Chemical admixtures designed for low-temperature situations modify the hydration means of concrete, permitting it to treatment correctly even when temperatures drop beneath freezing. These admixtures usually operate by accelerating the early levels of hydration, producing warmth and offsetting the chilling results of the surroundings. One instance is calcium chloride, which acts as an accelerator. Different sorts embody non-chloride accelerators for functions the place chloride corrosion is a priority, in addition to air-entraining brokers that enhance freeze-thaw sturdiness.
Defending concrete from freezing throughout its early levels is important for reaching the specified energy and sturdiness. With out correct safety, younger concrete can endure important injury, together with scaling, cracking, and diminished final energy. Traditionally, strategies akin to heated enclosures and insulated types had been employed. Nevertheless, chemical admixtures provide a extra environment friendly and cost-effective answer, notably for large-scale tasks or distant areas. They enhance workability in chilly situations, scale back the necessity for in depth protecting measures, and guarantee constant curing, resulting in stronger and extra sturdy constructions.
Additional exploration will embody the varied varieties of admixtures appropriate for chilly climate concreting, their particular functions, benefits and downsides, advisable dosages, and compatibility with different concrete constituents. Environmental concerns and greatest practices for chilly climate concrete placement will even be examined.
1. Accelerated Hydration
Accelerated hydration is essential for chilly climate concreting. Admixtures designed for this function modify the chemical reactions throughout the concrete combination, enabling quicker hardening even at low temperatures. This accelerated course of is important for mitigating the detrimental results of chilly on concrete energy growth and general sturdiness.
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Early Power Achieve
Accelerators improve the speed of early energy achieve, permitting the concrete to succeed in a important energy stage earlier than it turns into susceptible to frost injury. This speedy energy growth is important in chilly situations, the place the hydration course of would in any other case be considerably slowed. For instance, a construction’s formwork could be eliminated sooner, enhancing development effectivity.
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Warmth Technology
The accelerated hydration course of generates warmth throughout the concrete. This internally generated warmth offsets the influence of low ambient temperatures, defending the concrete from freezing. This exothermic response is especially helpful in stopping early-age thermal cracking.
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Decreased Set Time
Accelerating admixtures shorten the setting time of concrete. This diminished timeframe minimizes the period throughout which the concrete is inclined to wreck from freezing temperatures. Speedy setting permits for quicker ending operations and earlier software of protecting measures if wanted.
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Forms of Accelerators
A number of varieties of accelerating admixtures exist, together with calcium chloride, non-chloride accelerators, and specialty blends. The selection is dependent upon the particular software, the specified efficiency traits, and potential considerations like chloride-induced corrosion in strengthened concrete.
By accelerating hydration, these admixtures allow concrete to attain ample energy and sturdiness inside a shorter timeframe, even in difficult chilly climate situations. This course of is key to profitable chilly climate concreting, guaranteeing structural integrity and longevity. Understanding the affect of accelerators on hydration kinetics is important for choosing the suitable admixture and reaching optimum concrete efficiency in chilly environments.
2. Freeze Safety
Freeze safety is paramount in chilly climate concreting. Recent concrete is very inclined to wreck from freezing temperatures, notably in the course of the preliminary hydration interval. Specialised admixtures play a important function in mitigating this threat, guaranteeing the event of sturdy and resilient concrete constructions in chilly environments.
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Ice Crystal Formation Inhibition
Freezing injury primarily arises from the formation of ice crystals throughout the concrete’s pore construction. These increasing crystals exert strain on the encircling cement paste, resulting in micro-cracking and weakening of the matrix. Sure admixtures disrupt the formation of those ice crystals, safeguarding the concrete’s integrity. As an illustration, air-entraining admixtures create microscopic air bubbles throughout the concrete, offering area for the growth of freezing water, thus lowering inner strain and stopping injury.
