WO2013098434A1 - Concrete-production method - Google Patents

Abstract

Concrete-production method characterized in that it comprises the steps of: - initially placing cement, water, volcanic-aggregate sand and/or volcanic aggregate in a mixer in order to obtain volcanic-aggregate mortar; - placing, in a mortar mixer, firstly the volcanic-aggregate mortar obtained and then pre-wetted expanded polystyrene with E.I.A® additive, and mixing; - next, applying vibration to the mixture for 30 seconds for each one third of volcanic-aggregate mortar/expanded polystyrene mixture; - and, finally, simultaneously compressing and vibrating the mixture.

Description

 CONCRETE MANUFACTURING PROCEDURE

Field of the Invention

 The present invention falls within the field of construction materials, more specifically in the area of precast concrete for construction.

Background

 The concrete used for prefabricated building must be thermal and acoustic insulation.

 The places like the Canary Islands, the aggregate that is used for the manufacture of lightened vibrated concrete vaults and vaults is the picón, by themselves, they do not meet the basic requirements against noise and energy demand, to achieve thermal well-being and Acoustic required.

 With the entry into force of the Basic Document "DB-HR Protection against noise" and "the limitation of energy demand" of the Technical Building Code in 2007, constructive solutions are studied that comply with the new regulations, one of these lines It is the study to improve the acoustic and thermal resistance of the concrete blocks lightened with picón.

 The most characteristic materials used in this study are picon and expanded polystyrene, two completely different materials:

 The picón is formed naturally, due to volcanic eruptions, when the lava cooled more than twenty million years ago, Alonso, J. "Volcanic-stratigraphic and Volcanological Study of the Sálicos Pyrolasts of the South of Tenerife". Thesis, University of La Laguna, (1989), as well as Carracedo, J.C. Pérez Torrado, F.J. Ancochea, E. Meco, J .; Hernán, F. Cubas, C.R. Casillas, R. Rodríguez Badiola, E. & Godson, A .: "Cenozoic volcanism II. The Canary Islands." Ed. Gíbbson, W. & Moreno, T. pp. 439-472. London, (2002). Regarding the blocks of vibrated concrete lightened with picón there are publications such as Gómez, I .: Hygroscopic characterization of construction materials: lightened clay and picón "thesis Higher Technical School of Industrial and Telecommunications Engineers. Bilbao (2006). As well as Source, M; De Rozas, M.; Jubera, J. "Building with picon blocks: acoustic quality of the Canarian dwellings"., University of Coimbra October 20-22. Portugal. (2008)

The expanded polystyrene was synthesized for the first time at the industrial level, in the year 1930, from which you can find publications such as "Concrete with Light aggregates "Department of Applied Mechanics and Structures. Faculty of Exact Sciences Engineering and Surveying. National University of Rosario. Argentina, (2003), and Ravindrarajah RS, Tuck AJ. (1994)" Properties of hardened concrete containing treated expanded polystyrene beads. Cement Concrete Compos. Description of the invention

 The invention relates to a concrete manufacturing process comprising:

 - Introduce cement, water, picón sand and / or picón in a mixer until obtaining picón mortar,

 - Introduce the obtained picon mortar into a kneader and then expanded polystyrene mixed with a specific additive, E.I.A®, such as POLITERM BLU®, previously moistened, and knead,

 - Subsequently, apply vibration on the mixture for 30 seconds for every third of the mixture of picon mortar with expanded polystyrene added with E.I.A® with E.I.A® ®

 - Finally compress and vibrate the mixture at the same time.

 POLITERM BLU® is an expanded polystyrene mixed with a specific additive, E.I.A® ®, marketed by EDILTECO GROUP, which allows the mixing of polystyrene with binder water, eliminates the flotation phenomenon and guarantees the homogeneous distribution of the mixture.

 The advantages of picon mortars, with the addition of expanded polystyrene mixed with a special additive, E.I.A®, over traditional picon mortars are:

 - Lighter: The decrease in weight, proving to be 32.82% lighter.

