructions. In the same way, the sustainable reuse of wastes in building materials is not so great, but it has grown, becoming increasingly important. In Brazil, a great amount of waste is generated by the manufacture of electrical porcelain insulators and red ceramic. These materials are formed mainly by amorphous silicates and aluminosilicates, which when added as cement replacement can generate pozzolanic reactions. The present study evaluated the feasibility of using such wastes to replace cement to make SLM. Mortars were studied in the fresh state (fluidity, segregation and/or bleeding, outflow rate, outflow time, and kinetics of temperature) and in the hardened state (compressive strength, flexural tensile strength, capillary water absorption, water penetration height, and air permeability). According to the results, the cement replacement by porcelain or ceramic in SLM diminishes the flow and increases the setting time. The compressive strength is higher than the minimum related to literature, and the low values of water absorption and permeability were reached with porcelain waste.


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