Concrete (types of road)

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Types of Road
(Concrete Road)
By
Hemn Omer Hamadamin
Shadi Hamed Salih
Fatima Sherzad Muhamad
Supervisor
Zina M. Mudheher
Ali Rizgar
April, 2019
Salahuddin University – Erbil
College of Engineering
Civil Engineer Department

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Abstract
This reports will going to talk about type of roads like (Asphalt and Concrete ) roads but
we will focus on concrete roads , this report will help us to know about concrete road
and analyzing advantage and disadvantage of concrete roads and why we should
create roads with concretes or why shouldn’t create roads with it , and knowing the
Duration of the Concrete Roads Resistance and telling that what type of concrete is the
best to use it in road , and the report will give us information about whether it is suitable
for every type of roads .

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Table of Contents
Preliminary pages
Abstract ………………………………………………………………………(2)
Body of the report
1.0 Introduction…………………………………………………… (4)
2.0 What is the Concrete ………………………………………. (4)
2.1 Cement
2.2 Aggregate
3.0 Process of construct concrete road ………………………. (6)
4.0 Classification of cement concrete roads…………………... (12)
5.0 Types which used to plain concrete road…………………. (15)
6.0 Duration and cost of concrete road …………………….…. (18)
7.0 Advantage and Disadvantage of Concrete Road: (19)
7.1 Advantage………………………………………………………………(19)
7.2 Disadvantage…………………………………………………………..(20)
8.0 Equipments which use to concrete roads in generally…… (21)
9.0 Solution of concrete roads error …………………………… (23)
10.0 References table & pictures table …………………………. (24)
11.0 Table of Pictures ……………………………………………. (25)

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1.0 Introduction:
For more than a century in the countries of the European Union roads are built with
cement-concrete. Starting with Poland's first cement-concrete pavement in Wroclaw,
built in 1888, with nearly 80 years of concrete pavement , Concrete road is a type of
roads that created by concrete which contain of cement, aggregate and water,
sometimes we will add other minerals to make deferent types of concrete for deferent
uses , there is some advantage and disadvantage of concrete roads and we can solve
some of the concrete roads error , we have long process to construct concrete road.
2.0 What is the Concrete:
Concrete is an Eng. material that simulates the properties of rock being a combination
of particles nearly bound together. It is simply a blend of aggregates. Simply natural
sand and gravel or crushed rock bound together by a hydraulic binder e.g. Portland
cement, activated by water, to form a dense semi homogenous mass, Concrete is very
strong in resisting compression. In use where tensile stresses have to be
accommodated reinforcement is incorporated into the concrete to absorb tension.
Concrete is the most widely used construction material. It allows flexibility in structural
form as it can be molded into a multiplicity of shapes.

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2.1 Cement:
It is wrong that we say concrete and cement are the same thing; cement is normally just
a combination of concrete. Concrete is creating by three basic components: water,
aggregate (rock, sand, or gravel) and Portland cement. Cement, usually in powder form,
acts as a binding agent when mixed with water and aggregates. This combination, or
concrete mix, will be poured and harden into the durable material with which we are all
familiar, so cement is a powder of alumina, silica, lime, iron oxide, and magnesium
oxide burned together in a kiln and finely pulverized and used as an ingredient of mortar
and concrete and it is a building material made by grinding calcined limestone and clay
to a fine powder, which can be mixed with water and poured to set as a solid mass or
used as an ingredient in making mortar or concrete.
2.2 Aggregate:
Aggregate is the most mined material in the world. Aggregates are a component of
composite materials such as concrete and asphalt concrete; the aggregate used to
reinforcement to add much more strength to the overall composite material. Due to the
relatively high hydraulic conductivity value as compared to most soils, aggregates are
widely used in drainage applications such as foundation and French drains, septic drain
fields, retaining wall drains, and roadside edge drains. Aggregates are also used as
base material under foundations, roads, and railroads. In other words, aggregates are
used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to
help prevent differential settling under the road or building), or as a low-cost extender
that binds with more expensive cement or asphalt to form concrete.

