It has also been possible to optimize the thickness of the walls, reducing the total cost in materials and workforce. Fire protection and impact resistance are increased, the risk of oxidation and degradation is reduced, also obtaining elements with a longer useful life.
Through this application, important benefits are also achieved, such as obtaining lighter elements, which allow to carry out simpler operations in terms of handling, storage, transfer to construction and installation.
These actions are relevant in prefabrication, because the most of the possible failures can happen in the processes prior to installation. Therefore, the application of fibers generates a three-dimensional reinforcement in the structure that eliminates weak points, in such a way that they better withstand these efforts.
For the calculation of the sections it’s to consider the own weight of the structure, the overloads of use and the permanent loads that will act on it.
The verifications of resistant and acting moments are carried out using the values of the residual resistance of the selected polymeric fibers, obtained by means of laboratory tension tests, made in rimsa.
This application can also be carried out with the use of steel fibers, which generally have higher residual strengths compared to polymer fibers. For this reason, according to the requirements of each project, an analysis of the best option to be considered must be done, with differences in the dosages to be used.
In both cases, the use of fibers makes it possible to obtain prefabricated items with any desired shape, more easily than using traditional armor, where certain limitations are present due to its structure.
As part of the second phase of the Iberum Central Platform, the first eco-industrial park in Spain, rimsa has participated with the technical study and supply of 470 tons of steel fibers as reinforcement for a 68,000 m2 concrete floor.
This important logistics building is strategically located in the Illescas Green Logistics Park, in Toledo, and has been built under responsible environmental standards, with photovoltaic panels on the roof, and is expected to have BREEAM certification for its operation
The concrete floor was executed without shrinkage cuts, and designed to withstand loads of 5T/m2, by adding steel fibers. The application of these fibers provides a reinforcement that, in addition to controlling shrinkage cracking in the concrete, generates an increase in its tensile and flexural strength.
The eco-industrial park seeks to obtain economic, environmental and social performance, reducing the generation of waste and pollution, and seeking energy savings in water, using sustainable drainage systems, and light, through LED lighting and a translucent design on deck
The Illescas Green Logistics Park aims to have the 0 Emissions certification, thus becoming the first logistics industrial estate with measures to eliminate the carbon footprint.
The building, which has racking areas, circulation areas for forklift trucks and loading docks with leveling platforms, will come into operation in the first half of 2022.
The Port of Huelva construction, currently in process, consists of a total of 180,000 m2 divided into 6 phases of approximately 30,000 m2 each.
Port infrastructures require great capacities, both in design and execution, and that they are being led by experts who collaborate in detail with the knowledge that involves work and professionalism to adapt to the customer’s needs.
rimsa has collaborated in the construction of several ports, offering optimal proposals, adapting them to the needs of each project. In the case of port pavements, the solution contemplates the replacement of the traditional reinforcement by steel fibers, thus speeding up the time of installation and reducing the cost.
In this project, rimsa has collaborated successfully supplying 1,900 T of steel fibers of their reference r glued 60 /0, 75 which provides the maximum exponent of reinforcement and simple addition to concrete since the fibers are supplied glued.
This format is excellent for high dosages since it allows greater ease in mixing the concrete avoiding the formation of hedgehogs. In addition, the fibers are distributed homogeneously once the glue dissolves on contact with water in the mixing phase of the concrete, achieving less distance and less dispersion between fibers within the network that forms the matrix of the concrete. The slenderness of these fibers provides a greater quantity of fibers/kg achieving an increase in benefits.
Our experience of more than 35 years focused on researching and developing innovative works, allows us to plan and generate optimal stocks to avoid causing delays in large-scale works.
We have a wide network of our own warehouses, strategically located in different points of Spain, which allow us to offer an excellent service, as well as to optimize the transport costs to avoid making the product more expensive and to reduce delivery times.
“To date, rimsa has reinforced around 300,000m2 of port pavements with our reference r glued 60 / 0.75, distributed in seven State Ports, in different phases of execution, and through 16 different contractors”
Silvia Russo – Construction Division
These reinforced slabs are executed on a specially designed and prepared sub-base and both the ground and the sub-base must be well-drained and compacted to provide adequate and uniform support to the slab.
