scholarly journals Application of Fuzzy and Rough Sets to Environmental Zonation for Concrete Durability: A Case Study of Shaanxi Province, China

2020 ◽  
Vol 12 (8) ◽  
pp. 3128 ◽  
Author(s):  
Daming Luo ◽  
Yan Wang ◽  
Shaohui Zhang ◽  
Ditao Niu
Keyword(s):  
Service Life ◽  
Rough Sets ◽  
Concrete Structures ◽  
Shaanxi Province ◽  
Maintenance Cost ◽  
Concrete Durability ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
The Impact ◽  
Durability Of Concrete

The durability of concrete structures is influenced by various factors, and the durability damage mechanism is different when the structure is in different environmental conditions. This will have implications for improving the durability of concrete structures and extending its service life if the special environmental condition is taken into account in the durability design. Aimed at the environmental zonation for concrete durability, this paper investigated the durability factors influencing concrete structures in Shaanxi Province, China, including atmospheric temperature, precipitation, corrosive gas, and acid rain. The variations of the above-mentioned factors were analyzed and the indexes of environmental zonation were proposed. According to the zoning principle, the weights of zoning indexes calculated using fuzzy rough sets were used to divide Shaanxi Province into three first-level zones, namely the Freeze-Thaw Cycle Zone, the Neutralization–Freeze-Thaw Interaction Zone, and the Neutralization Zone. These three zones were then subdivided into nine second-level zones. The main mechanism of concrete deterioration and the environmental characteristics of all zones were then analyzed. The method proposed in this paper puts forward clear zoning indexes and quantifies them, which can improve the quality and accuracy of the zoning results. Moreover, the research achievements are helpful for engineers to reduce the impact of the environment on structure and the maintenance cost during the structural service life to a certain extent.

scholarly journals Numerical Simulation of the Effect of Freeze–Thaw Cycles on the Durability of Concrete in a Salt Frost Environment

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1198
Author(s):  
Hao Li ◽  
Yuan Zhang ◽  
Haolong Guo
Keyword(s):  
Numerical Simulation ◽  
Bending Moment ◽  
Temperature Curve ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact ◽  
Erosion Environment

In order to improve the accuracy of the analysis of the impact of freeze–thaw cycle on concrete durability in a salt freezing environment, the numerical simulation of the impact of the freeze–thaw cycle on concrete durability in a salt freezing erosion environment is studied in this paper. Firstly, considering the influence of axial force and bending moment on the relationship between bending moment and curvature, a concrete fiber beam column model is established. Then, according to the joint influence of temperature field, stress field and seepage field on concrete in the process of freezing and thawing, the control differential equation of the freezing and thawing cycle is established. The freeze–thaw damage section is divided, the non-uniform distribution of freeze–thaw damage is determined, and the division of the freeze–thaw damage section is completed. According to the linear relationship between freeze–thaw damage degree, relative dynamic elastic modulus, freeze–thaw cycle times and position variables, the durability of concrete is numerically simulated, and the attenuation law of bond strength at different section depths after freeze–thaw is determined. The results show that the temperature curve simulated by the design method is consistent with the actually measured temperature curve, which can better reduce the temperature change of the inner core of the test block during freezing and thawing, and the relative dynamic elastic modulus is in good agreement with the actual value, which can prove that the method in this paper has certain practical application value. It is expected to provide some reference for solving the durability problem of concrete in a salt frost erosion environment and the optimal design of concrete structures.

Can Soy Methyl Esters Improve Concrete Pavement Joint Durability?

