Wpływ czasu utwardzania na wydajność betonu na bazie scorii wulkanicznej

The objective of the presented paper is to investigate the performance of concrete containing volcanic scoria as cement replacement after 7, 28, 90, and 180 days curing. Five performance indicators have been studied. Compressive strength, water permeability, porosity, chloride penetrability, and reinforcement corrosion resistance have all been evaluated. Concrete specimens were produced with replacement levels ranging from 10 to 35%. Test results revealed that curing time had a large influence on all the examined performance indicators of scoria-based concrete. Water permeability, porosity, and chloride penetrability of scoria-based concrete mixes were much lower than that of plain concrete. Concretes produced with scoria-based binders also decelerated rebar corrosion, particularly after longer curing times. Furthermore, an estimation equation has been developed by the authors to predict the studied performance indicators, focusing on the curing time and the replacement level of volcanic scoria. SEM/EDX analysis has been reported as well.W Syrii znajdują się ważne obszary wulkaniczne o szacowanych rezerwach wynoszących około trzy czwarte miliardów ton wulkanicznej scorii. Jednakże, ich potencjalne zastosowanie w produkcji betonu nie jest powszechnie znane. Powszechnie uznaje się, że jakiekolwiek zwiększenie wydajności konstrukcji żelbetonowych zwiększa stabilność branży budowlanej. Prawdopodobnie jednym z najskuteczniejszych podejść jest zastąpienie pucolanów częścią cementu portlandzkiego. Wytrzymałość betonu jest powszechnie uważana za jego najcenniejszą właściwość, chociaż jego inne właściwości, takie jak trwałość i przepuszczalność, mogą być w rzeczywistości ważniejsze. Obecnie uważa się, że korozja indukowana chlorem jest najpoważniejszym mechanizmem niszczenia konstrukcji żelbetonowych. Korozja stali zbrojeniowej jest istotnym problemem spotykanym w branży budowlanej w Syrii, zwłaszcza w środowiskach przemysłowych i morskich. Wiele konstrukcji żelbetonowych zetknęło się z tym zjawiskiem, co znacząco skróciło ich żywotność. Celem niniejszej pracy jest zbadanie wpływu wykorzystania scorii wulkanicznej jako zamiennika cementu, w odniesieniu do niektórych właściwości użytkowych cementu. W szczególności zbadano wytrzymałość na ściskanie, przepuszczalność wody, porowatość, przenikalność chlorków i odporność na korozję zbrojenia osadzonego w betonie zawierającym cement na bazie scorii, po utwardzaniu przez 7, 28, 90 i 180 dni

Producción de hormigones más durables y sostenibles utilizando escoria volcánica como sustitutivo de cemento

The objective of the study is to investigate strength and durability-related properties of volcanic scoria-based cements. Compressive and tensile strength development of mortars and concretes containing volcanic scoria with replacement levels ranging from 10 to 35% was investigated. Water permeability, chloride penetrability and porosity of concretes cured for 2, 7, 28, 90 and 180 days were also examined. Results revealed that volcanic scoria could be suitable for making blended cements. The strength of mortar/concrete containing volcanic scoria was lower than that of plain cement mortar/concrete at all ages. However, at 90 day curing, the strengths of volcanic scoria-based mortars/concretes were comparable to those of plain cement. In addition, water permeability, chloride penetrability and porosity of scoria-based concretes were much lower than those of plain concrete. Further, the results were statistically analysed and estimation equations have been developed to predict the studied properties. SEM/EDX analysis was employed, as well.El objetivo del estudio fue investigar la resistencia y durabilidad de cementos basados en escoria volcánica. El desarrollo de resistencias a flexión y compresión, se estudió en morteros y hormigones con escoria volcánica en porcentajes de reemplazo desde 10 al 35%. Se realizaron ensayos de permeabilidad al agua, penetración de cloruros y porosidad de los hormigones a las edades de 2, 7, 28, 90 y 180 días. Los resultados revelaron que la escoria volcánica podría ser adecuada para la fabricación de cementos con adiciones. La resistencia de morteros/hormigones que contiene escoria volcánica fue menor que la de los correspondientes morteros u hormigones sin adición a todas las edades. Sin embargo, a los 90 días de curado, las resistencias de los morteros/hormigones con escoria fueron comparables con las del cemento sin adición. La permeabilidad al agua, penetrabilidad de cloruros y porosidad de los hormigones con escoria fueron mucho más bajos que los del correspondiente hormigón sin escoria. Los resultados se analizaron estadísticamente y las ecuaciones de estimación se han desarrollado para predecir las propiedades estudiadas. También se empleó el análisis SEM/EDX

