Self-healing of concrete is the process in which the material regenerates itself repairing inner cracks. This process can be produced by autogenous or autonomous healing. Autogenous healing is a natural process, produced by carbonation and/or continuing hydration. Autonomous healing is based on the use of specific agents to produce self-healing, which can be added directly to the concrete matrix, embedded in capsules or introduced through vascular networks. Some examples are superabsorbent polymers, crystalline admixtures, microencapsulated sodium silicate, and bacteria. This review is structured into two parts. The first part is an overview of self-healing concrete that summarises the basic concepts and the main advances produced in the last years. The second part is a critical discussion on the feasibility of self-healing concrete, its possibilities, current weaknesses, and challenges that need to be addressed in the coming years.
{"title":"Self-healing concrete-What Is it Good For?","authors":"M. Roig-Flores, S. Formagini, P. Serna","doi":"10.3989/MC.2021.07320","DOIUrl":"https://doi.org/10.3989/MC.2021.07320","url":null,"abstract":"Self-healing of concrete is the process in which the material regenerates itself repairing inner cracks. This process can be produced by autogenous or autonomous healing. Autogenous healing is a natural process, produced by carbonation and/or continuing hydration. Autonomous healing is based on the use of specific agents to produce self-healing, which can be added directly to the concrete matrix, embedded in capsules or introduced through vascular networks. Some examples are superabsorbent polymers, crystalline admixtures, microencapsulated sodium silicate, and bacteria. This review is structured into two parts. The first part is an overview of self-healing concrete that summarises the basic concepts and the main advances produced in the last years. The second part is a critical discussion on the feasibility of self-healing concrete, its possibilities, current weaknesses, and challenges that need to be addressed in the coming years.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2021-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45051441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Mejía-Arcila, W. Valencia-Saavedra, R. Mejía de Gutiérrez
This study proposes using two types of binders based on fly ash (FA) as primary raw material and a calcium source such as ground granulated blast furnace slag (GBFS) or Portland cement (OPC) for the production of eco-efficient pre-fabricated materials. These binders are denoted FA/GBFS (70/30) and FA/OPC (80/20). A mix of commercial sodium silicate and sodium hydroxide was used as a traditional activator (SN), and the mix of rice husk ash (RHA) and NaOH as an alternative activator (RN). The results show the possibility of obtaining a binary cement (FA/GBFS-RN) with compressive strength up to 38 MPa after curing for 28 days and 65 MPa after curing for 360 days. The hybrid binder (FA/OPC-RN) reported 30 MPa and 61 MPa at the same age of curing. Additionally, FA/GBFS-RN reports reductions in the environmental and health impacts of up to 75% compared to systems made with sodium silicate and sodium hydroxide. Based on the results, FA/ GBFS-RN paste was selected as the optimal material for producing masonry blocks and pedestrian pavers, which met the Colombian standards.
{"title":"Eco-efficient alkaline activated binders for manufacturing blocks and pedestrian pavers with low carbon footprint: Mechanical properties and LCA assessment","authors":"J. Mejía-Arcila, W. Valencia-Saavedra, R. Mejía de Gutiérrez","doi":"10.3989/mc.2020.17419","DOIUrl":"https://doi.org/10.3989/mc.2020.17419","url":null,"abstract":"This study proposes using two types of binders based on fly ash (FA) as primary raw material and a calcium source such as ground granulated blast furnace slag (GBFS) or Portland cement (OPC) for the production of eco-efficient pre-fabricated materials. These binders are denoted FA/GBFS (70/30) and FA/OPC (80/20). A mix of commercial sodium silicate and sodium hydroxide was used as a traditional activator (SN), and the mix of rice husk ash (RHA) and NaOH as an alternative activator (RN). The results show the possibility of obtaining a binary cement (FA/GBFS-RN) with compressive strength up to 38 MPa after curing for 28 days and 65 MPa after curing for 360 days. The hybrid binder (FA/OPC-RN) reported 30 MPa and 61 MPa at the same age of curing. Additionally, FA/GBFS-RN reports reductions in the environmental and health impacts of up to 75% compared to systems made with sodium silicate and sodium hydroxide. Based on the results, FA/ GBFS-RN paste was selected as the optimal material for producing masonry blocks and pedestrian pavers, which met the Colombian standards.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"232"},"PeriodicalIF":2.1,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49653419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Sanrı-Karapınar, A. Pehlivan, S. Karakuş, A. E. Özsoy-Özbay, A. Yazgan, N. Taşaltın, A. Kilislioğlu
This study is a preliminary attempt to present the preparation and the first time a κ-carrageenan/PVA/eggshell nanostructure is used as a novel biodegradable and homogeneous nanostructure in cement composition. In order to clearly understand the effects these additives have on the mechanical properties of cementitious composites, they were synthesized in double and triple combinations and added into mortar mixtures. Three different cement mortar specimens were prepared by integrating the additives in ratios of 0, 0.1, 0.5 and 1% by cement weight and flexural and compressive strengths of the specimens were determined at the ages of 7 and 28 days. The flowability of the presented nanostructures was also discussed. The results revealed a 10–11% increase in both compressive and flexural strengths for the specimens prepared with the triple combination of the proposed additives. Moreover, strain capacity was enhanced as a result of the efficient dispersion of additives in the cement matrix.