2012 ◽  
Vol 2290 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Michael Golias ◽  
Javier Castro ◽  
Alva Peled ◽  
Tommy Nantung ◽  
Bernard Tao ◽  
...  
Keyword(s):  
Methyl Esters ◽  
Field Trials ◽  
Chemical Degradation ◽  
Maintenance Cost ◽  
Concrete Durability ◽  
Concrete Pavements ◽  
Freeze Thaw ◽  
Fluid Saturation ◽  
Soy Methyl Ester ◽  
Term Performance

Although many concrete pavements provide excellent long-term performance, some pavements (primarily in the Midwest) have shown premature deterioration at the joints. This premature deterioration is a concern because such deterioration can shorten the life of pavements that are otherwise functioning well. Previous work has hypothesized that these joints may be susceptible to preferential fluid saturation, which can lead to freeze–thaw damage or chemical degradation. This work examines the use of soy methyl ester–polystyrene (SME-PS) blends as a method to reduce the rate of fluid ingress into the pore system of the concrete and thereby make the concrete more resistant to deterioration. SME-PS is derived from soybeans and has demonstrated an ability to reduce fluid absorption in concrete when used as a topical treatment. A series of experiments was developed to evaluate the effectiveness of various dosage rates of SME-PS for increasing concrete durability at pavement joints. The experiments show that SME-PS reduces fluid ingress, salt ingress, and the potential for freeze–thaw damage. As a result of the positive experimental results, the Indiana Department of Transportation is conducting field trials that use SME-PS on concrete pavements that are beginning to show signs of premature deterioration with the expectation that SME-PS will extend the life of the joints and thereby reduce maintenance cost and extend the life of concrete pavements.

scholarly journals USING SMOS PASSIVE MICROWAVE DATA TO DEVELOP SMAP FREEZE/THAW ALGORITHMS ADAPTED FOR THE CANADIAN SUBARCTIC

2015 ◽  
Vol XL-1-W5 ◽  
pp. 365-368 ◽  
Author(s):  
P. Kalantari ◽  
M. Bernier ◽  
K. C. McDonal ◽  
J. Poulin
Keyword(s):  
Land Cover ◽  
Time Series Data ◽  
Passive Microwave ◽  
Soil Freezing ◽  
Series Data ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact

Seasonal terrestrial Freeze/Thaw cycle in Northern Quebec Tundra (Nunavik) was determined and evaluated with passive microwave observations. SMOS time series data were analyzed to examine seasonal variations of soil freezing, and to assess the impact of land cover on the Freeze/Thaw cycle. Furthermore, the soil freezing maps derived from SMOS observations were compared to field survey data in the region near Umiujaq. The objective is to develop algorithms to follow the seasonal cycle of freezing and thawing of the soil adapted to Canadian subarctic, a territory with a high complexity of land cover (vegetation, soil, and water bodies). Field data shows that soil freezing and thawing dates vary much spatially at the local scale in the Boreal Forest and the Tundra. The results showed a satisfactory pixel by pixel mapping for the daily soil state monitoring with a > 80% success rate with in situ data for the HH and VV polarizations, and for different land cover. The average accuracies are 80% and 84% for the soil freeze period, and soil thaw period respectively. The comparison is limited because of the small number of validation pixels.

scholarly journals Diagnosis of concrete structures distress due to alkali-aggregate reaction

2015 ◽  
Vol 63 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Z. Owsiak ◽  
J. Zapała-Sławeta ◽  
P. Czapik
Keyword(s):  
Concrete Structures ◽  
Chemical Exposure ◽  
Alkali Silica Reaction ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Alkali Aggregate Reaction ◽  
Freeze Thaw Cycle ◽  
Concrete Elements ◽  
Reaction Attack

Abstract Damage and defects observed in concrete elements, such as a network of microcracks, popouts and eflorrescence can be caused by a variety of deleterious processes. The causes can include mechanical (overloading), physical (freeze-thaw cycle) or chemical exposure (sulphate corrosion, alkali-aggregate reaction). This paper analyses distress due to alkali-silica reaction, detected in selected concrete structures. The analysed concrete elements exhibited cracking, exudations and surface popouts. Identification of the presence of hydrated sodium-potassiumcalcium silicate gel can be considered the primary symptom suggestive of an alkali-silica reaction attack. Other damage-causing mechanisms can occur simultaneously.

