Durability Life Research Articles

Overview of irradiation: advantages to foods of plant origin

The technology of food irradiation is gaining more attention around the world. This method is recognized by using ionising radiation in order to control foodborne pathogens, reduce microbial load and insect infestation, inhibit the germination of root crops, extend the durable life of perishable produce, and reduce plant-derived allergens. According to the International Atomic Energy Agency (IAEA), more than 50 countries have approved the use of irradiation for about 50 different types of food, and 33 are using the technology commercially. Despite the fact that irradiation has been used for decades for food disinfection that satisfies quarantine requirements in trade, health concerns over the consumption of irradiated food continue to attract attention. This low-cost method has the advantage that the organoleptic properties of irradiated foods are not altered, allowing, however, to increase their bioactivity and nutritional quality. This review focuses on the advantages of irradiation applied to foods of plant origin. With proper application, irradiation can be an effective means of eliminating and/or reducing microbial and insect infestations along with the foodborne diseases they induce, thereby improving the safety of many foods as well as extending shelf life.

Durability improvements of Exhaust pipe joints during operating Condition

Medium and Heavy Commercial Tipper vehicles in India are mainly used for off-road and mining applications where the vehicles are subjected to severe and irregular road load patterns. In such cases it is imperative that quality of weld joints in Exhaust pipes should be capable of withstanding off road duty cycle. The negative impact of any kind of defect will be magnified due to presence of such harsh road & environment conditions. The current paper focus discussion on the various failures and defects found in weld joints of exhaust pipes. Various methodology has been introduced to detect the modes of Weld failure. After detailed study and analysis, a set of recommendations are proposed for welding of Exhaust pipe flange joints to ensure high durability life of weld joints

Ecofriendly new nanocomposites coating formulation of zinc reinforced with calcium oxide nanoparticles synthesis from oyster shell

The zinc coating of mild undergoes rapid corrosion for a short period of time in harsh environments. This affects the durable life and overall performance of the zinc coatings. The electrochemical, oxidation, and wear performance, as well as the surface morphological properties of new nanocomposites coating formulations of zinc reinforced with calcium oxide nanoparticles, were studied in order to improve the corrosion and wear performance of zinc coatings. A current density of 1.5–2.0 A/cm2 was used for the electrodeposition. The wear, oxidation, hardness, corrosion rate, and morphological properties were evaluated. The characterization of these composite coatings showed low wear rates and higher corrosion and oxidation resistance. At 1.5A/cm2 current density, a 65.53% enhancement in the hardness values and 57.14% oxidation protection were obtained. The smaller crystallite size of the deposited sample is the main reason for the lower corrosion and wear resistance and higher hardness values obtained. It was established that waste oyster can be used for the electrodeposition of mild steel to enhance corrosion resistance and hardness values. CaOnp made from oyster shells has been shown to make mild steel more resistant to corrosion, wear, and oxidation.

Research on the carbonation resistance of concretes containing dolomite powder

This study focused on the carbonation resistance of concretes incorporating dolomite powder with water–binder ratio (w/b) of 0.55 and 0.36. The micro-morphology, micro-pore structure and carbonation depth of cement-based materials incorporating dolomite powder were investigated by scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and carbonization test box. The 28-day carbonation depth of concretes with a w/b of 0.55 in the case of dolomite powder at 50 wt% replacement level decreased by 39.62% compared with that of pure concretes. The carbonation resistance of concretes was improved with increasing dolomite powder dosage due to the fact that dolomite powder had the pore refinement efficiency on the carbonated cement pastes. The service life of concretes with a w/b of 0.55 incorporating dolomite powder under natural carbonation condition was obtained based on Alekseyev’s carbonation correction model. The durability life of concrete structure with a w/b of 0.55 was prolonged with the addition of dolomite powder. After carbonation for 28 days, concretes with a w/b of 0.36 were hardly affected by carbonation corrosion. The pore structure of concretes with a w/b of 0.36 became dense, inhibiting the penetration of CO2 into the concretes due to a lower water–binder ratio.