{"title":"Application of novel synthesized nanocomposites containing κ-carrageenan/PVA/eggshell in cement mortars","authors":"I. Sanrı-Karapınar, A. Pehlivan, S. Karakuş, A. E. Özsoy-Özbay, A. Yazgan, N. Taşaltın, A. Kilislioğlu","doi":"10.3989/mc.2020.06720","DOIUrl":"https://doi.org/10.3989/mc.2020.06720","url":null,"abstract":"This study is a preliminary attempt to present the preparation and the first time a κ-carrageenan/PVA/eggshell nanostructure is used as a novel biodegradable and homogeneous nanostructure in cement composition. In order to clearly understand the effects these additives have on the mechanical properties of cementitious composites, they were synthesized in double and triple combinations and added into mortar mixtures. Three different cement mortar specimens were prepared by integrating the additives in ratios of 0, 0.1, 0.5 and 1% by cement weight and flexural and compressive strengths of the specimens were determined at the ages of 7 and 28 days. The flowability of the presented nanostructures was also discussed. The results revealed a 10–11% increase in both compressive and flexural strengths for the specimens prepared with the triple combination of the proposed additives. Moreover, strain capacity was enhanced as a result of the efficient dispersion of additives in the cement matrix.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"235"},"PeriodicalIF":2.1,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48911469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Shafigh, I. Asadi, A. R. Akhiani, N. Mahyuddin, M. Hashemi
The energy required for the heating and cooling of buildings is strongly dependant on the thermal properties of the construction material. Cement mortar is a common construction material that is widely used in buildings. The main aim of this study is to assess the thermal properties of cement mortar in terms of its thermal conductivity, heat capacity and thermal diffusivity in a wide range of grades (cement: sand ratio between 1:2 and 1:8). As there is insufficient information to predict the thermal conductivity and diffusivity of a cement mortar from its physical and mechanical properties, the relationships between thermal conductivity and diffusivity and density, compressive strength, water absorption and porosity are also discussed. Our results indicate that, for a cement mortar with a 28-day compressive strength in the range of 6–60 MPa, thermal conductivity, specific heat and thermal diffusivity are in the range of 1.5–2.7 W/(m.K), 0.87–1.04 kJ/kg.K and 0.89–1.26 (x10 -6 m 2 /s), respectively. The scanning electron microscope (SEM) images showed that pore size varied from 18 μm to 946 μm for samples with different cement-to-sand ratios. The porosity of cement mortar has a significant effect on its thermal and physical properties. For this reason, thermal conductivity and thermal diffusivity was greater in cement mortar samples with a higher density and compressive strength.
{"title":"Thermal properties of cement mortar with different mix proportions","authors":"P. Shafigh, I. Asadi, A. R. Akhiani, N. Mahyuddin, M. Hashemi","doi":"10.3989/mc.2020.09219","DOIUrl":"https://doi.org/10.3989/mc.2020.09219","url":null,"abstract":"The energy required for the heating and cooling of buildings is strongly dependant on the thermal properties of the construction material. Cement mortar is a common construction material that is widely used in buildings. The main aim of this study is to assess the thermal properties of cement mortar in terms of its thermal conductivity, heat capacity and thermal diffusivity in a wide range of grades (cement: sand ratio between 1:2 and 1:8). As there is insufficient information to predict the thermal conductivity and diffusivity of a cement mortar from its physical and mechanical properties, the relationships between thermal conductivity and diffusivity and density, compressive strength, water absorption and porosity are also discussed. Our results indicate that, for a cement mortar with a 28-day compressive strength in the range of 6–60 MPa, thermal conductivity, specific heat and thermal diffusivity are in the range of 1.5–2.7 W/(m.K), 0.87–1.04 kJ/kg.K and 0.89–1.26 (x10 -6 m 2 /s), respectively. The scanning electron microscope (SEM) images showed that pore size varied from 18 μm to 946 μm for samples with different cement-to-sand ratios. The porosity of cement mortar has a significant effect on its thermal and physical properties. For this reason, thermal conductivity and thermal diffusivity was greater in cement mortar samples with a higher density and compressive strength.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"224"},"PeriodicalIF":2.1,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42163276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Faneca, T. Ikumi, J. Torrents, A. Aguado, I. Segura
This paper presents a broad experimental study performed at laboratory and industrial facilities to develop conductive concrete for self-heating and de-icing applications in urban furniture. Self-heating capacity is achieved by the application of electric current through a highly dense matrix containing recycled carbon fibers and graphite flakes. Prisms and slabs were fabricated with two different conductive concretes and electrode configurations to characterize the electrical properties and heating performance. Finally, 3 benches with different electrode disposals were fabricated to assess the heating capacity in real-scale applications. The results presented indicate promising results about the use of recycled carbon fibers for electrothermal concrete applications and identify the electrode configuration that allows the most efficient heat transfer and reduction of temperature gradients within the heated element. Real-scale tests show that the current technology developed is potentially applicable at de-icing applications in climates where temperatures remain within the range of -3 or -5 oC.