The relevant design methods assume specific models for the interaction between slab and subbase. The rigid pavement is a concrete structure supported on the ground, whose main purpose is to resist the loads applied through the support provided by the ground. The steel fibers behave as suture points within the concrete, thus preventing the propagation of cracks towards the interior and delaying collapse.
The pavement or slab behaves in a linear elastic way until the first crack; while the elastic limit is exceeded, the load capacity increases but the system remains rigid even though the slab modulus softens slightly.
In the case of steel fiber reinforced concrete, there is a loss of strength after the crack appears (reaching the fLOP value), and the material doesn’t break brittle under any circumstances. In the case of high dosages, residual strengths higher than fLOP cracking strengths are achieved. In all cases, the residual resistance fR1 depends linearly on the fiber content.
To avoid or control the stresses caused by deformations due to immobilization, the surface on which the concrete is poured must be uniform and without relief. In addition to the dosage fiber, the proper formulation of the concrete and the appropriate subsequent curing must be taken into account.
The pavement must be disconnected from all other structural elements by means of properly dimensioned isolation joints. The retraction cuts, with a depth of usually 1/3 of the thickness of the slab, are made at regular intervals between working joints to remove stress from deformations. The requirements of flatness and leveling are met by the proper execution method.
Selecting the correct type and dosage of fibers depends on their effectiveness and their influence on the concrete consistency. Increasing the fibers’ slenderness and using high dosages lead to an increase in mechanical efficiency, but also, can lead to a consistency decrease and a greater risk of fiber hedgehogs formation that will segregate from the concrete, which is why it is necessary to dose the right amount.
The upper limit of the fiber content is set at 1.5% by volume of the concrete. The use of very high dosages requires significant modification of the granular structure of the concrete.
The kneading is a critical phase of concrete with fibers; therefore it is necessary to check the homogeneity of the mixture. The risk of hedgehogs is reduced with the correct dosage with enough content of fine aggregate; as a general rule, the fibers will be incorporated together with the aggregates, preferably with the coarse aggregate at the beginning of the mixing, being discouraged as the first component of the mix. The pouring of the fibers is carried out slowly to guarantee the homogeneous distribution of the fibers in the mass of the concrete.
The characterization of HRFA campaigns (in this case the reference r glued 60 / 0.75) by rimsa and Smart Engineering, Spin-Off of the UPC, were carried out in the Polytechnic University of Catalonia (UPC) in order to evaluate the potentiality of the application and to study the behavior of the fiber 1769.
The most widespread test for characterizing the post-cracking behavior of HRF is the bending according to UNE-EN 14651. The residual strengths of the HRF used with the testing machine INSTROM 8505 are obtained.
The test UNE-EN 14651 was carried out to determine the values of residual resistance to bending fR, 1, m and fR, 3, m at 28 days of age. In each kneading, the fiber content was also determined according to UNE 83512-1 or UNE 83512-2.
In steel fiber reinforced concrete there is a loss of strength after the crack appears (reaching the fLOP value), not produced in any case the brittle breakage of the material. Even with high dosages, residual strengths higher than fLOP cracking strengths are achieved. In all cases, the residual resistance fR1 depends linearly on the fiber content.
The relationship between both residual resistances (fR1 and fR3) is also linear, with a slope value between 0.80 and 1.16; showing that the material maintains a stable behavior for both small and large crack widths.
The results of the residual strengths obtained in this test are valid and recommended for the incorporation of this reference in this type of work.
Another test carried out is the Barcelona Test, this is an alternative test to the notched beam test. This type of test is especially interesting and recommended for quality control during production, particularly in high volume concrete works.
Traction resistance: In the direct tensile stress-strain diagram of HRFA, the fibers significantly stiffen the response in the pre-crack phase compared to that of traditional concrete, in an outstanding way, provide a residual post-crack resistance capacity due to the stitching effect between the two sides of the crack.
The most important effect on the mechanical behavior of concrete, due to the presence of the fibers, is manifested in the post-cracking tensile strength.