Ultrathin ZrO2 coating layer regulates Zn deposition and raises long-life performance of aqueous Zn batteries

Rechargeable aqueous zinc metal batteries (ZMBs) have been regarded as one of the promising energy storage technologies for low-cost, use-safe, and large-scale applications. However, Zn metal anode is known to suffer from serious inherent problems of unwanted dendrite growth and side reactions, which significantly affect the cycling stability. Herein, a dense and ultrathin ZrO2 coating is purposely designed on the Zn surface by atomic layer deposition (ALD). The ZrO2 coating thus developed enables uniform Zn deposition, lowers the nucleation overpotential for Zn2+ deposition, and effectively suppresses side reaction of Zn anode, whereby generating an interfacial polarization effect, and thus promoting reversible Zn2+ plating/stripping behavior. Therefore, the Zn anode with optimized ZrO2 coating thickness of 40 nm ZrO2 shows an excellent cycling life. Additionally, the surface protection of ZrO2 is extended to boost the cycling performance of Zn–MnO2 battery, achieving a durable life of over 2500 cycles at 10 C.

Durable life assessment of centrifugal stratified PHC piles in marine environment

This study proposes an analytical approach to assess the durable life of pre-stressed high-strength concrete (PHC) pipe piles exposed to the marine environment with consideration of centrifugal stratification and different end types. The durable life of the PHC pile is divided into two stages: the initiation stage for chloride penetration and the propagation stage for rust accumulation. To simulate the two stages, a two-layer composite cylinder diffusion model and a thick-walled ring mechanical model are developed based on the governing mechanisms. The proposed diffusion model is verified via comparisons with the numerical models with respect to chloride concentration under different stages. Then, extensive parametric studies based on the proposed method are performed to investigate the effects of end type, cover thickness, and steel bar diameter on the durable life of a PHC pipe pile. The results indicate that both increasing the cover thickness and using the closed-ended pile can significantly extend the durable life of a PHC pipe pile. Furthermore, the open-ended pile with a thinner mortar layer has a longer durable life, while the durable life of a closed-ended pile only slightly increases with a larger thickness of the mortar layer.

Life Prediction of Iron Ore Tailings Concrete under Freeze-Thaw Cycle Based on Weibull Distribution

It is urgent to improve the comprehensive utilization rate of tailings, especially to solve the problem of fine iron ore tailings treatment and the shortage of natural sand, so iron ore tailings concrete with different replace rates was prepared in this paper. At the same time, in order to further popularize the wide application of iron tailings concrete, it is of great significance to study the frost resistance and life prediction of it in cold regions. Thereby, a series of experimental research on iron ore tailings concrete under freezing-thawing cycles was carried out to analyze the attenuation law of quality, compressive strength, and relative dynamic elastic modulus after different freezing-thawing cycles. In this paper, the relative dynamic elastic modulus was used to define the damage factor, and the freezing-thawing damage model of iron ore tailings concrete was established based on Weibull distribution. Here, the specific function form of two-parameter Weibull distribution of iron ore tailings concrete under freezing-thawing cycle was proposed, and the model was used to predict life of it. The results showed that, compared with the replacement rates of 20%, 60%, and 80%, the iron ore tailings with 40% replacement rate had the best improvement effect on the frost resistance of concrete and can delay the attenuation of the compressive strength of concrete. This model can not only predict the durability life of iron ore tailings concrete under freezing-thawing conditions, but also provide theoretical reference for the application of iron ore tailings concrete in cold areas.

Parametric optimization of durable sheeting fabric using Taguchi Grey Relational Analysis

ObjectivesThe present work describes the application of Taguchi Grey Relational Analysis in order to optimize the durability of sheeting fabrics. The existing study investigates the multi-response optimization of certain parameters of yarn process including FL, RS and RT on tensile strength, tear strength and abrasion resistance of durable fabric sheets after washing. MethodsIn the development process L9 orthogonal array in Taguchi design was used. The results have been analyzed by using statistical multi-response optimization technique, grey relational analysis to set the process parameters and to decide the simultaneous optimization of responses including tensile strength, tear strength and abrasion resistance. In addition, the analysis of variance (ANOVA) was used to determine the most significant factors. Reference sheeting fabric with same construction parameters was also tested. ResultsThe results show a greater improvement in parameters of developed samples quality. The experimental results show parameter fiber length has the most significant effect on the multiple performance characteristics. ConclusionsThe developed fabric sheet having durable life would help to reduce consumption of resources of both consumers and manufacturers. Manufacturers can have great chance to establish their image and can increase the profit margin over products. Therefore, the integration of grey relational analysis and the Taguchi Method can be applicable for the optimization of process parameters and help to conserve resources by extending the lifetime of sheeting fabrics.

