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A study on the mixed properties of green controlled low strength cementitious

Chen Sung-Ching, Lin Wei-Ting, Lin Kae-Long, Huang Po-Yu

Materials Science Poland

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2021

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Vol. 39, No. 1

59--74

EN

In this study, two industrial wastes – circulating fluidized bed combustion co-fired fly ash (CFA) and ground granulated blast-furnace slag (GGBS) – were used as green materials instead of cementitious materials in controllable low strength material (CLSM). CLSM was used to backfill the pavement. CLSM should meet the compressive strength requirements of the CLSM specification (under 8.24 MPa), and it had the self-consolidating characteristics of fluidized concrete. In order to comply with the characteristics of self-consolidation, a mix design including superplasticizers, adhesives, and accelerators were used to ensure that the proportion could meet the requirements of both CLSM and the self-consolidating properties. The test methods included the slump flow test, ball drop test, strength activity index, compressive strength, mercury intrusion porosimetry, chloride migration test, and scanning electron microscope. A water/cement ratio of 0.85 was used as the mix design for the CLSM requirements. The CFA and GGBS used in CLSM could replace 78 wt.% of the cement, and CLSM could effectively meet the requirements of the workability, strength and microscopic properties.

2

Składy mieszanek z betonu geopolimerowego

Mallikarjuna Rao G., Gunneswara Rao T. D., Ramaseshu D., Venkatesh A.

Cement Wapno Beton

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2016

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R. 21/83, nr 4

274--285

PL

Opracowano metodę projektowania geopolimerowego betonu o spoiwie złożonym z popiołu lotnego i mielonego granulowanego żużla wielkopiecowego (MGŻW) i sprawdzono ją doświadczalnie. Ustalono najkorzystniejsze stosunki: roztwór zasadowy/spoiwo, spoiwo/kruszywo, drobne kruszywo/grube kruszywo. W spoiwie stosunki krzemionkowego popiołu lotnego do MGŻW były następujące: 70:30, 60:40 i 50:50. Ustalono, że dodatek granulowanego żużla wielkopiecowego do betonu geopolimerowego skraca znacznie czas wiązania i przyczynia się do zwiększenia wytrzymałości. Wytrzymałość betonu geopolimerowego wzrasta ze zwiększeniem zawartości MGŻW w mieszance. Beton geopolimerowy daje zadowalające wyniki w przypadku dojrzewania w warunkach polowych gdy popiół lotny zastępuje się żużlem. Ze wzrostem stosunku roztwór zasadowy/ spoiwo powyżej pewnego poziomu wytrzymałość na ściskanie zmniejsza się zamiast rosnąć. Ten maksymalny stosunek przekracza 0,45 a jest mniejszy od 0,55.

EN

The method for designing of geopolimer concrete mix proportioning was presented and experimentally verified. The binder was composed of siliceous fly ash and ground granulated blastfurnace slag (GGBS). The best relations of the following ratios was establish: alkaline solution/binder, binder/aggregate, fine aggregate/coarse aggregate. Siliceous fly ash - GGBS in the binder was varied as: 70-30, 60-40 and 50-50 and it was shown that the addition of GGBS in geopolymer concrete significantly reduces the setting time and helps in attaining strength. The strength of geopolymer concrete was increased with increase in percentage of GGBS in a mix. Geopolymer concrete gives satisfactory result at outdoor temperature by the replacement of fly ash with GGBS. When the alkaline liquid to binder ratio is increased up to a certain point, instead of the compressive strength increasing it actually decreases. The ratio of this maximum has been found to be above 0.45 and below 0.55.

3

Determining equivalent performance for frost durability of concrete containing different amounts of ground granulated blast furnace slag

Wawrzeńczyk J., Juszczak T., Molendowska A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2016

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Vol. 64, nr 4

731--737

EN

This paper deals with the issues pertinent to the design of frost-resistant concretes in exposure class XF3 (high water saturation) when the concretes are made with cements containing ground granulated blast furnace slag (ggbs). The testing programme covered four series of non-air entrained concrete made with cements CEM I, CEM II/A-S, CEM II/B-S and CEM III/A containing 0%, 13%, 28% and 53% ggbs respectively, and two non-air entrained concrete series with the binder made from CEM I and 0 to 55% ggbs. The water-binder (w/b) ratio ranged from 0.25 to 0.55. Frost durability testing was performed using a modified ASTM C666A procedure to determine changes in mass (dm) and beam length (dL). The relationships occurring between the w/b ratio and ggbs content in the binder and the length change (dL) of the specimens were described using curvilinear regression functions, through the analysis of artificial neural networks. Slag-content-dependent critical values of the w/b ratio were determined taking the length change dL = 1.3 mm to be the criterion for the resistance to internal cracking. In the authors’ view, this approach can be a good method for checking equivalent performance of concretes made with cements containing mineral additions.