Compressive strength: The compressive strength of concrete does not vary significantly by the addition of fibers, although there may be a modest increase in relevant percentages of metallic fibers, there is a difference over simple concrete in ductility, this being higher when the concrete is reinforced with fibers.
Flexural strength: The increase in flexural strength when adding steel fibers are added to concrete is considerably greater than that of compressive and tensile strength. This is due to the ductile behavior of HRFA in the tensile cracked area, developing residual strengths.
Typically, the first crack strength, the resistance to breakage by flex traction, and the residual resistance to flex traction are determined. The increase in the resistance to the first crack obtained with the addition of steel fibers is minimal, which indicates that this property depends basically on the matrix and very little on the fiber content, size, and shape of these.
The breaking strength depends mainly on the volume of fibers and their slenderness, achieving important increases with respect to the resistance of the matrix if fibers with shaped ends are used.
Greater resistance to dynamic loads (impact): One of the main characteristics of HRFA is its resistance to impacts due to energy absorption, being in this case its resistance from 3 to 10 times the resistance of mass concrete. Additionally, the HRFA has a lower tendency to defragment and detach. All of the above is due to the sensitivity of the matrix, the resistance of the fibers to tearing and deformation.
Greater Tenacity: The variable that most influences the tenacity is the adherent capacity of the fibers.
Fiber-matrix adhesion: Fiber-matrix adhesion is the phenomenon that governs the behavior of HRFA after cracking when the fibers stitch the cracks delaying and making more ductile the phenomenon of composite exhaustion.
Then it is understood the importance of the chemical, mechanical, and friction adhesion that starts after the total take-off of the fibers. In order to increase energy absorption, pull-out phenomena must be encouraged and the breakage of the fibers must be avoided.
Adhesion increases with the slenderness of the fibers and it has been proven that using fibers with shaped ends.
Steel fiber reinforced concrete durability: The addition of steel fibers in concrete generates mechanical behavior characterized by presenting a greater number of cracks with lower values of crack opening, an important factor in durability requirements.
In concrete without fissures it has been verified that the corrosion of the fibers is limited to the surface of the concrete. Once the surface is corroded, the effect of corrosion does not spread more than 2mm from the surface. The fibers show good resistance to corrosion in uncracked elements, even when the elements are exposed to seawater. Through X-ray analysis and electron microscopy, it has been observed that the reactions between HRFA and seawater are limited to a few millimeters below the concrete surface. These microchemical changes appear to have no negative effect on the durability and performance of concrete under sustained loads in a marine environment.
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The UNE-83510 standard specifies the conditions to which the fiber must be subjected. The test consists of stretching the fiber until it breaks. It should be remembered that before breaking metallic fibers undergo plastic deformation.
The force before breaking or deforming is called tensile strength and is given in stress values per unit area of the fiber cross section (N / mm2). A low or medium carbon fiber, it is characterized by having a tensile strength between 400-1500 MPa.
The dosage is defined as the amount of fibers (kg) per cubic meter (m3), the more fibers incorporated in a concrete, it will have greater benefits. However, exceeding the necessary amount can be counterproductive due to the formation of hedgehogs and low workability due to the reduced fluidity of the paste; For these reasons, it is necessary to calculate the optimal dosage for each case using computer software.
In order to use the software, the residual resistance results of the characterization tests were previously incorporated into it, according to the UNE-EN 14651 standard
Subsequently, for each type of work, the values of the terrain and the hypotheses of load that the floor will support, such as racking, distributed load, truck and truck traffic, are incorporated
Regarding the dosage, it is important to highlight the effect that the fibers have on the consistency of the concrete. The fibers increase the viscosity of the cementitious paste due to its structural rigidity, modifying the values of the Abrams cone (test that allows us to know the consistency of concrete due to its water / cement ratio)
The solution to the loss of fluidity is the use of superplasticizing additives; they are responsible for increasing the flow capacity of the concrete paste without modifying the water-cement ratio to a maximum of 5% of its weight. These additives modify the consistency of the concrete, thus improving its workability
As previously discussed, with low dosages, kneading problems are reduced in the same way as with fine aggregate content and lower fiber slenderness. The order of filling is decisive, as a general rule the fibers are incorporated next to the aggregate or just after introducing it at a slow speed, 20 kg and 60 kg per minute with the maximum speed of rotation for the mixer, with the intention of ensuring the maximum homogeneity of the concrete.
