DE377098C - Process for the production of improved, in particular watertight, hydraulic binders which can be regulated with regard to swelling and shrinkage - Google Patents

Description

Process for the production of improved, in particular waterproof and hydraulic binders adjustable with respect to swell and shrinkage. the Experience has shown that there are disadvantages and damage in both building and civil engineering arise from the fact that the hydraulic binders used to date are attached to them Requirements to be made regarding swelling and shrinkage as well as impermeability to water only exceptionally do justice. As is well known, it leads to swelling and shrinking to fine hairline cracks that endanger the building in the long run, which contain both water and carbonic acid and oxygen to any existing iron deposits as well as all kinds of chemical ones Let agents get into the interior of the concrete and so more or. less quickly destroy the structure. Low water impermeability has the same effect as To achieve tightness, greasier mixtures must be used, in addition to the disadvantage of higher costs also tend to shrink strongly. Occasionally If the concrete dries out, hairline cracks also occur, which later appear Sources no longer close completely, which means that the structure is both watertight loses the afore-mentioned as well as a result of the cracks leading to your interior Exposed to hazards.

Experiments have now surprisingly shown that a Content of barium or strontium compounds and more or less equivalents of these Amounts of such sulfates which are sparingly or insoluble with these alkaline earth salts Forming compounds, the swelling and shrinking of hydraulic binders and also has an extremely beneficial effect on impermeability, yes even that Swelling in water and air and, in connection therewith, also shrinkage can be regulated more or less as desired, with large expansions without the risk of blowing achieved «- which do not entail any major shrinkage, are suitable Assuming composition.

The amount of this content of compounds of both alkaline earths as well The aforementioned sulfates can be chosen very differently with respect to the Sulphates above normal, depending on the desired effect and the existing hydraulic Binder dependent and therefore to 'achieve the intended in the individual case Effect on the various cements and types of cement, such as B. Portland cement, Iron Portland cement, blast furnace cement, Roman cement, slag cement, natural cement, etc., different to choose. You can, for example, consider both additions together 7 or to or 2o, yes to even 6o and more percent, with sulfates and Alkaline earth compounds normally used in approximately equivalent amounts will. But the best successes are in certain cases i: tir then ni <iglic1i, if <nasty equivalent @ _ ratios are not adhered to, which in turn is related to the total amount of sulfate plus Hr (IalkallSalz im certain context.

Taking on the role of sulfates is z. B. gypsum, anhydrite, iron sulfate and Aluniiiiiutnstilfat are suitable, but all natural and artificial come sulfuric acid salts and mixtures of these, which with (len compounds of Strontiutn @ and barium () of their mixtures with the formation of difficult or. unli *) sliclier connections react, in question, of course only during the setting and hardening of the hydraulic Tie.

By this determination is the choice of compounds of barium and strontium are limited in that only such compounds contain these both l # -. relallkalieti brings success, rlie in sales with your sti'.fat both insoluble ir (lall: alisulphate as well as sparingly or inli *) soluble compounds of the bases which are bound to the sulfuric acid prior to this reaction are formed permit. Such reactions are e.g. B. the - (wipe baritone oller Strotitiullikarliotiat or silicate or phosphate with sulphurate of calcium in fortn fully natural () of artificial anh_vdrit or plaster of paris or mixtures of cure.

For example, a mixture of 72 per cent of a certain portland cetnentidinker, 5 percent natural or artificial baritone carbonate and 13 percent natural or artificial plaster of paris produced very favorable results after the addition, while the addition of barium carbonate or plaster of paris alone did not produce a corresponding oil result was to be achieved. Well, z. For example, larger amounts of plaster of paris alone cause shrinkage, but then there is a risk in-liner (let the cement or concrete or irtel, with shorter or longer contact, give water the familiar sulfuric acid content Gypsum drifts to be returned shows this danger is further delayed by (let many waters often contain more or more large amounts of sulphates, which can also get into the substance through a content of the air in sulfur dioxide. Also, different ones tolerate Hydraulic binders only contain very small amounts of this salt from the start, as can be seen from this, for example (let the content of all sulfuric acid anhydride in cement (such as Portland cement) be relatively low by ornien.

