Journal articles on the topic 'Concrete durability'
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1
Mather, Bryant. "Concrete durability." Cement and Concrete Composites 26, no. 1 (January 2004): 3–4. http://dx.doi.org/10.1016/s0958-9465(02)00122-1.
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Tian, Xiao, and Niankun Zhu. "Durability Prediction Method of Concrete Soil Based on Deep Belief Network." Advances in Civil Engineering 2022 (January 6, 2022): 1–7. http://dx.doi.org/10.1155/2022/4338306.
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To truly reflect the durability characteristics of concrete subjected to multiple factors under complex environmental conditions, it is necessary to discuss the prediction of its durability. In response to the problem of durability prediction of traditional concrete structures, there is a low prediction accuracy, and the predicted time is long, and a concrete structural durability prediction method based on the deep belief network is proposed. The influencing factors of the concrete structural durability parameters are analyzed by two major categories of concrete material and external environmental conditions, and the transmission of chloride ions in the concrete structure is described. According to the disconnection of the steel bars, the durability of the concrete structure is started, and the determination is determined. The concrete structural antiflexural strength, using a deep belief network training concrete structural antiflexural strength judgment data, constructs a concrete structural durability predictive model and completes the durability prediction of the concrete structure based on the deep belief network. The proposed prediction method based on the deep belief network has a high prediction accuracy of 98% for the durability of concrete column structures. The simulation results show that the concrete structural durability’s prediction accuracy is high and the prediction time is short. The prediction of concrete durability discussed here has important guiding significance for the improvement of concrete durability test methods and the improvement of concrete durability evaluation standards in China.
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Wang, Hai Long, Xiao Yan Sun, Qi Wen Peng, and Feng Xue. "Durability and Mechanical Behaviors of Steel Slag Powder Concrete." Applied Mechanics and Materials 438-439 (October 2013): 58–62. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.58.
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The mechanical behaviors and durability of concrete containing steel slag powder (SSP), silica fume (SF) and fly ash (FA) were presented in this study. The fresh concrete properties, compressive strength, split tensile strength, elastic modulus, stress-stain curve, chloride permeability as well as carbonation of concretes mixed with different SSP contents or concretes containing compound mineral admixture were tested. The experimental results reveal that the mechanical behaviors and durability of concrete with 10% SSP replacing cement are both improved than that of the reference concrete. Mechanical behaviors and durability of concrete with 20% SSP replacing cement are similar to the reference concrete. Concrete with compound mineral admixture of SSP and SF obtain the highest enhancement in both strength and chloride resistance.
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Czarnecki, Lech, Robert Geryło, and Krzysztof Kuczyński. "Concrete Repair Durability." Materials 13, no. 20 (October 13, 2020): 4535. http://dx.doi.org/10.3390/ma13204535.
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The repairs of building structures are inevitable and indispensable. Repairs are used to restore or maintain the usability of existing facilities, often contributing to the extension of their expected service life, increasing the sustainability of building resources. Given that conservation rules are observed, repairs are also used to save monuments. The concept of repair durability brings to the foreground the durability of the repaired structure (after repair): what service life has been obtained/recovered as a result of the repair. Based on the available data (limited set), a generalised distribution function of repair durability was developed, with a disappointing course. This, however, applies (necessarily) to the past. Significant progress was shown to have been achieved in the theoretical and technical fundamentals of technical repair measures. In this situation, a prognostic distribution function was also designed for future repairs according to EN 1504. A rule of thumb called estimating concrete repair durability, CRD was proposed. The risk associated with estimating the durability of repairs was indicated. A reason for optimism is that proactive monitoring of the condition of the structure and, consequently, management of the repair strategy allows to reach the designed life of the structure.
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Wedding, PA, and LE Rodway. "Durability of Concrete." Cement, Concrete and Aggregates 7, no. 1 (1985): 43. http://dx.doi.org/10.1520/cca10043j.
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Shaikh, Faiz. "Mechanical and Durability Properties of Green Star Concretes." Buildings 8, no. 8 (August 17, 2018): 111. http://dx.doi.org/10.3390/buildings8080111.
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This paper presents mechanical and durability properties of green star concretes. Four series of concretes are considered. The first series is control concrete containing 100% ordinary Portland cement, 100% natural aggregates and fresh water. The other three series of concretes are green star concretes according to Green Building Council Australia (GBCA), which contain blast furnace slag, recycled coarse aggregates and concrete wash water. In all above concretes compressive strength, indirect tensile strength, elastic modulus, water absorption, sorptivity and chloride permeability are measured at 7 and 28 days. Results show that mechanical properties of green star concretes are lower than the control concrete at both ages with significant improvement at 28 days. Similar results are also observed in water absorption, sorptivity and chloride permeability where all measured durability properties are lower in green star concretes compared to control concrete except the higher water absorption in some green star concretes.
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Cheng, Qi Feng, Bao Lian Wen, Mei Dan Li, Wen Ling Tian, Chun Yang Wang, Zheng Zhong Li, and Hui Ming Huang. "Analysis on the Correlations between Preservatives and the Durability of High Performance Structural Concretes." Advanced Materials Research 374-377 (October 2011): 1380–84. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.1380.
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Concrete is the most consumed building material worldwide today, which durability has been paid close attentions for a long time. Currently，the design lifetime of many buildings is over 100 years. At present, many projects adopt preservatives to extend the durability of concrete. the paper makes contrastive studies on mechanical properties, ASTM flux, RCM chloridion diffusion, Permit in situ chloridion permeability, Autoclam water absorption, and freezing & thawing resistance between preservatives-added and non-preservative concretes at different typical strengths; and concludes correlations between the preservatives at different strengths and the durability of concrete, thus to evaluate the influence of various preservatives on the durability of high-performance concrete.
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Mishutin, Andriy, Kos Zeljko, Grynyova Iryna, and Lucia Chintea. "Durability of Modified Fiber Concrete for Rigid Pavements." Croatian Regional Development Journal 2, no. 1 (June 1, 2021): 30–40. http://dx.doi.org/10.2478/crdj-2021-0006.
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Abstract Modified concretes and fiber concretes for rigid pavements have been investigated. Four-factor experiment was conducted. The amount of Portland cement, polypropylene fiber, metakaolin and polycarboxylate superplasticizer varied in the experiment. All mixtures had the same mobility S2. The active mineral additive metakaolin increases the compressive strength of concrete and its tensile strength in bending. The amount of metakaolin at the level of 15.20 kg/m3 is rational. Due to a decrease in W/C with an increase in the amount of superplasticizer Coral ExpertSuid-5 to 0.9.1%, the compressive strength of concrete increases by 5.7 MPa, the tensile strength in bending increases by 0.5.0.6 MPa. Due to the introduction of polypropylene fiber, the tensile strength of concrete in bending increases by 0.6.0.9 MPa, the frost resistance of concrete increases by 50 cycles. Due to the use of a rational amount of superplasticizer and metakaolin, the frost resistance of concretes and fiber concretes concrete increases by 50-100 cycles. The use of a rational amount of modifiers and fiber reduces the abrasion of concretes by 40.45%. The developed modified fiber concretes of rigid pavements, depending on the amount of Portland cement, have compressive strength from 55 MPa to 70 MPa, tensile strength in bending from 8 MPa to 9.5 MPa, frost resistance from F350 to F450, abrasion from 0.30 to 0.40 g/cm2. Such strength, frost resistance and abrasion resistance allow the use of fiber concretes in pavements with the greatest load and ensures high durability of the material and corresponds to the directions and tasks of the state scientific and technical program “National Transport Strategy of Ukraine for the period up to 2030”
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Sideris, Kosmas K., A. Chatzopoulos, Ch Tassos, and P. Manita. "Durability of concretes prepared with crystalline admixtures." MATEC Web of Conferences 289 (2019): 09003. http://dx.doi.org/10.1051/matecconf/201928909003.
