R&D&I

The amount of hexavalent chromium present in the cements used or manufactured in Spain is regulated following the legal requirements established by Directive 2003/53/CE, transposed to our regulations via Order PRE/1954/2004, of 22nd June.
Once the disadvantages of the additives traditionally used in Europe for hexavalent chromium reduction and the technical limitations of the few alternative additives present in the market were known, the laboratories of Tudela Veguín started developing a good Cr(VI) reducing product, which also eliminates the limitations and disadvantages of the additives already in existence.
Patent protection has been requested for this product, both at national and European level, with the file being in the final resolution stage at present.
The redox Cr(VI)/Cr(III) system has characteristics that are oxidising and very dependent on the pH of the means in which the reaction takes place. For this reason and given that cement leaching water is very alkaline, redox systems with reducing power under these specific conditions must be found.
CrO4 2- + 4H2O + 3e- ↔ Cr(OH)3 + 5OH-
In connection with the above, the great difficulty for reducing chromium (VI) in alkaline pH and the scarcity of reducing agents working effectively under these conditions should be highlighted.

The Technical Construction Code (CTE) is a mandatory document that includes the basic quality requirements with which buildings must comply. The CTE establishes these requirements for each requisite considered as being basic, such as energy savings and thermal insulation. The Basic Document describes the insulation/conductivity requirements of the different materials intervening in any construction. This point presents the opportunity of introducing innovative mortars, lighter than those usually used in construction. The use of this mortar improves the insulation properties, contributing in an essential manner towards energy savings.
There are many ways of lightening the materials in terms of the on-site implementation required, it being common to do so with expanded clay aggregates as this is more cost-effective. In this way, mortar mass is made lighter as these aggregates contain air microcells resulting from the high temperature expansion process through which they were generated. This ensures a lower thermal conductivity coefficient, translating into lower wall transmittance, as long as the bricks used are also compliant with the CTE requirements.

This binder is born as a response to the European and worldwide trend towards developing more ecologically-friendly binders by means of reducing emissions and a greater sustainability index, as its main component is blast furnace slag, a steel manufacturing by-product. When this slag is cooled suddenly, then subjected to a milling process and activated afterwards, it reaches similar properties to those of cement with regard to setting and hardening, with the advantage of a retraction which is hardly unnoticeable.
One of its possible applications is the use in pedestrian paths being carried out at several points throughout the Spanish geography, may they be fluvial, coastal or agricultural. The solution often applied due to its speed is asphalting, with the resulting negative visual impact caused in certain environments. A finish similar to that of earth which blends in with the surroundings is achieved with this binder.
It is also an innovative and environmentally friendly material for several reasons:

• It is based on steel manufacturing by-products.
• There are no CO2 emissions in its manufacture.
• It avoids the use of bituminous materials.
• It reduces the visual impact of the path executed, as a finish in the colour of the aggregate chosen is obtained without the need for pigments.
• It avoids the use of gravel in agricultural tracks, in this way eliminating the formation of dust which is very harmful to crops.

Due to its chemical composition, it is a highly DURABLE product as it is resistant to the attack of sulphides, often present in water flows or gypsum areas.
Its composition based on blast furnace slag translates into the DEVELOPMENT of RESISTANCES beyond 28 days.
On top of this, its RETRACTION is practically nonexistent, therefore eliminating the problem of cracks and gaps appearing, through which aggressive external agents could penetrate.
On the other hand, its low heat of hydration and long SETTING TIME make it very convenient regarding transport from the plant and its laying and compacting tasks, without the need for retarders.
Apart from the lines of research described, Tudela Veguín is also working on other lines which are not as developed as the ones already stated:

• Emission reduction and control.
• Innovation in sustainable quarry management.
• More sustainable cement production, minimising the use of natural resources.
• Energy efficiency improvement in the production process.
• The application of nanotechnologies to create concrete with new features.
• The logistical optimisation of the product and the raw materials.
• The development of products or solutions for eco-efficient construction (buildings and public works).
• A safe bet on the design and aesthetics of the final products.

This R&D work has become clear in both projects that are to be started up thanks to this Competitiveness Plan:

• The inclusion of a blast furnace slag mill in Aboño implies the use of this refuse as a Raw Material for the process, meaning its sustainable use. Also, adding this slag to clinker provides an added benefit which is the improved resistance of cement in aggressive environments such as marine ones.
• The adaptation of the fuel supply installations to the main intake of the clinker furnace of La Robla, in order to use organic waste which is not hazardous in small grain sizes (mainly made up by plastic with different cardboard, wood and textile ratios) as alternative fuels to oil, equally reduces the amount of waste dumped in the tip, as they are valued in compliance with the strict environmental air and waste incineration quality standards, while complying with the European waste regulations currently in force which forbid dumping in the tip any waste flow which could have any kind of alternative use. Also ahead of its time is the compliance with the new European framework regulations on waste management, published in 2008 and about to be transposed to the national legal ordinances, taking a step forward in the philosophy of using, as far as possible, the resources contained in waste to avoid this from being squandered in tips. The inclusion of waste valuation processes to obtain energy reduces the dependency on fossil fuels and, similarly, their consumption.

This generic terms designates all the physical forms in which calcium oxide, also denominated quicklime, may appear and forming part of the so-called aerated limes which are those which harden slowly through contact with air and, in general, without hydraulic properties.
Within the range of lime-based products, the R&D&I department of Cementos Tudela Veguin has developed a new product called “MICRONIZED LIME”.
Micronized lime is a type of finely milled quicklime, with its maximum particle size in the micron range. This lime allows for a reactivity and solubility improvement as opposed to lime with conventional grain sizes (0-2 mm), making it ideal for its use in industries requiring a larger specific surface area or greater fluidity of the lime used.

USES

Micronized lime is used mainly in the siderurgical and metallurgical industry, in the treatment of acid waste, while also as a biocide in agriculture and in the treatment of sewage sludge.

BENEFITS 

The fineness of micronized lime makes it have a greater fluidity and larger specific surface area, together with greater reactivity.

TECHNICAL DATA 

The chemical values are the normal ones for siderurgical lime, the only difference being the size. The average chemical values, together with the grain size curve of micronized lime are as follows:

A family of cements with differentiated characteristics from those of common cements was born from the need to respond to the needs of clients in the field of special binders.
The objective consisted in achieving cements with an extremely high fineness and a specific grain-size distribution for their application in civil engineering and building constructions:

• Impregnation injections: previous and subsequent stabilisation in tunnels, mines,…
• Jet grouting applications: land consolidation, waterproofing of filtrations due to a rising water table.
• Injection in micro-fissures: rehabilitation of all types of work: bridges, dams, viaducts, singular and historical buildings,

DEVELOPMENT

The function of this product is to achieve a high penetration in land with low permeability, in such a way that the process is similar to granular matrix filtering. This improves the range of the injections and their durability, as a high stability cement matrix is created. Also, it is not degraded throughout time, as opposed to other types of chemical product injections, making it a recommendable solution from the environmental point of view.
Taking into account these premises from the start and always in permanent contact with our commercial team, the Production and Quality and R&D&I departments of the industrial branch of Corporación Masaveu commenced working in a joint manner to find the technical solutions leading to a product which could satisfy the following requirements:

• A fineness under 32 microns..
• Optimum dispersion in water. High fluidity..
• The achievement of stable and non-exuding grout..
• Great penetration in fissures and closed spaces..
• Optimum mechanical resistances..
• The possibility of being resistant to sulphides (upon request).

SUPPLY FORMATS

• Paper sack with a plastic film.
• Different capacity big bags.
• Gravity silos with mixer included at the base, refillable by means of tank trucks.