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Journal ArticleDOI: 10.1080/17486025.2019.1645361

Estimating the efficiency of the sandy soils-cement based grout interactions from Particle size distribution (PSD)

04 Mar 2021-Geomechanics and Geoengineering (Taylor & Francis)-Vol. 16, Iss: 2, pp 81-98
Abstract: The particle size distribution of the soil fines content and mean particle size (d50) are used in a number of soil property relationships and in the soil classification. To analyze and model partic...

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Topics: Soil classification (56%), Grout (54%), Soil water (52%) ... read more

21 results found

Journal ArticleDOI: 10.1016/J.PETROL.2020.107029
Abstract: Quantification of fluid losses and filter cake formations during the drilling operations using water-based muds (WBM) are some of the critical issues related to successful operations. In this study, short term (30 min) and long term (420 min) fluid loss tests on the drilling mud with various amounts of bentonite contents were performed using the API fluid loss device with filter paper and compared it to the field clay soil (porous media) at a pressure of 100 psi (0.69 MPa). The permeability of the saturated clay soil was 0.026 mD, representing a porous formation. Bentonite content in the drilling mud was varied from 2% to 8% (by the weight of water). The field soil and bentonite were characterized using the particle size distribution and X-ray diffraction (XRD) analyses. Bentonite particle size distribution was finer than the field clay soil. Vipulanandan correlation model predicted the changes in the permeability with time in the clay soil with the filter cake formation very well. With the API fluid loss study, the long-term (420 min) fluid losses were about 2.5–4 times greater than the standard fluid loss study of 30 min (short-term). The filter cake thickness was high with the soil formation compared to the API method. Also, the fluid loss per unit area with the API method was higher than the clay soil formation agreeing with the observed differences in the filter cake thicknesses. The Vipulanandan fluid loss model predictions were compared to the API model and it predicted both short term and long term fluid losses very well based on the root mean square error (RMSE) values. Also, the Vipulanandan fluid loss model predicted the maximum fluid losses under various testing conditions.

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Topics: Filter cake (62%), Drilling fluid (58%), Bentonite (56%) ... read more

32 Citations

Open accessJournal ArticleDOI: 10.1016/J.RINMA.2019.100043
Wael Mahmood1, Ahmed Mohammed1, Kawan Ghafor1Institutions (1)
01 Dec 2019-
Abstract: In this study, two types of polycarboxylate (PCE) polymer (DBC-21 and VK-98) were used as additives in the cement-based grout. The water-cement ratio (w/c) was fixed to 0.6 and 1.0 ​at temperature of 25° Celsius and 50° Celsius. Experimentalists were conducted to study the chemical composition of the cement-based grout, the mass loss, the rheology behavior, and the compressive strength. Numerical studies were performed to understand the shear strength, rheological properties and compressive strength by taking advantages of numerical models. The results show that the 0.16% PCE polymer additive leads to low cement weight loss at 800° Celsius, drastic increase of apparent and plastic viscosity, and significant improvement of compressive strength. Effects of polymer content, w/c, curing period and the temperature on the rheological properties and compressive strength (CS) of cement-based grout were investigated using a multiple nonlinear regression analysis.

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Topics: Compressive strength (67%), Grout (60%), Cement (53%) ... read more

31 Citations

Journal ArticleDOI: 10.1016/J.CONBUILDMAT.2020.119590
Ahmed Mohammed1, Serwan Rafiq1, Wael Mahmood1, Riyadh Noaman  +3 moreInstitutions (1)
Abstract: In this study, the effect of nano-silica (NS) as an additive to the Ordinary Portland Cement was evaluated and quantified. Scanning Electronic Microscope (SEM), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Fourier-Transform Infrared Spectroscopy (FTIR), and Raman Spectroscopy analysis were used to identify the cement and NS content. Experimental tests and modeling were conducted to quantify and predict the rheological properties of the modified cement in the liquid phase such as yield stress, maximum shear strength, plastic viscosity, and mechanical properties such as compressive strength of cement after hardening. The cement modified with NS was tested at water-to-cement ratios (w/c) of 0.35 and 0.45 and temperatures ranging from 25 °C to 75 °C. Non-linear regression (NLR) based model was used to evaluate the effect of nano-silica on the rheological properties and compressive strength of cement. Modifying the cement with nano-silica substantially reduced the volume of Ca (OH)₂. TGA tests showed that the 1% nano-silica additive leads to a decrease in the total weight loss of the cement at 800 °C by 82% due to the de-carbonation of CaCO3 in the hydrated compound and due to interacting the NS with the cement. The addition of NS increased the ultimate shear stress (τmax) and the yield stress (τo) by 15% to 53% and 23% to 186% respectively based on the NS content, w/c, and temperature. An additional 1% of NS to the cement paste the compressive strength increased by 14%–66% based on the curing time, and w/c. The unprecedented conclusions can be drawn in this study, which is the effect of the nano-silica content, water-cement-ratio and temperature effect on the plastic viscosity, yield stress and shear stress limit in the fresh stage (slurry) of the cement paste and also, the impact of the nano-silica content, water-cement-ratio and curing time on the compressive strength in the hardened stages of the cement modified with nano-silica were modeled. The experimental and the modeling results illustrated that the SiO2 nanostructure, which was mixed with the cement paste was highly beneficial in improving the rheological properties of cement paste and compressive strength after hardening.

