Papers by Keyword: Permeability

Abstract: In Lima, many concrete structures experience accelerated deterioration due to physical and chemical factors, limiting their durability. This study evaluates the effect of recycled glass powder (RGP) and a nanosilica additive (1.5 %) on concrete with f’c = 27.5 MPa (280 kg/cm²), focusing on optimizing its mechanical properties, durability, and economic feasibility. Mixtures with 10 %, 15 %, and 20 % cement replacement by RGP were prepared, assessing compressive, tensile, and flexural strength, as well as permeability and water absorption. The mixture with 10 % RGP (RGP-10) showed the best early age mechanical performance, increasing compressive strength by 39.1 %, tensile strength by 12.7 %, and flexural strength by 26.2 % compared to the concrete control. Mixtures with 15 % and 20 % RGP showed lower initial strength, although future gains are expected due to delayed pozzolanic reactions. Regarding durability, RGP-10 reduced permeability by 9.02 % and water absorption by 6.45 %, while RGP-15 and RGP-20 achieved even greater reductions, with permeability decreasing by 11.48 % and 9.84 %, and water absorption by 8.68 % and 10.56 %, respectively. Although the nanosilica additive increases the initial cost, its combination with RGP produces significant improvements in mechanical properties and durability, contributing to a reduction in maintenance related costs, resulting in a durable, sustainable, and economically viable material.

Abstract: Understanding how oil and water interact at the surface level is essential for enhancing crude oil recovery, particularly in Enhanced Oil Recovery (EOR) techniques. This study explores the effects of three types of nanoparticles, aluminum oxide (Al₂O₃), zinc oxide (ZnO), and silica-coated iron oxide (Fe₃O₄@SiO₂) on key interfacial properties such as wettability and interfacial tension. Using a sand pack displacement setup under controlled flow conditions, nanofluids were prepared at concentrations ranging from 0.1 wt% to 0.5 wt% and evaluated for their dynamic viscosity and permeability characteristics. Results showed that ZnO reached the highest viscosity at 1.694 cP (0.5 wt%), while Fe₃O₄@SiO₂ recorded the lowest at 0.995 cP (0.1 wt%). Interestingly, permeability increased with viscosity, contrary to conventional expectations, with ZnO achieving a peak of 90 mD. Oil recovery also improved with higher nanoparticle concentrations. Al₂O₃ delivered the best performance at 0.5 wt%, recovering 27 mL of oil, followed by ZnO (24 mL) and Fe₃O₄@SiO₂ (15 mL). These findings underscore the importance of selecting the right nanoparticle type and concentration to improve EOR performance, with Al₂O₃ showing the most promise for enhancing both permeability and displacement efficiency.

Abstract: This research explores the feasibility of incorporating dust stone into cement gravel columns to enhance their mechanical properties and sustainability profile. A series of laboratory experiments including unconfined compressive strength (UCS) and permeability tests were carried out. 15 mixture designs were prepared to investigate the effect of stone dust (5-20% of cement and 0, 5, 10, 15, and 20% by weight of highest porous sample) on volume fractions of CG samples on engineering and physical properties of cemented gravel samples, at 7 and 28 days. The findings indicate that the ideal proportion of stone dust is 10%, which significantly enhances the compressibility of the CG mixture while preserving satisfactory permeability. The finding indicates that stone dust is a feasible and efficient additive for improving the performance of cement gravel columns in civil engineering applications. Moreover, stone dust provides sustainability advantages by minimizing waste production and contributing to a circular economy.

Abstract: During the research study focused on 100-year-old concrete bridges, a couple of them were found with a very low carbonation depth under an ordinary cement-based protective render coat (PRC). Phenolphthalein test showed at this place carbonation depth up to 2 mm. Bridge concrete was carbonated up to 80 mm, when a PRC spalled up. Close correlation between the surface permeability of a PRC estimated by the Torrent method and the carbonation depth of the base concrete beneath it, was observed. Most of the PRCs appeared to be almost impermeable showing the coefficient of permeability below 0.01 × 10^-16 m². The field experiments were replaced by those of laboratory-made aiming to a PRC development from currently available materials. For this purpose, material composition and rheological optimization of the PRCs were suggested and relevant tests performed. The PRCs applied to a surface of concrete panel were tested for permeability (Torrent method), adhesion (target) and crack propagation. The resistance to carbonation of the plain concrete C8/10 strength class according to EN 206 + A2 and those of PRC-protected were verified by an accelerated carbonation in 20 °C/60 % R.H./20 % vol. CO₂-exposure. By contrast, dry-air cure served as a reference cure. This article is mainly focused on the laboratory tests evaluation and explanation of the observed low carbonation of the base concrete covered by a PRC.