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For many years, steel fiber-reinforced concrete has been successfully used worldwide in projected concrete applications. This reinforced concrete provides multiple advantages such as:
As in conventional concrete, projected concrete is a fragile material, with limited traction and bending resistance, and with very good compression resistance.
To turn it into a soft material, projected concrete can also be reinforced with conventional steel, however the installation is complex, it takes a long time and sometimes it is not possible to guarantee the minimum safety conditions. In addition, this type of reinforcement does not adapt well to the design of the thikness of the flexible layer of the projected concrete.
The following aspects should be taken into account for the production of fiber-reinforced projected concrete:
The consistency of fresh concrete should be more plastic so that fiber reinforced shotcrete can be pumped. The use of fibers in concrete can cause a loss of workability, the magnitude of which will depend on the type and length of the fiber used, as well as the amount. This factor should be especially considered when requesting the consistency of the concrete on site.
Dosage depends on the type of fiber and can be replaced by another reference if problems occur (e.g. hedgehog formation).
There are fibers that get lost in the rebound so the determination of the content and efficiency of shotcrete are the determining factors, not the theoretical dosage of the steel fibers.
Support is used to maintain the stability and bearing capacity of the ground. The supports may be needed temporarily or permanently. Concrete sprayed with steel or gunite fibers forms a ring.
There is another system for the sustenance such as the use of a ring of segments. It is very common to make temporary and permanent holding systems in combination. This support works in the opposite direction to the force exerted by the terrain, exerting radial forces.
Structural use of fibers occurs when the addition of fibers is designed to contribute to the load-bearing capacity of the concrete. This standard covers fibers intended for this use in all types of concrete and mortar, including concrete for paving, precasting, in-situ, repairing concrete and shotcrete.
Final, secondary or definitive coating
The final coating is the most important stage in the execution of a tunnel. Represents and determines the durability and structural strength and is also the support for infrastructure installations for lighting and ventilation.
In traditionally excavated tunnels, our steel fibers are used to structurally reinforce the final coating of shotcrete or pumped directly on the formwork carriage; this formwork carriage must have a series of windows that allow concreting and vibrating. This coating can be used for several reasons: To improve ventilation, because of the presence of water or even for aesthetic reasons.
In cases where traditional mesh reinforcement is reduced and even eliminated, productivity increases and the thickness of the lining can be decreased. Steel fiber reinforced concrete is stronger, more ductile and less permeable than traditional concrete.
In tunnels excavated using modern automated TBM (Tunneling Boring Machine) excavators, the lining of voussoirs (precast concrete) can also be used as a final coating and is one of the fastest growing applications today.
The primary coating provides stability to the tunnel structure while providing also immediate support to the excavated terrain. This support cladding is temporary and commonly executed in shotcrete reinforced with steel fibers.
When necessary, this phase also includes the installation of additional reinforcement elements consisting of sections in steel arches (trusses) in the shape of the tunnel contour, resting on the ground, which resist the stresses of the terrain. It is necessary to execute a running beam or a footing in cases where there is a risk that the truss might get sticked into the ground.
At rimsa we have extensive experience in the application of steel fibers and synthetic macro fibers in shotcrete. Contact our technical sales team to analyze your specific case.
If you want to know more about the use of steel fibers through shotcrete, access this link.
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For many years, steel fiber-reinforced concrete has been successfully used worldwide in projected concrete applications. This reinforced concrete provides multiple advantages such as:
As in conventional concrete, projected concrete is a fragile material, with limited traction and bending resistance, and with very good compression resistance.
To turn it into a soft material, projected concrete can also be reinforced with conventional steel, however the installation is complex, it takes a long time and sometimes it is not possible to guarantee the minimum safety conditions. In addition, this type of reinforcement does not adapt well to the design of the thikness of the flexible layer of the projected concrete.
