civil techniques

Railway Rail Tracks

abbu riyaz 1 May, 2023

Railway Rail Tracks are the main important components in tracks. Rails are unsymmetrical I-sections. It composes of steel. Rails lay parallelly over sleepers. Railway Rail Track lies parallel to the entire track. Rails carry the wheel load of trains providing them a smooth way. And transfer the load safely to sleepers.

These rails are of high carbon steel to resist and withstand wear and tear. Rails joints together longitudinally with welding and with fishplates.

Functions of Railway Rail Tracks

Rails in the Railway Track serves the following purposes:

Rails transfer loads from wheels safely to sleepers and ballasts.
Provides a smooth level surface for movement of trains.
Provides an unchanging surface for passage of heavy moving loads with minimum friction between steel rail and wheels.

It guides the wheel of trains throughout the trackway.
High carbon steel has high strength, stiffness, and durability.
The web of rail is strong enough and support head of rails.
Rails acts as girders and bear stress develop by heavy vertical/lateral loads, breaking force and thermal stress.

Length of Railway Rail Tracks

Longer rails are highly economic. And it gives a high strength. Joints are weak points in Railway Rail Tracks. So long rails consider mainly than short rails. Short rails consume more rail joints. This decrease the efficiency of rails. These rails joints with welding and by fish plates.

In the modern railways with the technological advancement, keeping gaps between rails avoids. The welding of rails introduces. These rails welds into three rails, five rails and ten rails. Welding of jointing rails is by melting them together. These welding rails has many advantages. It is economical, low maintenance, increase stability, reduce creeps. Creeps are longitudinal movement of rail tracks. It is common to all railway rail tracks. It measures regularly in rail tracks. A creep of up to 150 mm permits in rail tracks.

Construction materials

Railway Track Components

abbu riyaz 1 May, 2023

There are some important Railway Track Components in the construction of railway track. The railway track is a permanent way for all trains. A railway track is a combination of rails, sleepers, ballast, and subgrades. The systematic rails fit on a number of sleepers. This sleeper rests on ballast supports by subgrades. These rails fix or welds together by a component name as fishplates.

The trach consists of two parallel rails fix at a specific distance. This distance depends upon the gauge of tracks. These rails are parallel to each other.

Railway Track Components

A Railway Track has many Components in it. they are as follows,

Rails
Sleepers
Ballast
Formations or subgrades

A good quality and strong aggregate materials, steel I section to use in the construction of railway tracks.

1. Rails

Rails are the first main element in the Railway Track Components. It is of an I section make with steel. Two rails fix opposite to each other. These rails are vertical I section elements places vertically throughout the track. It lies parallel to the entire track. It carries the wheel load of trains providing them a smooth way. And transfer the load safely to sleepers.

2. Sleepers

Sleepers are concrete beds in the railway tracks. It is the second main important thing in Railway Track Components. Sleepers are of concrete, timbers, steel, cast iron, RCC, and prestress concrete. These sleepers fix vertical to each other. It fixes throughout the track. The main work of sleepers is to hold rails in a strong position. It receives the loads from rails and spread to ballast and subgrades.

3. Ballast

Ballasts are stone, aggregates, and gravels. these places below and around the sleepers. The main work of ballast is to hold sleepers and rails. And provides them a strong grip. Stone ballasts widely use in railway tracks in modern railways.

4. Formations or subgrades

These are natural soils on the bottom of a track. These are the foundations of tracks. It holds rails, sleepers, ballast and the entire track together. It supports the railway track from the bottom layer.

civil techniques

Rail transport

abbu riyaz 1 May, 2023

Rail transport is a major means of passenger transport, mainly for large and quick travel between cities. And for transport in industrial areas. It uses little for goods movement. Railways are the most important means of passenger transportation.

The Rail transport network is highly useful and running punctually.

Railways is a useful transportation system for a country that does not have fossil fuels. And is completely dependent on imports.

It is the backbone of transport between the city forms around the railway lines extends out from industrial areas.

Features of Rail transport

Gauge
Electrification
Loading gauge
Ticket charges

Rail transport is an important mode of long-distance transportation. It has important features, they are as follows

1. Gauge

It is the space between the rails on a railway track.

2. Electrification

Electric engines benefit from the high efficiency of electric motors. Electric engines are easier on the track, reducing track maintenance. This electrification is perfect for railways that cover long distances. And carrying a heavy traffic.