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3.0 process of construct concrete road:
3.1 Preparation of sub grade.
3.2 Preparation of sub base.
3.3 Fixing of farm.
3.4 Batching of materials and mixing.
3.5 Carrying and placing concrete.
3.6 Compaction and finishing.
3.7 Floating and edging.h. Belting and edging.
3.8 Curing.
3.9 Final Surface Check.
3.10 Removing the Forms.
3.11 Sealing of The Joints.
- All these operations have been discussed one by one:
3.1 Preparation of Sub Grade:
Where geological organization soil is of very good quality, cement slab may exactly be
laid over the prepared sub grade. The top 15 cm layer of the sub grade should be
compacted and checked for truth by mean of scratch template. Unevenness of the
surface should not exceed 12 mm in3 m length. Sub grade should be prepared and
checked at least two days in advance of concreting. It is desirable to lay a layer of water
proofing paper then even concrete can be laid directly over the soil sub grade. Prepared
sub grade should complete the following requirements:

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i. There should not be any soft patches on the prepared sub grade.
ii. Sub grade should present the uniform support to the concrete slab.
iii. Should be properly drained.
iv. Minimum modulus of sub grade reaction obtained with plate bearing test
should be 5.5 kg / cm2.
v. If water proof paper is to be laid directly over the subgrade, moistening of sub
grade prior to placing of the concrete over it, is not required. Moistening is
essential in case water proof papers are not used.
3.2 Preparation of Sub Grade:
When we have not a good quality, or traffic load expected on the pavement is very
heavy, a 15 cm thick sub base layer may be used over the prepared sub grade before
lying of cement concrete slab. The sub base slab may consist of:
i. One layer of flat brick soling below one layer of Water Bound Macadam.
ii. Two layers of Water Bound Macadam may consist of stone, hard rock,
dense blast furnace slag, brick aggregate or any other granular materiel
which is not likely to soften under action of water.
iii. Well graded soil gravel mixture. iv. Soil stabilized with 3 – 4 % lime or
cement.
iv. Lime concrete or lean concrete giving 28 days compressive strength in the
field as 40 – 60 kg / cm2.
v. Existing macadam sub base.vii. Existing black top surface sub base.

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Note: From (i to v), all the points are for new constructions and can be adopted as per
design requirements. But (vi and vii) points are for existing sub base and thus have
been given in details:
❖ Existing Macadam Sub Base:
In case concrete slabs are to be laid on existing Water Bound Macadam roads, it should
be seen that Water Bound Macadam should extend at least 30 cm beyond the proposed
concrete slab edges. Water Bound Macadam should be at least15 cm thick. If Water
Bound Macadam surface is smaller in width than the proposed width of the concrete
slab up to 30 cm on either side, the extra width may be developed by placing 10 cm of
1:4:8 lean cement concrete.
❖ Black Topped Surface:
Where concrete slab is to be laid over existing black – topped surface no special
treatment is necessary. Concrete should not be laid on black topped surfaces having
soft spots caused by excessive bitumen or where thick premixed carpets have been
rutted badly under traffic. In such cases entire surfacing material should be removed up
to the top of compacted macadam and the surface should be prepared as explained in
existing Water Bound Macadam surfaces.

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c. Fixing of Forms.
Forms may be made from mild steel channel sections or wooden planks. Depth of the
forms should be equal to the thickness of the slab to be provided. Length of the section
for side forms is kept at least 3m except on curves of less than 45 m radius where
shorter lengths Wooden forms should be dress on one side and should have a minimum
base width of 10 mm for slab thickness of 20 cm and have a minimum base width of 15
mm for slabs over 20 cm thickness. Deviation of more than 3mm in a length of 3 m
should not occur when forms are filled with concrete. Sufficient number of stakes or pins
should be put at the back of the form to impart sufficient support to it.
d. Batching of Materials and Mixing.
Cement is measured in number of bags. If cement stored in silos is used, its weight is
taken as 1440 kg / m3
Coarse aggregate and fine aggregates are batched in weigh batching plant and put into
the hopper of the mixer along with required quantity of cement. Water is measured by
volume. The mixing of each batch should be at least for 1 ½ minutes counted after all
the materials have been put into the mixer.
e. Carrying and Placing of Concrete:
Prepared premix is carried immediately to the place of actual use by filling into wheel
barrows, hand carts or baskets. While concreting, it should be ensured that there is on
segregation in the concrete. Concrete put at site is spread uniformly as per
requirements of the thickness of the slab. While being placed, the concrete should be
rodded so that the formations of voids or honey comb pockets are prevented. The
concrete should be particularly well placed and tapped against the forms and along all
the joints.

