When it comes to
construction and design of road, there are many factors to consider. One of the
most critical aspects and essential components to consider in the construction
and design of roads is the road kerb. Road kerbs are raised edges or barriers
positioned at the sides of roadways to separate the road surface from adjacent
areas like sidewalks or medians. Road kerbs serve both functional and aesthetic
purposes. They play a crucial role in guiding traffic, preventing vehicles from
straying off the road, and providing delineation between different sections of
a road. They come in various shapes and sizes, each designed to meet specific
requirements, and offer advantages in terms of safety, traffic management, and
overall infrastructure durability.
Engineering
Functions of Road Kerbs
Reinforces the Asphalt
Pavement. When a vehicle passes over an asphalt pavement, the load is
transmitted across the pavement. Without concrete kerbing, this load will
likely push the asphalt outwards over time, resulting in pavement failure. This
explains why most high-traffic areas, like parking lots and urban streets, are
usually lined with kerbs.
Provides Edge Protection.
The edges of asphalt pavement are its most vulnerable point; they are the most
susceptible to crumbling, chipping, and breaking due to the constant stress of
traffic and environmental factors. By installing concrete kerbing, a sturdy
barrier is created that shields these vulnerable edges, significantly extending
the lifespan of asphalt pavement.
Improves Drainage. Another
key benefit of concrete kerbing is that it improves pavement’s drainage
capabilities. It directs runoff away from the pavement and towards proper
drainage structures, such as storm drains or swales, thus preventing water from
pooling on the surface. This is important because it prevents water from
seeping into the pavement’s base layers, which can severely shorten its
lifespan.
Concrete
Kerb Placing and Kerb Laying Machine
Concrete kerbs can be
prepared by precast and cast in situ methods. Precast concrete kerbs are
manufactured offsite and bought to site for laying manually by labours. This
method is labourious, costly and time consuming. In cast in situ method
concrete kerbs are either casted on site using fixed forms and pouring
concrete, which is again labourious, costly and time consuming, or
machine-placed using dedicated kerb laying machines that effectively slip-form
(or extrude) the kerb.
A concrete kerb laying
machine is an industrial scale piece of construction equipment used to
continually create uniform kerbs, gutters and other concrete boundaries
flawlessly. It automates the pouring, shaping and edging process, ensuring
consistent quality and efficiency for various kerbing projects. For large-scale
construction work, these machines provide a cost-effective solution for
creating durable, precise concrete kerbs with reduced manual labour and
increased production speed. Whether it is about the sidewalk, golf course
edging or pavement construction project, accomplishing the project becomes easy
with the help of this machine.
A typical concrete kerb
laying machine is generally equipped with concrete feeding and extrusion
systems, often using hoppers and moulds, to shape concrete, auger or conveyor
systems to move and mix concrete efficiently, adjustable moulds for different
concrete object shapes and sizes, hydraulic systems for precise control and
flexibility, elevated operator platforms for better visibility and ergonomics,
and mobility features like tracks or wheels for easy movement along
construction sites.
Slipform
Concrete Kerb Laying Machine
These machines utilize a
continuously moving form, along the construction path, to shape concrete kerbs,
offering high efficiency and precision. Slip form machines combine wet mix and
vibration for compaction and propulsion.
A slipform kerb paver is a
large machine that acts as an extruder to create the kerb shape while also
finishing the project. It comes with a built-in hopper and belt system. Paver
receives concrete into a hopper and carefully sends it through a forming mould
which shapes the kerb in the exact section shape specified. It is guided by the
string system, where a string line is setup to guide the kerb machine. However,
some more advanced ones come equipped with 3D guidance and smart sensors that
remove the machine's need to be string-guided.
The concrete mix design is
specially formulated to assure the concrete is just plastic/wet enough to pass
smoothly through the slipform but with a low enough slump (typically 1-2″) to
maintain its own weight on the ground. The slip mould is kept continuously wet
through the machines water tank (or by direct water spray from the operator)
which helps the concrete pass smoothly through the mould and provides a smooth
appearance. The operator will also typically spray the top of the concrete
trucks chute to maintain a lubricated path for the concrete.
Extrusion
Concrete Kerb Laying Machine
Extrusion machines push
concrete through a mould to create kerbs, providing versatility and speed in
production. They use dry mix and a ramming mechanism for compaction and
propulsion. An auger on extruders compacts concrete and propels it through a
mould, producing a uniform kerb with high density.
An almost dry, zero slump
concrete is fed into the hopper of the kerb machine, and is forced under
pressure through a specially designed mould, much like a tooth paste is
squeezed through a tube. Augers cause the voids to be squeezed out by pressure
build-up. The machine moves away from the abutment that is formed as the mould
is filled. This results in a compacted, high-density kerb that is uniform in
size and shape, freestanding without forms, and structurally sound. The
finished product left behind requires only minor hand finishing where joints
are cut or where special shaping for driveways is necessary. Brushing and
curing are the only other hand finishing jobs required.
Benefits
of Using Kerb Laying Machine
Kerbing machine streamline
the process of laying kerbs, saving time and labour. It enables continuous
operation, minimizing downtime and maximizing output. Kerb laying machine
produces high quality results providing uniformity in kerb construction
throughout the project ensuring accurate dimensions and smooth finishes. It is
equipped with steering mechanisms and guidance systems for precise kerb laying.
Kerb laying machine have adjustable controls for height, width, and slope thus
offering flexibility in design options to suit project requirements. It can
create various shapes and sizes to meet project specifications. Use of kerbing
machine reduces environmental impact by minimising concrete wastage. It require
fewer workers compared to manual methods thus improving job site safety by
minimising manual handling.