Electric power from a generating station transfer to substations using a three-phase distribution system.

3. Loading gauge

It defines as the maximum height and width for railway vehicles. And to ensure their loads safely pass through bridges, tunnels, and other structures.

4. Tickets Charges

Railways are the most important means of passenger transportation. The superfast trains charges on all passengers, irrespective of distance, separately for each journey.

The Stations

Railway stations classified into many types. These stations handle large numbers of passengers, pieces of baggage, goods and loads every day.

Bridges

The rail network makes large use of bridges and tunnels. In modern times, advances in bridge-building and tunneling technique has makes the railroad builders to reduce the track length. This increase train speeds on rail lines through hilly areas and mountains.

High-speed rail

The High-speed rail lines construct on high-level tracks to reduce the need to occupy the land. And involve very long bridges.

High-speed rail in refers to train service (passenger only) with average train speeds above 200 km/h.

High-speed service trainsets are introducing. These trains run on main lines as well as a passenger-dedicated high-speed track that allows a speed of up to 350 kilometers per hour.

In the introduction of high-speed rail, the travel speed of trains raises on the mainlines. The top speed for passenger trains reaches 200 kilometers per hour on main lines.

Rail is one of the main modes of transport. Railways deliver more trips and create a more passengers distribution and high income. The sharp increase in the number of train trip makes the fast growth of high-speed rail service in a country.

Roadways

Road Classifications

abbu riyaz 6 Apr, 2018

Road Classifications base on location and function and has many categories. Road transportation is the main thing in modern times worldwide. Roads make the main income for economic development and growth. They are very important to make a nation grow and develop.

It provides access to employment, social, health and education. For this reasons, the road is the most important of all public assets. Roads help in the transportation of each and everything. These roads are of many categories base on needs.

Road Classifications

Road classifications are of two main categories. They are,

Rural
Urban

Rural

Rural roads in the country classified into six major categories. They are,

Expressways
National Highways
State Highways
Major District Roads
Other District Roads
Village Roads

1. Expressways

Expressways are divided highways use for heavy traffic at high speed with full control. It connects major places of traffic. Slow moving traffic, walker, Resting along the roadsides, loading, and unloading activities are not allowed in Expressways.

The design speed of Expressways is 120 km/hr. Expressways are of four-lane and six-lanes.

2. National Highways

The National Highways runs through length and breadth of the country. National Highways represents as NH. It connects capital of large states, like, Major ports, large-scale industries, factories and tourism centers. They provide continuous road connection throughout the country. And connect the whole road network.

3. State Highways

It connects the national highways to states. It connects the important places within the state. State highways connect towns, important cities within the state. State Highways represent as SH.

4. Major District Roads

It connects major district within states. And provides a link between national highways and state highways. It connects important areas of production and the consumption, railways, and harbors.

5. Other District Roads

They provide a link between village roads and other district roads. It connects rural areas with market centers.

6. Village Roads

It connects a group of villages within districts.

Urban

It connects urban areas. They perform three main functions like mobility, accessibility, and parking. Urban road classifies base on location and function. Some of the main classifications are as follows,

Arterial
Sub-Arterial
Collector Streets
Local Streets

1. Arterial

It is mainly for the purpose of traffic distribution. It distributes traffic throughout areas. And minimize overcrowding. The maximum limit of these roads is 80km/hr.

2. Sub-Arterial

It also serves the purpose of traffic sharing. It shares traffic throughout areas with a lower level of Arterial. The maximum speed limit of these roads is of 60 km/hr.

3. Collector Streets

It collects and shares traffic from local areas to streets. It provides access to arterial roads. The maximum speed limit of these roads is of 50 km/hr. Roadside Parking and loading and unloadings allow here.

4. Local Streets

It provides entrance to living areas and local streets. They do not carry a large amount of traffic. It connects living areas to market areas.

civil techniques

Concrete Proportioning and Properties

abbu riyaz 1 May, 2023

Concrete Proportioning and Properties are the two main fundamental things a civil engineer has to know about the construction. Concrete possess certain Proportioning and Properties. These Concrete Proportioning and Properties are as follows

Concrete Proportioning and Properties

Proportioning

The concrete in the construction field using for construction has many classifications. There are different grades of concrete in construction. These grades design according to the strength of concrete. It bases on the calculation of time period the concrete attains full strength. The grades of concrete are

M5, M7.5, M10, M15, M20, M25, M30, M35, M40.