{"title":"Conductive concrete made from recycled carbon fibres for self-heating and de-icing applications in urban furniture","authors":"G. Faneca, T. Ikumi, J. Torrents, A. Aguado, I. Segura","doi":"10.3989/MC.2020.17019","DOIUrl":"https://doi.org/10.3989/MC.2020.17019","url":null,"abstract":"This paper presents a broad experimental study performed at laboratory and industrial facilities to develop conductive concrete for self-heating and de-icing applications in urban furniture. Self-heating capacity is achieved by the application of electric current through a highly dense matrix containing recycled carbon fibers and graphite flakes. Prisms and slabs were fabricated with two different conductive concretes and electrode configurations to characterize the electrical properties and heating performance. Finally, 3 benches with different electrode disposals were fabricated to assess the heating capacity in real-scale applications. The results presented indicate promising results about the use of recycled carbon fibers for electrothermal concrete applications and identify the electrode configuration that allows the most efficient heat transfer and reduction of temperature gradients within the heated element. Real-scale tests show that the current technology developed is potentially applicable at de-icing applications in climates where temperatures remain within the range of -3 or -5 oC.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"223"},"PeriodicalIF":2.1,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46729888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Sánchez-Roldán, I. Valverde-Palacios, I. Valverde-Espinosa, M. Martín-Morales
Recycled concrete has a microstructure more complex than natural concrete, as it includes new interfacial transition zones, the quality of which is conditioned by the state of humidity of the aggregates used, which in turn will affect the final properties of the concrete. Bearing in mind the greater absorption capacity of recycled aggregates, it is important to improve its properties by means of a treatment method that is capable of reducing the negative effects that this may produce in the new concrete. Therefore, the influence of the pre-soaking method of recycled aggregates on the formation of the microstructure of concretes manufactured with these aggregates is analysed, to determine which treatment is the most effective for the production of concretes for non-structural use. The results show that the microstructure of the evaluated concretes differs according to the treatment method used, the most optimal method being one that uses aggregates without pre-soaking.
{"title":"Microstructural analysis of concretes manufactured with recycled coarse aggregates pre-soaked using different methods","authors":"Z. Sánchez-Roldán, I. Valverde-Palacios, I. Valverde-Espinosa, M. Martín-Morales","doi":"10.3989/mc.2020.16919","DOIUrl":"https://doi.org/10.3989/mc.2020.16919","url":null,"abstract":"Recycled concrete has a microstructure more complex than natural concrete, as it includes new interfacial transition zones, the quality of which is conditioned by the state of humidity of the aggregates used, which in turn will affect the final properties of the concrete. Bearing in mind the greater absorption capacity of recycled aggregates, it is important to improve its properties by means of a treatment method that is capable of reducing the negative effects that this may produce in the new concrete. Therefore, the influence of the pre-soaking method of recycled aggregates on the formation of the microstructure of concretes manufactured with these aggregates is analysed, to determine which treatment is the most effective for the production of concretes for non-structural use. The results show that the microstructure of the evaluated concretes differs according to the treatment method used, the most optimal method being one that uses aggregates without pre-soaking.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"228"},"PeriodicalIF":2.1,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41500295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Gaibor, J. Coelho, D. Leitão, T. Miranda, P. Tavares, N. Cristelo
Environmental concerns are becoming increasingly more significant worldwide, thus creating the urgent need for new sustainable alternatives in the industrial sector. The present study assesses the fundamental properties of ceramic residue (CR) originated by demolition operations, specifically, the floor and wall tiles and sanitaryware furniture, for further incorporation in the construction sector, namely in alkali-activated binders, mixed with other better-known precursors - fly ash (FA) and ladle furnace slag (LFS). Different CR/FA and CR/LFS weight ratios were considered and analyzed by mechanical behavior and microstructural analysis, which included uniaxial compression strength (UCS) tests, Scanning Electron Microscopy (SEM), X-ray Energy Dispersive Analyser (EDX), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Results obtained showed that the combination of CR and FA or LFS, activated with sodium silicate, produced UCS values higher than 20 MPa and 59 MPa, respectively, after 90 days curing.
