Urban Structures: Composition & Construction of Infrastructure

The world is undergoing unprecedented urbanization, which is expected to accelerate further, with India leading the growth map. India is the world's fastest-growing economy, thanks to rapid urbanization along with other factors like demographic trends, policy reforms, and prudent macroeconomic dynamics.

Composition of a structure

Foundation

The main purpose of the foundation is to transfer the load from the columns and beams above to the firm ground.

Slabs

A slab is a structural element that is used to produce flat and functional surfaces like floors, ceilings, and roofs. It's a horizontal structural component with parallel or nearly parallel top and bottom surfaces. Slabs are commonly supported by beams, concrete or steel columns, walls, or the ground. In comparison to its span, the depth of a concrete slab floor is quite tiny.

Beams

Vertical loads, shear stresses, and bending moments are all absorbed by the beam, which is a horizontal structural element. The loads that are delivered to the beam cause reaction forces at the beam's support points. All of the forces operating on the beam combine to produce shear forces and bending moments within the beam, which result in internal stresses, strains, and deflections.

Columns

A column is a vertical structure that carries compression stresses. The column is seen to be the most important structural part of a building because the building's safety is dependent on its strength. This is because the failure of a column would result in a building's progressive collapse, whereas this would not happen if other parts failed. Vertical loads are transferred from a ceiling, floor, or roof slab, or from a beam, to a floor or foundation via columns. They also have bending moments in one or both cross-section axes.

Footings

They are designed to transfer the loads to the soil while staying within the earth's safe bearing capacity. As a result, keep the structure's settlement to a bare minimum, reduce differential settlement, and avoid sliding and overturning.

Girder

A girder is a beam that supports other smaller beams and serves as the structure's main horizontal support. Unlike beams, girders are meant to sustain large, concentrated loads like columns or beam responses, and their load-bearing capability is substantially higher. It can be constructed from a variety of materials, including concrete, stainless steel, or a mix of the two. It can be made up of a single piece or multiple pieces tied together to support vertical weights.

Materials used to build structures

Any substance that can be utilized in construction is referred to as a building material. Materials like steel, wood, concrete, stone, etc. are widely used for construction purposes. Let us understand each with their attributes.

1. Steel

Steel is a metal alloy made up of iron and carbon, with additional alloying ingredients added to make it stronger and more fracture-resistant than iron. The extra chromium in its composition makes stainless steel resistant to corrosion and oxidation.

Steel has high strength-to-weight and strength-to-size ratios which makes it a durable option for structures and buildings.
Steel is costlier when compared to other metals.
Installing steel takes less time than concrete.

2. Concrete

Concrete is a mixture of fine aggregates (such as gravel, crushed stone, recycled concrete, and geosynthetic aggregates) held together by a liquid binder like cement that solidifies over time.

Concrete is poured into a mould to take almost any shape and harden into a stone-like material.
It's an excellent material for a house foundation because of its adaptability, low cost, and strength.
Engineers frequently plan for increased tensile strength in concrete.

3. Wood

Wood is one of the oldest building materials and has qualities that make it a suitable building material, even in the days of designed and synthetic materials.

It's a cheap and readily available natural resource.
Wood is a lightweight material that is easy to size.
It provides excellent insulation.
Wood has a high tensile strength, which means it can bend without losing its strength.

4. Stone

Stone has been used in structures for ages and is the most durable material used in construction. In fact, the stone is used in the construction of the world's oldest structures.

Stone can be difficult to work with because of its density, which makes it heavy and difficult to move.
Stone is an ineffective insulator.
Various stone varieties are excellent for various applications. Slate, for example, is fire-resistant.

5. Brick/Masonry

Individual pieces (such as bricks) are used in masonry construction to create structures that are usually held together by mortar. Concrete blocks, which can be reinforced with steel, are today the strongest and most extensively used masonry unit.

Masonry is a long-lasting and fire-resistant material.
Because this style of construction can withstand compression stresses, it's an excellent choice for load-bearing walls.
Masonry can support multi-story buildings when reinforced with concrete or in combination with reinforced concrete.

Types of load on structures

A force, distortion, or acceleration applied to structural parts is referred to as a structural load. A structure in any load induces stress and displacement. The engineering subject of structural analysis examines the effects of loads on structures and structural elements.

Different forms of loads can produce structural stress, displacement, and deformation, which can lead to structural issues and even failure. The total load operating on a structure is a critical and difficult calculation to make.

Different types of loads

The loads in buildings structures are classified into vertical loads, horizontal loads and longitudinal loads.

Verticle loads

Let's take a look at vertical loads first. The forces that are delivered perpendicular to the roof or floor system are known as vertical loads or gravity loads.

They are separated into dead loads and live loads.

The weight of the structural parts that make up the structure, as well as all of the finishes that make it appear good and pretty, make up the dead load! These are referred to as "dead loads" since they never change.

Live loads are the loads imposed on a building by the people who use it and what they select to put in it (furniture, storage, etc.).

Horizontal loads

The horizontal loads include wind and earthquake loads.

Wind loads can be applied to a building's surface, but they can also be applied away from the building, resulting in a suction force. Positive and negative pressures are the terms used to describe these forces. The higher the wind loads are applied to a structure, the greater the wind loads become.

The inertia force created in the building as a result of seismic excitations causes earthquake load. The inertia force varies with the mass. Because the structure has a bigger mass, the earthquake loading will be higher as well.