The effect of the simultaneous content; in 1 -. R (lalkaliverliindtuigen and the sulphates in question are based on your artificially produced Unisatze, 1.e1 which Er (alkali sulfate and at the same time another poorly or insoluble Salt is created. It is easy to see (1a13 that the salts precipitate there where pores or cavities of the mortar or concrete the presence of water of dissolution enable. Ground through the slower or faster turnover now these brown oaks or fine pores through the relatively voluminous Precipitation filled and clogged, depending on the: Amount of the specified Senses reacting substances once (read shrinkage more or less canceled and then the mortar or concrete is made waterproof.

The addition of barium or strontium compounds alone is not New. But it was made only for your purpose in small quantities, which in yours hydraulic 13inrlmittel available or those from your make-up or storage water to render sulphates harmless, be it to prevent full efflorescence, be it to avoid destruction of the concrete t> fler '.mortel. It follows from this without further ado, (leave no interest, in this case large amounts of sulfuric acid. than they arise in the manufacture of the hydraulic binder or for regulation must necessarily be added to the ahbilide period. in (read binders in question bring in. In the present invention, contrasts are intentional so large amounts of sulfates added, (omit the various binders in all circumstances contain sulfuric acid blends which can be described as abnormally large. The `` @le; ige '' to be added can best be identified in this way (let it be in Your hydraulic binding agent is generally large in the long run Elongation or more or less strong sulphate driving phenomena would produce, provided Barium Strolltiutn compounds are not added at the same time.

Likewise, the addition of sulfates, e.g. B. plaster, known and old and is used for the purpose of slowing down the setting time or to achieve greater strength, sometimes also used to reduce sore eyes. However, the latter is conditional larger 1leligen, which whenever they had the effect, the existence of the concrete or mortar, as already mentioned, and not your cement itself respond in a certain way.

What is new and completely unknown, however, is what is intended at the same time and arbitrarily achieved presence of the already characterized links of strontium or barium and the sulphates in more or less abnormally large amounts; it becomes artificial as a result a certain reaction caused by the hydraulic binder not involved alone, and which almost invariably increases strength, absolutely sure but with a suitable choice of quantity (read livdraulic binders or the Mortar or concrete watertight and with regard to () curling and therefore also shrinkage makes it adjustable.

The content in question of the compounds of barium described or strontium as well as the simultaneous, necessary for the reaction, on the likewise characterized Sulphates can be used in several ways to achieve the intended effect the hydraulic binder are brought, so z. B. by making one of Hydraulic binder containing barium or strontium from the start and subsequently Addition of the necessary sulfate or by generating one from the outset that is abnormal large amounts of sulphate-containing binder and subsequent addition of barium or strontium compounds or their mixtures or, finally, by subsequent Adding the alkaline earth compounds and sulfates; this adding to the same Time one after the other or even in different phases of further processing of the Crushed or uncomminuted hydraulic binding agent can be done, included also the different phases of mortar preparation.

With these subsequent additions, the hydraulic Binder quantities of sulfates present from the outset are also taken into account will.

The procedure is for all hydraulic binders or mixtures applicable from different.

Claims (1)

PATENT CLAIMS: r. Process for the production of improved, in particular watertight and hydraulic with adjustable swelling and shrinkage Binders, characterized in that in the hydraulic binder on the The presence of a sufficient quantity of such sulphates for the stated purpose, those with barium or strontium compounds with formation difficult or. more insoluble Compounds react, as well as the addition of natural or known per se artificial barium or strontium compounds, or mixtures of both, in more or less equivalent amount is worked towards. a. Embodiment of the method according to claim t, characterized in that any hydraulic binders before, during or after the grinding or the mortar from these hydraulic binders natural or artificial barium or strontium compounds, or mixtures of both, as well as sufficient quantities of the marked for the intended purpose Sulphates can be added. These are additions of alkaline earth compounds and sulfates together or one after the other or separately in different phases of processing the binding agent. 3. embodiment of the method according to claim i, characterized by the production of a from the outset strontium or barium or Mixtures of both containing binders and subsequent addition to the more or less processed binders from those sulfates that come with them Alkaline earth salts react to form poorly or insoluble compounds. Embodiment of the method according to claim i, characterized by the generation of one from the start Above normal amounts of sulphate-containing binding agent and subsequent addition to the more or less widely processed binder of such compounds of barium or strontium, which with these sulfates with formation difficult or of insoluble compounds react.