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

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

Studia Geotechnica et Mechanica

Volume 40 (2018): Issue 3 (November 2018)

By: Aref M. Al-Swaidani, Ibraheem Hamood and Ayman Meziab

Open Access

|Nov 2018

Figures & Tables

Photograph of the modified Chapelle test set-up.

Photograph of 4´4´4 cm3 clay mortar cubes prepared by mixing the clayey soil thermally treated at 850°C for 3 hours, lime and standard sand.

XRD analysis of the soil S1 before and after the thermal treatment (I: illite; Q: quartz; M: montmorillonite; K: kaolin; F: feldspar; C: calcite; Ch: chlorite).

XRD analysis of the soil S2 before and after the thermal treatment (I: illite; Q: quartz; M: montmorillonite; K: kaolin; F: feldspar; C:calcite).

XRD analysis of the soil S3 before and after the thermal treatment (I: illite; Q: quartz; M: montmorillonite; K: kaolin; F: feldspar; C:calcite).

Pozzolanic activity numbers of clay soils treated at different temperatures.

Linear shrinkage index values of the soil mixtures.

Photograph of soil S3 (some untreated and treated samples).

SEM micrograph and EDX analysis of natural soil 2 cured for 7 days.

SEM micrograph and EDX analysis of CC20L0 mixture (soil 2) cured for 7 days.

SEM micrograph and EDX analysis of CC20L6 mixture (soil 2) cured for 7 days.

Values of free swelling and swelling pressure versus the combinations of soil and stabilisers (calcined clay and lime)_

Clay mixture	Soil 1		Soil 2		Soil 3
	Free swell (%)	Swelling pressure (kPa)	Free swell (%)	Swelling pressure (kPa)	Free swell (%)	Swelling pressure (kPa)
CC0L0	8.35	80	9.24	125	10.55	150
CC0L6	2.56	40	2.65	35	2.16	35
CC10L0	5.85	75	8.56	100	7.12	110
CC20L0	4.17	60	4.85	65	3.92	60
CC10L6	1.75	25	1.66	20	1.19	20
CC20L6	1.44	10	1.12	5	0.88	5

Clay mixtures used in the study_

Clay mixtured	Percentage
	Clay soil	Thermally treated clay	Lime
CC0L0 (control)	100	0	0
CC0L6	94	0	6
CC10L0	90	10	0
CC20L0	80	20	0
CC10L6	84	10	6
CC20L6	74	20	6

Some physical properties with chemical composition of quick lime_

Chemical composition(%)				Physical properties
CaO	MgO	Fe₂O₃	Sulphates (SO₄)	Loss of ignition (%)	Specific gravity (g/cm³)	Blaine fineness (cm²/g)
93.5	0.53	0.47	1.2	3.9	2.2	4000

Basic properties of the studied clayey soils_

Soil	Depth(m)	Specific gravity, Ρ (g/cm³)	Clay particles, d<0.002 mm	Plasticity index (PI), %	Soil classification (USCS) [13]	Optimum water content, W_opt (%)	Maximum dry unit weight, γ_dmax(g/cm³)
S1	1	2.69	23	29	CH	25.5	1.42
S2	0.75	2.67	31.5	35	CH	23	1.38
S3	1.25	2.72	35	42	CH	26	1.30

Compressive strength of clay mortar cubes cured for 2, 7 and 28 days_

	Compressive strength (MPa)
Clay soils	2 days	7 days	28 days
Soil 1	2.64	6.73	11.93
Soil 2	2.80	5.23	8.45
Soil 3	2.35	5.36	9.86

Atterberg limits of the studied mixtures_

Soil mixture designation	PI (%)
	S1	S2	S3
CC0L0	29	35	42
CC0L6	9	6	7
CC10L0	19	21	19
CC20L0	14	17	16
CC10L6	7	5	6
CC20L6	4	3	4

Linear shrinkage values of the investigated clay mixtures_

Clay mixture	Linear shrinkage (LSI%)
	Soil 1	Soil 2	Soil 3
CC0L0	16.46	21.4	24.3
CC0L6	13.63	14.3	18.6
CC10L0	10.06	8.6	12.9
CC20L0	3.64	5.7	5.7
CC10L6	2.93	3.6	4.3
CC20L6	2.57	2.1	2.9

Maximum dry unit weight γdmax and optimum water content Wopt of the clay mixtures_

Clay mixture	γ(_dmaxg/cm³)			W_opt (%)
	S1	S2	S3	S1	S2	S3
CC0L0	1.48	1.38	1.30	25.5	23	27
CC0L6	1.29	1.17	1.12	32.1	29.75	34.21
CC10L0	1.52	1.51	1.36	24.32	21.6	24.75
CC20L0	1.67	1.65	1.56	23.51	19.18	23.89
CC10L6	1.39	1.31	1.27	28.68	25.88	30.11
CC20L6	1.49	1.43	1.33	27.08	24.45	29.87

DOI: https://doi.org/10.2478/sgem-2018-0025 | Journal eISSN: 2083-831X | Journal ISSN: 0137-6365

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Language: English

Page range: 220 - 232

Submitted on: Jul 23, 2018

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Accepted on: Oct 4, 2018

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Published on: Nov 22, 2018

Published by: Wroclaw University of Science and Technology

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

thermally treated clay,

soil improvement,

plasticity index,

linear shrinkage

Related subjects:

Geosciences, other,

Materials sciences,

Porous materials,

Mechanics and fluid dynamics

© 2018 Aref M. Al-Swaidani, Ibraheem Hamood, Ayman Meziab, published by Wroclaw University of Science and Technology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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