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Hydration Modification
Some admixtures modify the hydration course of itself, accelerating early energy achieve and lowering the timeframe throughout which the concrete is most susceptible to frost injury. By quickly growing the concrete’s energy, these admixtures permit it to resist the inner stresses attributable to freezing temperatures extra successfully. For instance, accelerators allow the concrete to succeed in a sure energy threshold earlier than important ice formation can happen, minimizing potential injury.
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Antifreeze Properties
Sure admixtures possess antifreeze properties, reducing the freezing level of water throughout the concrete combination. This successfully extends the temperature vary at which the concrete can safely hydrate with out the chance of ice formation. This mechanism is especially helpful in extraordinarily chilly situations the place customary air entrainment alone could not suffice.
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Lengthy-Time period Sturdiness Enhancement
The usage of freeze safety admixtures contributes considerably to the long-term sturdiness of concrete constructions uncovered to freeze-thaw cycles. By stopping early-age freeze injury, these admixtures guarantee the event of a robust and dense concrete matrix, proof against scaling, cracking, and different types of deterioration attributable to repeated freezing and thawing.
The multifaceted strategy of freeze safety admixtures, combining ice crystal inhibition, hydration modification, and antifreeze properties, ensures the profitable placement and curing of concrete in chilly climate. This safety is key to reaching sturdy and resilient concrete constructions in difficult environmental situations, lowering the chance of untimely deterioration and increasing service life.
3. Improved Workability
Sustaining appropriate workability in chilly climate is important for correct concrete placement and consolidation. Low temperatures considerably have an effect on concrete’s plasticity, making it stiff and tough to deal with. This diminished workability can result in insufficient compaction, honeycombing, and chilly joints, compromising the structural integrity and sturdiness of the completed product. Chemical admixtures designed for chilly climate concreting handle this problem by enhancing workability with out compromising different important properties. These admixtures typically operate by lowering the viscosity of the concrete combination, permitting for simpler placement and ending even at low temperatures. This improved flowability facilitates correct consolidation, guaranteeing full filling of formwork and minimizing the chance of defects. For instance, in giant pours the place sustaining constant workability all through the location course of is essential, these admixtures stop delays and guarantee uniform concrete high quality.
The advantages of improved workability prolong past placement and consolidation. A extra workable combination permits for environment friendly ending operations, contributing to a smoother floor end and improved aesthetics. Moreover, enhanced workability reduces the bodily effort required for placement and ending, growing productiveness and minimizing labor prices. In tasks with difficult entry or complicated formwork, the improved movement traits of the concrete turn out to be much more important, enabling environment friendly placement in confined areas and round intricate reinforcement. Contemplate the development of a bridge deck in freezing situations: with out admixtures to enhance workability, reaching correct consolidation and minimizing chilly joints could be considerably harder, probably compromising the long-term efficiency of the construction.
Understanding the influence of chilly climate on concrete workability and the function of specialised admixtures is key for profitable chilly climate concreting. Improved workability facilitated by these admixtures ensures correct placement, consolidation, and ending, resulting in sturdy and high-quality concrete constructions. This understanding permits practitioners to pick out the suitable admixture and implement efficient chilly climate concreting practices, mitigating the challenges posed by low temperatures and guaranteeing the specified efficiency traits of the completed product. Ignoring the influence of temperature on workability can result in important development difficulties and long-term structural points, highlighting the sensible significance of this side in chilly climate concreting.
4. Decreased Set Time
Decreased set time is a important issue when utilizing concrete components in chilly climate. Concrete’s vulnerability to freezing temperatures is highest in the course of the preliminary hydration interval, earlier than the combination begins to harden. By accelerating the setting course of, specialised admixtures decrease the period of this susceptible interval. This speedy setting permits the concrete to realize energy rapidly, mitigating the chance of harm from ice crystal formation, which might happen if the concrete freezes earlier than reaching a ample energy threshold. This interaction between set time and temperature instantly influences the concrete’s final energy and sturdiness. As an illustration, in establishing a basis in freezing temperatures, a diminished set time ensures the concrete achieves ample energy earlier than it’s uncovered to probably damaging sub-zero situations.