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The objective of this work was to study the influence of crystalline admixtures on the durability of concrete. Four concrete mixtures – two reference concretes and two alternative mixtures-were produced during the first phase of the research. Influence of curing on the activation of the crystals was investigated on concrete slab specimens. The properties measured were the compressive strength and different durability indicators. The results revealed that crystalline admixtures enhanced the strength and the durability of the alternative mixtures.
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Krishnaraj, L., P. T. Ravichandran, M. V.A.Karthik, N. Satheeshram Avudaiyappan, and . "A Study on Porous Sealing Efficacy of hydrophilic Admixture on Blended Cement Concrete." International Journal of Engineering & Technology 7, no. 2.12 (April 3, 2018): 446. http://dx.doi.org/10.14419/ijet.v7i2.12.11514.
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The life of the concrete is strongly influenced by durability parameters. The permeability is one of the main characteristics influencing the durability of concrete. The concrete is more permeable due to the ingress of water, oxygen, chloride, sulphate, and other potential deleterious substances. The durability of concrete is mainly affected by pore structure system of concrete and addingthe supplementary cementitious materials (SCM), such as fly ash, slag cement, and silica fume can be decrease permeability. Crystalline technology enhances the strength of concrete by filling the poresand micro-cracks with non-dissolvable substances. To study the efficiency of crystalline formation in concrete in terms of more permeable should be guaranteed through a specific technique.The effectiveness of crystalline waterproofing system with partial replacement cement by GGBS is studiedin terms of strength and durability. The performance of the two different types of crystalline waterproofing integral admixtures has been studied for compressive strength, Split tensile strength, workability, water permeability, Rapid chloride permeability test and porosity in this paper.The early strength increased in GGBS with crystalline admixture concretes compare to the control concrete. No significant strength reduction is observed in GGBS concretes with crystalline admixture when replaced with 20% and 40% of cement than control concrete.
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Domagała, Lucyna. "Durability of Structural Lightweight Concrete with Sintered Fly Ash Aggregate." Materials 13, no. 20 (October 14, 2020): 4565. http://dx.doi.org/10.3390/ma13204565.
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The aim of this study was to present the problem of durability of structural lightweight concrete made of a sintered fly ash aggregate. The issue of durability was researched for 12 concrete series in terms of their water absorption, water permeability, and freeze-thaw resistance. Additionally, the microstructure of several concretes was analyzed with a scanning electron microscope (SEM). In the durability research, the influences of the following parameters were taken into consideration: The initial moisture content of sintered fly ash (mc = 0, 17–18, and 24–25%); the aggregate grading (4/8 and 6/12 mm); and the water-cement ratio (w/c = 0.55 and 0.37). As a result of various compositions, the concretes revealed different properties. The density ranged from 1470 to 1920 kg/m3, and the corresponding strength ranged from 25.0 to 83.5 MPa. The durability research results of tested lightweight concretes showed that, despite considerably higher water absorption, a comparable water permeability and comparable or better freeze-thaw resistance in relation to normal-weight concrete may be present. Nevertheless, the fundamental requirement of lightweight concrete to achieve good durability requires the aggregate’s initial moisture content to be limited and a sufficiently tight cement matrix to be selected. The volume share of the cement matrix and aggregate, the cement content, and even the concrete strength are of secondary importance.
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Qiao, Hong Xia, Yu Li, Zhong Mao He, and Jin Mei Dong. "The Durability Study of Concrete in Sulfate Environment." Applied Mechanics and Materials 204-208 (October 2012): 3137–41. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.3137.
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Aiming at determining the durability of concrete in very salty regions, this study examines the performance of various high performance fine aggregate concretes in a sulfate environment, such as high performance concrete inside a composite additive, and Portland cement concrete and sulfate resistant cement concrete, all of which experienced dry-wet cycles in sodium sulfate solutions. By examining the changes of elastic moduli and analyzing the SEM of the concrete, this paper has found that the salt resistance of sulfate resistant cement concrete is no better than that of Portland cement concrete in the extremely aggressive dry-wet cycle environment but high performance concrete containing a composite additive has better resistance in a sulfate environment. Besides, the composite additive can create the environment for a second hydration to reduce the amount of Ca(OH)2 inside the concrete, and build additional C-S-H gel to reform the microstructure of concrete effectively. Finally, the paper offers some advice for mixing concrete in salt regions.
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Stott, D., T. Rezansoff, and B. F. Sparling. "Loss of freeze–thaw durability of concrete containing accelerating admixtures." Canadian Journal of Civil Engineering 21, no. 4 (August 1, 1994): 605–13. http://dx.doi.org/10.1139/l94-062.
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Rapid freeze–thaw durability tests on air entrained concrete mixes containing a proprietary nonchloride accelerating admixture or CaCl2 show that although early age compressive strength acceleration is achieved, the freeze-thaw durability is reduced when compared with the durability of control concretes of similar mix proportions, but without accelerating admixtures. Although the compressive strength gains were accelerated in mixes containing either the proprietary accelerating admixture or CaCl2, the tensile strengths at 28 days were similar for mixes with and without the admixtures.Petrographic analyses showed air contents and air void spacing factors in concretes with accelerating admixtures, either nonchloride or CaCl2, to be similar to the air systems in the control concrete, though more air entraining agent was required with the mixes containing accelerating admixtures. Local aggregates as well as aggregates from three alternate sources were used. Test results did not show any significant differences in durability on the basis of aggregate source.As the larger reduction measured in freeze–thaw durability for concrete mixes containing either chloride or nonchloride accelerating admixtures could not be attributed to either a deficient air void system in the cured concrete or inferior aggregate, it is believed that the cause is some characteristic or a hydration product in the cement paste microstructure produced by accelerated hydration. Key words: concrete, durability, freeze–thaw testing, strength acceleration, admixtures, air void system.
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Ma, Hai Yan, Hong Fa Yu, Wen Tao Cao, Kang Bai, Peng Zhou, and Li Juan Han. "Freeze-Thaw Durability of Portland Cement Concrete Subjected to Aircraft Deicer." Advanced Materials Research 152-153 (October 2010): 1856–61. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1856.
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Influence of glycol, which is the main composition of the most frequently used aircraft dicer, on the freeze-thaw durability of Portland cement concrete were investigated. Freeze-thaw durability of Portland cement concrete was tested by accelerated freeze-thaw test. Four kinds of solutions, namely tap water, 3.5% NaCl solution, glycol solutions and a LBR-A type commercial aircraft deicer were employed to be the freezing-thawing mediums. Results show that freeze-thaw durability of concrete exposed to glycol solutions is closely related to the solution concentrations. Failure of concretes exposed to 3.5% glycol solution is similar to that of those exposed 3.5% NaCl solution, which are attributed to serious surface scaling. While damage of concrete exposed to 12.5% and 25% glycol solutions are postponed, and the durability of concrete are increased. Compared with glycol solution, the commercial aircraft deicer demonstrated much more negative effect to concrete freeze-thaw durability, and the degree even exceeds 3.5% NaCl solution. Consequently, the commercial aircraft deicer is not a kind of environmental friendly deicer as usually considered.
