CS259678B1 - A method for treating fillers or reinforcements in compositions - Google Patents

Abstract

The method of treating fillers or reinforcements in composites consists in adjusting the pH value of the filler or reinforcement surface to a value within the range of 2 pH around the pH value of the binder with acidic or alkaline reacting substances in the liquid or gaseous state, or with substances simultaneously regulating the curing of the binder.

Description

The invention relates to a method for treating fillers or reinforcements in composites. ·

So far, the chemical compatibility of fillers with binders in composites has not received special attention. When incompatible components are combined, these components interfere with each other and suffer. especially their mutual adhesion. As far as binders are concerned, the question of the reaction of the acidic components of the binder with alkali as a function of the specific surface area of the binder and the resulting mechanical properties of hardened binder mixtures has been studied since the 1940s. In this shift, many mortar binders have been developed and patented, some of which have been used for special construction practice cases. For example, binders allowing high strengths are known, but the disadvantage is the considerable brittleness of the resulting structural. material. These principles were also used for laboratory evaluation of so-called acid hydraulic additives in the production of binders.

Because the adhesion of the filler surface. respectively. reinforcement was systerna ^ • * cally investigated based on the assessment of suitability or unsuitability of these components only in terms of granulometry and a Pediatric morfoloyického _f occurred and therefore results often very different from empirical experience. Fillers and, to a limited extent, reinforcement are only selected so that the adhesion with the binder is as good as possible. However, the chemical and physical properties of fillers or reinforcements in relation to the properties of binders have not been systematically checked or modified. In demanding cases, such as in glass laminates, aprotations are relatively used, which are relatively expensive.

Said shortcomings from the side are well-known fillers of the fillers in the life, in the commodities, whose essence. ° hears that in the ρ ' ^τ of the filler corner, the reinforcement is adjusted to a value in the range of - 2 nV around the pU value and you put the acidic binder with reactive substances in the liquid gaseous state or with regulators at the same time curing binders. For example, acidic slag aggregates are protected with a base such as potassium or sodium hydroxide solution before being added to the concrete mixture or mortar. Similarly, the limestone filler of the half-yearly filler is first neutralized. is, for example, a solution of acetic acid.

Both potassium and sodium sealants, thereby contributing to the aggregate as well as to the higher.

stimulate hydrataei cement for faster growth ··! its adhesion adhesion final. The acid builds up after the reaction, the reaction no longer breaks down the limestone filler since it forms an insoluble calcium salt.

the adjustment of the surface pH of the filler or the reinforcement, respectively, is usually carried out by spraying them with the appropriate solution in the container before processing them into the mixture. The same treatment can be performed in some cases by passing a moist gas, for example sulfur dioxide, ammonia and the like. Usually quite sufficient to altered pH or a reinforcing filler surface-lasted until time ^1, wherein to achieve a sufficient cure of the binder.

The advantage of the p _ut ge invention is to improve useful properties. composite, especially its strength, toughness, impermeability, durability, etc., in an inexpensive way. This makes it possible, for example, to efficiently utilize acidic slags, which have been a useless waste, in a concrete structure, or to use an easily obtainable fine limestone filler in polyester cement concrete without the risk of saponification. polyester resins with alkaline reactive limestone.

Example 1 2

Bodies - rollers with a cross-sectional area of 400 m and a height of 20 mm were made from a mixture of acidic steel slag Kladno containing 56 µViO ₉ and a grain size of 0.1 to 2.0 mm in a mixture, with:

cement grade 325 in the ratio 3: 1. and a cortical coefficient of 0.5 · The slag was neutralized 1/2 hour before production - the bodies were neutralized with 5% sodium hydroxide solution, after 10 minutes washed with clear water and dried. Comparative bodies were made from the original truss. The bodies were manufactured, compacted and stored according to ČSN 72 2121 and after 3 days the transverse tensile strength was determined. The following strength values were obtained:

for bodies with 5 µ NaOH treated with 3.50 MPa for bodies with original Etruscan. 3.01 PIPa averages from 5 tests. The increase in the given filler treatment is therefore 16.3 r.

Example 2

A polyester plaster concrete made of limestone filler (aggregate) with a grain size of 0.8 to 1.2 mm and polyester resin Polyester 141 with increased water resistance mixed in a weight ratio of 3: 1 were prepared. 3.0 wt.% Were used to cure the polyester resin. % of catalyst (peroxide solution of 40% by weight of methyl ethyl in dibutyl phthalate); accelerators (solution of 10% by weight of cobalt naphthenate in toluene). 7.5% by weight were added to adjust the consistency of the mixture. toluene, based on the weight of the resin. The purpose of this choice of composition was to achieve a gradual hardening of the concrete when the bodies were subsequently placed in water. The limestone filler for mixture B was treated by pouring it twice with a 20% oxalic acid solution followed by drying at room temperature, comparative mixture. And it was prepared from raw filler. Both blends were made with 40 mm cube and aged. 3 days tested for fissile strength (transverse tensile strength) and compressive strength. Additional cubes from these series were placed in a 20 ° C water bath for 18 days on the strength test day and were also subjected to strength tests. While confirmed in the piss? ' The plaque strength of the cubes of the series is determined during the water bedding. B from treated concrete with modified filler increased by 80.5 0, the fissile strength of the cubes of the comparative series A increased only by 33.3 Also, 1 • I

υ. that are. less sensitive to adhesion between the binder filler, some gain was noted. While compressive strength - accelerates. pXrie.B increased after water deposition by 29.4 to increase the compressive strength of the cubes of comparative series A only. so that said gain in the case of compressive strength is. 4.6%. Beneficial effect chemical modification of calcite filler was also reflected in the increase the degradation resistance of a polyester plastbe- ^J tonne against water. The degradation resistance was assessed according to the water absorption, which in the case of plastic concrete B with a chemically modified filler reached the value of 8.3% by weight after 18 days of water storage, while in the comparative plastic concrete A the value of 9.2% by weight, ie 0.83% more.

Claims (3)

Method for treating fillers or reinforcement in composites, characterized by adjusting the saw surface value of the filler or reinforcement respectively to a value in the range. -2 pH around the pH value binds acid or alkaline reacting substances in liquid or gaseous state! or binder-regulating agents at the same time. O 2. Method according to claim 1, characterized in that the acidic slag aggregate is sprayed with a basic substance, for example potassium or sodium hydroxide solution, before it is added to the cement concrete or mortar, respectively. 3. A process according to claim 1, wherein the limestone filler is first neutralized into the polyester plastics material. is, for example, a solution of oxalic acid.