Durability life prediction of RC piles subjected to localized corrosion in chloride environments

In this study, an analytical model for evaluating the durability life of reinforced concrete (RC) piles subjected to localized corrosion under chloride attack is proposed. The localized corrosion process is divided into three stages, and a predictive method is presented to predict the durability life of the pile by calculating the time of each stage. The time of each stage is determined based on the chloride diffusion model, the pitting corrosion model and the crack propagation model. The effects of the water-cement ratio, concrete cover thickness, pile concrete quality, relative humidity, chloride threshold level, pitting factor, corrosion current density and initial surface chloride ion concentration on the various stages of localized corrosion and the durability life of the pile are investigated. The analysis results show that the effects of the water-cement ratio and concrete cover thickness on the durability life of the pile are the most significant in the corrosion initiation stage. The durability life is increased by a reasonable choice of both concrete water-cement ratio and concrete cover thickness with constant concrete quality. The durability life of the pile increases with increasing concrete cover thickness, concrete quality, chloride threshold value and limit crack width, while it decreases with increasing water-cement ratio, relative humidity, corrosion current density and initial surface chloride concentration. The influence of the pitting factor is minimal and is mainly in the pit nucleation stage.

Time-temperature-dependent mechanical durability analysis of short (glass) fiber-reinforced polyethylene terephthalate injection molding composites with weld line

The mechanical property and long-term durable life of short fiber composites are inevitably subjected to internal and external influences during molding and afterwards, such as weld, temperature, stress type, and so on. This study was concerned with the influence of weld on mechanical properties of short glass fiber reinforced polyethylene terephthalate injection molding composites and the investigation of their tensile properties at different temperatures and tensile speeds with varying fiber contents. The weld strength was about 50–60% less than the tensile strength at different temperatures and tensile speeds. As the fiber content increased from 15 wt% to 30 wt%, the weld strength was reduced by 10%. The tensile and weld strength were in general inversely proportional to the temperature and linearly proportional to the tensile speed. Tensile modulus showed an inverse association with temperature and a mostly non-linear relation with the tensile speed. The weld line integrity in tensile strength was independent of tensile speed and temperature below the glass transition temperature level. Morphology evaluation testified that the higher test speed emanated better fracture surface fiber–resin adhesion properties with comparatively brittle fracture tensile behavior. The time-temperature superposition principle was applied to find the scope of long-term durability, lifetime prediction and to describe the viscoelastic properties of the welded glass fiber reinforced polyethylene terephthalate composites. An Arrhenius type of shift factor was obtained to fit the tensile strength data which was independent of the fiber contents of the welds. The experimental results can provide a valuable reference for the design and manufacture of short fiber-reinforced composites in long-term durability applications.

Damage and Deterioration Model of Basalt Fiber/Magnesium Oxychloride Composites Based on GM(1, 1)-Markov in the Salt Spray Corrosion Environment

This study was designed to solve the problem of magnesium hazards due to potash extraction in the salt lake region. Using basalt fiber (BF) as the reinforcement material and magnesium oxychloride cement (MOC) as the gelling material, a BF/MOC composite material was prepared. Firstly, the effect of BF addition content on the basic mechanical properties of the composites was investigated. Then, through the salt spray corrosion test, the durability damage deterioration evaluation analysis was carried out from both macroscopic and microscopic aspects using mass change, relative dynamic modulus of elasticity (RDME) change, SEM analysis and FT-IR analysis. Finally, a GM(1, 1)-Markov model was established to predict the durability life of composite materials by using durability evaluation indicators. The results show that: when the BF content is 0.10% (by volumetric content), the composites have the best mechanical properties and resistance to salt spray corrosion. However, when the volume of BF content exceeds 0.10%, a large number of magnesium salt crystallization products are observed from the microscopic point of view, and the corrosion of the main strength phase of MOC is more serious. The prediction results of the GM(1, 1)-Markov model are highly identical with the raw data. In addition, using the change of RDME as a predictor, RDME is more sensitive to environmental factor compared to the change of mass. Predictions using the change of RDME as a threshold indicate that MOC-BF0.10 has the longest durability life, which is 836 days. The model is important to promote the application of MOC composites in the salt lake region and to promote the healthy development of green building materials.