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f. Compaction and Finishing:
After having uniformly spread, the concrete is compacted either with the help of power-
driven finishing machine or by vibrating screed. For constrained areas like corners and
junctions, hand compaction can be done using tampers. Hand tamper is also known as
hand tamping beam. It consists of a wooden beam 10 cm wide and 25 cm depth.
Length of the tamping beam should be equal to the width of the slab plus 30 cm. A steel
plate is fixed at the underside of this beam. Tamper is used by placing it on the side
forms. Tampers are lifted and dropped to affect compaction. Tamper beam is provided
with handles to lift and drop.
Fig 1
g. Floating and Edging:
After compaction, with vibrating screed or tamper, the concrete is further compacted
and smoothened by means of longitudinal floats. The float is worked longitudinally with
sawing motion from one edge of the pavement to the other edge. After this operation,
excess water gets disappeared but while concrete is still plastic; the surface of the slab
should be tested for trueness with the help of 3 m straight edge.

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h. Belting and Edging:
Just before the concrete becomes non-plastic, the surface should be belted with the
help of a two-ply canvas belt which is usually 20 cowhide and at least 1 m longer than
the width of the slab. The belt is worked on the surface in transverse direction in short
forward and back ward strokes.
After belting and as soon as surplus water disappears from the surface, the pavement is
given a boomed finish with an approved steel or fiber broom not less than 45 cm wide.
The broom should be pulled gently over the surface of the pavement from edge with
each stroke slightly over lapping the adjacent one. After belting and booming and before
the concrete has taken initial set, the edges of the slab should be carefully finished with
an edger of 6mm radius.
I. curing:
Immediately after finishing, the entire surface of the newly laid concrete should be
covered against rapid drying with wetted burlap, cotton or jute mat. Covering operation
with wet burlap is known as initial curing. Burlap curing is carried out for at least two
days. After this, wet burlaps are removed and surface is covered either with damp
saturated sand or with free water. Final curing can also be done by applying an
impervious membrane which does not impart slipperiness to the pavement. Impervious
membrane which is in form of liquid, is applied under pressure, covering the entire
surface uniformly. The liquid may be applied immediately after finishing of the surface
and before the set of the cement has taken place. If the pavement is first covered with
burlap it may be applied upon removal of the burlap. This method of curing can be
adopted at places where there is scarcity of water.
j. Final Surface Check:
This check is done after curing period when curing sand has been removed from the
surface. Undulations in the surface should not exceed 6mm in length of 3 m.

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k. Removing the forms:
Forms should be removed after a lapse of about 12 hours from placing of concrete.
Forms should be removed carefully avoiding any damage to the pavement edges.
m. Sealing of the Joints:
After curing period, and before the pavement is opened to traffic, all the joints should be
cleared of intruded materials and suitable sealing material put into them.
4.0 Classification of cement concrete roads:
Cement concrete roads can be of following types. Out of all these types, cement
concrete slab roads, are most commonly used, and hence construction details of this
type of road are discussed in this topic:
a. Cement concrete slab pavements.
b. Cement grouted macadam pavements.
c. Roller concrete layer pavements.
d. Cement-bound macadam sandwich type.
e. Crete-ways.
a. Cement Concrete Slab Pavements:
In this type of cement concrete roads, cement, sand, coarse aggregate water is
premixed in batch mixtures to form cement concrete. Cement concrete so prepared is
spread on the prepared sub grade or subbase and consolidated with the help of
vibrators or tamper and surface finished smooth. In this construction, joints at frequent
intervals both longitudinally and transversely are provided to nullify the harmful effects
of contraction and expansion due to variation in temperature and also during setting.