The sensible implications of diminished set time are important in chilly climate concreting. Quicker setting permits for faster ending operations, lowering the general development timeframe. This time-saving side could be essential in tasks with tight schedules or the place climate situations are unpredictable. Moreover, diminished set time minimizes the necessity for prolonged safety measures towards freezing, akin to heated enclosures or insulated types. This discount in protecting measures interprets to decrease prices and elevated effectivity. Contemplate a situation the place concrete is being poured for a bridge deck in late autumn; a diminished set time would allow the concrete to harden rapidly, probably avoiding the necessity for expensive in a single day heating measures if temperatures drop unexpectedly.
Managing set time via specialised admixtures is subsequently important for profitable chilly climate concreting. This exact management over the hydration course of permits for optimized energy growth and enhanced sturdiness, even in difficult environmental situations. Understanding this intricate relationship between set time, temperature, and admixture efficiency permits knowledgeable choices relating to admixture choice and concrete placement methods. Neglecting the influence of diminished set time can result in compromised concrete efficiency, probably leading to expensive repairs or diminished service lifetime of the construction. The efficient manipulation of set time by way of admixtures thus represents a key ingredient in guaranteeing sturdy and resilient concrete constructions in chilly climate environments.
5. Power Improvement
Power growth in concrete is essentially linked to the hydration course of, a chemical response considerably influenced by temperature. Chilly climate situations retard hydration, probably resulting in insufficient energy achieve and compromised sturdiness. Concrete components designed for chilly climate functions mitigate this problem by modifying the hydration course of, guaranteeing ample energy growth even at low temperatures. Understanding this relationship is essential for establishing sturdy constructions in chilly environments.
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Early Power Achieve
Early energy achieve is paramount in chilly climate concreting. Components, notably accelerators, considerably affect the speed of early energy growth. Speedy early energy achieve permits the concrete to succeed in a important energy stage earlier than changing into susceptible to frost injury. This accelerated growth permits earlier formwork removing and quicker development progress. As an illustration, in precast concrete manufacturing, accelerated energy achieve permits for faster demolding and elevated manufacturing effectivity.
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Hydration Management
Chilly climate components modify the hydration course of to optimize energy growth at low temperatures. Some admixtures speed up the hydration reactions, whereas others operate by miserable the freezing level of water, permitting hydration to proceed even beneath 0C. This managed hydration ensures constant energy achieve, mitigating the detrimental results of chilly on the concrete matrix. For instance, in establishing pavements uncovered to freezing temperatures, managed hydration via admixtures is important for reaching the required energy and stopping untimely deterioration.
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Mitigation of Temperature Results
Low temperatures instantly influence the speed and extent of hydration, hindering energy growth. Components counteract these results by both accelerating hydration or offering freeze safety, permitting the concrete to realize energy as meant. This mitigation of temperature results is essential for guaranteeing the structural integrity of concrete parts uncovered to chilly environments. Contemplate the development of a dam in a chilly local weather: components play a significant function in guaranteeing satisfactory energy growth regardless of the low temperatures, guaranteeing the long-term stability of the construction.
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Lengthy-Time period Power and Sturdiness
Correct energy growth within the early levels, facilitated by chilly climate components, instantly influences the long-term energy and sturdiness of the concrete. By guaranteeing ample early-age energy, these components contribute to a dense and resilient concrete matrix that may stand up to freeze-thaw cycles and different environmental stresses. This long-term efficiency enhancement is essential for infrastructure tasks and constructions uncovered to harsh climate situations. As an illustration, in constructing bridges in areas with important temperature variations, utilizing chilly climate components contributes to the construction’s long-term sturdiness and minimizes the chance of untimely deterioration.
The usage of concrete components in chilly climate is subsequently important for guaranteeing satisfactory energy growth, a important issue influencing the structural integrity and repair lifetime of concrete constructions. These components allow constant and managed hydration, mitigating the detrimental results of low temperatures and guaranteeing the specified long-term efficiency traits of the concrete. Ignoring the influence of chilly on energy growth can result in important structural deficiencies and untimely deterioration, highlighting the significance of incorporating applicable admixtures in chilly climate concreting practices.