Prediction of durability of structural concrete in aggressive exposures

2018 ◽  
Author(s):  
Сергей Леонович ◽  
Sergey Leonovich ◽  
Валентин Доркин ◽  
Valentin Dorkin ◽  
Оксана Чернякевич ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Building Materials ◽  
Limit State ◽  
Concrete Structures ◽  
Life Cycles ◽  
Reinforced Concrete Structures ◽  
Concrete Durability ◽  
Concrete Carbonation ◽  
Corrosion Of Steel

The monograph is devoted to the prediction of the longevity of reinforced concrete structures, the destruction of which is associated with corrosion of steel reinforcement caused by chloride aggression or concrete carbonation. On the basis of a comprehensive analysis of models for calculating the service life of structures and experimental data, preference is given to the mathematical model Dura Crete. Life cycles for the main degradation processes in concrete and reinforcement, periods of initiation and propagation of corrosion are considered. Particular attention is paid to the influence of environmental factors and the quality of concrete on the kinetics of chloride penetration and movement of the carbonization front. Formulated limit state design reinforced concrete durability in chloride attacks and carbonation. The basic provisions of the method of calculating the durability of reinforced concrete structures, based on the use of the reliability coefficient for the service life. The practical assessment of service life of reinforced concrete elements taking into account stochastic processes in concrete and reinforcement is made. Verification of the model reliability is performed. For all those interested in the issues of building materials and processes occurring in them.

scholarly journals Durability and service life prediction for concrete structures – developments and challenges

2018 ◽  
Vol 149 ◽  
pp. 01006 ◽  
Author(s):  
Mark G Alexander
Keyword(s):  
Service Life ◽  
Life Prediction ◽  
Concrete Structures ◽  
Performance Testing ◽  
Integrated Approach ◽  
Service Life Prediction ◽  
Site Quality ◽  
Concrete Durability ◽  
Durability Prediction ◽  
Service Life Modelling

The paper reviews developments in service life prediction for concrete structures. It indicates the difficulties inherent in rational service life design, in view of the multiple factors and variabilities involved in the process. The paper also emphasises the advantages of performance-based approaches to durability prediction, and considers performance testing, which is critical to achieving intended service life. Such approaches allow service life modelling, which the current prescriptive approaches do not. The concept of ‘durability indicators’ is covered, with a practical example showing how this can be used to improve concrete durability in construction. The paper also stresses the importance of an ‘integrated approach’ to durability specifications, performance-based predictions, and site quality control.

scholarly journals The importance of freeze/thaw cycles on lateral tracer transport in ice-wedge polygons

2021 ◽  
Author(s):  
Elchin Jafarov ◽  
Daniil Svyatsky ◽  
Dylan Harp ◽  
Brent Newman ◽  
David Moulton ◽  
...  
Keyword(s):  
Climate Models ◽  
Lateral Flow ◽  
The Arctic ◽  
Tracer Transport ◽  
Lateral Transport ◽  
Dissolved Carbon ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact

Abstract. A significant portion of the Arctic coastal plain is classified as polygonal tundra and plays a vital role in soil carbon cycling. Recent research suggests that lateral transport of dissolved carbon could exceed vertical carbon releases to the atmosphere. However, the details of lateral subsurface flow in polygonal tundra have not been well studied. We incorporated a subsurface transport process into an existing state-of-art hydrothermal model. The model captures the physical effects of freeze/thaw cycles on lateral flow in polygonal tundra. The new modeling capability enables non-reactive tracer movement within subsurface. We utilized this new capability to investigate the impact of freeze/thaw cycle on lateral flow in the polygon polygonal tundra. Our study indicates the important role of freeze/thaw cycle and freeze-up effect on lateral tracer transport, suggesting that dissolved species could be transported from the middle of the polygon to the sides within a couple of thaw seasons. Introducing carbon lateral transport in the climate models could substantially reduce the uncertainty associated with the impact of thawing permafrost.