{"title":"Alkali activation of recycled ceramic aggregates from construction and demolition wastes","authors":"N. Gaibor, J. Coelho, D. Leitão, T. Miranda, P. Tavares, N. Cristelo","doi":"10.3989/mc.2020.13619","DOIUrl":"https://doi.org/10.3989/mc.2020.13619","url":null,"abstract":"Environmental concerns are becoming increasingly more significant worldwide, thus creating the urgent need for new sustainable alternatives in the industrial sector. The present study assesses the fundamental properties of ceramic residue (CR) originated by demolition operations, specifically, the floor and wall tiles and sanitaryware furniture, for further incorporation in the construction sector, namely in alkali-activated binders, mixed with other better-known precursors - fly ash (FA) and ladle furnace slag (LFS). Different CR/FA and CR/LFS weight ratios were considered and analyzed by mechanical behavior and microstructural analysis, which included uniaxial compression strength (UCS) tests, Scanning Electron Microscopy (SEM), X-ray Energy Dispersive Analyser (EDX), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Results obtained showed that the combination of CR and FA or LFS, activated with sodium silicate, produced UCS values higher than 20 MPa and 59 MPa, respectively, after 90 days curing.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"222"},"PeriodicalIF":2.1,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42982325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The synthesis of belite clinker was studied using industrial wastes: paper sludge, cement kiln dust and rice husk ashes, as substitutes for natural raw materials. Wastes were characterized by XRF, XRD and TG analysis. Different formulations were prepared to produce clinker at 1300, 1350 and 1400 °C. The clinker obtained was characterized using optical microscopy, XRD and f-CaO content determined by ethylene glycol method. Finally, the hydration of prepared cements with the clinkers was evaluated by isothermal microcalorimetry. It was found that by mixing paper sludge, cement kiln dust and rice husk ashes, it is possible to obtain belite clinker with f-CaO content below 0.5%, in clinkering temperatures between 1350 °C and 1400 °C without the use of natural raw materials. It was found that these cements have a high hydration kinetic, far above the rate of Ordinary Portland Cement, due mainly by the amorphous phase content in clinkers obtained.
{"title":"Use of industrial wastes for the synthesis of belite clinker","authors":"M. Enríquez, J. Tobón, J. Ramírez","doi":"10.3989/mc.2020.14219","DOIUrl":"https://doi.org/10.3989/mc.2020.14219","url":null,"abstract":"The synthesis of belite clinker was studied using industrial wastes: paper sludge, cement kiln dust and rice husk ashes, as substitutes for natural raw materials. Wastes were characterized by XRF, XRD and TG analysis. Different formulations were prepared to produce clinker at 1300, 1350 and 1400 °C. The clinker obtained was characterized using optical microscopy, XRD and f-CaO content determined by ethylene glycol method. Finally, the hydration of prepared cements with the clinkers was evaluated by isothermal microcalorimetry. It was found that by mixing paper sludge, cement kiln dust and rice husk ashes, it is possible to obtain belite clinker with f-CaO content below 0.5%, in clinkering temperatures between 1350 °C and 1400 °C without the use of natural raw materials. It was found that these cements have a high hydration kinetic, far above the rate of Ordinary Portland Cement, due mainly by the amorphous phase content in clinkers obtained.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"226"},"PeriodicalIF":2.1,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46916397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Reyes, J. Massana, F. Alonso, N. León, A. Moragues
In this paper, the influence of additions of nanosilica (nSi) and microsilica (mSi) on the behaviour of binary and ternary mixtures in chloride environments is studied. The main objective is to obtain high-performance self-compacting concrete (HPSCC) with a high durability which can meet specific demands in such aggressive environments. Ten blends were manufactured using Portland cement (CEM I 52.5 R) and additions of nSi and mSi in binary and ternary mixtures. The results of three tests frequently used to evaluate resistance to chloride penetration– electrical resistivity, migration and chloride diffusion –were studied and compared. Both binary and ternary mixtures presented significant improvements in chloride resistance, generally in proportion to the total content of the addition. In all the ternary mixtures, high resistivity is obtained, which indicates that such mixtures have a notably low chloride penetrability. Furthermore, these mixtures provided extremely low chloride diffusion coefficients even at small addition ratios.