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Sanjuán, Miguel Ángel, and Carmen Andrade. "Reactive Powder Concrete: Durability and Applications." Applied Sciences 11, no. 12 (June 18, 2021): 5629. http://dx.doi.org/10.3390/app11125629.
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Reactive powder concrete (RPC) is an ultra-high-performance concrete (UHPC) developed years ago by Bouygues, with the aim to build strong, durable, and sustainable structures. Some differences can be underlined between the RPC and high-performance concrete (HPC); that is to say, RPC exhibits higher compressive and flexural strength, higher toughness, lower porosity, and lower permeability compared to HPC. Microstructural observations confirm that silica fume enhances the fiber–matrix interfacial characteristics, particularly in fiber pullout energy. This paper reviews the reported literature on RPC, and it offers a comparison between RPC and HPC. Therefore, some RPC potential applications may be inferred. For instance, some examples of footbridges and structural repair applications are given. Experimental measurements on air permeability, porosity, water absorption, carbonation rate, corrosion rate, and resistivity are evidence of the better performance of RPC over HPC. When these ultra-high-performance concretes are reinforced with discontinuous, short fibers, they exhibit better tensile strain-hardening performance.
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Stavař, Tomáš, and Michal Stehlík. "The Assessment of Durability of Fibre Concretes with Dense Aggregate and Concrete Recyclate from the Results of Permeability and Diffusion Tests." Advanced Materials Research 1100 (April 2015): 106–11. http://dx.doi.org/10.4028/www.scientific.net/amr.1100.106.
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The mechanical and deformation characteristics of mass concrete are considerably improved by adding long structural fibres. This addition, however, does not always extend the durability of concrete. One of the key factors in the evaluation of durability of fibre concretes is the assessment of permeability of their surface layer using one of the non-destructive methods. In this research, three of these methods were used: two permeation methods with a gaseous medium, TORRENT and CO2 permeability method, and the British ISAT with a liquid medium, on the grounds of their simplicity of application and their possible combinability. The test results show that both TORRENT and ISAT methods can be used to assess the durability of both concrete and fibre concrete with dense aggregate. In the case of concrete containing concrete recyclate, however, the TORRENT method was not effective. Also the method of determining the permeability for CO2 was not suitable for the concrete with concrete recyclate. Even for other concretes this method was too complicated and too dependent on the marginal conditions of the measurement.
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Jin, Hui, Qing Chun, Chengwen Zhang, and Yidan Han. "A Durability Prediction Method for Historical Square Rebar Reinforced Concrete Buildings." Applied Sciences 11, no. 24 (December 10, 2021): 11737. http://dx.doi.org/10.3390/app112411737.
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Square rebars were developed and used for decades in the early development of reinforced concrete (RC) structures; however, the objectives of modern concrete structure durability analyses and standards are centered on round rebars in past decades, which are not suited for RC buildings utilizing square rebars. Considering the absence of proper evaluation techniques to evaluate the square rebar RC structures’ durability accurately, a novel durability prediction method has been proposed for this type of historical building. The method is based on major parts as in-situ investigation, finite element model simulation, component importance analysis, and structural durability prediction. The durability prediction calculation method was established on the experimental results of the realistic historical concrete tests and corrosion-induced cover cracking experiments for square rebar components. It was found that the carbonization-resistant ability of historical concretes was relatively weaker than that of current concretes and the calculation method for critical corrosion depth of square rebar was different from that of round rebar. Furthermore, two typical application cases are presented to introduce the procedure of the method in detail. Consequently, the research outcomes can be directly used on the durability prediction and protection works for historical RC buildings.
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French, C. "Durability of concrete structures." Structural Concrete 4, no. 3 (September 2003): 101–7. http://dx.doi.org/10.1680/stco.2003.4.3.101.
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Hope, Brian. "Improvement of concrete durability." Canadian Journal of Civil Engineering 14, no. 3 (June 1, 1987): 425. http://dx.doi.org/10.1139/l87-064.
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Gjørv, Odd E. "Durability of Concrete Structures." Arabian Journal for Science and Engineering 36, no. 2 (January 15, 2011): 151–72. http://dx.doi.org/10.1007/s13369-010-0033-5.
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Gaspar Tébar, Demetrio. "Durabilidad del hormigón." Materiales de Construcción 41, no. 221 (March 30, 1991): 7–18. http://dx.doi.org/10.3989/mc.1991.v41.i221.751.
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Pani, Luisa, Lorena Francesconi, James Rombi, Fausto Mistretta, Mauro Sassu, and Flavio Stochino. "Effect of Parent Concrete on the Performance of Recycled Aggregate Concrete." Sustainability 12, no. 22 (November 12, 2020): 9399. http://dx.doi.org/10.3390/su12229399.
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Recycling concrete construction waste is a promising way towards sustainable construction. Indeed, replacing natural aggregates with recycled aggregates obtained from concrete waste lowers the environmental impact of concrete constructions and improves natural resource conservation. This paper reports on an experimental study on mechanical and durability properties of concretes casted with recycled aggregates obtained from two different parent concretes, belonging to two structural elements of the old Cagliari stadium. The effects of parent concretes on coarse recycled aggregates and on new structural concretes produced with different replacement percentages of these recycled aggregates are investigated. Mechanical properties (compressive strength, modulus of elasticity, and splitting tensile strength) and durability properties (water absorption, freeze thaw, and chloride penetration resistance) are experimentally evaluated and analyzed as fundamental features to assess structural concrete behavior. The results show that the mechanical performance of recycled concrete is not related to the parent concrete characteristics. Furthermore, the resistance to pressured water penetration is not reduced by the presence of recycled aggregates, and instead, it happens for the chloride penetration resistance. The resistance to frost–thawing seems not related to the recycled aggregates replacement percentage, while an influence of the parent concrete has been assessed.
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Karavadra, Hiral. "Effects of Micro Silica & Flyash on Strength & Durability Parameters of High Strength Concrete." International Journal for Research in Applied Science and Engineering Technology 9, no. VI (June 30, 2021): 4650–53. http://dx.doi.org/10.22214/ijraset.2021.34845.
