Porosity estimation and pore structure characterization of foamed cement paste using non-specialized image digital processing

Abstract

In foamed concrete, porosity is essential because it is strongly related to other properties such as density, permeability, and strength. Porosity measurement (usually expressed as a percentage of total volume) is obtained in a laboratory using experimental water vacuum saturation and MIP methods. However, pore structure -including size, distribution, shape, and connection- is also needed to understand foamed concrete performance. Pore structure characterization is estimated through specialized digital image analysis. Micro CT, scanning electron microscopy or X-ray tomography images are frequently used to obtain pore structure on cellular concrete. However, these images are highly specialized and require equipment that is not easy to find and very expensive. Also, image processing is complex, and it includes some specialized software. This paper presents a pore structure characterization and porosity estimation using non-specialized digital images on foamed cement paste made with alternative agents. The procedure for acquiring images uses only a camera without any specialized equipment. The proposed methodology isolates the pores in the image and measures shape features such as pore diameter, eccentricity, and solidity. Acquiring and processing the images is simpler, faster, and cheaper than other specialized analyses. Results show that the volumetric porosity estimation was entirely accurate, with an estimation deviation of less than 10%. Also, the pore structure parameters such as pore size and distribution of foamed pastes can be quantified accurately.

Challenges in Foamed Concrete: Exploring Alternative and Sustainable Materials – A Comprehensive Review

“…There are many studies aimed at providing guidelines for expected mechanical properties of foamed concrete compared with density and processing (4,38,39). In the same wavelength, others studies focus on compression properties affected by pore construction (8,(39)(40)(41)(42)(43), which modifies the cementitious matrix and plays a crucial role in dry. In all cases, the binder must hold the components together, and any change determines the material's behavior under service conditions.…”

Study on geopolymer recycled foam concrete based on waste wood flour and its engineering performance

“…According to an actual case [28], foam may be a good choice to further improve the thermal insulation and reduce the bulk density of concrete prepared using biomass aggregates to fill some of the original defects in concrete.In addition, foam concrete prepared using different foaming agents can enhance the thermal insulation effect and improve the degree of bonding between cement and foam to varying degrees [29][30][31][32]. Furthermore, it is necessary to pay attention to the mechanical failure stage and strength of the foam itself after it forms a skeleton structure [33,34].…”