{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T01:17:30Z","timestamp":1772587050243,"version":"3.50.1"},"reference-count":45,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,20]],"date-time":"2021-09-20T00:00:00Z","timestamp":1632096000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>Chemical stabilization is one of the most successful techniques that has been applied to improve the geomechanical behavior of soil. Several additives have been studied to be a sustainable alternative to traditional additives (Portland cement and lime) normally associated with high cost and carbon footprint. Nanomaterials are one of the most recent additives proposed. This work is focused on one type of nanomaterial, multiwall carbon nanotubes (MWCNTs) with unique characteristics, applied to chemical stabilization of soils and aiming to identify the key-parameters affecting the stabilization improvement. It was found that a surfactant should be added in order to oppose the natural tendency of MWCNTs to aggregate with the consequent loss of benefits. The surfactant choice is not so dependent on the charge of the surfactant but rather on the balance between the concentration and the hydrodynamic diameter\/molecular weight due to their impact on the geomechanical compression behavior. As time evolves from 7 to 28 days, there is a decrease in the geomechanical benefits associated with the presence of MWCNTs explained by the development of the cementitious matrix. MWCNTs applied in a proper concentration and enriched with a specific surfactant type may be a short-time valid alternative to the partial replacement of traditional additives.<\/jats:p>","DOI":"10.3390\/app11188754","type":"journal-article","created":{"date-parts":[[2021,9,21]],"date-time":"2021-09-21T08:04:23Z","timestamp":1632211463000},"page":"8754","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Key-Parameters in Chemical Stabilization of Soils with Multiwall Carbon Nanotubes"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3260-8729","authenticated-orcid":false,"given":"Ant\u00f3nio Alberto S.","family":"Correia","sequence":"first","affiliation":[{"name":"CIEPQPF\u2014Chemical Process Engineering and Forest Products Research Centre, Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal"}]},{"given":"Pedro D. F.","family":"Casaleiro","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal"}]},{"given":"Diogo T. R.","family":"Figueiredo","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, Portugal"}]},{"given":"Marta S. M. R.","family":"Moura","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6084-4553","authenticated-orcid":false,"given":"Maria Gra\u00e7a","family":"Rasteiro","sequence":"additional","affiliation":[{"name":"CIEPQPF, Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,20]]},"reference":[{"key":"ref_1","unstructured":"Bolt, G.H. (1983). Composition and Physical Properties of Soils. Developments in Soil Science, Elsevier."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Conklin, A.R. (2005). Introduction to Soil Chemistry: Analysis and Instrumentation, Wiley.","DOI":"10.1002\/0471728225"},{"key":"ref_3","unstructured":"Chu, J., Varaksin, S., and Menge, U.K.P. (2009, January 5\u20139). Construction Processes\u2014State of the Art Report. Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering, Alexandria, Egypt."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"04014053","DOI":"10.1061\/(ASCE)GT.1943-5606.0001158","article-title":"Effect of organic matter content and binder quantity on the uniaxial creep behavior of an artificially stabilized soil","volume":"140","author":"Correia","year":"2014","journal-title":"J. Geotech. Geoenviron. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"810","DOI":"10.1061\/(ASCE)GT.1943-5606.0000762","article-title":"Effect of Stress Level and Binder Composition on Secondary Compression of an Artificially Stabilized Soil","volume":"139","author":"Correia","year":"2013","journal-title":"J. Geotech. Geoenviron. Eng."},{"key":"ref_6","unstructured":"Mithcell, J.K. (1981, January 15\u201319). Soil Improvement\u2014State-of-the-Art Report. Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, Sweden."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1680\/jgeen.17.00011","article-title":"Strength assessment of chemically stabilised soft soils","volume":"172","author":"Correia","year":"2019","journal-title":"Proc. Inst. Civil Eng. Geotech. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1016\/j.colsurfa.2014.12.027","article-title":"Surfactants for dispersion of carbon nanotubes applied in soil stabilization","volume":"480","author":"Figueiredo","year":"2015","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1042","DOI":"10.1061\/(ASCE)1090-0241(2004)130:10(1042)","article-title":"Fundamental Parameters of Cement-Admixed Clay\u2014New Approach","volume":"130","author":"Lorenzo","year":"2004","journal-title":"J. Geotech. Geoenviron. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.geotexmem.2014.11.008","article-title":"Effect of polypropylene fibres on the compressive and tensile strength of a soft soil, artificially stabilised with binders","volume":"43","author":"Correia","year":"2015","journal-title":"Geotext. Geomembr."},{"key":"ref_11","unstructured":"Edil, T., and Staab, D. (2005). Practitioner\u2019s Guide for Deep-Mixed Stabilization of Organic Soils and Peat, p. 60."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1680\/gi.1998.020204","article-title":"State of the art in deep mixing technology: Part I. Basic concepts and overview","volume":"2","author":"Porbaha","year":"1998","journal-title":"Proc. Inst. Civil Eng. Ground Improv."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Kitazume, M., and Terashi, M. (2013). The Deep Mixing Method, CRC Press.","DOI":"10.1201\/b13873"},{"key":"ref_14","unstructured":"Janz, M., and Johansson, S.-E. (1992). The Function of Different Binding Agents in Deep Satbilization, Swedish Deep Stabilization Research Centre."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"639","DOI":"10.1016\/j.acme.2017.01.010","article-title":"Geotechnical properties of the soils modified with nanomaterials: A comprehensive review","volume":"17","author":"Ghasabkolaei","year":"2017","journal-title":"Arch. Civ. Mech. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1007\/s12665-015-5118-8","article-title":"Experimental studies on nanomaterials for soil improvement: A review","volume":"75","author":"Huang","year":"2016","journal-title":"Environ. Earth Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"04019121","DOI":"10.1061\/(ASCE)MT.1943-5533.0002774","article-title":"Effect of Organic Matter Content on Enzymatic Biocementation Process Applied to Coarse-Grained Soils","volume":"31","author":"Neves","year":"2019","journal-title":"J. Mater. Civ. Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1680\/geot.SIP13.P.017","article-title":"Biogeochemical processes and geotechnical applications: Progress, opportunities and challenges","volume":"63","author":"DeJong","year":"2013","journal-title":"G\u00e9otechnique"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"100458","DOI":"10.1016\/j.trgeo.2020.100458","article-title":"Review of current and future bio-based stabilisation products (enzymatic and polymeric) for road construction materials","volume":"27","author":"Ramdas","year":"2021","journal-title":"Transp. Geotech."},{"key":"ref_20","unstructured":"Axelsson, K., Johansson, S.-E., and Anderson, R. (2002). Stabilization of Organic Soils by Cement and Puzzolanic Reactions\u2014Feasibility Study, Swedish Deep Stabilization Research Centre."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1766","DOI":"10.1016\/j.proeng.2015.01.313","article-title":"Applying multiwall carbon nanotubes for soil stabilization","volume":"102","author":"Correia","year":"2015","journal-title":"Procedia Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1016\/j.jcou.2017.02.011","article-title":"Co-production of cement and carbon nanotubes with a carbon negative footprint","volume":"18","author":"Licht","year":"2017","journal-title":"J. CO2 Util."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1405","DOI":"10.1007\/s12205-014-0721-x","article-title":"Optimum mix ratio for carbon nanotubes in cement mortar","volume":"19","author":"Manzur","year":"2015","journal-title":"KSCE J. Civ. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Taylor, H. (1997). Cement Chemistry, Thomas Telford.","DOI":"10.1680\/cc.25929"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Gopalakrishnan, K., Birgisson, B., Taylor, P., and Attoh-Okine, N.O. (2011). The Effect of SWCNT and Other Nanomaterials on Cement Hydration and Reinforcement. Nanotechnology in Civil Infrastructure, Springer.","DOI":"10.1007\/978-3-642-16657-0"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1080\/15376494.2012.736052","article-title":"Damping Performances of Carbon Nanotube Reinforced Cement Composite","volume":"22","author":"Luo","year":"2015","journal-title":"Mech. Adv. Mater. Struct."},{"key":"ref_27","first-page":"22","article-title":"Micromechanical Analysis of Cement Paste with Carbon Nanotubes","volume":"52","author":"Padevet","year":"2012","journal-title":"Acta Polytech."