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High strength concrete is a term used to describe concrete with special properties not attributed to normal concrete. High-performance means that the concrete has one or more of the following properties: low shrinkage, low permeability, a high modulus of elasticity, or high strength. The application of nanotechnology in concrete has added a new dimension to the efforts to improve properties of High strength concrete. Nano materials, by virtue of their very small particle size can affect the concrete properties by altering the microstructure. Concrete can deteriorate for a variety of reasons, and concrete damage is often as result of combination of factors. This causes stresses in the concrete, which can eventually have resulted in cracking, delamination, and spalling. Concrete resists weathering action, chemical attack, and abrasion while maintaining its desired engineering properties throughout its lifespan. Different concretes require different degrees of durability depending on the exposure of environment and the properties desired. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. The main characteristics influencing the durability of concrete is its permeability to the ingress of water, oxygen, carbon dioxide, chloride, sulphate and other deleterious substances. It became necessary to impart knowledge about durability of concrete and factors affecting durability to the society, as the wide use of concrete as a material in the constructions. This study concerns with the use of Nano silica of size 12 nm in M60 grade of concrete to improve the compressive strength of concrete and study on various durability parameters of High strength concrete. An experimental investigation is planned to carry out with different amount of Fly ash as 15% ,20%, 25%,30% and Micro silica as 5.5%,7%,8.5%,10% in concrete by weight of concrete. have been planned to carry out are workability, compressive test, flexural test, split tensile test. To study durability parameters of High strength concrete with nano silica Rapid chloride penetration test (RCPT), Water Sorptivity test, Acid attack test, Sulphate attack test are conduct. In this study it was observed that t the durability, strength and workability are increase as the percentage of fly ash & micro silica increses
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Costa, Carla, and José Marques. "Feasibility of Eco-Friendly Binary and Ternary Blended Binders Made of Fly-Ash and Oil-Refinery Spent Catalyst in Ready-Mixed Concrete Production." Sustainability 10, no. 9 (September 3, 2018): 3136. http://dx.doi.org/10.3390/su10093136.
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Large-scale recycling of new industrial wastes or by-products in concrete has become a crucial issue for construction materials sustainability, with impact in the three pillars (environmental, social and economic), while still maintaining satisfactory, or improved, concrete performance. The main goal of the paper is to evaluate the technological feasibility of the partial, or total, replacement of fly-ashes (FA), widely used in ready-mixed concrete production, with spent equilibrium catalyst (ECat) from the oil-refinery industry. Three different concrete mixtures with binary binder blends of FA (33.3% by mass, used as reference) and of ECat (16.7% and 33.3%), as well as a concrete mixture with a ternary binder blend with FA and ECat (16.7%, of each) were tested regarding their mechanical properties and durability. Generically, in comparison with commercial concrete (i) 16.7% ECat binary blended concrete revealed improved mechanical strength and durability; (ii): ternary FA-ECat blended binder concrete presented similar properties; and (iii) 33% ECat binary blended concrete has a lower performance. The engineering performance of all ECat concretes meet both the international standards and the reference durability indicators available in the scientific literature. Thus, ECat can be a constant supply for ready-mixed eco-concretes production, promoting synergetic waste recycling across industries.
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Ziane, Sami, Mohammed-Rissel Khelifa, and Samy Mezhoud. "A Study of the Durability of Concrete Reinforced with Hemp Fibers Exposed to External Sulfatic Attack." Civil and Environmental Engineering Reports 30, no. 2 (June 1, 2020): 158–84. http://dx.doi.org/10.2478/ceer-2020-0025.
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AbstractThe purpose of this paper is to study the durability of concrete reinforced with hemp fibers in the face of external Sulfatic attack. For this purpose, five types of concrete were formulated; three types of concrete reinforced with hemp fibers (HC-0.25, HC-0.5, and HC-1) at 0.25%, 0.5%, and 1 % of hemp fibers in volume, respectively. And two control concretes, being ordinary concrete (OC) and polypropylene fiber reinforced concrete (PC). To assess the sulfatic attacks, the described concrete types underwent two aging protocols: 1) a complete immersion in 12.5 % Sodium Sulfate (Na2SO4) solution, and 2) an accelerated aging protocol consisting of immersion/drying in the same sulfate solution at a temperature of 60°C. The results show that concrete reinforced with 0.25 % of hemp fibers is the optimal amount compared to control concretes in terms of physico-mechanical performance and durability under sulfate attack. This number of fibers could enable the production of green and durable structural concretes based on untreated hemp fibers.
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Alzeebaree, Radhwan, Abdulkadir Çevik, Alaa Mohammedameen, Anıl Niş, and Mehmet Eren Gülşan. "Mechanical performance of FRP-confined geopolymer concrete under seawater attack." Advances in Structural Engineering 23, no. 6 (November 14, 2019): 1055–73. http://dx.doi.org/10.1177/1369433219886964.
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In the study, mechanical properties and durability performance of confined/unconfined geopolymer concrete and ordinary concrete specimens were investigated under ambient and seawater environments. Some of the specimens were confined by carbon fiber and basalt fiber–reinforced polymer fabric materials with one layer and three layers under chloride and ambient environments to observe mechanical strength contribution and durability performances of these hybrid types of materials. These fiber-reinforced polymer fabric materials were also evaluated in terms of retrofit purposes especially in the marine structures. In addition, microstructural evaluation is also conducted using scanning electron microscope on geopolymer concrete and ordinary concrete specimens to observe the amount of deterioration in microscale due to the chloride attacks. Results indicated that confined specimens exhibited enhanced strength, ductility, and durability properties than unconfined specimens, and the degree of the enhancement depended on the fiber-reinforced polymer confinement type and the number of fiber-reinforced polymer layer. Specimens confined by carbon fabrics with three layers showed superior mechanical properties and durability performance against chloride attack, while specimens confined by basalt fabrics with one layer exhibited low performance, and unconfined specimens showed the worst performance. Both fiber-reinforced polymer fabric materials can be utilized as retrofit materials in structural elements against chloride attacks. The results also pointed out that seawater attack reduced the ductility performance of the geopolymer concrete and ordinary concrete specimens. Furthermore, geopolymer concrete specimens were found more durable than the ordinary concrete specimens, and both types of concretes exhibited similar fracture properties, indicating that geopolymer concrete can be utilized for structural elements instead of ordinary concretes.
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Zanotto, Federica, Alice Sirico, Sebastiano Merchiori, Francesca Vecchi, Andrea Balbo, Patrizia Bernardi, Beatrice Belletti, Alessio Malcevschi, Vincenzo Grassi, and Cecilia Monticelli. "Durability of Reinforced Concrete Containing Biochar and Recycled Polymers." Key Engineering Materials 919 (May 11, 2022): 188–96. http://dx.doi.org/10.4028/p-mwn300.
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In the field of sustainable construction materials, the production of eco-friendly concretes, obtained by the addition of waste products such as biochar and recycled polymer particles, offers interesting alternatives to traditional materials. Biochar is a carbonaceous solid by-product obtained from the thermo-chemical conversion of biomass and its addition into concrete admixtures can offer an eco-friendly carbon sequestration solution, capable to slightly improve concrete properties. Recycled polymer materials can be used to partially replace conventional aggregates with the aim of obtaining lighter concretes that help to face the disposal challenge presented by this non-degradable plastic waste. However, the influence of these waste additions on the corrosion behavior of steel rebars embedded in these “eco-concretes” is still unexplored. Within this context, this work presents some results of an extensive study dealing with the concrete mechanical and physical properties and the rebar corrosion resistance during cyclic exposures to chloride-containing solutions.
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Zhang, Peng, Qingfu Li, Yuanzhao Chen, Yan Shi, and Yi-Feng Ling. "Durability of Steel Fiber-Reinforced Concrete Containing SiO2 Nano-Particles." Materials 12, no. 13 (July 7, 2019): 2184. http://dx.doi.org/10.3390/ma12132184.
