In this article, the results of the hygroscopic characterization of a building material called ‘picón’, consisting of cement mortar and pyroclastic deposits from volcanic eruptions, are presented. The material obtained is used for the manufacture of blocks used in the construction of buildings in the Canary Islands. Picón is a heterogeneous material with uncontrolled particle size, having a pore system of very scattered sizes, what affects the moisture behaviour of the blocks. This heterogeneity results in a pore structure that affects the determination of the moisture properties of the material. In this work, this difficulty is faced, separately studying the pore structure of the cement paste and the aggregates, to come to a better interpretation of the concrete behaviour. The results indicate that the pore structure of the heterogeneous concrete differs from what could be expected from separately obtained porosimetry of each component of the concrete.
Baroghel-BounyV (2007) Water vapour sorption experiments on hardened cementitious materials. Part II: essential tool for assessment of transport properties and for durability prediction. Cement and Concrete Research37(3): 438–454.
2.
BentzDPPeltzMADurán-HerreraA. (2011) Thermal properties of high-volume fly ash mortars and concretes. Journal of Building Physics34(3): 263–275.
3.
BurchDMChoiJ (1997) MOIST: A PC Program for Predicting Heat and Moisture Transfer in Building Envelopes (NIST Special Publication 917). Gaithersburg, MD: National Institute of Standards and Technology, U.S. Department of Commerce.
4.
CarmelietJRoelsS (2002) Determination of the moisture capacity of porous building materials. Journal of Building Physics25: 209–237.
5.
ChatterjiS (2001) A discussion of the paper ‘Mercury porosimetry – an inappropriate method for the measurement of pore size distributions in cement-based materials’ by S. Diamond. Cement and Concrete Research31: 1657–1658.
6.
CookRAHoverKC (1999) Mercury porosimetry of hardened cement pastes. Cement and Concrete Research29: 933–943.
7.
DiamondS (2000) Mercury porosimetry: an inappropriate method for the measurement of pore size distributions in cement-based materials. Cement and Concrete Research30: 1517–1525.
8.
DurnerW (1994) Hydraulic conductivity estimation for soils with heterogeneous pore structure. Water Resources Research30: 211–223.
9.
GalleC (2001) Effect of drying on cement-based materials pore structure as identified by mercury intrusion porosimetry: a comparative study between oven-, vacuum-, and freeze-drying. Cement and Concrete Research31: 1467–1477.
10.
GómezISalaJMMillánJA (2007) Characterization of moisture transport properties for lightened clay brick – comparison between two manufacturers. Journal of Building Physics31: 179–194.
11.
GómezISalaJMMillánJA (2008) Moisture storage properties of multi-slotted light-weight ceramic blocks: comparison between two manufacturers. Journal of Building Physics31: 225–242.
12.
KrusM (1996) Moisture Transport and Storage Coefficients of Porous Mineral Building Materials: Theoretical Principles and New Test Methods. Fraunhofer IRB Verlag.
13.
KrusMHansenKKKünzelHM (1997) Porosity and liquid absorption of cement paste. Materials and Structures30: 394–398.
14.
KumaranMK (1996) Heat, air and moisture transport in envelope parts. Final Report, Task 3 Material Properties, IEA, ECBCS, Leuven.
15.
KunzelHM (1995) Simultaneous heat and moisture transport in building components, one-and two-dimensional calculation using simple parameters. Report, IRB-Verlag Fraunhofer-Institut für Bauphysik, Stuttgart.
16.
NBN B 24-213 (1976) Essais des materiaux de maconnerie. Absorption d’eau sous vide. Brussels: Institu Belge de Normalisation (IBN).
17.
RoelsSCarmelietJ (2006) Analysis of moisture flow in porous materials using microfocus X-ray radiography. International Journal of Heat and Mass Transfer49: 4762–4772.
18.
RoelsSCarmelietJHensH (2003) HAMSTAD, WP1: Final Report Moisture Transfer Properties and Materials Characterization (HAMSTAD Document KUL2003-h18). Leuven: KU Leuven.
19.
RoelsSCarmelietJHensH. (2004) Interlaboratory comparison of hygric properties of porous building materials. Journal of Building Physics27(4): 307–325.
20.
RoelsSElsenJCarmelietJ. (2001) Characterisation of pore structure by combining mercury porosimetry and micrography. Materials and Structures34: 76–82.
21.
Sánchez FajardoVMTorresMEMorenoAJ (2015) Hydraulic and hygrothermal properties of lightweight concrete blocks with basaltic lapilli as aggregate. Construction and Building Materials94: 398–407.
22.
SongHWKwonSJ (2007) Permeability characteristics of carbonated concrete considering capillary pore structure. Cement and Concrete Research37(6): 909–915.
23.
UNE-EN ISO 12571:2015 (2015) Hygrothermal performance of building materials and products – determination of hygroscopic sorption properties (ISO 12571:2013).
24.
WildS (2001) A discussion of the paper ‘Mercury porosimetry – an inappropriate method for the measurement of pore size distributions in cement-based materials’ by S. Diamond. Cement and Concrete Research31: 1653–1654.
25.
WinslowDNCohenMD (1994) Percolation and pore structure in mortars and concrete. Cement and Concrete Research24(1): 25–37.
26.
WinslowDNLiuD (1990) The pore structure of paste in concrete. Cement and Concrete Research20(2): 227–235.
27.
WuMJohannessonBGeikerMR (2014) A study of the water vapor sorption isotherms of hardened cement pastes: Possible pore structure changes at low relative humidity and the impact of temperature on isotherms. Cement and Concrete Research56: 97–105.
