DE2315851B2 - Glass fiber reinforced building material - Google Patents

Description

are not permitted.

15 to 50 percent by weight CaO. The high production costs are also disadvantageous

40 to 65 percent by weight SiO ₈ , which is made of the resistant glasses, for example boron

1 to 20 percent by weight Al ₁ O ₃ «5 silicate glasses, produced glass fibers.

There are also for use in building materials such as

and a content of impurities from iron portland cement, molten cement, gypsum, mortar are suitable. and alkali oxides of a total of at most 2 genes mineral fibers with a substantial proportion of weight percent for the purpose according to claim 1. Crystal phase known, which from an oxide melt with

4 Use of phosphorus slag made from an SiO ₁ - Al ₁ O ₃ - CaO and FejO ₃ content and provided calcium silicate fibers of vitreous structure, a possible addition of secondary components herder the composition according to claim 2 or 3, and one of the wollastonite or have a content of impurities of calcium orthosilicate type, iron and alkali oxides of a maximum of 1% to settle. These known mineral fiber purposes according to claim 1. 35 are, for example , 60% in the form of a glass phase

5. Use of phosphorus slag and 40% in the form of a crystalline phase as presented calcium silicate fibers of vitreous structure pseudo-woolastonite. They do not have a homogeneous one the composition of claim 2 or 3 glass structure.

and a content of impurities according to the subject matter of the present invention is the promise 2 and 3 as well as low content of fluorine 40 turn of made from phosphorus slag and phosphorus for the purpose of claim 1. Calcium silicate fibers of vitreous structure for reinforcement

of building materials made from inorganic binders. The calcium silicate fibers used according to the invention vitreous structure have the following 45 composition:

10 to 60 percent by weight CaO,
35 to 75 percent by weight SiO ₁ ,

The present invention relates to the use of 0 to 20 percent by weight Al ₁ O ₃

of calcium silicate fibers, which compared to basic 50

Solutions, in particular to solutions such as those found and a content of impurities from iron and in concrete, are resistant, to alkali oxides of a total of at most 2 percent by weight reinforcement of external inorganic binders.
building materials provided. In particular, glass fibers are suitable whose chemical

Commercially available glass fibers are known to be within the following ranges based on their chemical composition and structure: their chemical composition and structure are attacked and decomposed by basic solutions, 15 to 50 percent by weight CaO,
SO that the favorable mechanical properties, 40 to 65 percent by weight SiO ₁ ,
In particular, the high tensile strength of the fibers, 1 to 20 percent by weight of Al ₁ Oc, is lost. Their use in construction for 6o

improvement of the mechanical properties of construction * The use of these calcium silicate fibers vitreous

materials, especially concrete, based on inorganic structure for reinforcing concrete Jag by no means close, shear binders such. B. cement or building lime is they move in their chemical composition not possible, because these binders with water settlement in the area of the well-known calcium-rich Prepared solutions with pH values between about 6J glassy blast furnace slags, which are known to be latent and 13 that attack the glass fibers and are hydraulic and z. B. destroy with Portland cement, grind calcium hydrosilicates when exposed to water

Ε »so far there are mainly three ways of being able to label (slag cement), which is supposed to be

2316851

let that QUsem made from calcine strings Fibers in connection with cement would be dissolved or destroyed in the manufacture of building materials.

Surprisingly, however, it has been shown that there is a high level of resistance to the basic environment in concretes made from inorganic binders.

The glass fibers suitable for reinforcing building materials made from inorganic binders are made from the electrothermal Manufacture of phosphorus produced phosphor slag These fibers are also very Can be produced economically because the CaO and SiOj coraponents are already homogeneously melted in them. Their chemical composition falls into that areas listed above. The usability of this phosphorus slag for the production of calcium silicate fibers with a vitreous structure is therefore surprising, because it has a strong tendency to crystallize and crystalline calcium silicate can be produced therefrom by simple tempering.

