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Towards sustainable construction: Harnessing potential of pumice powder for eco-friendly concrete, augmented by hybrid fiber integration to elevate concrete performance
(2024-12-01)
Farooq, Umar
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Rizwan, Muhammad
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Khaliq, Wasim
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Ejaz, Ali
;
Saingam, Panumas
This study investigates the innovative use of industrial waste pozzolana, specifically pumice powder (PP), as a partial replacement for cement, combined with hybrid fibers in concrete. Seven formulations varying PP content from 10 % to 35 % were tested, identifying 15 % PP as optimal. PP improved porosity due to its fineness, leading to better homogeneity, a refined microstructure, and an optimum compressive strength of 28.8 MPa with reduced permeability, enhancing durability. Hybrid fibers, including steel fibers (SF) from waste tires and polypropylene fibers (PF), improved toughness, ductility, and resistance to brittle failure. Tests on hybrid fiber-reinforced concrete (HyFRC) mixes with 1 % and 2 % hybrid fibers showed up to an 18.09 % increase in compressive, tensile, and flexural strengths. Energy dissipation in compressive response improved by 544.20 %, while flexural and splitting responses increased by up to 299.65 % and 208.57 %. Durability assessments in hydrochloric (HCl) and sulfuric acid (H<inf>2</inf>SO<inf>4</inf>) exposure revealed the synergy of fibers and PP enhanced resistance to chemical degradation, with high PF mixes losing as little as 0.04 % strength. Scanning electron microscopy (SEM) confirmed a dense, well-bonded matrix with reduced porosity. Analytical characterizations of mixtures such as energy dispersive x-ray spectroscopy (EDX) were studied. Regression models developed using Popovic's and Mander's models, accurately predicted HyFRC stress-strain behavior, closely aligning with experimental results. The integration of PP and hybrid fibers not only improved mechanical properties but also extended service life in harsh environments, offering a cost-effective, sustainable concrete solution.
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Effect of para-wood ash and calcium carbonate on the properties of eco-friendly self-compacting mortar reinforced with electronic waste fibers
(2024-10-15)
Makul, Natt
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Hussain, Qudeer
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Nawaz, Adnan
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Saingam, Panumas
;
Sua-iam, Gritsada
This paper deals with reducing CO<inf>2</inf> emissions from cement production and finding alternative uses for electronic waste (E-waste) fibers in some innovative applications in self-compacting mortar (SCM). In the present research, an attempt has been made to establish the optimum incorporation of E-waste fiber into SCM by varying the fiber content from 5 % to 25 %, combined with para-wood ash and calcium carbonate as supplementary cementitious materials. In this laboratory study, the mix design had a constant water-to-powder ratio of 0.35 and a cement content of 550 kg/m³. Additionally, 20 % of the cement volume was replaced by 10 % para-wood ash and 10 % calcium carbonate. The results indicated a continuous increase of the mini-slump values from 255 mm for the control mix to 270 mm for the mix with the highest fiber content. Mini V-funnel flow times increased from 3.63 to 8.83 s as the fiber content increased. Lower fiber contents of 5 % improved compressive strength because they had a reinforcing role in the matrix of SCM besides the microcrack-bridging role. Higher contents of 10–25 % decreased the strength due to the clustering of fibers and resulting voids. SEM analysis at 28 days showed increased voids with higher percentages of E-waste fibers and para-wood ash alone. The results underline that optimizing fiber content is critical in balancing workability and mechanical properties, and 5 % e-waste fiber content can be considered optimal for enhancing the performance of SCM. This work also creates part of sustainable construction practice with the green solution required to reduce CO<inf>2</inf> emissions and work accumulation against E-waste.
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Destructive and nondestructive characteristics of solidified reservoir sediments incorporating microstructural analyses
(2022-08-01)
Jamsawang, Pitthaya
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Poorahong, Hatairat
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Jongpradist, Pornkasem
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Likitlersuang, Suched
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Chaiyaput, Salisa
Reservoir sediments create a range of severe problems for hydropower dams. Although reservoir sediments can be excavated, nonetheless, sizeable dumping lands for such excavated sediments are unavailable at this time. This paper presents an experimental investigation of the destructive and nondestructive properties and microstructural characteristics of reservoir sediments solidified with fly ash–cement blend for reuse as construction materials. The obtained natural sediment was classified as well-graded sand with silt. The destructive experiments comprised unconfined compression, indirect tension, California bearing ratio, resilient modulus, and durability against wet–dry cycle tests, while the nondestructive experiments included a free–free resonance test. Microstructural investigations consisting of X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectrometry were performed to verify the macroscale test results. The results showed that fly ash–cement blend exhibited increased strength values on the order of 2 to 9 times that of unsolidified sediments. Using fly ash-blended cement was more effective than using sole cement or sole fly ash, and mixtures with 10% fly ash delivered the best strength and modulus values. Various functional empirical correlations were proposed. Utilizing six wet–dry cycles is acceptable because the strength of the samples subjected to the six wet–dry cycles was lower than the given value. The results of the peak intensities of calcium silicate hydrate, mass losses, calcium contents, and scanning electron microscopy images derived from the microstructural investigations confirmed the macroscale test results.
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Swine house floor durability enhancement using Pozzolan-containing concrete mix designs
(2021-01-01)
Lapcharatsangroj, L.
;
U-Tapao, C.
This research investigates the effect of pozzolanic materials on the performance of swine house concrete floor. The experimental pozzolans are fly ash (FA) and silica fume (SF), and the performance metrics are compressive strength, abrasion resistance, and resistance to lactic and sulfuric acids. There are nine experimental concrete mix designs: concrete without floor hardener (conventional concrete or non-CFH), concrete with floor hardener (CFH), concrete with 15%, 30%, 45% fly ash, and concrete with silica fume and fly ash (CSF4FA26, CSF6FA24, CSF8FA22, CSF10FA20). In acid resistance tests, a groove was cut across the specimen surface to simulate floor spallation. The results showed that the CFH floor had the highest abrasion and acid resistance but suffered from severe acid damage under spallation conditions. Meanwhile, the CSF10FA20 floor had the highest compressive strength and acid resistance under spallation conditions. The statistical analysis indicated that the pozzolanic materials significantly improved the performance metrics of concrete mix designs (p<0.05), compared with the non-CFH mix design (control). The construction costs of CSF-FA floors (THB 118 – 121) and non-CFH floor (THB 116) were comparable, but they were considerably lower than that of CFH floor (THB 196). The acid resistance of CSF-FA floors was higher than that of non-CFH and CFH floors. As a result, the CSF-FA concrete mix designs should be adopted for the construction of swine house floor due to longer durability and better investment return, in comparison with non-CFH and CFH floors which are commonly used in small- and industrial-scale swine farms.
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