Abstract: In this paper, a numerical study of fluid flow through perforated panels with square holes and open-cell material with cubic cells is presented. Structures with a wide variety of porosities (0.15<φ<0.94) and Reynolds numbers (0.01<Re<6000) are studied. Among the various outcomes obtained, the results indicate that pressure gradient vs Reynolds number exhibits three different forms of variation, including linear (Re<1), nonlinear (1≤Re<4000), and one where the pressure gradient is virtually constant with the Reynolds number (Re≥4000). The results were provided in terms of loss factor, but also of intrinsic permeability and the Forchheimer coefficient. Relationships that connect porosity to the loss factor, intrinsic permeability, and Forchheimer coefficient are also presented. These findings may prove useful in better understanding the flow behaviors in perforated panels and cell metal foams, which have a wide range of applications.

Abstract: 3D printing technology has gained popularity among researchers since it can produce complex geometries, such as open-cell foam. The open-cell foam shows potential in a range of applications such as energy absorption, thermal management, filtering, and acoustic damping. However, the feasibility of the applications depends on the material used to construct the 3D printed open-cell foam and its physical properties e.g, pore size and porosity. Therefore, understanding the physical properties is crucial in classifying this new generation of open-cell foams. This study aims to determine the permeability of 3D printed foams using the Forchheimer equation and compared the results with a fractional estimation method to reduce the duration of future experiments. The fractional results were validated through computational fluid dynamics (CFD) simulations. The result shows that the proposed estimation method can be used to determine the permeability of 3D printed foam with a height of 60 mm or larger, and up to six times larger than 5 PPI (pores per inch). However, it is recommended to conduct simulations of large pore size foam using a 3D model to accurately describe the local velocities in the free stream region.

Abstract: The use of waste materials as a substitute for natural aggregate has been widely tested in all areas of the construction industry. Yet, there is a lack of study on the suitability of the physical properties of waste material when used as one of the components in track ballast. This study evaluates the suitability of conventional ballast (CB) incorporated with concrete debris (CD) and bottom ash (BA) as track ballast material. To achieve the objective, sieve analysis, shape analysis, specific gravity test, water absorption test, and permeability test were carried out. Furthermore, microscopic analysis was used to validate the presence of voids. The result shows that the waste mixed ballast has a coefficient of uniformity (Cu) in the range of 1.92 to 12, a coefficient of curvature (Cc) in the range of 0.8 to 1.18, fines less than 14 mm account for 0.1 % to 28 %, and the mean size is in the range of 22.5 mm to 27.5 mm. Furthermore, the flakiness ranged from 7.56% to 22.5%, the void ratio was 0.43 to 0.55, and water absorption was 2.86% to 4%. The specific gravity was found to range from 2.30 to 2.77 when the permeability measurement was in between 30 cm/sec to 61 cm/sec. All these promising values of engineering properties exhibit the confidence of a suitable alternative to track ballast materials. Hence, CD and BA waste materials incorporated into conventional ballast have a high potential to exhibit better performance and reduce the dependency on natural aggregate.

Abstract: The effect of hydraulic fracturing on the permeability and fluid flow of various Iraqi oil storage cores has been studied. Rumaila, Majnoon, and Zubair fields with different permeability were included in this study. Experiments were performed to determine the breaking pressure of the permeable core. Therefore, numerical and experimental results were compared to test the constant pressure on the impermeable core. Finite Volume Method (EbFVM) corresponding to the Dual Porosity Dual Permeability Model (DPDP) was used. A fractured reservoir in the Iraqi fields was studied for its single-phase fluid flow behavior. To represent the pressure distributions, ANSYS-CFX program was used. The comparisons between the fractured and non-fractured cores has been presented. In this paper, the pressure for permeable cores of Rumaila field has been determined and verified during the experimental and numerical simulation due to its lower fracture pressure. Hence, the required pressure has been determined for impermeable cores of Majnoon and Zubair fields due to the difficulties to measure such high pressure. The results show that the expected pressure to make a flow for the core belongs to the Majnoon field reaches to 1.724×107 Pa (2500 psi), while the expected pressure for the fluid to flow into the core belongs to the Zubair field reaches 1.379×108 Pa (20000 psi).

Abstract: A surface layer of permeable bituminous mixture has been laid on an existing pavement section. This layer, in addition to providing the pavement with draining characteristics and acoustic comfort, incorporates a residue that is difficult to apply, the ladle furnace steel slag. The tests carried out show that the designed mixture meets the requirements in terms of mechanical properties, resistance to the action of water, and porosity. Furthermore, in-situ tests on the completed layer demonstrate its excellent permeability, as well as a surface texture suitable for use on roads and highways. The introduction of the ladle furnace slag makes it possible to design a high-performance, but also environmentally sustainable, mix.

Abstract: The application of bamboo by-products such as bamboo branches, chips to recycle and produce pressed bamboo pulp is an urgent task in Vietnam. It perfectly replaces natural wood with artificial wood embryos from bamboo powder, which has both economic benefits of reserving the source of raw materials, environmental protection... The paper presents a study of the influence of technological parameters on the water absorption and swelling thickness of pressed bamboo pulp plywood in order to ameliorate the quality of pressed bamboo pulp plywood in production of new materials for civil engineering with environmentally friendly bamboo wood pulp materials.