Successes in the area of construction of buildings and constructions, roads and bridges,
reconstruction and remodeling of buildings, practical application of original architectonic
solutions to construction in many respects are obliged to development and broad introduction of
new modern building materials and kinds of building equipment.
The variety of engineering and technical problems facing to experts in the field of
construction provides availability of wide scale of the specialized equipment and tools for
processing of building materials, first of all concrete and reinforced concrete.
In third quarter of the 20th century on the construction sites of Europe the essentially new
technical equipment using diamond tools appeared.
For manufacture of diamond tools natural technical diamonds have been used. The word
"diamond" in ancient Hindu language means "unbreakable". According to another version, the
name of diamond is derived from Greek "adamas" (invincible, indestructible). It is supposed that
diamonds were one of the first minerals crystallized at cooling of the mantle silicate liquid melt
on the depth 150 to 200 km at pressure 5000 MPa, and then they were carried to the surface of
the Earth as a result of explosive processes accompanying formation of kimberlitic tubes, 15 to
20% of which contain diamonds. There is another point of view according to which the
diamonds crystallized on rather small depth due to dissociation or partial oxidation of methane in
the gas system C-H-O-S at temperature from above 1000 C and pressure 100 to 500 MPa.
Diamonds are also found in deep rocks - eclogites and the some deeply metamorphosed
garnet gneisses. Fine diamonds in significant amounts are found in meteorites (ureilites), and
also in huge meteoric craters where melted rocks contain significant amounts of fine crystal
diamonds.
Diamond is the hardest matter of all natural substances. By Mohs scale the relative
hardness of diamond is equal to 10, in 1000 times greater than the hardness of quartz and in 150
times - than that of corundum. The maximal hardness is on the sides of the octahedron, and the
minimal - on the sides of the cube.
The mineralogist Friedrich Mohs developed in the beginning of the last century a
conditional scale which is widely used till now.
The scale of hardness (Mohs scale) is resulted in Table 1.
Table 1.
33
Material
Hardness
1.
Talcum
1
2.
Gypsum
2
3.
Calcite
3
4.
Fluorite
4
5.
Apatite
5
6.
Feldspar
6
7.
Quartz
7
8.
Topaz
8
9.
Corundum
9
10.
Diamond
10
3
The density of pure diamond makes 3.511 g/cm . In the air diamond burns down at
temperature 850°C with formation of carbon dioxide of, and in vacuum - at temperature from
above 1500°C the diamond converts into graphite.
The diamond tool has received wide application after development of industrial
production technique of synthetic diamonds.
In December, 1954 General Electric Co (USA) has informed on production of artificial
diamonds in the form of fine triangular plates by the company employees Hall, Bandy and
others. The process of synthesis was conducted under pressure about 100 thousand atmospheres
and at temperature 2600°C. The catalyst was tantalum and if to speak more precisely, the
diamond was generated from graphite on a thin film of tantalum carbide formed during diamond
synthesis.
However, even earlier, in February 1953, the first artificial diamonds were made by Eric
Gunnar Lundblad's team (Sweden), but the Swedish scientists did not hurry to publish the results
of their works.
Since then, from the middle of the 50s, successful works on industrial synthesis of
diamonds have been conducted in some countries. In our country this work was headed by V.N.
Bakul and academician L.F. Vereschagin.
The diamonds are synthesized at temperature 1200 to 2000°C and pressure more than
5000 MPa from graphite powder mixed with powdered catalyst (iron, nickel, chrome and other
metals). The diamonds are crystallized due to insufficient saturation of melt mix at high
pressures in respect to graphite and its oversaturation in respect to diamonds. Annually in the
world about 50 tons of small crystal diamonds are synthesized and used for manufacturing of
diamond tools. The mentioned quantity makes about 70% from the annual world consumption of
diamonds. Other quantity is taken by the share of natural technical diamonds.
The synthesized jeweler diamonds are much more expensive than some natural
diamonds. Technical diamonds used for the diamond tools cost from 3 up to 12 dollars for carat,
and synthetic diamonds - about 2 dollars for carat.
The diamond tools have been widely spread due to unique properties of diamonds fixed
on the surface. Fixing of diamonds can be carried out by galvanic way, by sintering and pressing.