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An experimental study was conducted to investigate the effect ofnano-SiO2 and steel fiber content on the durability of concrete. Five different dosages of nano-SiO2 particles and five volume dosages of steel fiber were used. The durability of concretes includes permeability resistance, cracking resistance, carbonation resistance, and freezing-thawing resistance, and these were evaluated by the water permeation depth, number of cracks, total cracking area per unit area of the specimens, carbonation depth of the specimens, and the relative dynamic elastic modulus of the specimens after freezing-thawing cycles, respectively. The results indicate that the addition of nano-SiO2 particles significantly improves the durability of concrete when the content of nano-SiO2 is limited within a certain range. With the increase of nano-SiO2 content, the durability of concrete first increases and then decreases. An excessive number of nano-SiO2 particles could have an adverse effect on the durability of the concrete. The addition of the correct amount of steel fibers improves the carbonation resistance of concrete containing nano-particles, but excessive steel fiber reduces the carbonation resistance. Moreover, the addition of steel fibers reduces the permeability resistance of concrete containing nano-particles. The incorporation of steel fiber enhanced the freezing-thawing resistance and cracking resistance of concrete containing nano-particles. With increasing steel fiber content, the freezing-thawing resistance of the concrete containing nano-particles increases, and the cracking resistance of the concrete decreases gradually.
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Teplý, Břetislav, Markéta Chromá, Pavla Rovnaníková, and Alfred Strauss. "Probabilistic Modelling and the k-Value Concept." Key Engineering Materials 635 (December 2014): 198–203. http://dx.doi.org/10.4028/www.scientific.net/kem.635.198.
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The durability of concrete structures is an important issue. Eurocode EN 206-1 introduces the k-value concept for concretes made with supplementary cementitious materials; a prescriptive concept that recommends limiting water/cement ratio values for a specified exposure class. A more advanced performance-based concept directly requires that concrete be designed in terms of performance-related parameters, an approach which seems to be more suitable when durability must be achieved. The application of mathematical models in durability assessment is advocated, and an example is shown.
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Liu, Shiming, Miaomiao Zhu, Xinxin Ding, Zhiguo Ren, Shunbo Zhao, Mingshuang Zhao, and Juntao Dang. "High-Durability Concrete with Supplementary Cementitious Admixtures Used in Corrosive Environments." Crystals 11, no. 2 (February 17, 2021): 196. http://dx.doi.org/10.3390/cryst11020196.
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Durability of concrete is of great significance to prolong the service life of concrete structures in corrosive environments. Aiming at the economical and environment-friendly production of concrete by comprehensive utilization of the supplementary cementitious materials made of industrial byproducts, the resistances to chloride penetration, sulfate attack, and frost of high-performance concrete were studied in this paper. Fifteen concretes were designed at different water–binder ratio with the changes of contents of fly ash (FA), silica fume (SF), ground granulated blast-furnace slag (GGBS), and admixture of sulfate corrosion-resistance (AS). The compressive strength, the total electric flux of chloride penetrability, the sulfate resistance coefficient, and the indices of freezing and thawing were measured. Results indicate that, depending on the chemical composition, fineness, and pozzolanic activity, the supplementary cementitious admixtures had different effects on the compressive strength and the durability of concrete; despite having a higher fineness and pozzolanic activity, the GGBS gave out a negative effect on concrete due to a similar chemical composition with cement; the SF and FA presented beneficial effects on concrete whether they were used singly with GGBS or jointly with GGBS; the AS improved the compressive strength and the sulfate corrosion resistance of concrete. In general, the grade of durability was positively related to the compressive strength of concrete. Except for the concretes admixed only with GGBS or with GGBS and FA, others had super durability with the compressive strength varying from 70 MPa to 113 MPa. The concretes with water to binder ratio of 0.29 and total binders of 500 kg/m3 admixed with 7% FA + 8% SF + 8% GGBS or 7% FA + 8% SF + 8% GGBS + (10~12)% AS presented the highest grades of resistances specified in China codes to chloride penetration, sulfate corrosion, and frost, while the compressive strength was about 100 MPa.
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Benali, Redha, Mekki Mellas, Mohamed Baheddi, Tarek Mansouri, and Rafik Boufarh. "Physico-mechanical Behaviors and Durability of Heated Fiber Concrete." Civil Engineering Journal 7, no. 9 (September 1, 2021): 1582–93. http://dx.doi.org/10.28991/cej-2021-03091745.
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The objective of the present manuscript is to describe the impact of polypropylene fibers on the behavior of heated concrete subjected to heating and cooling cycles at temperatures of 200, 450 and 600 °C respectively for six hours, through a series of experimental tests on mass loss, water absorption, porosity, compressive and tensile strength. For this purpose, mixes were prepared with a water/cement ratio with the incorporation of polypropylene fibers with a rate varying from 0.5 to 1.5%. These fibers were added in order to improve the thermal stability and to prevent the concrete from splitting. The results show that a considerable loss of strength was noticed for all tested specimens. The relative compressive strengths of the concretes containing polypropylene fibers were higher than those of the concretes without fibers. Also, a greater loss of mass of the polypropylene fibers compared to those without fibers was noticed when increasing the temperature. The flexural tensile strength of the concrete was more sensitive to elevated temperatures than the compressive strength and a rapid increase in porosity was observed for the fiber-reinforced concrete compared to the reference concrete. Furthermore, water absorption by the fibers is proportional to the fiber content of the concrete. Doi: 10.28991/cej-2021-03091745 Full Text: PDF
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Melchers, Robert E. "Long-Term Durability of Marine Reinforced Concrete Structures." Journal of Marine Science and Engineering 8, no. 4 (April 18, 2020): 290. http://dx.doi.org/10.3390/jmse8040290.
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The sustainability of reinforced concrete is critical, particularly for structures exposed to marine environments. Chlorides are implicated in causing or accelerating reinforcement corrosion and potentially earlier expensive repairs, yet there are many older reinforced concrete structures in good condition for many decades despite very high chloride levels at the reinforcement. The reasons for this are reviewed briefly, together with recent experimental work that better defines the role of chlorides. One is initiation of reinforcement corrosion but only through localized pitting at air-voids in concrete at the interface with the steel reinforcement. These tend to be small or negligible for high quality well-compacted concretes. The other role for chlorides has been shown, in experimental work, to accelerate the long-term loss of concrete alkali material. On the other hand, a review of practical experience shows that what has been termed chloride-induced reinforcement corrosion often is not that at all, but is the end-product of factors that impair the protective nature of the concrete. As reviewed herein, these include poor compaction, physical damage to concrete cover, concrete shrinkage, and alkali-aggregate reactions. The various observations presented are important for the proper understanding, analysis, and design of durable reinforced concrete structures exposed to chloride-rich environments.
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Langan, B. W., R. C. Joshi, and M. A. Ward. "Strength and durability of concretes containing 50% Portland cement replacement by fly ash and other materials." Canadian Journal of Civil Engineering 17, no. 1 (February 1, 1990): 19–27. http://dx.doi.org/10.1139/l90-004.