Performance evaluation of a coating protection system for concrete structures affected by internal expansive reactions

In the last decades, a significant number of large concrete structures with deterioration problems, related to internal expansive chemical reactions, have been detected in Portugal. This type of degradation is associated with the formation of expansive products in concrete causing its disruption, leading to the decrease of the structure’s service life and, ultimately, to the decommissioning or demolition of the structure. In Portugal, structures affected by this pathology are very important in economic and strategic terms, since these reactions are usually encountered in large dams, bridges and viaducts. Two separate material-based mechanisms have been identified to cause the concrete swelling: Alkali-Silica Reaction (ASR) and Delayed Ettringite Formation (DEF). Both reactions result in the formation of expansive products and a common requirement for their occurrence is the presence of a sufficient moisture content inside concrete. By controlling the humidity level in concrete, coatings applied onto the concrete surface should contribute to mitigate ASR or DEF by acting as a barrier against ingress of water and allowing the concrete to dry, as long as they have adequate water permeability characteristics. This paper presents the general criteria that may be followed to select a surface protection system, based on coating materials (hereinafter designated by coating system), for the rehabilitation of concrete structures affected by expansive reactions, in order to mitigate them and, thus, contribute to improve durability and service life of affected structures. In addition, a laboratory study is presented concerning the performance evaluation of a surface protection system, composed of two coating materials, in terms of its capacity to bridge cracks, its permeability to liquid and to water vapour, and on its effectiveness on controlling humidity inside concrete.

Durability Life Prediction and Horizontal Bearing Characteristics of Cfrp Composite Piles in Marine Environments

Durability Life Prediction and Horizontal Bearing Characteristics of Cfrp Composite Piles in Marine Environments

Quantifying Crack Self-Healing in Concrete with Superabsorbent Polymers under Varying Temperature and Relative Humidity

During their service life, concrete structures are subjected to combined fluctuations of temperature and relative humidity, which can influence their durability and service life performance. Self-healing has in recent years attracted great interest to mitigate the effects of such environmental exposure on concrete structures. Several studies have explored the autogenous crack self-healing in concrete incorporating superabsorbent polymers (SAPs) and exposed to different environments. However, none of the published studies to date has investigated the self-healing in concrete incorporating SAPs under a combined change in temperature and relative humidity. In the present study, the crack width changes due to self-healing of cement mortars incorporating SAPs under a combined change of temperature and relative humidity were investigated and quantified using micro-computed tomography and three-dimensional image analysis. A varying dosage of SAPs expressed as a percentage (0.5%, 1% and 2%) of the cement mass was incorporated in the mortar mixtures. In addition, the influence of other environments such as continuous water submersion and cyclic wetting and drying was studied and quantified. The results of segmentation and quantification analysis of X-ray µCT scans showed that mortar specimens incorporating 1% SAPs and exposed to environments with a combined change in temperature and relative humidity exhibited less self-healing (around 6.58% of healing efficiency). Conversely, when specimens were subjected to cyclic wetting and drying or water submersion, the healing efficiency increased to 19.11% and 26.32%, respectively. It appears that to achieve sustained self-healing of cracks, novel engineered systems that can assure an internal supply of moisture are needed.

The tribological performance of W-DLC in solid–liquid lubrication system addivated with Cu nanoparticles

Judicious selection of additives having chemical and physical compatibility with the DLC films may help improving the triboligical properties and durability life of DLC-oil composite lubrication systems. In this study, Cu nanoparticles were added to PAO6 base oil to compose a solid-liquid composite lubrication system with W-DLC film. The effects of nanoparticle concentration, test temperature and applied load on tribological performance were systematically studied by a ball-on-disk friction test system. The tribological results illustrated that Cu nanoparticles could lower the coefficient of friction (COF) and dramatically reduce the wear rates of W-DLC films. The optimal tribological behavior was achieved for the 0.1 wt% concentration under 30 °C and the applied load of 100 N. The test temperature and applied load were vital influencing factors of the solid–liquid lubrication system. The bearing effect and soft colloidal abrasive film of spherical Cu nanoparticle contributed to the excellent tribological performance of the composite lubrication system under mild test conditions, meanwhile, the local delamination of W-DLC film and oxidation were the main causes of the friction failure under harsh test conditions. With test temperature and applied loads increase the degree of graphitization of the W-DLC film increased. In conclusion, there are several pivotal factors affecting the tribological performance of solid–liquid lubrication systems, including the number of nanoparticles between rubbing contact area, graphitization of the worn W-DLC films, tribofilms on the worn ball specimens and oxidation formed in friction test, and the dominant factor is determined by the testing condition.

Durability Life Prediction of Reinforced Concrete Structure Corroded by Chloride Based on the Gamma Process

AbstractIn this paper, a new method for durability life prediction of reinforced concrete structures in a chlorine-eroded environment is presented based on the Gamma process. The Gamma process mode...