6. Sturdiness Enhancement
Sturdiness enhancement is a major goal when utilizing concrete components in chilly climate. Concrete uncovered to freezing and thawing cycles is inclined to numerous types of deterioration, together with scaling, cracking, and diminished service life. Chilly climate admixtures play an important function in mitigating these dangers, enhancing the concrete’s resistance to the detrimental results of low temperatures and guaranteeing long-term structural integrity. These admixtures obtain sturdiness enhancement via numerous mechanisms, impacting the hydration course of, pore construction, and resistance to freeze-thaw injury.
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Freeze-Thaw Resistance
Freeze-thaw resistance is paramount for concrete constructions in chilly climates. Air-entraining admixtures create microscopic air voids throughout the concrete matrix. These voids present area for the growth of water throughout freezing, relieving inner strain and stopping cracking. This mechanism considerably enhances the concrete’s resistance to wreck attributable to repeated freeze-thaw cycles. For instance, pavements and bridge decks in areas with frequent temperature fluctuations profit considerably from air entrainment, extending their service life and lowering upkeep wants.
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Permeability Discount
Decreased permeability is essential for enhancing concrete sturdiness. Sure admixtures refine the pore construction of the concrete, lowering the ingress of water and aggressive chemical compounds. This decreased permeability minimizes the chance of harm from freeze-thaw cycles, in addition to corrosion of reinforcing metal. As an illustration, incorporating permeability-reducing admixtures in concrete uncovered to de-icing salts considerably enhances its resistance to chloride-induced corrosion, a serious trigger of degradation in strengthened concrete constructions.
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Scaling Resistance
Scaling, characterised by the lack of floor mortar as a result of freeze-thaw injury, is a typical sturdiness situation in chilly climate concrete. Air-entraining admixtures and different specialised components mitigate scaling by lowering the inner pressures generated by freezing water. This safety of the concrete floor enhances its aesthetic attraction and extends its service life. For instance, concrete sidewalks and driveways in chilly climates profit from scaling-resistant admixtures, sustaining their floor integrity and minimizing the necessity for expensive repairs.
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Lengthy-Time period Efficiency
The mixed results of improved freeze-thaw resistance, diminished permeability, and enhanced scaling resistance contribute to the general long-term efficiency and sturdiness of concrete constructions in chilly environments. By mitigating the dangers related to low temperatures, these admixtures prolong the service lifetime of concrete parts, lowering upkeep necessities and lifecycle prices. As an illustration, utilizing durability-enhancing admixtures within the development of dams, retaining partitions, and different important infrastructure tasks ensures their long-term stability and minimizes the chance of untimely deterioration.
The enhancement of concrete sturdiness via the usage of specialised admixtures is subsequently important for establishing resilient and long-lasting constructions in chilly climate environments. These admixtures handle the particular challenges posed by freezing and thawing cycles, guaranteeing the structural integrity and minimizing the long-term deterioration of concrete parts. Understanding the multifaceted function of those admixtures in sturdiness enhancement permits knowledgeable decision-making relating to admixture choice and concrete combine design, optimizing efficiency and guaranteeing the specified service lifetime of concrete constructions in chilly climates.
7. Value-Effectiveness
Value-effectiveness is a vital consideration in any development challenge, and chilly climate concreting presents distinctive challenges that may influence the general funds. Conventional strategies for shielding concrete in chilly climate, akin to heated enclosures and insulated types, could be costly and labor-intensive. Concrete components designed for chilly climate functions provide a cheap various, offering quite a few advantages that contribute to important price financial savings all through the challenge lifecycle.
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Decreased Labor Prices
Chilly climate admixtures streamline the concreting course of, lowering the necessity for in depth and time-consuming chilly climate safety measures. This interprets to decrease labor prices related to duties akin to heating, insulation, and prolonged monitoring. As an illustration, eliminating the necessity for steady temperature monitoring in a single day can considerably scale back labor hours and related bills.
