CZ264U1 - Wood-cement particleboards hardened under pressure - Google Patents

Description

The technical solution relates to pressure-cured chipboards. Thatches are designed for making double-skinned shuttering.

D o t e r i i i s t e c h e s

Previously developed wood thatch? materials, cement bonded, have various applications, especially as partial thermal insulation, sound insulation in interiors, sandwich thatch in combination with polystyrene foam and the like. In view of the physico-mechanical properties, most of these slabs are not suitable for the formation of a double-skinned shuttering, filled with a foamed concrete casting. In some cases, their application is possible, but they do not satisfy the technical properties. Since the exact applications are intended, the economic issue also plays a negative role. All so far building thatchs of wood-based and cement-based materials have higher coefficients. ET thermal conductivity, greater compressibility, which does not suit the building's peripheral construction in terms of its width and construction economics, subject to the demands arising from the innovated thermal-fire criteria construction of buildings.

Currently, the best known wood wool and cement that have the disadvantage of insufficient bending strength, thermal conductivity and strength. but they have a higher coefficient. I ´ o d o b n e did not satisfy even more than 1 of properties and volume weight. and thatch, i.e., eco-color, tile, have an unsuitable shape and is used for building structures, i.e. non-economic.

The essence of the technical solution

These drawbacks eliminate the pressure-cured chipboard cement composite from the composite material. Their basis consists of cement mat.rica, filled with wood chips from coniferous trees, shaped unsuitable for processing into lumber. The principle is that the starting mixture of chip-cement thatch content is 264 to 200 parts by weight. wood chips with • floor i »ax. 70 mm, max. 3 mra, with a moisture content of max. 20% by weight, 190 to 210 parts by weight; cement, 4 to 6 die hunting mass. 2 to 2.5 parts by weight of a mineralizing additive; and a cementitious cementing compound and 240 to 280 parts by weight. mixed water. Sodium silicate Na 2 SiCl 3 can be used as the mineralizing additive in the form of an aqueous solution, preferably as a 30% aqueous solution. Calcium formate CaCHCOO12 can be used as an accelerator for setting and hardening cementitious cement. In view of the resulting strength parameters, it is preferred that the wood chips contain: a fraction of 35 to 70 mm in an amount of 75 to 87% by weight, a fraction of a length of 1 to 35 mm in an amount of 10 to 22% by weight. and a fraction with a length of up to 1 round in an amount of max. 3% w ..

The chipboard in question is unreinforced, f single-layered. Their advantage is low weight with improved thermal insulation properties, sound insulation as well as increased flexural strength. They are intended, in particular, for the production of double-wall permanent shuttering, filled with ambulatory foamed concrete over the perimeter load-bearing and internal structures of existing buildings, attics and wherever there is a need to realize perimeter and internal structures with reduced weight. Thanks to excellent thermal insulation property. It is possible to adhere to the chip-cement boards by their combination with a foam concrete. the optimum width of the outer circumferential constructions even with the desired increase in the thermal resistance of the outer constructions. They are resistant to rotting processes and have increased fire resistance uos i-.

Examples are carried out

Example 1 ad

Coniferous wood (spruce) was split into fractions with a thick raax. 35 to 70 mra. Wood mm and with a length of up to 10 mm, up to 35 mm and the chips were dried to moisture. 20 wt. After drying, 275 kg of wood chips consisting of 75 wt. fraction 35 to 70 mm, 22 wt. fraction 1 to 35 mm and 3 wt. the fractions up to 1 mm were mixed with 4 kg of sodium silicate dissolved in 40 l of water until the wood chips were soaked with solution (<8 min). Then a suspension of 2 kg of calcium nitrate and 250 l of mixing water was prepared from 190 kg of PC 400 cement, which was added to the partially contained wood chips. The resulting mixture was stirred until all the chips were covered with cementitious sealant (<15 min). The mixture was then spread into the prepared die to a height of 90 mm and loaded under a pressure of 0.7 MPa. After 24 h, when the handling strength was reached, the board was demolded (thatch thickness 50 mm). Expedition strength is achieved after 14 days of curing in air at a temperature above 5 ° C, 8

-'ý

The procedure was as in Example 1 except that the starting mixture contained 300 kg of wood chips <87% by weight. fraction 35 to 70 mm, 10% w / w. fraction 1 to 35 mm, 3 wt. fractions up to 1 mra), 6 kg of sodium silicate in 60% water, 210 kg of PC 400 cement, 2.5 kg Ca (HCL) 12 and 280 L of water. The embankment height was 63 mra, pressure 0.65 MPa, thatch thickness 35 mm.

In the following table, the parameters of the prepared chipboard chipboards are the parameter size / mm /

1000: 1500: 2000 width / mm /

500 cont. tables

parameter size thickness / mm / 20 ⁺  35-50 bulk density v s u c. li ora s t a e / k p. m > / 500 : 470: 471

· W

tensile strength • flexural / min /

1.6: 1.0: 0.7 compresses the net.

/ ¾ depth / absorbency. 3-volume / ¾ volume / 44.0 with effect t. e 1 te h e s / s / Vm ~ ¹ .K ' ¹ / 0,08 sound absorption coefficients prl 1 = 2000 Hz / - / 0,65 flammability, / degree / B Thicknesses with a thickness of 20 mm are considered lamination with high-performance heat insulating materials

Claims (4)

PROTECTION REQUIREMENTS 1- Pressure-cured chipboard that is characterized by by that in the starting point mixture is 264 until 300 parts by weight wood chips with a length of max. 70 mm and max. 3 mm, 190 until 210 parts by weight cement, 4 until 6 parts by weight * rai nera1 i starts the next sets, 2 until 2.5 parts by weight of accelerator setting and t.vrdnutía _te * cement sealant and 240 until 280 parts by weight mixed water. » The cement-lime thatch according to claim 1, characterized in that the wood chips contain 75 to 87% by weight. % fraction 35 to 10 to 22 wt. fractions of 1 max. 3 wt. fractions up to 1 and max. 20% by weight, moisture. characterized by up to 70 mm, up to 35 mm, mra 3. The chipboard cementite of claim 1, wherein the mineralizing agent is sodium silicate in the form of a 30% aqueous solution. 4. A chip of cement-cement according to claim 1, characterized in that the accelerator is set and hardened and the cementitious sealant is measured.