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b. Cement Grouted Macadam Pavements:
In this type of construction, Water Bound Macadam layer or stabilized soil is used as
foundation. Existing foundation layer is reconditioned to correct grade and profile and a
loose layer of road metal or coarse aggregate of 36 to 50 mm size is laid in 125 cm
thickness. This course aggregate layer is rolled lightly dry to a compacted thickness of
about 10 cm. Minimum size of coarse aggregate should not be less than20 mm as
sufficient void spaces are to be deliberately left in this rolled layer. Cement and sand are
taken in ration of about 1:2 and grout is prepared by adding sufficient quantity of water
in it. Cement-sand mix, having one bag cement, requires about 35 liters water to form a
fluid mortar to be used as grout. The grout so prepared is poured over the lightly rolled
macadam layer and allowed to seep into the voids deliberately left in the macadam
layer. After grouting, stone chippings of size 5 mm and above, are spread to smoothen
the top finished surface and also to help rolling so that grout is further helped in the
process of penetration. Finished surface is checked for trueness, camber and profile.
The surface is lastly cured as usual. Longitudinal and transverse joints should be
provided at suitable interval.
c. Rolled Concrete Pavement:
This construction consists of a lean premix of cement concrete which is laid on the
prepared sub grade of sub base and rolled with light roller just like Water Bound
Macadam Road construction. Rolling operation should be finished before the final
setting time of the cement. Curing has to be done for 28 days as usual.

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d. Cement Bound Macadam Sandwich Type:
In this type of construction, Water Bound Macadam existing layer or stabilized soil base
are used as foundation or base. The base layer is reconditioned by carrying out all sorts
of repairs. Now take coarse aggregate varying in size between 36 mm and 50 mm and
spread it on the prepared base. This layer is rolled dry to get a compacted thickness of
about 5 cm. Cement and sand are taken ratio of 1:2 and a stiff mortar is made, using
appropriate quantity of water (30 liters / cement bags). This mortar is spread on the
rolled surface in about 4 cm thick layer. Now lay another layer of coarse aggregate of
the same size and grading as is used below mortar layer, in a loose thickness of about
6cm. After spreading the second layer of coarse aggregate over stiff mortar layer, rolling
is done using heavy roller about 12 ton. By rolling, the mortar layer is squeezed in to the
voids of both the layers of coarse aggregate (one layer above and another below mortar
layer) and about 10 cm thick combined layer developed. Rolling should be stopped as
soon as the mortar works up just to the surface. After rolling, the surfacing is finished
and checked for camber and profile. Joints are provided at suitable intervals. This type
of construction is superior to the grouted macadam roads. These roads exhibit rough
texture on the surface and hence are useful in hilly areas, where gradients are steep
and other types of roads become slippery and dangerous for use.
e. Crete-ways:
Crete ways are track ways made with the help of cement concrete. In village roads
there is generally bullock cart traffic. It was originally thought that if only that portion of
the road is treated with concrete where wheels of cart are to move lot of savings can be
affected because width of treatment to be provided shall be very small. In Crete ways,
only 60 – 70cm wide two parallel concrete strips, at center to center spacing of about1.5
meters are constructed. The space between strips is left untreated or may be treated
with very inferior type of material. Thickness of strip may vary from 10 – 15 cm.