Effects of Curing Time on the Performance of Volcanic Scoria-Based Binder Concretes

The objective of the presented paper is to investigate the performance of concrete containing volcanic scoria as cement replacement after 7, 28, 90, and 180 days curing. Five performance indicators have been studied. Compressive strength, water permeability, porosity, chloride penetrability, and reinforcement corrosion resistance have all been evaluated. Concrete specimens were produced with replacement levels ranging from 10 to 35%. Test results revealed that curing time had a large influence on all the examined performance indicators of scoria-based concrete. Water permeability, porosity, and chloride penetrability of scoria-based concrete mixes were much lower than that of plain concrete. Concretes produced with scoria-based binders also decelerated rebar corrosion, particularly after longer curing times. Furthermore, an estimation equation has been developed by the authors to predict the studied performance indicators, focusing on the curing time and the replacement level of volcanic scoria. SEM/EDX analysis has been reported as well

Study on the optimum nano-natural pozzolan content in the concrete binder

Abstract The objective of this study is to investigate the optimum nano-natural pozzolan (NNP) content in the NNP-based binder concrete. NNP was obtained by grinding a local volcanic scoria for six hours. Twenty-four concrete mixes with four w/b ratios (0.4, 0.5, 0.6 and 0.7) and six-replacement levels of NNP (0%, 1%, 2%, 3%, 4%, and 5%) have been produced. The investigated concrete properties were the compressive strength, the water penetration depth, the concrete porosity and the chloride ion permeability. The efficiency factor (k) of NNP in terms of compressive strength was calculated using the Bolomey equation. Durability indicators have been used to globally evaluate the behavior of NNP-based binder concrete versus control concrete. The results revealed that the efficiency factor (k) decreased to some extent when the NNP content was more than 4%. The calculated durability indicators showed that NNP contents of 3-4% had approximately the highest indicators values. These indicators would be helpful for concrete mix designers. Some correlations between the investigated properties were derived from the analyzed data. The modification of the microstructure of NNP-based cement paste has been observed, as well.</jats:p

Datainbrief-21.05.2022-all results-revised

The excel sheets are results of experimental tests conducted by the author. Water permeability and chloride ion penetrability tests were conducted after 5 curing times; namely 2, 7, 28, 90 and 180 days. Concrete mixtures were prepared with six replacement levels of nano volcanic scoria; namely 0%, 1%, 2%, 3%, 4% and 5%, four water/binder ratios, namely 0.4, 0.5, 0.6 and 0.7. Volcanic scoria was ground to 2 different sizes; i.e. 100 &amp; 500 nm.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Datainbrief-03.05.2022-all results

The excel sheets are results of experimental tests conducted by the author. Water permeability and chloride ion penetrability tests were conducted after 5 curing times; namely 2, 7, 28, 90 and 180 days. Concrete mixtures were prepared with six replacement levels of NNP; namely 0%, 1%, 2%, 3%, 4% and 5%, four water/binder ratios, namely 0.4, 0.5, 0.6 and 0.7. NP was ground to 2 different sizes; i.e. 100 &amp; 500 nm.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Thermally Treated Clay as a Stabilizing Agent for Expansive Clayey Soil: Some Engineering Properties