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Quicker Challenge Completion
By accelerating energy growth and lowering set instances, chilly climate admixtures allow quicker challenge completion. This accelerated schedule reduces general challenge period, minimizing overhead prices and permitting for earlier challenge turnover. For instance, earlier formwork removing facilitated by accelerated energy achieve contributes to quicker development cycles and diminished challenge timelines.
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Minimized Materials Prices
The usage of admixtures can scale back the necessity for supplementary cementitious supplies or different costly measures usually employed to attain satisfactory energy achieve in chilly climate. This optimized materials utilization contributes to decrease materials prices and a extra sustainable development strategy. As an illustration, lowering the amount of cement required to attain goal energy via the usage of admixtures leads to direct materials price financial savings.
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Decreased Threat of Repairs
By defending concrete from freeze-thaw injury and different cold-weather associated points, admixtures decrease the chance of expensive repairs and rework. This proactive strategy to sturdiness enhancement interprets to long-term price financial savings and reduces the probability of sudden upkeep bills. For instance, stopping scaling and cracking via the usage of air-entraining admixtures minimizes the necessity for future floor repairs, lowering long-term upkeep prices.
The associated fee-effectiveness of chilly climate concrete components extends past direct price financial savings. By guaranteeing constant concrete high quality and enhancing long-term sturdiness, these admixtures contribute to a extra resilient and sustainable infrastructure. The preliminary funding in admixtures typically yields important returns via diminished labor, materials, and upkeep prices over the lifespan of the construction. This holistic perspective on cost-effectiveness underscores the worth of incorporating these specialised admixtures in chilly climate concreting tasks, optimizing each short-term budgetary concerns and long-term efficiency outcomes.
Regularly Requested Questions
This part addresses widespread inquiries relating to the usage of concrete components in chilly climate, offering concise and informative responses to make clear potential uncertainties and promote greatest practices.
Query 1: What are the first dangers related to inserting concrete in chilly climate with out utilizing specialised admixtures?
With out correct precautions, concrete positioned in chilly climate is inclined to a number of dangers, together with delayed or incomplete hydration, diminished energy growth, early-age freezing injury, elevated permeability, and long-term sturdiness points akin to scaling and cracking.
Query 2: How do chilly climate concrete components mitigate the dangers of inserting concrete in low temperatures?
These admixtures modify the hydration course of, enabling concrete to treatment successfully even at low temperatures. They will speed up energy growth, scale back set time, present freeze safety, and improve general sturdiness, mitigating the dangers related to chilly climate placement.
Query 3: Are all chilly climate concrete components the identical? How does one choose the suitable admixture for a particular challenge?
No, numerous varieties of chilly climate admixtures exist, every with particular functionalities. Choice is dependent upon components just like the anticipated temperature vary, desired setting time, required energy growth, challenge specs, and potential compatibility points with different concrete constituents. Consulting with concrete professionals is advisable.
Query 4: What’s the typical dosage charge for chilly climate concrete admixtures, and the way is it decided?
Dosage charges differ relying on the particular admixture, concrete combine design, and ambient temperature. Producers’ suggestions and trade requirements present steerage. Trial batches are sometimes performed to optimize dosage for particular challenge necessities.
Query 5: Are there any environmental concerns related to the usage of chilly climate concrete admixtures?
Some admixtures could include chemical compounds that require cautious dealing with and disposal. It’s important to pick out environmentally acutely aware merchandise and comply with producer tips for correct utilization and disposal to reduce environmental influence.
Query 6: Past admixtures, what different precautions needs to be taken when inserting concrete in chilly climate?
Defending contemporary concrete from freezing is essential. Different precautions embody utilizing heated mixing water, sustaining mixture temperatures above freezing, offering insulation for formwork, and monitoring concrete temperature throughout curing. A complete chilly climate concreting plan ought to embody all these facets.
