ES2391959B1 - SELF-COMPACTING CONCRETE. - Google Patents

Abstract

Self-compacting concrete with: Cement I 52.5 R / SR, Microsilica (MEYCO MS 610 {reg}), water, sand 0/4 crushing limestone, 0/2 crushing limestone sand, aggregate 4/11 crushing limestone , superplasticizer agent for high performance concrete (Glenium B255 {reg}), Superplasticizer agent for precast concrete (Glenium ACE 381 {reg}), retardant for the setting of concrete (Pozzolith 140 R {reg}), getting an initial fluidity ( UNE 83.361) df> = 800 mm, Initial viscosity (funnel in? V? UNE 83.364) T {sub, V} of 5-8 sg, an initial viscosity (UNE 83.361) T {sub, 50} of 1-3 sg . 120-minute maintenance of fluidity (UNE 83.361) df> = 785 mm and viscosity (UNE 83.361) T {sub, 50} <= 3 sg, characteristic compressive strength at 28 days fck> = 90 N / mm {sup , 2}, and at 90 days fck> = 100 N / mm {sup, 2}.

Description

OBJECT OF THE INVENTION

It is the object of the present invention, as the title of the invention itself establishes, a self-compacting concrete that is used for very reinforced concrete, for molds (formwork) with complicated shapes or any other circumstance that implies an important difficulty in vibrating the concrete .

It characterizes the present invention the materials and the proportion of the materials that are part of the concrete, obtaining a concrete that has characteristics of fluidity, viscosity, maintenance of fluidity and viscosity and compressive strength at 28 and 90 days, which No other known concrete presents so far.

Therefore, the present invention is circumscribed within the scope of concrete and particularly among self-compacting concrete.

BACKGROUND OF THE INVENTION

Self-compacting concrete are state-of-the-art concrete that is achieved thanks to a studied dosage of the materials that make up the concrete that are capable of flowing inside the formwork, passing between the reinforcement bars and compacting thanks to their own weight without presenting any type of segregation

Self-compacting concrete has a number of advantages that are indicated below:

• From the point of view of Quality and Performance: -Durability guaranteed. -Good mechanical resistance.

-Good surface finish. -Lower execution errors.

•

New structural possibilities: -Elements of difficult access or high density of armor. -New architectural forms and designs. -Structural sections of smaller thickness.

•

From the point of view of the improvement of the environment: -Reduction of the noise level of 90%. -Reduction of the physical load of heavy vibration work. -Elimination of electrical hazards by eliminating vibration. -Improvement of verbal communication in the work by eliminating vibration. -Elimination of circulation problems ("White fingers") in the

Operator fingers that vibrate.

•

From the point of view of Productivity: -Higher placement speed. -Reduction of labor and auxiliary means.

However, given the increasing complexity of civil and building works, the market demands self-compacting concrete with better characteristics in terms of fluidity, viscosity, maintenance over time of fluidity and viscosity, compressive strengths at 28 and 90 days.

Some known data of self-compacting concrete in the national technical literature indicate that the vanguard in terms of fluidity and resistance would be:

Fluency, measured as final runoff diameter UNE 83.361 df =

703 mm

Compressive strength at 28 days = 85.5 N / mm2 (test data,

not statistical).

Therefore, it is the object of the present invention to develop a self-compacting concrete that exceeds the performance provided by the concrete known until now, in terms of fluidity, viscosity, maintenance of fluidity and viscosity, compressive strength after 28 days and 90 days, developing a concrete such as the one described below and which is collected essentially in the first claim.

DESCRIPTION OF THE INVENTION

The object of the invention is a self-compacting concrete that presents the

following features:

Fluency (runoff 1UNE 83,361)

df ~ 800mm

Viscosity (funnel in "V" 1UNE 83.364)

Tv = 5-8 sg

Viscosity (UNE 83.361)

Tso = 1-3 sg

Maintenance of 120 minutes of fluidity (runoff df ~ 785 mm) and the Viscosity Tso :::; 3 sg very similar to when the concrete is freshly kneaded Characteristic (statistical) resistance at 28 days fck ~ 90 N / mm2.

Characteristic (statistical) resistance at 90 days fck ~ 100 N / mm2.