The following aspects should be taken into account for the production of fiber-reinforced projected concrete:
The consistency of fresh concrete should be more plastic so that fiber reinforced shotcrete can be pumped. The use of fibers in concrete can cause a loss of workability, the magnitude of which will depend on the type and length of the fiber used, as well as the amount. This factor should be especially considered when requesting the consistency of the concrete on site.
Dosage depends on the type of fiber and can be replaced by another reference if problems occur (e.g. hedgehog formation).
There are fibers that get lost in the rebound so the determination of the content and efficiency of shotcrete are the determining factors, not the theoretical dosage of the steel fibers.
Support is used to maintain the stability and bearing capacity of the ground. The supports may be needed temporarily or permanently. Concrete sprayed with steel or gunite fibers forms a ring.
There is another system for the sustenance such as the use of a ring of segments. It is very common to make temporary and permanent holding systems in combination. This support works in the opposite direction to the force exerted by the terrain, exerting radial forces.
Structural use of fibers occurs when the addition of fibers is designed to contribute to the load-bearing capacity of the concrete. This standard covers fibers intended for this use in all types of concrete and mortar, including concrete for paving, precasting, in-situ, repairing concrete and shotcrete.
Final, secondary or definitive coating
The final coating is the most important stage in the execution of a tunnel. Represents and determines the durability and structural strength and is also the support for infrastructure installations for lighting and ventilation.
In traditionally excavated tunnels, our steel fibers are used to structurally reinforce the final coating of shotcrete or pumped directly on the formwork carriage; this formwork carriage must have a series of windows that allow concreting and vibrating. This coating can be used for several reasons: To improve ventilation, because of the presence of water or even for aesthetic reasons.
In cases where traditional mesh reinforcement is reduced and even eliminated, productivity increases and the thickness of the lining can be decreased. Steel fiber reinforced concrete is stronger, more ductile and less permeable than traditional concrete.
In tunnels excavated using modern automated TBM (Tunneling Boring Machine) excavators, the lining of voussoirs (precast concrete) can also be used as a final coating and is one of the fastest growing applications today.
The primary coating provides stability to the tunnel structure while providing also immediate support to the excavated terrain. This support cladding is temporary and commonly executed in shotcrete reinforced with steel fibers.
When necessary, this phase also includes the installation of additional reinforcement elements consisting of sections in steel arches (trusses) in the shape of the tunnel contour, resting on the ground, which resist the stresses of the terrain. It is necessary to execute a running beam or a footing in cases where there is a risk that the truss might get sticked into the ground.
At rimsa we have extensive experience in the application of steel fibers and synthetic macro fibers in shotcrete. Contact our technical sales team to analyze your specific case.
If you want to know more about the use of steel fibers through shotcrete, access this link.
Do not hesitate to contact us for any question or requirement you may have. We will be happy to collaborate with you
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Generally they are extensive surfaces with low hypotheses of loads and surface finish with decorative cladding.
Steel fibers and structural polymeric macro fibers added to concrete have become the most demanded solution to minimize execution times and cost.
The base or floor of these pavements is concrete reinforced with steel fibers (HRFA) or polymeric fibers. This is a composite material that has multiple advantages. With the addition of fibers to the concrete, mechanical strengths similar to those of concrete reinforced traditionally with electrowelded mesh are achieved, but cracking is better controlled, in addition to achieving significant cost and time savings, notably improving execution times.
The possible appearance of fissures due to retraction is avoided by making cuts with a maximum depth of 1/3 the thickness of the screed.
On this suitable concrete base, surface solutions are subsequently applied in resins, cementitious tread layers or various decorative resistant solutions.