The objective of this research was to investigate the effect of adding thermally treated clay on some engineering properties of the untreated expansive clayey soil. Three expansive clayey soil samples obtained from three different sites in the south of Syria have been investigated. They were thermally treated up to three different levels (450°C, 650°C and 850°C) for 3 hours. Three replacement levels of thermally treated clay were used, i.e. 0%, 10% and 20%. The X-ray diffractometer (XRD) technique has been used to detect the crystalline and glassy phase in the clayey samples before and after the thermal treatment. Pozzolanic activity of the thermally treated clayey soil has been studied using the modified Chapelle test and the mechanical strength test at each of the temperature levels. Atterberg limits, compaction, free swell, swelling pressure and linear shrinkage have particularly been investigated. Test results revealed the positive effect of thermally treated clay when added to the natural soil. Plasticity index (PI) was reduced by about 60% when 20% thermally treated clay was added to the natural soil. In addition, 6% lime was added to further investigate the combined effect of lime and calcined clay on the properties of the clayey expansive soil. All investigated properties were significantly improved when 20% thermally treated soil and 6% lime were added together. For instance, swelling pressure and linear shrinkage values were reduced to less than 15% or even much less when compared with those of the natural soil. Scanning electron microscopy (SEM) and energydispersive X-ray (EDX) analysis were employed as well

Corrigendum: Effect of adding nano-calcined clay and nano-lime on the geotechnical properties of expansive clayey soil (IOP Conf. Ser.: Mater. Sci. Eng. 615 012058)

This corrigendum corrects the following error. There was a missing reference in the reference list. This has been included as reference 18. [18] Al-Swaidani A M, Hammoud I., al-Ghuraibi I and Mezyab A 2019 Nanocalcined clay and nanolime as stabilizing agents for expansive clayey soil: Some geotechnical properties Advances in Civil Engineering Materials 8(3) 327-345 [19] Gueddouda M K, Goual I, Lamara M and Mekarta B 2011 Chemical stabilization of expansive clays from Algeria Global J. of Researches in Engineering: J. General Engineering 11(5) 1-8 Reference 18 should have been referred to at the following points. [20] Kariuki PC, Shephered K D and Van Der Meer F D 2006 Spectroscopy as a tool for studying swelling soils. In: alRawas AA, Goosen, MFA editors Expansive soils-recent advances in characterization and treatment 15-24 (London, UK: Taylor and Francis Group) Table 1. The reference [18] should have been indicated in the caption Figure 2(a), Figure 2(b) and Figure 2(c). The reference [18] should have been indicated. Figure 7 the reference [18] should have been indicated. The reference (Gueddouda et al.) numbered as 18 in the older copy was corrected to 19. See the selection of the reference list above. Figure 8 should include a reference to [18]. Figure 9. The reference [18] should be indicated. The reference (Kariuki et al.) numbered 19 in the older copy was corrected in this version to 20. See attached reference list above. Table 4. The reference [18] should have been indicated References list Reference [18] was added in this version. See above list.</jats:p

Effect of adding nano-calcined clay and nano-lime on the geotechnical properties of expansive clayey soil

Abstract The objective of this paper is to investigate the effect of nano-calcined clay (NCC) and nano-lime (NL) on some engineering properties of the expansive clayey soil. Three soil samples quarried from three different sites in the south of Syria have been investigated. They were thermally treated up to three different levels (450, 650 and 850°C) for 3 hours. Then, they were ground to have a particle size of less than 100 nano-meter. Three replacement levels of NCC were used, i.e. 0%, 1% and 2%. XRD technique has been employed to detect the phases occurring in the clayey samples before and after the thermal treatment. Pozzolanic activity of the calcined clayey soil has been studied using the modified Chapelle test. Atterberg limits, compaction, free swell, swelling pressure, linear shrinkage, shear strength and CBR have particularly been investigated. Test results revealed the positive effect of NCC. Plasticity index (PI) was reduced by more than 50% when 2% NCC was added to the natural soil. In addition, 0.6% NL was added to further investigate the combined effect of NL and NCC on the properties of the clayey soil. All investigated properties were significantly improved when NCC and NL were added together, i.e. swelling pressure and linear shrinkage values were reduced to less than 15% when compared with those of the natural soil.</jats:p