The material by which the diamonds are fixed on the cutting tool surface is named a sheaf. The
type of diamonds, their concentration and properties of sheaf determine the operation life and
efficiency of the tool.
In the 90s the new technology started to conquer the Russian market. This technology
had and still has a very serious opponent - a pick hammer. Should they be called competitors?
No, no, no. Diamond cutting and sawing is a surgically precision weapon. It does not
leave cracks which open a broad way for rust of armoring, its application is not accompanied by
noise and dynamic loadings. The rate of works is simply incomparable by the time. The cost of
the apertures executed by diamond drilling is much lower than that of the apertures executed by
shock way (pick hammer) because there is no necessity in recovery of destructions which have
occurred at destruction of walls or floorings by shock method.
Drilling under communications, cutting of apertures, destruction of volumetric reinforced
concrete constructions is the basic direction of application of the given advanced technology.
High chimneys, bridge transitions, piers and quay walls of harbor installations, road and
air field coatings are the areas of application of diamonds in construction, reconstruction and
restorations.
The leading manufacturers of the equipment for diamond drilling and cutting are the
following
companies:
"Hilti"
(Liechtenstein),
"Hydrostress"
(Switzerland),
"Cedima"
(Germany), "Gölz" (Germany), "Hydro-tech" (Germany), "Dr. Schulze" (Germany), "Fast
Verdini" (Italy), "Diamont Product" (USA), "Shibuya" (Japan), "Xcalibre" (Great Britain),
"Asahi" (Japan), "Consec" (Japan), "Braun" (Germany), "Milwaukee" (USA), "Weka"
(Germany), "Bort Longyear" (Germany), "Flex" (Germany), "Husqvarna" (Sweden), "Adamas"
(Germany), "Plattner" (Austria), "Eurodima", "Dimas", "Wakra" (Switzerland), "ICS Blount
Inc." (USA), “Pentruder” (Sweden).
The most known companies which make diamond tools for drilling and cutting are the
following: "Hilti" (Liechtenstein), "Tyrolit" (Austria), "Cedima" (Germany), "Gölz" (Germany),
"Dr. Schulze" (Germany), "Nimbus", "Norton" (Great Britain), "Solga" (Spain), "Fast Verdini"
(Italy), "Adamas" (Germany), "A.L.M.T. Corp." (Japan), "Dimu" (Germany), "Kermet" (Russia),
"Shinhan Diamond" (China).
Technologies of drilling and cutting the reinforced concrete constructions are based on
application of diamond tools to specially designed equipment.
The basis of diamond technologies is the process of cutting concrete and armoring by
diamond segments fixed on the case of the tool (core bits, disks, rope, etc.). The tools are driven
by means of the specialized gear of concrete sawing or drilling machine. The linear speed of the
diamond segment is brought to that of the effective material cutting. That is, the cutting speed is
maximal, and deterioration of the diamond segment is minimal.
Specific conditions of the diamond tool sawing and specially developed equipment
allows resolution of unique engineering and technical problems not only in the field of
construction, but also at carrying out of scientific, research and development works.
The distinctive features of diamond tool equipment are processing of materials without
dynamic loadings (unaccented method of processing), rather low noise level (the average level of
noise makes 86 dB) and rather low level of vibration (the level of vibration makes 2.5 m/c2).
The optimized technology of drilling and sawing allows production of surfaces with a
low coarseness level (high "smoothness").
The modern diamond tool equipment allows drilling and sawing with high accuracy,
small deviation from horizontal and vertical levels, and low deviation from the preset cutting
angle. The standards of tolerances and deviations are approved by the International association
of concrete cutting and drilling (IACDS).
The variety of engineering and technical problems facing to experts in the field of
construction provides availability of wide scale of the specialized equipment and tools for
diamond processing of materials, including unaccented (static) technologies of destruction.
The block diagram of classification of the basic kinds of concrete drilling and sawing
equipment is shown in figure 1.1.
Figure 1.1. Block diagram of classification of the basic kinds of concrete drilling and sawing
equipment
The drilling machines are intended for drilling reinforced concrete with high
reinforcement degree, and also concrete, natural and artificial stone and brick.
The drilling machines with diamond core bits are applied to drilling cylindrical holes in
the building designs at construction of buildings and constructions, roads and bridges, and also at
demolishing or reconstruction of buildings.