scholarly journals Influência de materiais de proteção na resistividade elétrica do concreto

2012 ◽  
Vol 2 (1) ◽  
pp. 46-56
Author(s):  
M. S. Santor ◽  
A. L. G. Gastaldini ◽  
C. Crauss ◽  
G. T. Dos Santos ◽  
F. C. Rossini
Keyword(s):  
Electrical Resistivity ◽  
Surface Treatment ◽  
Protective Action ◽  
Concrete Structures ◽  
Concrete Durability ◽  
Surface Protection ◽  
Different Types ◽  
Polymer Mortar ◽  
Durability Of Concrete

RESUMOA durabilidade das estruturas de concreto armado é resultado da ação protetora do concreto sobre a armadura. Quando a passivação do aço deixa de existir a estrutura torna-se vulnerável ao fenômeno da corrosão, cuja propagação, após iniciada é essencialmente controlada pela resistividade elétrica do concreto. O objetivo deste trabalho foi avaliar a alteração na resistividade elétrica de concretos produzidos com diferentes tipos de cimento, CP II F, CP IV e CP V, submetidos a tratamento superficial com produto obturador dos poros e argamassa polimérica. Para efeito de análise os resultados foram comparados com os mesmos concretos sem aplicação do produto. Esses tratamentos foram realizados em concretos confeccionados com resistências à compressão na idade de 28 dias de 21,6MPa, 26,6 MPa e 31,6 MPa. Para todos os tipos de cimento utilizados e níveis de resistência adotados o tratamento superficial com argamassa polimérica resultou em maiores valores de resistividade elétrica.Palavras chave: Concreto; durabilidade; material de proteção superficial; resistividade elétrica.ABSTRACTThe durability of concrete structures is a result of the protective action of concrete on the reinforcement. When there is no passivation of steel, the structure becomes vulnerable to corrosion, and once corrosion starts its propagation is essentially controlled by the electrical resistivity of concrete. The objective of this study was to evaluate the change in electrical resistivity of concretes produced with different types of cement: CP II F, CP IV and CP V that were surface-treated with pore filler and polymer mortar. For analysis purposes, the results were compared with those of the blanks that were not subjected to surface treatment. These treatments were performed in concretes with the following compressive strengths at the age of 28 days: 21.6 MPa, 26.6 MPa and 31.6 MPa. For all types of cement used and strengths adopted, surface treatment with polymer mortar led to higher electrical resistivity values.Key words: Concrete; durability; surface protection material; electrical resistivity.

The Research of Ring Pressure of the Pile Foundation on the Influence of the Durability of Concrete

2014 ◽  
Vol 687-691 ◽  
pp. 4389-4394
Author(s):  
Cheng Cheng Wang ◽  
Yue Zhong Ye ◽  
Shang Gao ◽  
Miao Miao He
Keyword(s):  
Mass Loss ◽  
Pile Foundation ◽  
Sulfate Solution ◽  
Mixed Solution ◽  
Steel Cylinder ◽  
Protective Measures ◽  
Freeze Thaw ◽  
Mass Losses ◽  
Thaw Cycle ◽  
Durability Of Concrete

The test make steel cylinder concrete, PVC protection tube cylinder concrete , spray coatings Outside the cylinder concrete and no protective measures on ordinary cylinder concrete in three different strength grade:C25, C35 and C50 , putting in the freeze-thaw cycle in three kinds of environment of 5% sulfate solution, 5% sulfate + 3% chlorine salt solution and distilled water,Analysis of the Research of Ring pressure of the Pile foundation on the influence of the durability of concrete by measuring the concrete of Pile foundation corrosion mass loss before and after freezing and thawing.Experiments show that:the concrete with protective measures almost has no mass losses with the level of pile foundation concrete in the same corrosive environment,that, s to say ,the durability is good.While the unprotected concrete has mass losses after the freeze-thaw action hitches in three kinds of solution,And the largest mass loss is in the mixed solution,the durability is the worst.

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