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Results are presented from an investigation on the compressive strength and durability of concretes containing substitute materials at a 50% replacement level (by mass) of Portland cement. Seven fly ashes (sub-bituminous, bituminous, and lignitic), together with limestone and an inert material (silica flour), were used as replacement materials. Durability studies included freeze–thaw testing (ASTM C666A), scaling resistance (ASTM C672), and abrasion resistance (ASTM C944). The air void system was assessed using the modified point count method of ASTM C457. The results indicate that although concretes with a 50% replacement level of cementitious material did not perform as well as the control concretes with no replacement, such concretes were able to meet minimum durability requirements. As anticipated, air-entrainment is the overriding factor that allows concrete to meet freeze–thaw durability requirements. In the context of this study, compressive strength does not appear to be a significant factor in freeze–thaw durability. Results indicated that concretes with compressive strengths of less than 10 MPa will still pass the freeze–thaw test, provided an adequate air void system is in place. Abrasion resistance tends to increase with compressive strength but not in all the cases. Key words: concrete, fly ash, compressive strength, durability, mineral admixtures.
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Landa-Ruiz, Laura, Aldo Landa-Gómez, José M. Mendoza-Rangel, Abigail Landa-Sánchez, Hilda Ariza-Figueroa, Ce Tochtli Méndez-Ramírez, Griselda Santiago-Hurtado, Victor M. Moreno-Landeros, René Croche, and Miguel Angel Baltazar-Zamora. "Physical, Mechanical and Durability Properties of Ecofriendly Ternary Concrete Made with Sugar Cane Bagasse Ash and Silica Fume." Crystals 11, no. 9 (August 24, 2021): 1012. http://dx.doi.org/10.3390/cryst11091012.
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In the present investigation, the physical, mechanical and durability properties of six concrete mixtures were evaluated, one of conventional concrete (CC) with 100% Portland cement (PC) and five mixtures of Ecofriendly Ternary Concrete (ETC) made with partial replacement of Portland Cement by combinations of sugar cane bagasse ash (SCBA) and silica fume (SF) at percentages of 10, 20, 30, 40 and 50%. The physical properties of slump, temperature, and unit weight were determined, as well as compressive strength, rebound number, and electrical resistivity as a durability parameter. All tests were carried out according to the ASTM and ONNCCE standards. The obtained results show that the physical properties of ETC concretes are very similar to those of conventional concrete, complying with the corresponding regulations. Compressive strength results of all ETC mixtures showed favorable performances, increasing with aging, presenting values similar to CC at 90 days and greater values at 180 days in the ETC-20 and ETC-30 mixtures. Electrical resistivity results indicated that the five ETC mixtures performed better than conventional concrete throughout the entire monitoring period, increasing in durability almost proportionally to the percentage of substitution of Portland cement by the SCBA–SF combination; the ETC mixture made with 40% replacement had the highest resistivity value, which represents the longest durability. The present electrical resistivity indicates that the durability of the five ETC concretes was greater than conventional concrete. The results show that it is feasible to use ETC, because it meets the standards of quality, mechanical resistance and durability, and offers a very significant and beneficial contribution to the environment due to the use of agro-industrial and industrial waste as partial substitutes up to 50% of CPC, which contributes to reduction in CO2 emissions due to the production of Portland cement, responsible for 8% of total emissions worldwide.
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Jain, Jitendra, Kho Pin Verian, Jan Olek, and Nancy Whiting. "Durability of Pavement Concretes Made with Recycled Concrete Aggregates." Transportation Research Record: Journal of the Transportation Research Board 2290, no. 1 (January 2012): 44–51. http://dx.doi.org/10.3141/2290-06.
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There is a growing trend to replace the traditional ingredients of concrete pavement mixtures with more sustainable materials from a perspective of both the cost of raw materials and the carbon dioxide footprint. The availability of quality natural aggregates, which make up about 70% to 80% of concrete (by volume), is becoming more limited because of environmental restrictions on quarrying operations and longer hauling distances. The other major concern is disposal of old concrete pavements, which unless used as fill or base material for construction of new roadways, will have to be placed in the landfills. In this study, recycled concrete aggregates (RCA) obtained from crushing old concrete pavement were used as coarse aggregates at 0%, 30%, 50%, and 100% replacement levels (by mass) for natural virgin aggregates (NVA). Concrete mixtures were designed and produced to meet the concrete pavement requirements for air content, slump, and flexural strength stipulated by the Indiana Department of Transportation. All concrete mixtures were produced with 18.5% to 20.0% of the cement replaced (by mass) with ASTM C618 Class C fly ash. The physical and mechanical testing involved evaluation of slump, air content, and development of both flexural and compressive strengths. In addition, durability was assessed with the freeze–thaw test, scaling test, rapid chloride permeability (RCP) test, and non–steady state migration test. The most advantageous dosages for replacing NVA with RCA for concrete pavements were found to be 50%, on the basis of fresh concrete properties and the results of strength and durability tests. The applicability of electrical impedance spectroscopy for quick performance appraisal is presented on the basis of the experimental relationship between the RCP charge and bulk resistance of concrete.
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Kadian, Amarender, and Sandeep Pannu. "A Study of Durability Properties of Bacterial Concrete." Journal of Advances and Scholarly Researches in Allied Education 15, no. 3 (May 1, 2018): 78–81. http://dx.doi.org/10.29070/15/56796.
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Jackiewicz-Rek, W., T. Drzymała, A. Kuś, and M. Tomaszewski. "Durability of High Performance Concrete (HPC) Subject to Fire Temperature Impact." Archives of Civil Engineering 62, no. 4 (December 1, 2016): 73–94. http://dx.doi.org/10.1515/ace-2015-0109.
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AbstractIn the recent years a tendency for design of increasingly slender structures with the use of high performance concrete has been observed. Moreover, the use of high performance concrete in tunnel structures, subject to high loads with possibility of extreme loads occurrence such as fire, has an increasing significance.Presented studies aimed at improving high performance concrete properties in high temperature conditions (close to fire conditions) by aeration process, and determining high temperature impact on the concretes features related to their durability.In this paper it has been proven that it is possible to obtain high performance concretes resistant to high temperatures, and additionally that modification of the concrete mix with aerating additive does not result in deterioration of concrete properties when subject to water impact in various form.
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Yu, Le Hua, Shuang Xi Zhou, and Hui Ou. "Experimental Investigation on Properties of High Performance Concrete with Mineral Admixtures in Pavement of Highway." Advanced Materials Research 723 (August 2013): 345–52. http://dx.doi.org/10.4028/www.scientific.net/amr.723.345.
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To meet demand of highperformance pavement concrete in highway, differentproportional concretes incorporating 30%—40% ground granulatedblast furnace slag and (or) fly ash were investigated on engineering properties in laboratory. Workability offresh concrete was evaluated by result of testing slump, mechanical property ofconcrete by flexural strength, abrasion resistance of concrete by index ofabrasion resistance and durability of concrete by chloride diffusioncoefficient and value of charge passed. The results indicate that measuredcharacteristics of concretes are superior to the relevant requisitions in specificationof highway. It was revealed that partial substitution ofmineral admixtures increased workability of fresh concrete, abrasion resistanceand durability of concrete. Addition of groundgranulated blast furnace slag is more favorable to flexural strength ofconcrete than that of fly ash, in particular for early-term to avoid delaying construction time with lower strength caused in use of greatvolume admixture.
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Cheng, Peng, Xin Fu Chen, and Lang Wu. "Research on Ordinary Concrete Durability." Applied Mechanics and Materials 584-586 (July 2014): 1318–21. http://dx.doi.org/10.4028/www.scientific.net/amm.584-586.1318.