To achieve these functional characteristics, the concrete object of the invention has the following elements in its composition:

Cement 1 52.5 R 1SR Microsilica. Water. Sand 0/4 crushing limestone. 0/2 crushing limestone sand. Arid 4/11 crushing limestone. Superplasticizing agent (high activity water reducer) for high performance concrete. Superplasticizing agent (high activity water reducer) for precast concrete. Retardant for setting concrete.

The nature of the materials used in the manufacture of concrete is fundamental, and as can be seen in addition to the classic elements such as cement, sand, aggregates and water, other elements are used as superplasticizers (Gienium 8255 andACE 381), microsilica (Meyco MS 61 O) and retardant (Pozzolith 140R).

Cement 1 52.5 R / SR of the company Financiera y Minera SA, which manufactures it in the Añorga factory, in San Sebastián (Guipúzcoa).

The limestone sand 0/4 of the Urnieta quarry (Guipúzcoa) belonging to Aizkibel SA (Grupo CALCINOR SA).

Limestone sand 0/2 from the Urnieta quarry (Guipúzcoa) belonging to Aizkibel SA (Grupo CALCINOR SA).

The 4/11 limestone aggregate of the Urnieta quarry (Guipúzcoa) belonging to Aizkibel SA (Grupo CALCINOR SA).

The densified microsilica Meyco MS 61 O (8ASF ®), is a filling material used in the concrete that causes the capillary pores to become clogged and the equivalent micropore diameter is significantly reduced.

The usual dosage is of the order of 5 to 10% by weight of cement. The dosage depends on the type of materials and the desired effect.

The superplasticizer agent for high performance concrete has been Glenium 8255 (8ASF®).

Glenium 8255 is a new generation high-activity, water-reducing superplasticizing additive 1 based on the technology of polycarboxylic derivatives. Specially designed for civil works and concrete prepared with high demands and high performance. Allows the preparation of fluid and liquid concretes based on dry consistencies without the need

to increase the kneading water and without causing setting delays, with high resistance and high durability.

Among the properties of Glenium, it is worth mentioning: Great plasticizing power It allows to obtain concretes of very low ratio NC Very good maintenance of consistency even with absorbent aggregates It does not cause delays in setting Improves the impermeability of concrete Increases durability Reduces porosity and improves finish Superficial Improves cohesion and reduces the risk of segregation and bleeding even at high consistency Improves mechanical resistance. Suitable for white concrete.

The recommended dosage of GLENIUM 8255 is 0.5 to 2.5% by weight of cement.

The superplasticizing agent for precast concrete has been Glenium ACE 381 (BASF ®)

Glenium ACE 381 is a superplasticizer additive 1reducer of water, of high activity based on polycarboxylates for applications in precast concrete, where high initial strength and very high plasticizing capacity or very low NC ratios are demanded. Among the properties of Glenium ACE 381 are:

Excellent plasticizing power without disintegration

High initial resistances, even with low dosages

Making more docile concrete

Improve concrete durability

Suitable for white concrete.

The usual dosage is between 0.3% and 1.0% by weight of cement according to increased workability and desired water reduction.

The agent or additive retardant for the setting of concrete, has been the Pozzolith 140 R (BASF®)

The Pozzolith 140 R is a retarding additive that allows setting the setting time according to the dosage used. Among the properties of this material are:

Reduces cracks caused by shrinking Concrete treated with POZZOLITH 140r can be compacted and vibrated for longer. Difficult premature evaporation of kneading water Increases long-term mechanical resistance.

The dosage will range from 0.3% to 3.5% on the weight of the cement and will be based on the desired delay and the conditions of work.

Fresh concrete is subjected to the following tests, according to the UNE standards specified

Fluency according to runoff test UNE 83.361.

· Initial fluency, 30 minutes, 60 minutes, 90 minutes and 120 minutes. Viscosity Tso according to the UNE 83.361 test. Viscosity T v according to the funnel test in "V" UNE 83.364.

The tests of the hardened concrete are the following.

Compressive strength 7/8 days. Compressive strength at 28/29 days. Compressive strength at 88/90 days.

None of the concretes developed so far have achieved the indicated results, and all this thanks to the special nature and synergy produced between the materials used in its preparation.

PREFERRED EMBODIMENT OF THE INVENTION.

The self-compacting concrete object of the invention has the aforementioned materials, and which in a possible embodiment could have the following proportions. These proportions are in no case limiting and simply reflect a particular embodiment, without being their quantities the object of the invention.