- More acoustic insulation: A 5 cm thick plate and plaster coated on both sides has the same acoustic insulation as a wall constructed with 15 cm thick vibrated concrete blocks and plaster coated on both sides.

- More thermal resistance: In the thermal resistance is where there is greater difference in the results, in which a plate constructed with traditional mortar has 0.1346 R (m2.K / W) compared to another plate of the same dimension and with POLITERM BLU ® whose thermal resistance is 0.2741 R (m2.K / W), that is an increase of 103.64% Concrete made from picon with the addition of expanded polystyrene added with EIA® has a great application in filling elements such as vaulted blocks, plates etc.

Detailed description of one embodiment

 An example of lightened concrete manufacturing by the described procedure is described below:

 - First the picon mortar is manufactured:

 An MF 3000 A mixer was used (Manufacturer: Poyatos)

 The dosage and kneading time are specified in the following table.

DOSAGE OF THE PICON MORTAR

 Table 1 Picon mortar dosage

- Subsequently, expanded polystyrene added with E.I.A® is added. Once the picon mortar has been made, expanded polystyrene added with E.I.A® is added.

 To make this mixture an electric mixer was used, features:

 Tank capacity, 36 liters

 Electric motor power, H.P 0.33

Volume m ³ 1.04

 The order of introduction of the materials in the mixer:

 1. Picon mortar.

 2. Expanded polystyrene additive with E.I.A®.

The polystyrene used was "POLITERM BLU®" marketed by the EDILTECO GROUP house, which is an expanded grain polystyrene of 3-6mm spherical diameter additive with EIA® To achieve a homogeneous mixture with the picon mortar, the beads of the additive expanded polystyrene they got wet before pour them into the concrete mixer. The dosage used was an addition of 36.85% by volume of polystyrene.

 For the filling of the mold with the concrete it was done in three stages, in each of them a third of the mortar volume was used, vibrating it for 30 seconds and in the last stage in addition to vibrating the compaction was performed, for this, it was placed a metal lid attached to the mold by two screws that at the same time as it vibrated compressed the dough on top of the mortar mass.

 To compare the properties of the concrete manufactured by the process of the invention, three series of seven specimens were made each of the following characteristics:

 - Series I: A series of seven 60 cm x 60 cm x 5 cm thick specimens were manufactured, using a lightened concrete mortar with picon equal to that used for the construction of blocks by the state of the art

- Series II: A series of seven 60 cm x 60 cm x 5 cm thick specimens were manufactured using a lightened concrete mortar with picon with 36.85% by volume of POLITERM BLU®

 - Series III: A series of seven 60 cm x 60 cm x 5 cm thick specimens were manufactured, using a lightened concrete mortar with picon with 73.70% by volume of POLITERM BLU®

 After 28 days the following tests were performed:

 A. Study of the variation of weight, to calculate the average weight of each series and elaborate the percentages.

 B. Sound insulation, was performed according to UNE EN 140-4: 1999.

 Five trials were performed.

 > On the wall that separated the two rooms, built with 15 cm thick vibrated concrete blocks and covered with plaster on both sides.

 > A 180 cm long x 120 cm high hole was made in the wall previously tested to place the first series of specimens built with the mortar that the blocks are made.

 > The first series plates were replaced with mortar and POLITERM BLU® plates.

 > Series II plates were exchanged for mortar plates and a large percentage of POLITERM BLU®, series III.

> The latter, were coated with plaster on both sides. C. Thermal resistance test, was carried out according to UNE-EN 12664: 2002 and UNE-EN 1745: 2002, test tubes 30 cm x 30 cm x 5 cm thick were used.

 D. Mechanical resistance to bending and compression, were performed according to Standard UNE-EN 1015-11: 200, 3 specimens of each series were cut, section 160 mm long x 40 mm wide x 40 mm high, once Performed the flexural test, with each half of the broken specimens, the compression test was performed.

 E. Determination of water vapor transmission properties was carried out according to the UNE-EN ISO 12572: 2001 Standard. Using test tubes 11 cm x 11 cm x 5 cm thick.