The distinctive feature of machines of the given class is the opportunity to carry out an
aperture not only on flat but also on curvilinear surfaces (pipes, arches, etc.). The range of
drilling diameters makes from 12 mm to 1 850 mm.
Drilling depth can reach 20 running meters.
Drilling can be performed on any plane and at any angle.
Depending on the engaged drive the drilling machines are subdivided into electric,
hydraulic, petrol and pneumatic.
Various hydraulic drill rigs are shown on figure 1.
a)
b)
c)
d)
e)
f)
Fig. 1.8. Various Hydraulic drill rigs
a) Hydraulic drill rig DD 750 HY («Hilti»);
b) Hydraulic drill rig НССВ-7Н («Hydrostress»);
c) Hydraulic drill rig M-6
(«Diamond Product»);
d) Hydraulic drill rig BBD 4W
(«Braun»)
e) Hydraulic drill rig KB-140/HBM-100 Hydraulik («Gölz»);
f) Hydraulic drill rig Drill 33 («Dr. Schulze»).
The wall saws are intended for sawing of monolithic reinforced concrete with high
degree of reinforcement and also concrete (including foamed concrete, expanded-clay concrete),
firm natural stone and brick (including slot-hole, fire clay, silicate).
The wall saws are applied for sawing of building designs at construction of buildings,
roads and bridges and at disassembly or reconstruction of buildings with the use of diamond
tools.
The distinctive feature of saws of the given class is the opportunity to perform cutting not
only on flat surfaces, but also on curvilinear surfaces (pipes, arches, etc.).
By the type of drive the wall saws are classified as electric and hydraulic.
The exterior of hydraulic disk wall saw is shown in figure 2.
a)
b)
c)
d)
e)
f)
Fig. 2. Various hydraulic wall saws
a) Hydraulic wall saws DS-TS 22 («Hilti»);
b) Hydraulic wall saws FZ-4S («Hydrostress»);
c) Hydraulic wall saws VS-355 («Dimas»);
d) Hydraulic wall saws WS 900 («Gölz»);
e) Hydraulic wall saws BWS 12 («Braun»);
f) Hydraulic wall saws WS-400H («Cedima»).
By means of the given sort of equipment it is possible to resolve the following problems:
horizontal cutting, vertical cutting, sharp in overhead position, cutting under an angle.
In practice the given technology allows c cutting of apertures of reinforced concrete
constructions of the following configurations: door, window, window round, window ellipse,
elevator, mine, ventilating, technological, interfloor, stairway, arch and other.
The sawing for the subsequent dismantling at disassembly or reconstruction of a building
supposes the following designs: columns, beam head, flooring, wall designs, balconies, consoles,
girders, fencing of elevator wells, bases.
In road and bridge construction cutting of the following constructions is provided:
bridges and overpasses, tunnels, stilts, "walls in ground", alcoves and nonthrough openings in
monolithic reinforced concrete.
The disk wall saws are intended for sawing of monolithic reinforced concrete with high
degree of reinforcement and also concrete (including foamed concrete, expanded-clay concrete),
firm natural stone and brick (including slot-hole, fire clay, silicate).
For disk wall saws the most effective application is cutting of extended building and
engineering designs having flat enough and equal surface, without dependence from its spatial
arrangement (floor, wall, ceiling).
The disk wall saws serve for sawing of building designs at any arrangement of a cutting
line: on floor, wall, or ceiling.
In practice the application of disk wall saws allows cutting out the following sorts of
apertures: door, window, elevator apertures, wells, ventilating, technological, interfloor and
stairway.
The cutting by disk wall saws for the subsequent dismantling at disassembly or
reconstruction of a building supposes the following designs: columns, beam head, flooring, wall
designs, balconies, consoles, girders, fencing of elevator wells, bases.
In road and bridge construction cutting of the following constructions is provided:
bridges and overpasses, tunnels, stilts, "walls in ground", alcoves and nonthrough apertures in
monolithic reinforced concrete.
The disk wall saws cut materials by means of a steel disk with diamond segments
soldered along the external contour. The given disk is installed on the head of the wall saw.
The most effective application of wire saws is cutting the building and engineering
designs having the minimal perimeter at the maximal cross area, and also shapeless designs,
irrespective of their spatial arrangement.