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5.0 Types which used to plain concrete road:
Since the first strip of concrete pavement was completed in 1893, concrete has been
used extensively for paving highways and airports as well as business and residential
streets. There are four types of concrete pavement.
5.1 Plain pavements with dowels that use dowels to provide
load transfer and prevent faulting:
How can two things be connected and separate at the same time? That may
sound contradictory, but it’s an important part of how concrete pavements work.
Concrete can expand or contract with changes in temperature, so pavements
are divided into slabs to prevent cracking and allow them to move
independently. At the same time, the slabs must stay connected so loads can
be shifted from one slab to the next, and to prevent faulting at the joints
between slabs. In this edition of the Road Ready newsletter, we’ll look at how
this is accomplished by using dowel bars.
Dowel bars are short steel rods placed at the transverse joints of a concrete
pavement to provide a connection between slabs. When a joint is created, some
level of load transfer can be achieved by aggregate interlock between the two
concrete slabs at the joint. However, higher traffic loads (especially trucks)
increase the stresses on the slab edges beyond this level, so dowel bars are
recommended to provide load transfer. In addition, aggregate interlock will not
be effective if horizontal slab movement widens the crack at the joint. The dowel
bars act to spread the load across both slabs when traffic is moving off the edge
of one slab to the next.

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Fig 2
5.2 Plain pavements without dowels, in which aggregate interlock
transfers loads across joints and prevents faulting
uses contraction joints to control cracking and does not use any reinforcing
steel. Transverse joint spacing is selected such that temperature and
moisture stresses do not produce intermediate cracking between joints. This
typically results in a spacing no longer than about 6.1 m (20 ft.). Dowel bars
are typically used at transverse joints to assist in load transfer. Tie bars are
typically used at longitudinal joints.
Joint Spacing Typically between 3.7 m (12 ft.) and 6.1 m (20 ft.). Due to the
nature of concrete, slabs longer than about 6.1 m (20 ft.) will usually crack in
the middle. Depending upon environment and materials slabs shorter than
this may also crack in the middle.

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5.3 Continuously reinforced pavements that have no contraction
joints and are reinforced with continuous longitudinal steel.
This type has no transverse joints, but contain a significant amount of
longitudinal rein-forcement, typically 0.6 to 0.8 percent of the cross-sectional
area. Transverse reinforcement is often used. The high content of
reinforcement both influences the development of transverse cracks within an
acceptable spacing (about 0.9 to 2.5 m [3 to 8 ft] apart) and serves to hold
cracks tightly together. Some agencies use CRCP designs for high-traffic,
urban routes because of their suitability for high-traffic loads.
Fig 3

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5.4 Conventionally reinforced pavements that contain steel
reinforcement and use dowels in contraction joints
This type contains both joints and reinforcement (e.g., welded wire fabric
deformed steel bars). Joint spacings are longer (typically about 9 to 12 m [30
to 40 ft]), and dowel bars and tie bars are used at all transverse and
longitudinal joints, respectively.
Fig 4
6.0 Duration and cost of concrete roads
Ignoring any maintenance costs, concrete is generally much expensive to install than.
On average concrete driveway with a smooth finish cost over $15.00 per square foot.
Concrete pavement's life can range anywhere from 20-40 years
the curing period of concrete should not be less than 10 days for concrete exposed to
dry and hot weather condition. It is recommended that above minimum periods may be
extended to 14 days where mineral admixtures or blended cements are used in the
concrete.

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7.0 Advantage Disadvantage of Concrete Road
7.1 Advantage
1) Durability and maintenance free live.
2) Concrete pavement is rigid pavement. Rigid pavement work very well under truck
loading.
3) Concrete has long life.
4) Concrete can withstand high temperatures.
5) Concrete roads are not damaged from oil leaks, like asphalt roads.
6) Vehicles consume less fuel: A vehicle, when run over a concrete road, consumes 15-
20% less fuel than that on asphalt roads.
7) Better encounter of surface water related problems.
8) Concrete is resistant to wind and water.
9) Extreme weather conditions are liable to damage asphalt roads more than concrete
roads.
10) Saving of natural resources: Asphalt(bitumen) is produced from imported petroleum,
the reserve of which is becoming reduced drastically. On the other hand,
concrete(cement) is produced from abundantly available limestone.
11) They provide excellent smooth surface for driving
12) They can deal with very heavy traffic
13) Considering their life span, maintenance cost etc., cement concrete roads prove
cheaper than bituminous roads.
14) Even after their span of life, they can be used as base course and surfacing can be
provided of bituminous materials.