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2379","DOI":"10.1177\/0021998319896835","article-title":"Properties improvement of multiwall carbon nanotubes-reinforced cement-based composites","volume":"54","author":"Wang","year":"2019","journal-title":"J. Compos. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/j.cemconcomp.2018.11.006","article-title":"Mechanical and microstructural properties of cement pastes containing carbon nanotubes and carbon nanotube-silica core-shell structures, exposed to elevated temperature","volume":"95","author":"Sikora","year":"2019","journal-title":"Cem. Concr. Compos."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1016\/j.conbuildmat.2016.12.147","article-title":"Enhanced mechanical properties of cement paste by hybrid graphene oxide\/carbon nanotubes","volume":"134","author":"Zhou","year":"2017","journal-title":"Constr. Build. Mater."},{"key":"ref_31","first-page":"757","article-title":"Performance of Soil Stabilized with Carbon Nanomaterials","volume":"63","author":"Taha","year":"2018","journal-title":"Chem. Eng. Trans."},{"key":"ref_32","unstructured":"Taha, M.R., and Ying, T. (2010, January 4\u201310). Effects of Carbon Nanotube on Kaolinite: Basic Geotechnical Behavior. Proceedings of the ICCE 18\u201418th International Conference on Composites\/Nano-engineering, Anchorage, AK, USA."},{"key":"ref_33","unstructured":"Arabani, M., Haghi, A., and Moradi, Y. (2012). Evaluation of Mechanical Properties Improvement of Clayey Sand by Using Carbon Nanotubes."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1252","DOI":"10.1016\/j.proeng.2016.06.113","article-title":"Nanotechnology Applied to Chemical Soil Stabilization","volume":"143","author":"Correia","year":"2016","journal-title":"Procedia Eng."},{"key":"ref_35","unstructured":"ASTM (1998). ASTM D2487, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), ASTM International."},{"key":"ref_36","unstructured":"Casaleiro, P.D.F. (2014). Chemical Stabilization of the Soft Soil of Baixo Mondego by Nanomaterials. [Master\u2019s Thesis, University of Coimbra]."},{"key":"ref_37","unstructured":"Figueiredo, D.T.R. (2014). Characterization of Carbon Nano-Tubes Dispersions for Application in Soil Stabilization. [Master\u2019s Thesis, University of Coimbra]."},{"key":"ref_38","unstructured":"Moura, M.S.M.R. (2015). Improvement of Carbon Nanotube Dispersions for Application in Soil Chemical Stabilization. [Master\u2019s Thesis, University of Coimbra]."},{"key":"ref_39","unstructured":"Correia, A.A.S. (2011). Applicability of Deep Mixing Technique to the Soft Soil of Baixo Mondego. [Ph.D. Thesis, University of Coimbra]."},{"key":"ref_40","unstructured":"BSI (1990). BSI 1377-7: Methods of Test for Soils for Civil Engineering Purposes. Shear Strength Tests (Total Stress), British Standards Institution."},{"key":"ref_41","unstructured":"ASTM (2000). ASTM D2166: Standard Test Method for Unconfined Compressive Strength of Cohesive Soil, ASTM International."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"868","DOI":"10.1061\/(ASCE)MT.1943-5533.0000454","article-title":"Effect of Organic Matter Content and Curing Conditions on the Creep Behavior of an Artificially Stabilized Soil","volume":"24","author":"Correia","year":"2012","journal-title":"J. Mater. Civ. Eng."},{"key":"ref_43","unstructured":"Horpibulsuk, S. (2001). Analysis and Assessment of Engineering Behavior of Cement Stabilized Clays. [Ph.D. Thesis, Saga University]."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Correia, A.A.S., Lopes, L., and Reis, M.S. (2021). Advanced predictive modelling applied to the chemical stabilisation of soft soils (Ahead of print). Proc. Inst. Civil Eng. Geotech. Eng., 1\u201311.","DOI":"10.1680\/jgeen.19.00295"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.compgeo.2017.07.007","article-title":"Numerical modelling of the effect of curing time on the creep behaviour of a chemically stabilised soft soil","volume":"91","author":"Correia","year":"2017","journal-title":"Comput. Geotech."}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/11\/18\/8754\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:02:33Z","timestamp":1760166153000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/11\/18\/8754"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,20]]},"references-count":45,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["app11188754"],"URL":"https:\/\/doi.org\/10.3390\/app11188754","relation":{},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,9,20]]}}}