The letter M denotes the mix. And the number indicates the compressive strength of concrete gain at 28 days in N/mm². M5 and M7.5 concrete grade of concrete use only for a simple foundation for masonry purposes. The grade of concrete below M15 not to use for Reinforce Cement Concrete. M20, M25, and M30 are the most common grade of concrete using in the modern construction field.

Some of the nominal mixes and mixing proportions are as follows

M5 Grade of concrete – 1:5:10
M7.5 Grade of concrete – 1:4:8
M10 Grade of concrete – 1:3:6
M15 Grade of concrete – 1:2:4
M20 Grade of concrete – 1:1½:3
M25 Grade of concrete – 1:1:2
M30 Grade of concrete – 1:1:3

Properties of Concrete

Some of the main and unique properties of concrete are its workability and water-cement ratios.

1. Workability

The ability of fresh mix concrete to fill the mold with proper vibration and poring method is workability. Workability depends on the water content, aggregate, binding materials, chemicals in concrete. Increasing water content and chemicals increase the strength and workability of concrete. Excessive water and chemicals lead to bleeding of the concrete/segregation. This leads to forming honeycomb in concrete structures. A good slump value to maintain in concreting for high strength.

2. Water-cement ratio

It is the weight of the mixing water divided by the weight of the cement. High-quality concrete produces by lowering the water-cement ratio without losing the workability of fresh concrete. And allowing it to properly place and cure.

A properly design mixture possesses desire workability for the fresh concrete and the long-life and strength of the concrete.

General properties of concrete

Some of the general properties of concrete are,

It possesses a high compressive strength and strength depends on the mix.

It hardens with age.

Free from corrosion and withstand chemical attacks

Bind strongly with steel as it is weak in tension

civil techniques

Bitumen Road Construction Steps

abbu riyaz 1 May, 2023

Bitumen Road Construction Steps involve many processes. It has important properties and advantages.The Bitumen Road Construction use in the construction of roads worldwide. Bitumen uses in construction for its unique properties. For the construction of a flexible road, smooth ride and comfort, bitumens use in the construction of the road.

Bitumen Road Construction Steps

The Bituminous road construction steps are as follows

Surface Preparation
Application of Coats
placing
Rolling
Quality control
Finishing

1. Surface Preparation

Preparation is the first step in the Bitumen Road Construction Steps. It is the cleaning of surfaces from hard rocks, stones holes, dust, and other materials. The uneven surface to fill with 12 mm to 40 mm aggregates. If the uneven surfaces are large coarse aggregates uses for filling. These fillings to make before the laying of the surface course.

2. Application of Coats

The second major step involves in Bitumen Road Construction steps is the application of coatings. A bituminous base course and a binder course to apply on ready surface. This coats name as tuck coat. This coating sprays or spreads manually or by machinery. These coatings spread to certain square meters according to the size of roads and pavements. It applies in 6 kg to 7.5 kg per 10 square meters.

3. Placing

The placing of bitumen and aggregates are the next step after application of coatings. The bitumen heats and transports from plant to the site with the help of trucks.

These mix with the aggregates and places with the help of modern machinery. Mixing and placing to take great care to provide a good pavement. A control climatic conditions to maintain according to mix. This increase the lifetime of roads.

4. Rolling

Rolling operations carries to provide a good compaction. This fills the air pores and loose soil in the surface course. These rollings make by mechanical rollers. The capacity of rollers to be 10 to 12 tonnes.

A pneumatic roller of 15 to 30 tones having a tire pressure of 7kg per sq.cm use for roads. The wheels of the roller to keep wet with water at rolling. The number of rolling depends on the thickness of the layer.

5. Quality control

Quality control is the main thing in Bitumen Road Construction step. This includes checking of bitumen and the aggregates. some of the small quantity collects at site and test is made to provide a good quality of roads. And this quality test to take a particular, distance of road construction. A good quality road provides a long life. And prevents accidents on roads due to damages.

6. Finishing

Finishing includes a proper finish of construction. It includes alignment, clearing undulations, etc. This finishing make with machines and by manually. With machines, it carries with pavers. It is most use nowadays in the construction of the roads.