The phosphorous slag melt is poured out after tapping and then solidifies as lump slag. However, it can also be quenched in water in a known manner, whereby a vitreous slag sand is formed, from which impurities can be removed mechanically if necessary. These products are melted again and then processed into glass fibers using known methods. But you can also use Al ₂ O ₃ - and / or SiO, -containing substances such as. B. add clay, kaolin or industrial waste products such as SiO, dust to lower the melting point of the slag.

Furthermore, a process step can be saved if the slag, which is still liquid, is immediately processed into glass fibers _{following the production of phosphorus, optionally with the addition of Al 1} O and / or SiO _{1 -containing substances.} It has been shown that the calcium silicate glass fibers produced from the phosphorus slag have a very high resistance and are particularly resistant to the basic environment in inorganic binder suspensions or in building materials made from inorganic binders.

The natural impurities in the phosphorus slag consist in particular as alkali and iron oxides. You are also said to be in these fibers altogether not exceed 2 percent by weight. It is beneficial if the content of these impurities also is a maximum of 1%. It has also been shown that here too low levels of fluorine and phosphorus are harmless. It can be assumed that in some cases impurities even contribute to that when using calcium silicate fibers with a vitreous structure to reinforce concrete, it has a particularly favorable effect on the strength of the concrete will.

For use in concrete, glass fibers between 0.5 and 5.0 mm in length and 0.0OS to 0.05 mm in diameter are preferred. They have a high modulus of elasticity in the range from about 5600 to 6400 kp / mm * and tensile strength values in the order of magnitude of 800 to 1300 kp / cm ¹ . It is for this reason that they can be used to reinforce concrete.

By means of X-ray diffraction analyzes it could be established that the used according to the invention

CaldumsUikatfasem have no kosieUfw phase, but have solidified glassy.

The invention is explained in more detail using the following example, S.

example

Using 95%. Portland cement PZ 350 and 5% glass fibers were mixed with a water cement

m factor of 0.30 prisms hammered in. As glass fibers AlkalisU & atfasttra, silica glass fibers, borosilicate glass fibers and calcium silicate fibers became more glassy Structure uses the calcium silicate fibers glassier Structure possessed the chemical composition

ts according to table 1:

Table 1

Chemical composition SiO, (Weight percent) CaO FeO, + FeO • silicate fiber + Na ₁ O glassier 43.57 AI ₁ O, 50.30 + K ₁ O structure 40.54 38.18 0.73 59.69 2.57 25.81 0.78 number 1 64.84 18.57 15.06 0.98 No. 2 11.74 0.84 No. 3 17.08 No. 4

They were produced from granulated vitreous phosphorus _{slag, in part with the addition of Al 1} O ₁ and / or SiOs-containing substances, using conventional methods.

The different types of fiber had fibers of the same length and diameter.

In addition to the reinforced prisms, pure cement prisms made of PZ 350 and prisms with additions were made an inert substance in amounts of 5% by weight percent made.

To determine the resistance of the fibers in an environment such as that found in hardened concrete, the prisms were ^{stored under water for 180 days at 20 °} C. and then the free Ca (OH) ₁ - Content of the prisms determined chemically. These values were compared in each case with the value of the prisms which had been produced with the addition of inert substance, the latter being set equal to 100. So when the glass fibers react with the free Ca (OH) _{1 and} so that they become unstable, the free Ca (OH) _a content of the comparison prisms must decrease in comparison with the inert substance prisms.

In table 2, column 2 shows the relative contents of free Ca (OH) after 180 days for the individual prism types put together. It can be seen that the calcium silicate fibers of vitreous structure No. 1 to 4 do not or only slightly Ca (OH) i while the comparison fibers clearly reacted with the free Ca (OH).

