Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B23/00—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects
  • B28B23/02—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members
  • B28B23/04—Arrangements specially adapted for the production of shaped articles with elements wholly or partly embedded in the moulding material; Production of reinforced objects wherein the elements are reinforcing members the elements being stressed

Definitions

• This invention consists of a method and materials used for manufacturing of prestressed reinforced concrete poles for agriculture in the construction of support structures for orchards and vineyards, as well as for support and protection structures such as anti-hail and sun shade protection systems.
• the said method comprises the following disadvantages for the lack of prestressing operations for the reinforcing structure:
• the manufactured reinforced concrete poles are highly fragile with low frost resistance and in their manufacturing is used a manual labour leading to low labour productivity. Their positioning and embedding in soil is a laborious, time-consuming and inefficient task, as it is necessary to pre-dug holes, which is a disadvantage too. After insertion into the hole, it is difficult for the pole to be embedded.
• These poles can not be placed with a vibrating head because of a danger of breakage or distortion and they do not differ in dimension as well.
• composition of materials used in the manufacture of reinforced concrete poles is well known including the making of a concrete mixture comprising the following percent composition by weight: 35% sand, 49% gravel, 14% cement and 2% water.
• the disadvantage of the well known compound is that the texture is from 0.01 to 1 cm giving thus a product without precise dimensions.
• the manufactured product is porous and easily destroyable due to climatic conditions.
• the object of the present invention is to provide a method and materials for manufacturing of reinforced concrete poles with prestressed reinforced concrete structure aimed to achieve crops service life when used and not needing a replacement.
• the reinforced concrete poles have to be resistant to bad weather conditions, unbreakable, corrosion-protected, easily cuttable to different lengths as may be needed and with low manufacturing cost.
• This object is achieved by providing a method and materials for manufacturing of reinforced concrete poles.
• the manufacturing process comprises the following stages:
• steel reinforcing structure of 4 to 12 pieces of parallel steel reinforcing ropes, arranged with each other at a predetermined distance which provides the necessary concrete cover. Then the said steel reinforcing ropes with a thickness of 3.50 to 7.50 mm are prestressed by a force of 54kN (depending on their thickness).
• Each of the steel reinforcing ropes comprises at least two pieces of steel wires, which have a minimum thickness of 1 .5 mm.
• the steel reinforcing ropes are fixed at their opposite ends along the metal mould and further tensioned by means of a hydraulic system and moving body at least at one side of the metal mould by a force to 54kN depending on their thickness.
• the metal mould may be with a circular, elliptical, square, trapezoidal or polygonal shape. Then the space in the metal mould is filled by means of a device for feeding and distributing the concrete.
• the concrete which has a strength class of C 12/15 MPa to a 60/75 MPa, a flexural strength of 1.5 to 6 WOG, is compacted in the metal mould by vibration, wherein is already placed the prestressing reinforcing structure (Drawing 1 to 4).
• the manufactured reinforced concrete poles are aging in the metal mould of 36 to 96-hour period at an average temperature of 20°C. Then they are removed with a machine specially designed for this purpose, cut to specified dimensions without further processing and used for the intended purpose.
• the fiexural strength of the manufactured product is at least 10 MPa ( N/m2).
• the concrete for the production of reinforced concrete poles used in compliance with the proposed method has the following percent composition by weight: 28% to 40% sand, 42% to 50% gravel, 12% to 25% cement, 6% to 8% water and 0.17% to 0.5% superplasticizer.
• the concrete components are stored in bunkers where they are measured by electronic scales. After dosing the components are homogenized in a mixing unit for 3 to 5 minutes and the produced concrete is further compacted in the metal mould by vibration.
• the advantage of this invention resides in the fact that the applied technique eliminates cracking of concrete. All processes are automated, which leads to high productivity. Manufactured reinforced concrete poles may be cut to different lengths as may be needed, they have high resistance, frost resistance and their positioning and embedding in a variety of ground are easy and efficient. Thus is avoided the danger of breakage or distortion thereof.
• Drawing 1 It represents a cross-sectional view of reinforced concrete poles with a variant arrangement of a minimal number of steel reinforcing ropes;
• Drawing 2 It represents a cross-sectional view of reinforced concrete poles with 6 steel reinforcing ropes and a variant of their arrangement-
• the metal mould which may be circular, elliptical, square, trapezoidal or polygonal, is coated with form oil, after that the steel reinforcing rope is placed in it.
• the steel reinforcing rope is rolled up and placed on a stand on the side of the tightening part of the mould. It is fastened with eyelets to fixing objects that are retrieved by winches to the opposite end of the mould and snaped there with brackets and screws.
• the steel reinforcing ropes are tensioned by hydraulic cylinder system located on the movable part of the mouild tension sensor. After achieving the required pulling force the hydraulic system is locked by additional security plates to prevent eventual rupture in hydraulic hoses.
• the concrete is compacted by vibration into the metal mould space where prestressing fixture has been already embedded.
• the mixture envisaged for manufacturing of reinforced concrete poles comprises the following percent composition by weight: 36.79% sand, 45% gravel, 12% cement, 6% water and 0.21 % superplasticizer.
• the concrete components are stored in bunkers where they are measured by electronic scales. After dosing the components are homogenized in a mixing unit for 3 to 5 minutes and the produced concrete is further compacted in the metal mould by vibration.
• the metal mould may be with circular, elliptical, square, trapezoidal or polygonal shape. After 96-hour period of aging at an average temperature of 20° C the reinforced concrete poles are removed from the mould.
• the technology is the same as specified in Example 2 herein above applying the compound percentage formula by weight: 32% sand, 43% gravel, 18% cement, 6.78% water and 0.22% superplasticizer. After 50-hour period of aging at an average temperature of 20° C the reinforced concrete poles are removed from the mould.
• Example 2 The technology is the same as specified in Example 2 herein above applying the compound percentage formula by weight: 30% sand, 42% gravel, 20% cement, 7.8% water and 0.20% superplasticizer. After 40-hour period of aging at an average temperature of 20° C the reinforced concrete poles are removed from the mould.
• Example 2 The technology is the same as specified in Example 2 herein above applying the compound percentage formula by weight: 28% sand, 42% gravel, 23% cement, 6.60% water and 0.40% superplasticizer. After 36-hour period of aging at an average temperature of 20° C the reinforced concrete poles are removed from the mould.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Mechanical Engineering (AREA)
• Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50488956

Family Applications (1)

Country Status (2)

Cited By (3)

Families Citing this family (1)

Citations (3)

• 2013
  • 2013-11-14 BG BG111621A patent/BG111621A/bg unknown
• 2014
  • 2014-03-06 WO PCT/BG2014/000012 patent/WO2015070296A1/en active Application Filing

Patent Citations (3)

Also Published As

Similar Documents

Legal Events