Understanding the complexities of chilly climate concreting and the function of specialised admixtures is important for profitable challenge outcomes. Consulting with skilled professionals is essential for choosing the suitable admixtures and implementing greatest practices to make sure sturdy and resilient concrete constructions.
The next sections will delve into particular varieties of chilly climate admixtures, offering detailed info on their functions and advantages.
Important Ideas for Chilly Climate Concreting
Profitable chilly climate concreting requires cautious planning and execution. The following tips present sensible steerage for guaranteeing optimum concrete efficiency and sturdiness in low-temperature environments.
Tip 1: Pre-Building Planning is Paramount
Thorough planning is essential for chilly climate concreting. A complete plan ought to handle temperature monitoring, materials storage, admixture choice, and contingency measures for sudden climate occasions. Early planning minimizes potential delays and ensures challenge success.
Tip 2: Temperature Monitoring is Important
Steady temperature monitoring of concrete, ambient air, and floor situations is important. Correct temperature knowledge informs choices relating to admixture dosage, safety measures, and curing period. Monitoring ensures the concrete stays inside acceptable temperature ranges all through the hydration course of.
Tip 3: Acceptable Admixture Choice is Key
Choosing the proper admixture is important for reaching desired efficiency traits. Elements influencing admixture choice embody anticipated temperatures, required setting time, desired energy growth, and compatibility with different concrete constituents. Consulting with admixture producers or concrete specialists is advisable.
Tip 4: Defend Concrete from Freezing
Defending contemporary concrete from freezing is paramount. Insulation, windbreaks, heated enclosures, or floor thawing could also be vital. The chosen methodology is dependent upon the severity of the chilly climate and the challenge’s particular necessities. Ample safety prevents early-age freezing injury and ensures correct hydration.
Tip 5: Prolong Curing Period
Chilly temperatures sluggish the hydration course of. Extending the curing period ensures the concrete achieves its desired energy and sturdiness. Curing time changes needs to be based mostly on temperature knowledge and concrete maturity testing. Ample curing is important for long-term efficiency.
Tip 6: Contemplate Heated Mixing Water and Aggregates
Utilizing heated mixing water and aggregates helps keep concrete temperature throughout placement. This apply accelerates early hydration and mitigates the chance of early-age freezing. Cautious temperature management throughout mixing is important for reaching optimum outcomes.
Tip 7: Examine Concrete Usually
Common inspection all through the location and curing course of is essential for figuring out potential points early on. Examine for indicators of cracking, scaling, or insufficient consolidation. Well timed identification of issues permits for immediate corrective motion, minimizing long-term penalties.
Implementing the following tips contributes to the profitable placement and curing of sturdy concrete in chilly climate situations. Consideration to element and proactive measures guarantee optimum concrete efficiency and decrease the chance of expensive repairs or untimely deterioration.
The next conclusion summarizes the important thing takeaways relating to chilly climate concreting and emphasizes the significance of correct planning and execution.
Conclusion
This exploration of concrete components for chilly climate development underscores their very important function in guaranteeing profitable challenge outcomes in difficult low-temperature environments. These specialised admixtures mitigate the detrimental results of chilly on concrete hydration, energy growth, and long-term sturdiness. From accelerating hydration and lowering set instances to offering freeze safety and enhancing workability, these components provide multifaceted advantages. The dialogue encompassed the important significance of correct admixture choice based mostly on project-specific necessities, ambient situations, and desired concrete properties. Moreover, the financial benefits of using admixtures had been highlighted, emphasizing their contribution to diminished labor prices, quicker challenge completion, and minimized threat of expensive repairs.
Profitable chilly climate concreting necessitates a complete strategy encompassing meticulous planning, stringent temperature monitoring, knowledgeable admixture choice, and diligent execution of greatest practices. Prioritizing these concerns ensures the development of sturdy, resilient, and cost-effective concrete constructions in chilly climates. Continued analysis and growth in admixture expertise promise additional developments in chilly climate concreting, paving the way in which for enhanced concrete efficiency and prolonged service life in more and more demanding environmental situations.
