Stiffness Behavior of Soil Stabilized with Alkali-Activated Fly Ash from Small to Large Strains

Rı́os, Sara; Cristelo, Nuno; Fonseca, António Viana da; Ferreira, Cristiana

doi:10.1061/(asce)gm.1943-5622.0000783

Cited by 62 publications

(31 citation statements)

References 27 publications

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“…The equipment consists of a pair of compression transducers and a pair of shear transducers, a pulse waveform generator, and data acquisition unit equipped with an amplifier connected to a personal computer with specific software to operate as an oscilloscope. Based on the propagation times evaluated with a time domain approach (Viana da Fonseca et al 2009;Rios et al 2016b), the wave velocities (V P and V S , respectively for P and S waves) were determined dividing the height of the specimen by the time. From the results of the seismic wave's velocities, the evolution of the dynamic Young's Modulus (E 0 ) was obtained according to the following elasticity theory equations:…”

Section: Laboratory Test Resultsmentioning

confidence: 99%

Characterization of Soil Treated With Alkali-Activated Cement in Large-Scale Specimens

Cruz¹,

Rı́os

Fortunato

et al. 2017

Geotech. Test. J.

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Soil improvement with hydraulic binders is currently used in practice because of the advantages of using the local soil enhancing its geotechnical properties. However, environmental issues related to quicklime applications and carbon-dioxide emissions associated to Portland cement production encouraged the development of new binders. In this work, alkaline-activated cement (AAC) synthetized by fly ash and an alkaline solution was used to stabilize silty sand. The behavior of the treated soil was evaluated performing tests on a physical model and the results were compared to laboratory data to define its compaction, strength, and stiffness properties. Those tests include nuclear density gauge measurements, light falling weight deflectometer tests, and plate load tests, whereas unconfined compression tests with unload-reload cycles and seismic wave measurements were performed at the laboratory. These tests, very common in current geotechnical practice, have proved to be also adequate to quality control and to evaluate the geomechanical properties of this material. The results at 28 days show a significant improvement given by the AAC, but still show some sensitivity to water when flooded. The comparison of results from different tests provided the evolution of stiffness with strain level.

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Section: Laboratory Test Resultsmentioning

confidence: 99%

Characterization of Soil Treated With Alkali-Activated Cement in Large-Scale Specimens

Cruz¹,

Rı́os

Fortunato

et al. 2017

Geotech. Test. J.

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“…Being a fast, non-destructive and reliable testing method it allows a good monitoring of a great number of specimens in a feasible time, conversely to strength tests which require a great amount of similar specimens to be tested at different curing periods. It comprises the evaluation of P and S wave propagation times with ultrasonic transducers as described in detail in Rios et al (2016c). These transducers are more convenient than bender elements (e.g., Ferreira et al, 2011) when used in very stiff materials such as cemented soils (Molero et al, 2011), because it is not necessary to perform a small incision to insert the bender element.…”

Section: Specimen Preparation and Testing Proceduresmentioning

confidence: 99%

“…Moreover, it is also clear that for mixture A1C7 the stiffness is still increasing significantly up to 180 days of curing as observed for strength in Figure 5, which is in agreement with previous studies (eg. Rios et al, 2016c).…”

Section: Dynamic Stiffness Evolution With Curingmentioning

confidence: 99%

Mechanical and durability properties of a soil stabilised with an alkali-activated cement

Rı́os

Ramos

Fonseca

et al. 2017

European Journal of Environmental and Civil Engineering

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Alkali activated cements (AAC) have been extensively studied for different applications as an alternative to Portland cement (which has a high carbon footprint) and due to the possibility of including waste materials such fly ash or slags. However, few works have addressed the topic of stabilised soils with AAC for unpaved roads, with curing at ambient temperature, where the resistance to wetting and drying as well as the mechanical properties evolution over time is particularly relevant. In this paper, a silty sand was stabilized with an AAC synthetized from low calcium fly ash and an alkaline solution made from sodium silicate and sodium hydroxide. The evolution of stiffness and strength up to 360 days, the tensile strength, and the performance during wetting and drying cycles were some of the characteristics analysed. Strength and stiffness results show a significant evolution far beyond the 28 th curing day, but still with a reasonable short-term strength. Strength parameters deduced from triaxial tests were found to be very high with stress-strain behaviour typical of cemented soils. Durability properties related to resistance to immersion and wetting and drying cycles were found to comply with existing specifications for soil-cement, giving validity for its use as soil-cement replacement.

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“…5 Many publications about soil stabilization using OPC, lime or both, together with the methodology followed to prepare large samples (NLT -310/90 6 and UNE EN 13286, parts 50, 51, 52 and 53 7 ) can be found. Finding bibliography on the stabilization of soils with AAC is less common, [8][9][10][11][12][13] where sodium silicate is frequently used as an activator. What is even less common is using AAC, whose activator is obtained from waste, [14][15][16][17] where sodium silicate can be synthesized from mixtures of rice husk ash and sodium hydroxide and can, thus, considerably reduce CO 2 emissions.…”

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confidence: 99%

Stabilization of soil by means alternative alkali‐activated cement prepared with spent FCC catalyst

Cosa

Soriano

Borrachero

et al. 2019

Int J Applied Ceramic Tech

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Alkali-activated cements are widely studied as alternative and sustainable binder in soil stabilization. In this research work, a mold was designed and constructed, which allowed small cubic specimens to be made (40 × 40 × 40 mm 3). With the newly designed mold, cubic samples of soil stabilized with portland cement (OPC) and alternative AAC (based on spent fluid catalytic cracking catalyst FCC) were prepared from which compressive strength was obtained. Cylindrical specimens were also prepared using the same binders as in the previous case to obtain their compressive strength. The results obtained in both cases were compared. Greater resistances for cubic samples were achieved. The cubic specimens were selected for being better in terms of standard deviation of compressive strength for AAC stabilized soil. The obtained compressive strength and standard deviation results were compared between the soil specimens stabilized with different stabilizers cured at 7, 14, 28, and 90 days. The method allows small-sized cubic specimens to be prepared. It improves ergonomics. It also facilitates a large number of specimens being obtained with a small amount of sample. Soil stabilized with AAC yielded higher compressive strength after 90 days compared to that with OPC.

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Stiffness Behavior of Soil Stabilized with Alkali-Activated Fly Ash from Small to Large Strains

Cited by 62 publications

References 27 publications

Characterization of Soil Treated With Alkali-Activated Cement in Large-Scale Specimens

Characterization of Soil Treated With Alkali-Activated Cement in Large-Scale Specimens

Mechanical and durability properties of a soil stabilised with an alkali-activated cement

Stabilization of soil by means alternative alkali‐activated cement prepared with spent FCC catalyst

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