By means of the given sort of equipment it is possible to carry out sawing in practically
any direction.
In practice the given technology allows cutting of apertures of reinforced concrete
constructions of following configurations: door, window, window round, window ellipse,
elevator well, wells, ventilating, arch, technological, interfloor, stairway, etc.
The cutting for the subsequent dismantling at disassembling or reconstruction of a
building supposes the following designs: columns, beam head, flooring, wall designs, balconies,
consoles, girders, fencing of elevator wells, bases.
In road and bridge construction the cutting of the following constructions is supposed:
designs of bridges and overpasses, tunnel designs, stilts, "walls in ground", alcoves and not
through apertures in monolithic reinforced concrete.
The wire saws use as the tool a wire with diamond containing bushes strung on it, and
between these bushes the ring springs interfering shear of bushes are inserted.
By the type of drive the wire saws are subdivided into electric and hydraulic machines.
By the type of distributive gears the wire wall saws are subdivided into roller, wheel and
circular machines.
The exterior of wheel wire saw is shown in figure 3.
a)
b)
c)
d)
Fig. 3. The wheel wire saw
a) Wheel wire saw DS-WSS30 («Hilti»);
b) Wheel wire saw SK-WA («Hydrostress»);
c) Wheel wire saw SSP 15 («Braun»);
d) Wheel wire saw CSA 1000 («Cedima»).
The cutting depth is limited by the length of mounted wire and can achieve 60 meters.
The efficiency of the given class of machines makes up to 2.0 m2/hour.
The electric wire wall saws are differentiated from hydraulic machines by the guiding
rollers installed directly on electric motors. The control of equipment of the given type is carried
out by a special console.
The machines with the electric motor power of 11.0 - 15.0 kW are most widespread.
For the most stable feeding of the wire and performance of cutting works of the big area
of reinforced concrete constructions, wire machines having hydraulic drive are applied. The
machines with the hydraulic assembly unit power of 15 - 20 kW are most widespread, but for
today there are also machines with hydraulic power packs with power up to 45 kW.
The wire wall saws are differentiated by the principle of wire feed, namely the wheel
type wire saws and roller type wire saws. To the first concern disk wall saws on which a steering
wheel is installed instead of a diamond disk. The steering wheel has a rubber film on the butt end
which provides the required cohesion of the wire and the steering wheel. At use of the given type
of wire saw an indispensable condition is the presence of additional rollers. They serve not only
for change of the moving direction of the wire, but also are the damping element interfering the
rupture of the diamond wire. During sawing of reinforced concrete constructions (at sawing the
reinforcement or at hit of the wire on the come off piece of concrete) dynamic loadings on the
diamond wire appear and can cause its rupture.
In the design of the roller type wire wall saws consider an opportunity of occurrence of
jerks in sawing is considered. That is expressed by availability of several guided rollers installed
on the rig or on carriages of the machine. They serve not only for passing the wire selected
during sawing, but also extinguish jerks of the wire by redistribution of dynamic impacts, both
on guiding, and on guided rollers.
The basic distinctive feature of wire wall saws from disk wall saws is practically not
restrained cutting depth. At maximum mounted wire length of 60 m the cutting depth can reach
up to 25 m. That enables cutting of any building designs, and also reinforced-concrete
constructions.
The application of circular wire saws allows performance of unique works on
manufacturing of apertures and apertures of the round form in diameter from 600 mm up to 9000
mm and depth from 600 up to 2500 mm. With the help of such equipment the arch apertures and
ellipse apertures, and also apertures of complex not the rectangular form are made.
General
idea
of
circular
sawing
is
shown
on
figure
4.
Fig.4. General idea of circular sawing
The application of the given type of equipment opens great opportunities to designers.
This technology allows changing not only the interior of a building, but also its facade. This
technology is applied both at erection of a new building, and at a rebuilding project of already
existing constructions.
Unlike the drilling machines using diamond core bits as cutting tools, the diamond wire is
applied which moves with linear speed up to 20 meters per second and cuts the reinforced
concrete on the circular trajectory.
The machines are equipped either with power pack, or the electric motors installed directly on
the guiding roller of the wire saw.
Control of the machines of the given type is carried out depending on mark and model. It
can be manual or by the control board for electric circular machines or from the panel of the
hydraulic unit, or from the remote console for hydraulic drive equipment.