1.- Preparation of the specimens

 An MF 3000 A mixer was used (Manufacturer: Poyatos)

 The mortar of picón used in the realization of the test pieces, had the following dosage:

Table 1 Mortar dosage to manufacture vibrated concrete blocks.

Three series were made, with different dosages, composed of seven specimens each series, using a 60 cm x 60 cm x 5 cm metal mold, incorporated into a shaking table.

To prepare the specimens, the same procedure was followed as in the factory, to build the vibrated concrete blocks. It consists of three stages: in each of them a third of the mortar volume was used, vibrating it for 30 seconds and in the last stage in addition to vibrating the compaction was performed, for this, a metal lid was placed on top of the mortar mass fastened to the mold by two screws that at the same time vibrated compressed the dough. Finally, they were unmold and placed on a pallet, where they were transported to the dryer, remaining for 28 days.

 Series I, (PI) specimens As mentioned above, it was made with a mortar equal to that used in the factory for the production of vibrated concrete blocks, so that their results in the different tests serve as a reference to specimens made with picon mortar and POLITERM BLU®.

 Series II probes, (P 2) They were made with the same mortar as the previous ones but once the mortar left the factory mixer, 36.85% by volume of POLITERM BLU® and 0.30 L were added of water to a total of 126 L. of mortar used to fill the seven specimens.

 Resulting: Picon mortar 62.91%. POLITERM BLU® 36.85% and water

0.24%

Table 2 Mortar dosage to manufacture the series II specimens

Series III probes, (P 3) They were made using the same mortar as the Pl, but adding: 73.70% by volume of POLITERM BLU® and 0.5L. of water to a total of 126 L. of mortar used to fill the seven specimens.

 Resulting: 25.93% volume of picon mortar. POLITERM BLU® 73.70% by volume and water 0.37% by volume.

DOSAGE PROBETAS SERIES III P (lll)

 Materials Type Quantity Consistency Kneading

Cement CEMII / AP 42.5R 230 kg

 Drinking Water 133.97 L.

Fine aggregate Picon sand (0 0/2) 200 kg Thick aggregate Picón (0 4/16) 1000 kg

 73.70% in

 POLITERM BLU®

 volume

Table 3 Mortar dosing to manufacture the series III specimens

2.- Conclusions of the trials.

 A. Study of the variation of the weight of the specimens.

 B. Study of sound insulation.

 C. Study of thermal resistance.

 D. Determination of mechanical resistance to bending and compression.

 E. Determination of water vapor transmission properties. A.- Study of the variation of the weight of the specimens.

With the addition of EPS _t , to the traditional picon block, a reduction in the weight of the specimens was achieved based on the percentage incorporated into the original dosage. Thus we see how the P (I) specimens made with traditional mortar were 23.79% heavier than the P (II) and 41.84% than the P (lll) .And the P (II) with 36.85% of the volume of POLITERM BLU®, were 23.69% heavier than the P (III) containing 73.70% by volume of POLITERM BLU®.

 B.- Study of sound insulation.

 The acoustic insulation of the separator element between rooms, improved with the incorporation to the test pieces with POLITERM BLU®. so that the partition constructed with the series 2 (PII) reflected 2 dBA of improvement with respect to the specimens of the series 1 (PI).

 In the modification of the partition, with the series 2 (PII) specimens, it obtained a better result than those of the series 3 (PIN) with a higher percentage of POLITERM BLU®. This could be justified because the last series contained more interconnected pores. In addition, it was detected that in some areas the expanded polystyrene beads were not surrounded by the mortar, they had been grouped in small groups, so that the noise passes without difficulty through the plate section. Finally, it was obtained by sealing the series 3 (PIN) with plaster paste on both sides, a great result matching that of the original wall of 15 cm thick, concrete blocks covered with plaster.

C- Study of thermal resistance. As observed in the results of thermal resistance by the heat flow meter method, the addition of POLITERM BLU® increases this parameter, making the material more thermally insulating compared to the original dosage, and this phenomenon is greater as the POLITERM BLU® percentage.