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Topics: Portland cement (64%), Compressive strength (61%), Cement (57%) ... read more

26 Citations

Journal ArticleDOI: 10.1007/S10706-019-01153-Z
Wael Mahmood1, Ahmed Mohammed1Institutions (1)
Abstract: In this study, permeability, particle size distribution of the sandy soils and collected data from several research studies were analyzed and modeled using Vipulanandan p–q model and the results of prediction were compared with the Fredlund and Logistic Growth models used in the literature. The Vipulanandan p–q model was modified and used to represent the particle size distribution of soils. The Vipulanandan p–q model parameters were correlated very well to various soil properties such as the diameter in the particle size distribution curve corresponding to 10%, 30%, 60%, and 90% of finer (d10, d30, d60, and d90 respectively), mean particle size the diameter in the particle size distribution curve corresponding to 50% finer (d50), and fines content (F%). The range of particle sizes investigated in this study was 0.14–0.94 mm, 0.075–1.76 mm, and 0.15–3.59 mm for the d10, d30, and d60, respectively. Also, from the Vipulanandan p–q model parameter, the permeability of the soils have been predicted successfully. A current study also had quantified the lower groutability limit based on the d50 and the Vipulanandan p–q model parameters. The relationship between fines content and d50 were also generalized using the Vipulanandan p–q model to quantify the upper and lower groutability limits for sandy-soils.

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Topics: Particle size (50%)

22 Citations

Journal ArticleDOI: 10.1007/S41024-019-0069-1
Ahmed Mohammed1, Wael Mahmood1, Kawan Ghafor1Institutions (1)
01 Dec 2020-
Abstract: Grouting is a comprehensive technology used in the construction projects due to the rapid development of sub-surface urban infrastructures, the main reasons for grouting soils are strengthened the cohesion-less soils and increasing the shear stress (pure shear) of the grouted soils. Providing high flowability with high viscosity for the cement-based grout in the liquid stage (slurry) and high compressive strength of the cement-based grout in the hardened stage are significant challenges. In this study, the impact of two types of water reducer [polycarboxylate (PCE)] polymer on the rheological properties with the ultimate shear strength and compressive strength of cement-based grout with water-cement ratios (w/c) of 0.6 and 1.0 at two different temperatures 25 °C and 50 °C were studied. XRD and TGA were used to analysis the cement, polymers, and cement modified with polymers. The behavior of cement-based grout in the liquid phase (slurry) and hardened phase modified with different percentages of polymer up to 0.16% (by dry weight of cement) were investigated. The compressive strength of cement-based grout modified with polymer was tested from the young age up to 28 days of curing. Vipulanandan rheological model was used to predict the shear stress-shear strain behavior of cement-based grout slurry and compared to the Herschel–Bulkley (HB) model. The rheological and the compressive strength are increased with increasing the of PCE content. The polymer modification increased the yield stress, apparent viscosity and plastic viscosity of the cement grout by 19–136%, 32–319% and 58–367%, respectively based on the types of polymer, polymer content, w/c, and temperature. The compressive strength of the cement-based grout increased by 94–786% based on the types of polymer, polymer content, w/c and curing time. Increasing the temperature of cement-based grout slurry to 50 °C increased the maximum shear stresses by 110% and 107%, respectively. Effects of polymer content, w/c, curing time and the temperature of the plastic and hardened properties of cement-grout were modeled using a multiple nonlinear regression analysis.