Cement 1 52.5 R 1SR 475 kg / m3 Microsilica MEYCO MS 61 O (BASF) 60 kg / m3 12.63% Water 154 kg / m3 Sand 0/4 crushing limestone 886 kg / m3 Sand 0/2 crushing limestone 200 kg / m3 Arid 4/11 crushing limestone 490 kg / m3 Glenium 8255 (BASF) 8.90 kg / m3 1.87% Glenium ACE 381 (BASF) 3.70 kg / m3 0.78%

-

Pozzolith 140 R (BASF) 3.70 kg / m3 0.78%

The percentages collected are as many percent in relation to the weight of the cement.

For a concrete, with the materials described and in the indicated proportions the following results have been achieved in the different test tests to which it has been subjected.

Characteristic resistance to compression at 28 days fck = 90 N / mm2. Characteristic resistance to compression at 90 days fck = 100 N / mm2. Initial fluidity according to the runoff test UNE 83 361 df = 81 O mm.

Initial viscosity according to the "V" funnel test UNE 83.364 Tv = from 5 to 8 sg. Initial viscosity according to the UNE 83.361 test Tso = 1 to 3 sg. Fluidity at 120 minutes according to runoff test UNE 83.361 df = 785mm. Viscosity at 120 minutes according to test UNE 83.361 Tso :::; 3 sec.

All these results together had not been achieved so far, although the materials used in its preparation are known, but not the use of them together, which results in a synergistic result, with special characteristics that exceeds all self-compacting concrete prepared and obtained so far.

The results obtained go beyond what is directly expected by the combination of materials whose properties are known, since the effects achieved are not only due to the nature of the additives used, but also to the combination of additives and additions, as well as to the characteristics and proportions of the aggregates used.

Describing sufficiently the nature of the present invention, as well as the way of putting it into practice, it is not considered necessary to make its explanation more extensive so that any expert in the field understands its scope and the sales derived therefrom, stating that, within its essentiality, it may be implemented in embodiments that differ in detail from that indicated by way of example, and to which it will also achieve the protection that is sought as long as it is not altered, changes or modifies its fundamental principle.

Claims (9)

1.-Self-compacting concrete characterized in that it has the following materials: Cement 1 52.5 R 1SR. Microsilica. Agua Arena 0/4 crushing limestone. 0/2 crushing limestone sand. Arid 4/11 crushing limestone. Superplasticizing agent for high performance concrete. Superplasticizer agent for precast concrete. Retardant for setting concrete. 2. Self-compacting concrete, according to claim 1, characterized in that the microsilica is Meyco MS 61 O (BASF ®). 3.-Self-compacting concrete, according to claim 1 or 2, characterized in that the microsilica dosage is of the order of 12.63% by weight of cement. 4.-Self-compacting concrete, according to claim 1, characterized in that the superplasticizing agent for high-performance concrete is Glenium 8255 (BASF ®). 5.-Self-compacting concrete, according to claim 1 or 4, characterized in that the dosage of the superplasticizer agent for precast concrete is 0.5% -2.5% by weight of cement 6. Self-compacting concrete, according to claim 1, characterized in that the high performance concrete superplasticizer agent is Glenium ACE 381 (BASF ®). 7. Self-compacting concrete according to claim 1 or 6, characterized in that the proportion of the superplasticizer agent for precast concrete is between 0.3% to 1.0% by weight of cement. 8.-Self-compacting concrete, according to claim 1, characterized in that the retarding agent or additive for setting concrete is Pozzolith 140 R (BASF®). 9. Self-compacting concrete, according to claim 1 or 8, characterized in that the proportion of the retarding agent or additive for setting the concrete is between 0.3% to 2.5% of the cement weight. 1 0.-Self-compacting concrete, according to the preceding claims characterized in that the quantities and / or proportions of each material is in the environment of: Cement 1 52.5 R 1SR 475 kg / m3 Microsylice MEYCO MS 61 O (BASF) 60 kg / m3 12.63% - Water 154 kg / m3 - Sand 0/4 Crushing limestone 886 kg / m3 - Sand 0/2 Crushing limestone 200 kg / m3 - Arid 4/11 limestone of crushing 490 kg / m3 Glenium 8255 (BASF) 8.90 kg / m3 1.87% Glenium ACE 381 (BASF) 3.70 kg / m3 0.78% Pozzolith 140 R (BASF) 3.70 kg / m3 0.78% where the percentage collected, are percentage amounts in relation to the weight of dement.