This fact is also reflected in the strength values which are listed in columns 2 to 4 in table 2. The strengths were each related to the value of the pure Zemein prisms and calculated in relation to this as a percentage. Thereafter

<S it follows that again using the Cakiumsilikatfaser vitreous structure No. 1 to 4 produced prisms achieve significantly higher strength, especially after 180 days.

Table 2

Re). M, Biegemgs 180 days ReI.
pressure Premium,
Ii ■■ ■■■■! «Ill at free strength (50 after 100.00 strength
(%)after manufactured
under to * 8te
of 5% Ca (OHH
after
180 days 90 days 180 days (%) 100.00 100.00 without addition., inert _ 125.74 , Substance., 100.00 103.85 Alkali silicate 121.23 77.88 glass fiber ...
Pebble. 85.88 96.12 103.88 80.86 A4C9V1-
glass fiber ... 80.86 Borosilicate 97.95 87.32 glass fiber .,. 79.77 136.74 Calcium SiHkat 137.21 fiber 112.26 1Ϊ3.33 100.53 number 1 100.12 112.33 137.98 101.18 No. 2 100.00 113.29 108.85 No. 3 99.33 110.96 112.68 No. 4 98.62

The calcium silicate fiber with a vitreous structure is suitable as an aggregate for reinforcing concrete on high-alumina cement and portland cement base alike. It increases the tensile strength of the concrete, aucii without that this steel reinforcement carries, and thus at the same time its flexural tensile strength and impact resistance as well as its Resistance to flattening at higher temperatures. The reinforcement of the concrete by glass fibers can be carried out in an advantageous manner δ steel inserts are combined.

The calcium silicate fiber with a vitreous structure is also suitable for the manufacture of other building materials based on cement, especially for those that were previously reinforced with asbestos fibers, such as Finishing plasters, ready-made mortars and plasters, as well as panels,

Corrugated sheets, pressure pipes, flower boxes, gutters, Gutter pipes and other products labeled as asbestos-cement items.

Furthermore, the use of calcium silicate fibers in building materials based on other inorganic binders such as B. Building lime and plaster and in Building materials based on organic binders are possible. Also use as a reinforcing filler for Plastics are ideal.

ao Another interesting field of application is the hydrothermally hardened concrete sector. here the glass fibers also serve as aggregate to reinforce the concrete. They react in the autoclave process with the basic solution only imperceptibly and

• S are therefore almost retained in their dimensional stability. Is particularly advantageous in this context their light color, so that the calcium silicate concretes made from them not only in terms of strength, but also their light or white hue keep.

Claims (3)

been the obstacle of the lack of chemical Claims: M euminate the resistance of the glass fibers. It was ^ ^H tries to increase the basfcdtSt of the binder suspensions !, Reduce the use of from PhosphorscWacke. This method can naturally be the Provided CalciumUikat fibero vitreous structure to 5 not completely prevent chemical attack. Of Reinforcement of other inorganic binders, glass fibers were developed, oils only one manufactured building materials. are coated with an alkali-resistant protective layer. the 2. Use of a protective layer made from phosphorus slag, e.g. from pivwylacetylenlack, Provided Calciurasilikatfasera glassy structure consist of polyvinyl acetate or Polyäthylhydrosüoxan, the composition m It is obvious that the bond between the like glass fibers and the binder through the 10 to 60 percent by weight CaO, plastic layer is weakened. Also can 35 to 75 percent by weight SiO ₁ , in the further processing of the glass fibers for manufacture 0 to 20 percent by weight Al ₁ O ₈ position of building materials damages the protective layer 15, so that then at least partially chemical and a content of impurities from iron corrosion can occur. and alkali oxides of a maximum of 2 ge even under normal conditions resistant glasses weight percent for the purpose according to claim 1. have been found in the form of fibers in the concrete as not 3. Use of proven resistant from phosphorus slag . That is why their use of calcium silicate fibers with a vitreous structure was only possible in connection with binders with a low alkali content such as the high-alumina cement composition, which, however, is used in building construction