In pavements in the food indusrtry sector such as meat, dairy, beverage, fishing and conservative industries, among others, the design of a base or screed suitable for the type of loads in combination with the coating solves diverse and complex needs of the food indusrtry industries in the phases of food processing, storage, preservation and transportation
On the screed, after concreting, surface finishes are usually made in resistant resins (epoxy, polyurethane), giving an optimal response in durability. This sector combines an aggressive chemical environment and very strict hygiene requirements. The use of polymeric macro fibers are ideal for this type of application, since polyolefins are very resistant materials to chemical agents
The main advantages of using steel fibers are:
-Effective control of cracking
-Homogeneous distribution generating a three-dimensional reinforcement
-Excellent resistance to impacts and fatigue
-Excellent corrosion resistance
-Agile and simple application
-Reduction of execution times
-Cheaper solution
-The handling problems of the traditional assembly are avoided and the risks of it’s bad placement are eliminated
-Easy to use the laser paver
The CE marking is guaranteeing that the performance of the product is as stated. According to the European standard UNE14889-1, two conformity verification systems are mainly defined:
The steel and polymeric structural fibers are classified in System 1, with the intervention of a notified body declaring the effects on the Strength of the concrete.
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It is an economical composite of materials that conforms a structure with great capacity to withstand compression without breaking.
However, once this effort has been overcome or a flexural tensile stress is experienced, the material begins to crack and breaks catastrophically due to the lack of ductility.
The method traditionally used to solve the cracking of concrete is by installing a steel mesh.
Steel mesh is a structure formed of steel bars welded together following the profile of the construction surface.
In addition to the installation problems, the entire structure is not reinforced in its whole; the vertices of the structure are fragile elements on impact, forming cracking of the concrete and being exposed to possible corrosion.
Fiber-reinforced concrete (HRF), on the other hand, is one in which short steel fibers are incorporated into its mix, randomly distributed in their mass, in order to improve its mechanical properties
The ease of putting the fibers in place compared to the mesh makes them a quick alternative by allowing them to mix and easily adhere with the concrete matrix
Once the fibers are mixed, the concrete is poured or pumped on site, thus becoming the most economical method since it does not require any specialization to mix and thus reduce the time of putting on site
There are a great variety of references with different geometries and dimensions on the market, which can be used to reinforce concrete structures, to provide an improvement in their mechanical properties or in order to improve their non-mechanical properties
1.Fibers with a non-structural purpose are those fibers that increase the non-mechanical properties of concrete.
As an example, it has been proven that some polymeric fibers can control the shrinkage that concrete experiences during its curing and, consequently, can control shrinkage cracking by providing flexibility.
In turn, some fibers can increase fire resistance, increasing so the durability of the structure.
2.On the other hand, fibers for structural purposes are those that increase mechanical properties such as traction or compression.
This fibers are distributed homogeneously throughout the concrete structure as they are added during the kneading of the raw materials, thus forming a cementitious paste that is pumped or poured.
The geometric characteristics of the fibers are established according to UNE 83500-1 and UNE 83500-2 standards, and the effectiveness can be assessed using UNE 8510 standard
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The Spanish Instruction on Structural Concrete (EHE-08 – RD 1247/2008) is the name given to the Spanish regulations on the calculation and safety of concrete structures. It is mandatory for all structures where concrete is used in Spain
For the purposes of this Annex, fiber-reinforced concretes (HRF) are defined as those concretes that include short fibers randomly distributed in their mass in their composition. The approach is general for all types of fibers, although it must be borne in mind that the fundamental basis of the knowledge available is for steel fibers
The use of fibers in concrete has a structural purpose when its contribution is used in calculations related to one of the ultimate or service limit states and its use may involve the partial or total replacement of reinforcement in some applications
Fibers will be considered to have no structural function when fibers are included for other purposes such as improving fire resistance or cracking control
Therefore, the application of nonlinear analysis may be especially recommended in cases where the fibers constitute an important part of the concrete reinforcement
Likewise, given the ductility introduced by the presence of fibers, the principles for the application of the linear analysis method with limited redistribution and the plastic calculation methods are considered valid
The combination of conventional reinforcement and fibers can be an alternative to reduce the amount of conventional reinforcement in regions where there is a high density of reinforcement that hinders the correct concreting of the element
The geometry of the fiber has an important impact on the adherent characteristics of the fiber with the concrete
Steel fibers must be in accordance with UNE 83500-1 and, according to the manufacturing process, are classified into:
The use of lengths of 2.5 to 3 times the maximum size of aggregate is usual. Furthermore, the diameter of the pumping pipe (in the case of sprayed concretes) requires that the length of the fiber is less than 2/3 of the diameter of the pipe. However, the length of the fiber must be long enough to give the matrix sufficient adhesion and avoid pulling out too easily
At the same length, fibers of reduced diameter increase the number of them per unit of weight and make the fiber framework or network denser. The spacing between fibers is reduced when the fiber is thinner, being more efficient and allowing a better redistribution of load or stress
Slenderness is a parameter that relates length to diameter of the fiber cross section
High values of fiber slenderness increase the performance of the concrete, but in turn, the possibility of forming hedgehogs in the fiber concrete mix increases.