 It is also observed in these experiments that, with the same amount of

POLITERM BLU®, but increasing the water content, as was done in the P2 + water dosage, it is possible to increase the thermal resistance. It follows that to increase the thermal resistance of the material, it is not only enough to add more POLITERM BLU®, which in many ways damages other properties, but the dosage of the original materials must be optimized.

 D. - Determination of mechanical resistance to bending and compression.

 The resistance of the specimens with the addition of POLITERM BLU®, decreases in proportion to the content of POLITERM BLU® and of the water, as observed in the test tube P (ll) + water. The loss of mechanical resistance being greater to compression than to bending.

 E. - Determination of water vapor transmission properties.

In the results of the Water Vapor Resistance Factor, the dosage P (II) obtains a better resistance with respect to the original dosage P (I), so that by adding EPS _t at a given concentration, the resistance of the material to the passage improves of water vapor, it follows that this addition of POLITERM BLU® decreases the porosity and water absorption of the material.

 This phenomenon increases, by modifying the water content of the original dosage, as can be seen in the dosage P (ll) + water, it is the dosage that obtains a greater resistance, therefore a lower water vapor permeability.

 With the dosage P (lll) the optimum dosage for this property was exceeded, since the "water vapor resistance factor" decreases, which therefore increases the "water vapor permeability", although everything depends on where it goes to place the material and the requirements that each case requires.

 Conclusions:

 The conclusions that can be provided, once analyzed the results of the tests of adding POLITERM BLU® to the traditional picon mortar, used for the construction of prefabricated elements such as blocks, vaults etc ... we can group them into two types.

 1.- Characteristics of the mortar.

a) The resulting mass was homogeneous. b) The mortar was adhered to the pearls of the POLITERM BLU® physical qualities.

a) Using the average between the two dosages used, the weight reduction of the specimens was 32.82% lighter.

b) A 5 cm thick plate and plaster coated on both sides turned out to have the same acoustic insulation as the original wall constructed with 15 cm thick vibrated concrete blocks and plaster coated on both sides.

c) The thermal resistance is where there is a greater difference in the results, going from a plate built with traditional mortar of 0.1346 R (m ² .K / W) to another plate of the same dimension and with POLITERM BLU® at 0.2741 R (m ² .K / W) that is an increase of 103.64%

The thermal resistance was increased by increasing the water in the dosage from 19.69 R (m ² .K / W) to 31.43 R (m ² .K / W).

d) Of all the tests carried out with the plates with the addition of POLITERM BLU®, where a negative result was obtained, it was in the resistance to bending and compression being 78.79% and 85.85% lower respectively. e) With respect to water vapor resistance, the plates with the addition of POLITERM BLU® were 63.57% more resistant and when the water in the dosage increased, the resistance reached 90.13% while if the amount of POLITERM BLU is increased ® decreases water vapor resistance.

Claims

 1- Concrete manufacturing procedure characterized by understanding the stages of:  - Initially introduce cement, water, picón sand and / or picón in a mixer until obtaining picón mortar,  - Introduce the picon mortar obtained in a kneader first and then introduce expanded polystyrene added with E.I.A® and previously moistened, and knead,  - Subsequently, apply vibration on the mixture for 30 seconds for every third of the mixture of picon mortar with expanded polystyrene, - Finally compress and vibrate the mixture at the same time.  2. Method according to claim 1 characterized in that in the step of introducing the picon mortar and the expanded polystyrene in the kneader, water is also added to a total proportion of the mixture of 100% by volume. 3. Method according to claim 2 characterized in that 25.93% by volume of picon mortar, 73.70% by volume of expanded polystyrene added with EIA® and 0.37% by volume of water are introduced into the kneader a . 4. Method according to claim 2, characterized in that 62.91% by volume of picon mortar, 36.85% by volume of expanded polystyrene added with E.I.A® and 0.24% by volume of water are introduced into the mixer.