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This paper introduces the common concrete durability research background of the status quo, summarizes the corrosion resistance of concrete under the background of the main influence factors. The corrosion types and corrosion mechanism of concrete are discussed, including the corrosion mechanism of concrete base material of cement, steel corrosion mechanism and corrosion mechanism of reinforced concrete structures. From the research and the analysis of the structure formation of ordinary concrete, summarizes the common strength grade of concrete high performance-based approach.
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Kubissa, Wojciech, Barbara Pacewska, and Iwona Wilińska. "Comparative Investigations of some Properties Related to Durability of Cement Concretes Containing Different Fly Ashes." Advanced Materials Research 1054 (October 2014): 154–61. http://dx.doi.org/10.4028/www.scientific.net/amr.1054.154.
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The results of research of mechanical properties and selected other characteristics influencing durability of cement concretes containing cement substitutes were presented. Cement concretes performed with conventional fly ash, fluidised fly ash and their mixture were investigated. The obtained results were compared with findings registered for two types of concrete performed without cement replacements and with cement concrete containing silica fume. The results have shown that cement concrete with predetermined 28-day compressive strength of about 50 MPa and good workability may be obtained using different cement replacements. Generally, these cement concretes exhibited also favorable properties related to concrete durability, i.e. low permeability and sorptivity, and significant reduction of chloride migration coefficient. Favourable results were obtained for cement concrete containing mix of conventional and fluidised fly ashes: good workability, compressive strength after 28th day exceeding 50 MPa, low permeability of water, and low sorptivity, as well as low coefficient of chloride migration. These features were similar as for cement concrete containing silica fume.
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Carré, Hélène, Céline Perlot, Atef Daoud, Md Jihad Miah, and Bassem Aidi. "Durability of Ordinary Concrete after Heating at High Temperature." Key Engineering Materials 711 (September 2016): 428–35. http://dx.doi.org/10.4028/www.scientific.net/kem.711.428.
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After a fire, the concrete structures are usually repaired. This repair requires a diagnosis so as to know the areas to be preserved and the areas to be demolished. In this analysis, the load-bearing capacity is often the primary endpoint. However, the question of the durability of the structure must also be asked. This experimental study aims to assess the durability of one ordinary concretes after heating at high temperature (up to 600 °C). The ordinary concrete have a compressive strength at 28 days of about 40 MPa. Five characteristics were determined for each target temperature (20, 120, 250, 400 and 600 °C): the compressive strength, the water porosity, the nitrogen permeability, the pore distribution by mercury porosimetry and the absorption coefficient. The evolution of the characteristics with temperature are evaluated. Their evolution with compressive strength is analysed and durability index are detailed. The results show that some correlation exist between the characteristics in particular between nitrogen permeability and water porosity. The evolution of durability index shows that the compressive strength is not sufficient to evaluate the durability of concrete after heating.
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Chen, Xupeng, Zhuowen Sun, and Jianyong Pang. "A Research on Durability Degradation of Mineral Admixture Concrete." Materials 14, no. 7 (April 2, 2021): 1752. http://dx.doi.org/10.3390/ma14071752.
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In order to study the degradation laws and mechanisms of admixture concretes with single-added SO42− and composite of Mg2+ and SO42−, respectively, the durability tests were conducted on three types of mineral admixture concretes (concretes with single-added metakaolin (MK), single-added ultra-fine fly ash (UFA), and composite of metakaolin and ultra-fine fly ash (MF), and one reference concrete. In these tests, the 10% Na2SO4 solution and the 10% MgSO4 solution were used as the erosion medium, and the drying-wetting circle method was applied. It can be seen from the compressive tests and grey relational analysis that the MK admixture can improve the anti-Na2SO4-erosion capability of the concrete significantly, but weaken its anti-MgSO4-erosion capability; the UFA admixture can improve both the anti-Na2SO4-erosion and the anti-MgSO4-erosion capability of the concrete; and the composite admixture has superimposed effects and can enhance erosion resistance against these two erosion mediums. The phase composition and the changes of the macro morphology and the micro structure during the erosion process caused by mono sulfate ions and complex ions has been observed through X-ray diffraction (XRD), FTIR spectrum (FTIR), and scanning electron microscope (SEM), based on which it was determined that the erosion of single-added SO42− ions can produce erosive outputs of ettringite, gypsum, and mirabilite in the concrete, and cause corner scaling or deformation. Mg2+ and SO42− reacted in the concrete and produced brucite, M-S-H, ettringite, and gypsum, etc. The erosion of complex ions can cause scaling of the cement mortar and aggregate from the surface or the desquamation of corners.
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YARMAKOVSKY, V. N., and D. Z. KADIEV. "PHYSICAL BASIS OF CONCRETE DURABILITY AT LOW SUBZERO TEMPERATURES." Building and reconstruction 90, no. 4 (2020): 122–36. http://dx.doi.org/10.33979/2073-7416-2020-90-4-122-136.
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Generalization and analysis of scientific hypotheses and theories of domestic and foreign researchers in the field of the frost action mechanism on concrete has been performed. A critical author's assessment of them from the point of view of the basics of physical chemistry of silicates and solid state physics is presented. The initial prerequisites for the frost resistance of heavy concrete and equal-strength structural light concrete in connection with their structure are formulated, including of this article author's targeted experimental studies on the relationship of the frost resistance of these concretes with their pore structure. Thermodynamic models of freezing-thawing of water, including its adsorption layers in capillaries of cement materials porous structures are used. The data of studies of the critical degree of water saturation of concrete are considered and a reasonable assessment of it is given as an integral characteristic that determines the possibility of formation of micro- and then macro-defects in the concrete structure during its cyclic freezing and thawing. Based on the results of analytical and experimental studies, using the basic principles of physics of the solid state, as well as the physical and physical-chemistry of silicates, has been developed the physical-chemical basis for the resistance of structural lightweight concrete in comparison with equally strong normal weight concrete to the effects of low (up to minus 70 °C) subzero temperatures. The results of this work are considered by the authors as a modern scientific basis for the development of the main provisions of the technology for manufacturing structural lightweight and normal weight concretes with high durability (frost resistance and water resistance), intended for reinforced concrete structures of engineering constructions, operated in severe climatic conditions, including in the conditions of the Arctic coast.
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Jaskulski, Roman, Marcin Supera, Wojciech Kubissa, Peter Koteš, and Miroslav Brodňan. "The influence of RCA addition on selected parameters of concrete." MATEC Web of Conferences 196 (2018): 02018. http://dx.doi.org/10.1051/matecconf/201819602018.
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The main goal of this research was to evaluate the effects of using recycled concrete aggregate (RCA) of an average quality as a 50% replacement for natural coarse aggregate. A total of 26 concrete mixtures were prepared, 13 containing RCA as a 50% of coarse aggregate and the same number of mixes only with natural aggregate (NA). The results show the influence of the RCA incorporation on concretes for the same w/c ratio. Both mechanical and durability parameters of the concretes made with recycled aggregate are worse, and the differences increase for low w/c ratio. Despite the reduction of these parameters in relation to concretes with only NA, both mechanical and durability test results obtained for concrete series with RCA can be described as good.