Use of Mixed Microbial Cultures to Protect Recycled Concrete Surfaces: A Preliminary Study.

One approach to tackle the problems created by the vast amounts of construction and demolition waste (CDW) generated worldwide while at the same time lengthening concrete durability and service life is to foster the use of recycled aggregate (RA) rather than natural aggregate (NA). This article discusses the use of polyhydroxyalkanoates (PHAs)-producing mixed microbial cultures (MMCs) to treat the surface of recycled concrete with a view to increase its resistance to water-mediated deterioration. The microorganisms were cultured in a minimal medium using waste pinewood bio-oil as a carbon source. Post-application variations in substrate permeability were determined with the water drop absorption and penetration by water under pressure tests. The significant reduction in water absorption recorded reveals that this bioproduct is a promising surface treatment for recycled concrete.

Experimental Study on Mechanical Properties and Pore Structure Deterioration of Concrete under Freeze-Thaw Cycles.

Understanding the evolution of mechanical properties and microscopic pore structure of concrete after freeze–thaw cycles is essential to assess the durability and safety of concrete structures. In this work, the degradation law of mechanical properties and damage characteristic of micro-structure of concrete with two water-cement ratios (w/c = 0.45 and 0.55) is investigated under the condition of freezing–thawing cycles. The influence of loading strain rate on dynamic compressive strength is studied. The microscopic pore structure after frost damage is measured by low-field nuclear magnetic resonance (LF-NMR) technique. Then, a damage model based on the porosity variation is established to quantitatively describe the degradation law of macroscopic mechanical properties. The test results show that the relative dynamic modulus of elasticity (RDME), dynamic compressive strength, flexural strength, and splitting tensile strength of concrete decrease with the increase of freeze–thaw cycles. Empirical relations of concrete dynamic increase factor (DIF) under the action of freeze–thaw cycles are proposed. Moreover, the experimental results of NMR indicate that the porosity as well as the proportion of meso-pores and macro-pores of concrete gradually increased with the increasing of freeze–thaw cycles. The research results can provide reference and experimental support for the anti-frost design theory and durability life prediction of hydraulic concrete structures in cold regions.

A chemical-mechanics model for the mechanics deterioration of pervious concrete subjected to sulfate attack

Strength deterioration is one of the primary indicators to reduce the durability of pervious concrete under sulfate attack. This study aimed to establish a chemical–mechanical model to predict the strength evolution. The compressive strength and splitting tensile strength of pervious concrete in three different concentrations of sodium sulfate solution were obtained by experiments. A corrosion coefficient was adopted to evaluate the deterioration of compressive strength. The corrosion coefficient model was developed by considering the pore filling effect of expansion products and the corrosion damage induced by expansion stress. Compared with the experimental results, the developed model could better characterize the deterioration process of pervious concrete. Therefore, the model proposed in this paper provides a more reliable solution for the design and durability life assessment of pervious pavement engineering in sponge city construction projects.

Birnbaum-Saunders Durability Life Prediction Model of Site-Exposed Concrete in the Saline Soil Area

Aiming at the prominent problem of short durability life of concrete in saline soil area and the shortcomings of indoor accelerated test, an outdoor field exposure test was designed. The concrete specimens were semiburied in the Tianshui area with salinized soil characteristics, and nondestructive testing was conducted every 180d (days). The durability evaluation parameters and mechanical performance indexes were selected for macroscopic analysis, and the corrosion mechanism was analyzed by using the SEM image and the XRD phase. The Birnbaum-Saunders model based on physical failure and probability statistics was used for life prediction. The results show that there are rod-shaped and chip-shaped crystals growing from the surface of the gel and the internal holes in the exposed end and the embedded end of the concrete. However, the damage and deterioration of the buried end are more serious than those of the exposed end. The corrosion products mainly included ettringite, gypsum, calcium carbonate, sodium sulfate hydrate, carbosilite, and Friedel’s salt. The reliability life curve based on the Birnbaum-Saunders model can describe the whole process of exposed concrete from damage accumulation to failure. In addition, the dynamic modulus degradation index is more sensitive to concrete durability damage, and the life obtained by the Birnbaum-Saunders model is shorter than the quality degradation index. The life obtained by this degradation index is taken as the life of the concrete exposed in the saline soil site, and the concrete life of C30, C40, and C50 is about 3340d, 3930d, and 4360d, respectively.