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In recent years Rimsa has collaborated successfully in the construction of pavements in several ports in Spain, among which stand out: port of Algeciras, port of Huelva, port of Malaga, port of Barcelona and port of Pasaia among others.
Steel fibre reinforced concrete (HRFA), the use of which is covered by Annex 14 to the EHE, has been used for many years as a solution in the construction of pavements. It is a material that achieves a mechanical resistance similar to that of reinforced concrete in a traditional way but better controls cracking and other advantages.
The possible appearance of cracks due to retraction is avoided by means of cutting joints with a maximum depth of 1/3 of the thickness of the slab. The size of the pads delimited by the gaskets is usually about 5 m x 5 m
The reference R GLUED 60/0.75 allows the total replacement of the traditional assembly in the case of port pavements.
Advantages of using steel fibres
– They improve the ductility. The steel fibres sew the cracks of the concrete into a “bridge”, allowing a controlled formation of the cracks, and leading the concrete to a ductile behavior after the initial cracking, thus preventing brittle breakage.
– There are no faults or weak points in the armor and the mechanical behaviour to the stresses is the same in all directions.
– Increase abrasion resistance due to reduced cracking.
– They control the opening of cracks by preventing water entry and corrosion. Erosion resistance is also improved
– They improve tensile strength, bending and cutting, producing an increase in load bearing capacity.
– They grant additional resistance capacity due to the redistribution of the plastic moment in the case of localized demands.
– High resilience (energy absorption capacity on impact).
– Dynamic fatigue resistance.
– Reduction of execution times.
– Increase the durability of concrete.
– Elimination of the risks of a bad placement of the traditional assembly, with an agile and simple application.
– They allow greater ease in mixing with concrete.
– They allow a dosage greater than 30 kg / m3.
– No hedgehogs are formed.
– They allow a homogeneous distribution, within the concrete matrix.
– Immediate dissolution of the tail on contact with water at the initial moment of kneading.
– They allow to achieve a smaller distance between fibers within the network that is formed in the matrix.
– They allow a smaller dispersion within the concrete, giving it greater performance.
– They are more slender, which allows a greater amount of fibers / kg.
Reference r glued 60/0.75 is served in 20 kg bags. 1,200 kg pallets and / or big bags.
In concrete plant or through conveyor belt directly to the concrete mixer truck.
Ductility is the property that some materials have in being able to deform when subjected to intense stress. This property is useful in engineering, since it allows to design safe structures.
With high dosages, it is possible to obtain a reinforced concrete with completely ductile steel fibers, with the capacity to withstand load similar to that of traditional reinforced concrete. The concrete formula is developed so that it is easily pumpable.
On the other hand, when a material does not have this ductility property, it breaks or breaks in the load limit, causing in some cases a catastrophic rupture, without experiencing any type of plastic deformation. A clear example is concrete.
To combat this problem of concrete fracture, a metal mesh was usually incorporated as a structural base. The placement of the mesh generally represented an increase in the term and cost of the work, due to the placement and welding of the mesh.
The following graph shows a diagram of the total time spent in a construction, divided into the different stages. The placement of the reinforcement mesh represents 13% of the time invested in a work and the assembly in general represents 22%.
Fibers that represent a structural function should not be used in dosages less than 20 Kg / m3 and also not greater than 1.5% of the volume of concrete.
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