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Afroughsabet, Vahid, and Matteo Gastaldi. "Preliminary Assessment on Durability of High Performance Fiber Reinforced Concrete with CSA Cement." Key Engineering Materials 919 (May 11, 2022): 161–70. http://dx.doi.org/10.4028/p-lp6w63.
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Concrete industry produces a great environmental impact. The total, or partial, substitution of ordinary Portland cement (OPC) with Calcium sulfoaluminate (CSA) cement could be a possible solution, due to its lower production temperature and thus lower CO2 emission. Therefore, there is an essential need to assess the durability properties of concrete produced with CSA cement. In this work a preliminary study on durability of high performance fiber reinforced concretes produced with CSA cement in total or partial substitution of OPC, also with ground granulated blast-furnace slag (GGBS), was performed. Compressive strength and electrical resistivity of the different concrete mixes and electrochemical tests to evaluate corrosion condition of the embedded steel fibers, were assessed. The results show that substitution of OPC with CSA cement improves the mechanical properties of concrete but promotes corrosion of the steel fibers, affecting the durability of this material.
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Huijun, Wu, Zhan Diao, and Kaizuo Fan. "Study on durability of non-dispersible concrete in seawater environment." International Journal of Structural Integrity 11, no. 3 (November 5, 2019): 443–52. http://dx.doi.org/10.1108/ijsi-07-2019-0066.
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Purpose The purpose of this paper is to focus on the durability of underwater non-dispersible concrete in seawater environment. Design/methodology/approach In this paper, ten groups of underwater non-dispersible concrete mixtures were designed, and the anti-dispersibility and fluidity of the mixtures were tested. Findings The durability test analysis shows that different pouring methods have different effects on the durability of concrete. The durability of concrete poured on land is better than that poured in water. Different mineral admixtures have different effects on the durability of concrete: the frost resistance of the underwater non-dispersible concrete specimens with silica fume is the best; the impermeability and chloride ion permeability of the non-dispersible underwater concrete specimens with waterproofing agent are the best; and the alternation of wetting and drying has adverse effects on the durability indexes of the non-dispersible underwater concrete. Originality/value The durability of underwater non-dispersible concrete is tested and the results can be used for reference in engineering practice.
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Benmarce, Abdelaziz, Hocine Boudjehem, and Robila Bendjhaiche. "Durability of Self-Compacting Concrete." Advanced Materials Research 324 (August 2011): 340–43. http://dx.doi.org/10.4028/www.scientific.net/amr.324.340.
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Abstract. Self compacting concrete (SCC) seem to be a very promising materials for construction thanks to their properties in a fresh state. Studying of the influence of the parameters of specific designed mixes to their mechanical, physical and chemical characteristics in a state hardened is an important stage so that it can be useful for new-to-the-field researchers and designers (worldwide) beginning studies and work involving self compacting concrete. The objective of this research is to study the durability of self compacting concrete. The durability of concrete depends very much on the porosity; the latter determines the intensity of interactions with aggressive agents. The pores inside of concrete facilitate the process of damage, which began generally on the surface. We are interested to measure the porosity of concrete on five SCC with different compositions (w/c, additives) and vibrated concrete to highlight the influence of the latter on the porosity, thereafter on the compressive strength and the transfer properties (oxygen permeability, chloride ion diffusion, capillary absorption).
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Jebelean, Eugen, Catalin Badea, Liana Iures, Cornel Jiva, and Ioan Borza. "Acoustical Methods Used in the Study of Concrete Durability." Applied Mechanics and Materials 430 (September 2013): 113–17. http://dx.doi.org/10.4028/www.scientific.net/amm.430.113.
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The paper presents the experimental research on concretes and in-situ research on existing reinforced concretes elements, using “Pulse Velocity Method”. The “Pulse Velocity Method” it is an acoustical method which uses the ultra-sounds with 20 to 200 kHz frequency. The in-situ acoustic results are used to establish the durability of the concrete in the tested elements.
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Stehlík, Michal. "ENHANCING THE DURABILITY OF CONCRETE MADE OF CONCRETE RECYCLATE BY ADDITIVES AND ADMIXTURES." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 20, no. 2 (March 10, 2014): 270–79. http://dx.doi.org/10.3846/13923730.2013.802708.
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The aim of this research is to find an optimum combination of silicate admixtures and epoxy dispersion additives which would positively influence the durability and mechanical properties of concretes made of concrete recyclate. The durability of concrete is dependent on its cover layer permeability and also on the overall permeability of concrete recyclate. The cover layer permeability was evaluated by means of three methods, namely the air permeability method TPT and two methods of measuring water permeability, GWT and ISAT. Fine silicate admixtures and dispersion additives influence the air and water permeability of concrete made of concrete recyclate in different ways. The dose of 10% of microsilica or 30% of slag or fly ash decreases the air permeability of concrete. Water permeability, on the other hand, is decreased by adding a dose of 12% of pure epoxy dispersion. As regards improving the mechanical properties of concrete made of concrete recyclate, it seems to be promising to use a combination of 30% of slag admixture or 10% of microsilica admixture with 12% of epoxy dispersion additive. However, the price of admixtures and additives is relatively high. That is why additive enhanced concretes made of concrete recyclate are intended for special purposes.
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Yum, Woo Sung, Juan Yu, Dongho Jeon, Haemin Song, Sungwon Sim, Do Hoon Kim, and Jae Eun Oh. "Mechanical and Durability Properties of Cementless Concretes Made Using Three Types of CaO-Activated GGBFS Binders." Materials 15, no. 1 (December 30, 2021): 271. http://dx.doi.org/10.3390/ma15010271.
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This study examined the mechanical and durability properties of CaO-activated ground-granulated blast-furnace slag (GGBFS) concretes made with three different additives (CaCl2, Ca(HCOO)2, and Ca(NO3)2) and compared their properties to the concrete made with 100% Ordinary Portland Cement (OPC). All concrete mixtures satisfied targeted air content and slump ranges but exhibited significantly different mechanical and durability properties. The CaO-activated GGBFS concretes showed different strength levels, depending on the type of additive. The added CaCl2 was the most effective, but Ca(NO3)2 was the least effective at increasing mechanical strength in the CaO-activated GGBFS system. The OPC concrete showed the most excellent freezing–thawing resistance in the durability test, but only the CaO-activated GGBFS concrete with CaCl2 exhibited relatively similar resistance. In addition, the chemical resistance was significantly dependent on the type of acid solution and the type of binder. The OPC concrete had the best resistance in the HCl solution, while all CaO-activated GGBFS concretes had relatively low resistances. However, in the H2SO4 solution, all CaO-activated GGBFS concretes had better resistance than the OPC concrete. All concrete with sulfate ions had ettringite before immersion. However, when they were immersed in HCl solution, ettringite tended to decrease, and gypsum was generated. Meanwhile, the CaO-activated GGBFS concrete with CaCl2 did not change the type of reaction product, possibly due to the absence of ettringite and Ca(OH)2. When immersed in an H2SO4 solution, ettringite decreased, and gypsum increased in all concrete. In addition, the CaO-activated concrete with CaCl2 had a considerable amount of gypsum; it seemed that the dissolved C-S-H and calcite, due to the low pH, likely produced Ca2+ ions, and gypsum formed from the reaction between Ca2+ and H2SO4.