4

The influence of fly ash type on properties of cements composites

Synowiec K.

Engineering Transactions

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2015

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Vol. 63, iss. 2

191--201

EN

This paper presents the results of tests carried out on mortars prepared with fly ash – slag cements. Two types of fly ash were used – siliceous (V) and calcareous (W). The influence of fly ash type on properties of mortars was evaluated on the base of results of following tests: compressive strength, consistency and its stability in time and chloride ions permeability and carbonation depth. It was claimed that mortars made with cements containing calcareous fly ash (W) are characterized by higher compressive strength (at each age). Moreover, negative impact of calcareous fly ash (W) on rheological properties of mortars was observed. Durability tests revealed favourable effect of calcareous fly ash on resistance of mortars to corrosive agents attack – lower chloride ions permeability and carbonation depth in comparison to siliceous fly ash – slag cement mortars.

5

Impedance spectroscopy study of the effect of environmental conditions in the microstructure development of OPC and slag cement mortars

Ortega J. M., Sánchez I., Climent M. A.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

569--583

EN

In this work, the microstructure of mortars made with an ordinary Portland cement and slag cement has been studied. These mortars were exposed to four different constant temperature and relative humidity environments during a 180-day period. The microstructure has been studied using impedance spectroscopy, and mercury intrusion porosimetry as a contrast technique. The impedance spectroscopy parameters make it possible to analyze the evolution of the solid fraction formation for the studied mortars and their results are confirmed with those obtained using mercury intrusion porosimetry. The development of the pore network of mortars is affected by the environment. However, slag cement mortars are more influenced by temperature while the relative humidity has a greater influence on the OPC mortars. The results show that slag cement mortars hardened under non-optimal environments have a more refined microstructure than OPC mortars for the studied environmental conditions.

6

Mieszaniny uszczelniające na bazie granulowanego żużla wielkopiecowego do likwidowania odwiertów w rejonie przedgórza Karpat

Rzepka M.

Nafta-Gaz

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2009

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R. 65, nr 2

145-151

PL

Artykuł przedstawia wyniki badań laboratoryjnych mieszanin uszczelniających sporządzanych z granulowanego żużla wielkopiecowego. Mieszaniny te badano w warunkach otworopodobnych w temperaturach od 20 do 60°C. Po wykonaniu szeregu badań opracowano receptury, które mogą być zastosowane do uszczelniania likwidowanych odwiertów naftowych na obszarze przedgórza Karpat.

EN

The article presents the research results of the sealing mixtures made from ground granulated blast furnace slag. The mentioned mixtures can be used for sealing the oil wells in the foreland of the Carpathians.

7

Wpływ powierzchni właściwej żużla wielkopiecowego na właściwości zapraw o dużej wytrzymałości

Łagosz A., Sowa A. I.

Cement Wapno Beton

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2008

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R. 13/75, nr 1

40-44

PL

Przedstawiono wyniki badań zapraw o wysokiej wytrzymałości, wykonanych z cementu portlandzkiego, cementu portlandzkiego z dodatkiem pyłu krzemionkowego i spoiwa, w którym 20% lub 40% masy cementu zastąpiono żużlem wielkopiecowym o różnym stopniu rozdrobnienia. Wykazano, że zastąpienie części cementu żużlem pozwala na uzyskanie porównywalnej lub wyższej wytrzymałości w odniesieniu do zapraw z cementu portlandzkiego lub tego cementu z dodatkiem pyłu krzemionkowego, już nawet po 7 dniach twardnienia. Występuje to jednak tylko w przypadku mniejszej ilości zastąpionego cementu oraz dużej powierzchni właściwej żużla. Natomiast żużel o małej powierzchni właściwej powoduje zmniejszenie wytrzymałości. Równoczesne dodanie wraz z żużlem pyłu krzemionkowego zmniejsza wpływ stopnia rozdrobnienia żużla w porównaniu do analogicznych zapraw bez tego dodatku.

EN

The results of high strength mortar produced from Portland cement and from this cement but with addition of silica fume and from binder in which 20% or 40% mass of cement was replaced by ground granulated blast furnace slag (GGBS), with different fineness. It was shown that the replacement of cement with GGBS gives the mortars of higher or comparable strength in comparison with those of Portland cement without or with silica fume addition, already after 7 days of hardening. However, it is true only in case of smaller slag content (20%) and with high specific surface arrear (SSA). Slag with small SSA causes decrease of strength. Simultaneous addition of slag and silica fume decreases the influence of slag SSA in comparison to mortars without silica fume.