本文研究了纳米二氧化硅(nSi)和微二氧化硅(mSi)的加入对二元和三元混合物在氯化物环境中的行为的影响。主要目标是获得高性能自密实混凝土(HPSCC)，具有高耐久性，可以满足这种恶劣环境下的特定要求。采用波特兰水泥(CEM I 52.5 R)和在二元和三元混合物中添加nSi和mSi制成了10种共混物。研究并比较了常用的三种抗氯化物渗透试验的结果——电阻率、迁移和氯化物扩散。二元和三元混合物的抗氯性都有显著的改善，通常与添加物的总含量成正比。在所有三元混合物中，获得了高电阻率，这表明这种混合物具有明显的低氯化物渗透性。此外，这些混合物即使在很小的添加比下也能提供极低的氯离子扩散系数。
{"title":"Behaviour of a high-performance self-compacting concrete (HPSCC) with ternary mixtures of nano- and microsilica in the presence of chlorides","authors":"E. Reyes, J. Massana, F. Alonso, N. León, A. Moragues","doi":"10.3989/mc.2020.10619","DOIUrl":"https://doi.org/10.3989/mc.2020.10619","url":null,"abstract":"In this paper, the influence of additions of nanosilica (nSi) and microsilica (mSi) on the behaviour of binary and ternary mixtures in chloride environments is studied. The main objective is to obtain high-performance self-compacting concrete (HPSCC) with a high durability which can meet specific demands in such aggressive environments. Ten blends were manufactured using Portland cement (CEM I 52.5 R) and additions of nSi and mSi in binary and ternary mixtures. The results of three tests frequently used to evaluate resistance to chloride penetration– electrical resistivity, migration and chloride diffusion –were studied and compared. Both binary and ternary mixtures presented significant improvements in chloride resistance, generally in proportion to the total content of the addition. In all the ternary mixtures, high resistivity is obtained, which indicates that such mixtures have a notably low chloride penetrability. Furthermore, these mixtures provided extremely low chloride diffusion coefficients even at small addition ratios.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"221"},"PeriodicalIF":2.1,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42783847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evelio Teijón-López-Zuazo, Á. Vega-Zamanillo, M. Á. Calzada-Perez, L. Juli-Gándara
Granite rock has powerful alterations at several meters of depth. The clayed sand resulting is commonly known as jabre. This “in situ” mixture of cement-stabilized soil requires a laboratory formula. Even when the test section is correctly verified, the mechanical properties of the homogeneous mixture of jabre exhibit high degrees of dispersion. The laboratory work undertaken included particle-size analysis and screening, definition of liquid and plastic limits, compressive strength, dry density and moisture content over stabilized samples, modified Proctor, California Bearing Ratio (CBR) and the determination of the workability of the hydraulically bound mixtures. The stress resistance curve was analyzed by means of a multilinear model of unconfined compressive strength (UCS). Since practical engineering only requires UCS for 7 days, in order to gain greater knowledge of the material, other UCS transformations were used at other curing times such as 7, 14 and 28 days.
{"title":"Estimation of unconfined compressive strength of cement-stabilized jabre as material upgrade on highway construction","authors":"Evelio Teijón-López-Zuazo, Á. Vega-Zamanillo, M. Á. Calzada-Perez, L. Juli-Gándara","doi":"10.3989/mc.2020.09019","DOIUrl":"https://doi.org/10.3989/mc.2020.09019","url":null,"abstract":"Granite rock has powerful alterations at several meters of depth. The clayed sand resulting is commonly known as jabre. This “in situ” mixture of cement-stabilized soil requires a laboratory formula. Even when the test section is correctly verified, the mechanical properties of the homogeneous mixture of jabre exhibit high degrees of dispersion. The laboratory work undertaken included particle-size analysis and screening, definition of liquid and plastic limits, compressive strength, dry density and moisture content over stabilized samples, modified Proctor, California Bearing Ratio (CBR) and the determination of the workability of the hydraulically bound mixtures. The stress resistance curve was analyzed by means of a multilinear model of unconfined compressive strength (UCS). Since practical engineering only requires UCS for 7 days, in order to gain greater knowledge of the material, other UCS transformations were used at other curing times such as 7, 14 and 28 days.","PeriodicalId":51113,"journal":{"name":"Materiales de Construccion","volume":"70 1","pages":"218"},"PeriodicalIF":2.1,"publicationDate":"2020-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46163140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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