As well as other diamond equipment the given sort of machinery demands water cooling.
At cutting of horizontal designs, the special attention should be paid to fixation of the cut
off element. In some cases, for amenity of the subsequent dismantling, the cut out element is
preliminary partitioned, by means of disk wall saw.
Before starting installation of the circular wire saw, it is necessary to make the central
aperture in the reinforced concrete construction in which further the axial pipe of the machine
will be established and fixed. Depending on mark and model, the diameter of bore makes from
160 up to 200 mm. After completion of cutting, the machine must be disassembled in order to
prevent damages at carrying out of subsequent works on dismantling the cut element.
Dismantling of the cut element at cutting of horizontal designs (floorings or coatings of a
building) can be carried out both by ascending upwards and loadings for further export from the
construction site, and lowering of the element downwards, on the previous floor for subsequent
recycling.
The chain wall saws work by the principle of usual chain saw for cutting wood, cutting
concrete by the chain with diamond segments.
They can be used in the manual mode (figure 5.b) or installed on a rail (fig. 5.a).
The specific operating conditions of the given class of equipment are necessity of
presence of power supply 380 - 400 V of the corresponding power and water supply.
Hydraulic drive, 32 l/min, 140 bars.
The chain wall saws are often used for performance of either auxiliary, or special works.
That is explained by high cost price of the given technology. It is necessary to specially mention
the unique sorts of sawing which can be executed only by the given sort of diamond equipment.
This is pure manufacturing of apertures. At cutting work by disk wall saw in the corners of the
formed aperture so-called notches remain. After performance of preliminary sawing by a
diamond disk which is made without angular notches, the head of the disk wall saw is dismantled
from the rail, and another chain wall saw is installed on its place. As the width of the diamond
tool at both machines is identical, the directing part of the chain saw enters the cut executed by
the disk and the remained part of concrete is cut. At consecutive use of disk and chain wall saws,
the angular part of the aperture is carried out with such cleanliness of processing of a concrete
surface that does not demand performance of subsequent furnish works of the aperture. The
above described technology has been recently widely applied by the European designers.
The manual chain saws cope well with the works of manufacturing of small windows,
and also apertures under communications in floorings.
The exterior of the chain saw is shown in figure 5.
a)
b)
Fig. 5. The exterior of the chain saw
a) Chain saw installed on a rail CSF 40 («Hydrostress»);
b) Manual chain saw 613 GC («ICS»).
There are two types of chain machines - with a hydraulic drive and with an internal
combustion engine. The opportunity of installation on the rails has only the hydraulic type in a
special complete set that is explained by various thickness of diamond disk and diamond chain in
a standard complete set.
The flat saws are intended for rectilinear narrow seams with use of the diamond tool
(diamond disks) at road and bridge construction and at disassembling or reconstruction of
buildings, under condition of performance of works on horizontal surfaces.
The flat saws are applied for sawing of asphalt and asphalted concrete, and also
monolithic reinforced concrete with the large-scale of reinforcement and green concrete.
The depth of cutting can achieve 900 mm and determined by the engine power.
According to the used drive the machines are divided into petrol, diesel and electric
types.
The applicability of a particular type of equipment is determined by particular conditions
of the carried out works and, first of all, depth of cutting.
The specific operating conditions of the given class of machines are absence of stationary
power supplies.
The machines of the given class are equipped with water vessels which are filled directly
ahead of the beginning of work, and that creates an additional weight positively influencing the
sawing process stability. After termination of the production cycle, the water remaining in the
vessels is drained off, that reducing the shipping weight of the equipment.
The flat saws of the given class in our country are usually applied to cutting off a
working lot at road patching repair, and also for strobes at lying of shallow laid communications.
The exterior of petrol flat saw is shown in figure 6.
а)
б)
Fig.6. Petrol flat saw
a) Petrol flat saw HFS-513 («Hydrostress»);
b) Petrol flat saw CF-12.4D («Cedima»).
Some models of the given class of machines have no drive on wheels and the process of
sawing occurs at moving the machine by the operator manually.
The cutting depth is set by an angle of slope of the platform on which the units and
assembly units of flat saw are mounted. The adjustment of depth is carried out by means of the
handle setting the cutting depth.