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7.2 Disadvantage
1) High initial cost required.
2) Concrete roads come with a higher paving cost than asphalt roads.
3) Maintenance problem: In case the concrete road breaks, the whole concrete slab
needs to be replaced.
4) Mud pumping related problems.
5) Filing of joints at frequent intervals.
6) Snow melts faster on asphalt roads than on concrete roads.
7) Safety features: in rainy and the winter season vehicles tend to slip or slide on
concrete road due to rain and snow.
8) Very often, on main streets, there are several utilities under the roadway. Utilities
often break or need maintenance. This requires that they tear up the roadway to fix
them. This is not so easy with concrete pavement.

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8.0 Equipment which use to concrete roads:
1. Laser screed technology: It is now available in India which could be used for
smaller industrial projects, commercial work and residential slab-on grade. It is a
ride on a machine that establishes grade by laser, disperses concrete by anger,
vibrates and consolidates the concrete.
2. Slip-form paving: There are two methods of paving with concrete: slip-form and
fixed form h sip-form paving, a machine rides over the area to be paved-similar to
a train moving on a set of tracks. Fresh concrete is deposited in front of the
paving machine which then spreads.

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3. Vacuum dewatering concrete flooring: Concrete in the conventional way but with
a higher slump so that the workability is good and concrete pouring and
spreading is done fast. Filter pad is placed on the fresh concrete leaving about 4
inches of fresh concrete exposed on all sides. The top cover is placed on the
filter pad and rolled out till it covers the strips of the exposed concrete on all
sides.

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9.0 Solution of concrete roads error
a. Solution for Smooth Surface
b. Recycling of concrete
c. Maintenance problem
a. Solution for Smooth Surface:
Finished concrete has a smooth surface; texturing of concrete surface is
done to impart required skid resistance to the concrete surface. The
texturing is done by means of wire brushing or grooving along the
transverse direction. Initial texturing may be done at the time of
construction of the paver itself (refer Figure 37). Final texturing is done no
sooner the sheen of the concrete surface goes off
Fig 5

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b. Recycling of concrete:
One of the disadvantages of concrete road using it for one time but now we can use it
like sub base layer for highways and The use of recycled "reclaimed" materials has
been increased during the last decades in order to obtain environmental benefits and to
reduce the pressure on natural material resources.
c. Maintenance problem:
we always hear that fixing of concrete road is expensive but we can solve it by
construction our road with a lots of part that will help us to fix only the parts which
broken.
10.0 References table
Harold N. Atkins , 1983 , Highway Materials , soil and concrete
Reston publishing com. , Virginia
Dr. S.K. Khanna , 1973 ,Highway Engineering
NEM CHAnd & BROS ROORKEE , INDIA
America’s Cement Manufacturers , 2018 , Concrete Pavement
Available from : https://www.cement.org/cement-concrete-
applications/products/concrete-pavement , 18 Feb 2019
Construction and maintenance of concrete pavement , 2004 , concrete
pavement construction process , Available from :
https://nptel.ac.in/courses/105104098/TransportationII/module4b/2slide.htm
, 24 Feb 2019
CIVILBLOG.org, 2016, TYPES OF CONCRETE PAVEMENT
Available from : https://civilblog.org/2016/02/18/3-basic-types-of-concrete-
pavement/ , 26 Feb 2019

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11.0 Table of Pictures
Fig 1 , Construction and maintenance of concrete pavement , 2004 , concrete pavement
construction process , Available from :
Fig 2 , CIVILBLOG.org , 2016 ,TYPES OF CONCRETE PAVEMENT
Available from : https://civilblog.org/2016/02/18/3-basic-types-of-concrete-pavement/ ,
26 Feb 2019
26 Feb 2019
26 Feb 2019
Fig 5 , Construction and maintenance of concrete pavement , 2004 , concrete pavement
construction process , Available from :
, 24 Feb 2019

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