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Topics: Grout (66%), Compressive strength (60%), Cement (57%) ... read more

22 Citations


24 results found

Open accessBook
01 Jan 1981-
Abstract: This manual presents data on soil behaviour, with emphasis on practical and empirical knowledge, required by geotechnical engineers for the design and construction of foundations and embankments It deals with: index and classification properties of soils; soil classification; clay minerals and soil structure; compaction; water in soils (capillarity, shrinkage, swelling, frost action, permeability, seepage, effective stress); consolidation and consolidation settlements; time rate of consolidation; the Mohr circle, failure theories, and stress paths; shear strength of sands and clays Four appendices deal with the following: application of the "SI" system of units to getechnical engineering; derivation of Laplace's equation; derivation and solution of Terzaghi's one-dimensional consolidation theory; pore pressure parameters (TRRL)

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Topics: Consolidation (soil) (67%), Soil mechanics (62%), Oedometer test (61%) ... read more

1,678 Citations

Journal ArticleDOI: 10.1139/T00-015
Abstract: The grain-size distribution is commonly used for soil classification; however, there is also potential to use the grain-size distribution as a basis for estimating soil behaviour. For example, much...

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167 Citations

Journal ArticleDOI: 10.1016/J.PETROL.2014.08.004
Abstract: The effects of additives on the flow characteristics of the drilling muds used in various drilling operations including oil and gas wells must be better quantified. In this study, acrylamide polymer was used to modify the water based bentonite mud to reduce the yield point and maximum shear stress produced by the mud during the drilling operation. The bentonite content in the drilling mud was varied up to 6% (by weight). Based on the X-ray diffraction (XRD) analyses the major constituents of the bentonite were montmorillonite (MMT, (Na,Ca) 0.33 (Al,Mg) 2 (Si 4 O 10 )(OH) 2 ·nH 2 O), feldspar (Albite, NaAlSi 3 O 8 ), kaolinite (Al 2 Si 2 O 5 (OH 4 )), Beidellite ((Na,Ca 0.5 ) 0.3 Al 2 ((Si,Al) 4 O 10 )(OH) 2 ·nH 2 O) and quartz (SiO 2 ). The bentonite was modified using a water soluble polymer solution before using it in the drilling mud. The rheological properties of bentonite were characterized from very low strain rate to relatively high strain rate to determine the nonlinear behavior of the shear thinning drilling mud. The polymer modification reduced the yield point by 26–66% based on the bentonite content in the drilling mud. The polymer treatment also reduced the apparent viscosity of the drilling muds. The shear thinning behavior of the bentonite drilling mud with and without polymer has been quantified using the new hyperbolic model and compared with two other constitutive models, Herschel–Bulkley and Casson models. While Casson model had two material parameters the other two models had three parameters. The results showed that the hyperbolic model predicated the shear thinning relationship between the shear stress and shear strain rate of the polymer modified bentonite drilling mud very well. Also the hyperbolic model has a maximum shear stress limit were as the other two models did not have a limit on the maximum shear stress. Based on the hyperbolic model the maximum shear stresses produced by the 2%, 4% and 6% bentonite drilling muds were 11 Pa, 18.5 Pa and 45.7 Pa respectively. The maximum shear stress produced by 0.24% polymer treated 2%, 4% and 6% bentonite drilling muds were 10.4 Pa, 16 Pa and 31 Pa respectively, hence a reduction of 5–33% in the maximum shear stress. Effects of bentonite content and polymer content on the model parameters have been quantified using a nonlinear model (NLM). The NLM quantified the effect of polymer treatment on all the model parameters.

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Topics: Drilling fluid (64%), Bentonite (61%), Shear stress (54%) ... read more

112 Citations

Journal ArticleDOI: 10.2136/SSSAJ2002.1143
Abstract: An accurate mathematical representation of particle-size distributions (PSDs) is required to estimate soil hydraulic properties or to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of seven models (i.e., five lognormal models, the Gompertz model, and the Fredlund model) to fit PSD data sets from a wide range of soil textures. Special attention was given to the effect of texture on model performance. Several criteria were used to determine the optimum model with the least number of fitting parameters when other conditions are equal. The Fredlund model with four parameters showed the best performance with the majority of soils studied, even when three criteria that impose a penalty for additional fitting parameters were used. Especially, the relative performance of the Fredlund model in regard to other models increased with increase of clay content. Among all soil classes, the lognormal models with two or three parameters showed better fits for silty clay, silty clay loam, and silt loam soils, and worse fit for sandy clay loam soil.

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Topics: Loam (65%), Soil texture (54%), Soil classification (50%)

111 Citations