Longitudinal loads

The frictional force or braking effort is often attributed to the longitudinal loads from trains on bridges. Bridges may be subjected to greater longitudinal loads than in the past due to the present use of high adhesion locomotives and the development of stronger braking systems.

Process of building structures

The construction process encompasses not only how something is built, but also all of the processes that lead up to it.

The construction process includes far more than the actual construction period, from site selection through final inspection (and all the hundreds of meetings with workers and stakeholders in between).

Let us dig deeper into all the construction processes:

Conception

The planning and development stage, often known as project conceptualization, is the first step in the construction process. Conception is the stage of the creative process when ideas are at their most flexible, yet it also serves as the basis for the building process.

Design

The design phase is when the client's unrealistic (or, at the very least, prohibitively costly) ideas collide with what is actually possible. Plans or a design are drawn up when you've managed to be practical without crushing your client's aspirations and dreams. Following the creation of a preliminary design, you must overcome additional limits and regulations in order to accommodate the client's "extra" ideas.

Pre-construction

The next is the pre-construction phase.Here, the clients receive a bid from a contractor or construction business and are instructed to begin work on the project. The general contractor now begins the process of bringing the team together.

Procurement

The next step in the construction process is procurement, which is the simplest. Procurement is essentially the process of purchasing (or renting) all of the items required for a construction project, such as labour, equipment, and building supplies. This is when scheduling can get extremely tangled up. You have a lot of different delivery dates and vendors to manage in order to get the appropriate products into the hands of the right people at the right time.

Construction

It's time to get into the actual construction phase where labours start digging, pouring concrete, bending rebar, and firing up the welder. The project has now made the transition from paper to the tangible world. We strongly encourage our clients to employ digital process management technologies during the construction phase.

Post-construction

The construction is now completed. Now comes the most important phase, which is examining the construction. Before the client moves in, the final checklist, known as a project punch list, must be signed off on. The final walkthrough inspection ensures that everything was completed properly. The architect then issues a substantial completion certificate. Following that, government personnel dress up for the final government inspection. Only when it has been completed can you fully hand over the project to the client!

Most commonly used Indian Codes

The Bureau of Indian Standards (BIS) is the main agency in charge of establishing engineering design, material specifications, and working processes. It has published the IS codes for civil engineering projects with the combined permission of the civil engineering council. While working on the construction project, we must adhere to the IS rules.

A list of 15 must-have IS Codes for construction professionals, civil engineers, and students is provided below.

Sr. No.	IS Code	Purpose
1	IS 4082	Specifications for storage of construction materials
2	IS 456	Plain and reinforced concrete practice code
3	IS 8112	Specifications for 43 grade OPC
4	IS 9103	Specifications for Concrete Admixtures
5	IS 383	Specifications for fine & Coarse aggregate for concrete
6	IS 1786	Reinforcement Steel - HYSD Rebars =(Physical & Chemical Properties)
7	IS 2502	Code for bending and fixing of bar reinforcement
8	IS 13920	Reinforced concrete structures subjected to seismic forces benefit from ductile detailing.
9	IS 2212	Code of Practice of Masonry work
10	IS 1077	Specification of Common Burnt Clay Building Brick
11	IS 2402	External Plaster Works OR Rendering Works
12	IS 516	Methods of test for the strength of concrete
13	IS 808	Dimensions & Weight for Hot Rolled Steel Beam, Column, Channel and angle
14	IS 2720-28	Determination of in-place dry density of soils via sand replacement
15	IS 13415	Safety protective barriers around the construction site

Source: https://civilguruji.com/blog/important-is-codes-for-site-engineers

Challenges in the Construction industry

The construction industry stands second in the Indian economic and industrial sectors. Yet, many challenges loom over the construction industry in India. Let's take a look at some of the most pressing challenges confronting India's construction sector.

An increase in the cost of materials

The price of raw materials is increasing. The main cause is a shortage of materials in the sector as a result of a disrupted supply chain. In addition, both the federal and state governments are implementing reforms to help stabilize the economy. An additional tax levy is being implemented, driving up the cost of basic commodities.

Skilled Manpower

The availability of trained labour at various stages of construction might be a source of concern. In addition, the lack of training provided to construction employees has hampered the timeline and quality of the project. To improve the workers' abilities and knowledge, they must pay close attention.

Safety Of The Employees

Globally, safety and security are becoming increasingly important. With viruses like Corona and potential variations, proper safety precautions must be taken inside the facility. Deploying a large number of personnel or construction workers may result in unprecedented illness outbreaks, causing delays in project completion. On the other hand, a smaller workforce has a significant impact on deadlines and timeframes.

Sustainability of the environment

The protection of the surrounding environment is a requirement of any construction project. Maintaining soil erosion and degradation in India is difficult. Floods, droughts, soil alkalinity, aridity, and salinity are the main causes. The condition of the soil in large cities has deteriorated, posing a threat to the ecosystem. Builders and real estate owners are being pushed to use new techniques and increase their investments in order to reduce the harmful impact on the environment.

Multiple Clearances Are Required

Any building project needs many permissions from various specified authorities. Clearances are required in a variety of fields, including electricity, pollution control, environmental preservation, land, services, and use, among others. Even if the project is completed on schedule, this slows down the delivery process.

The aforementioned issues have hampered India's building industry's growth. The urgent requirement is to address the difficulties by implementing modernization and expanding the labour force.

How is Cemtech playing a vital role in creating a sustainable future for India?

Cemtech Infra Solution Pvt. Ltd. (CISPL) is a construction company that combines cutting-edge technology with decades of technical expertise. Cemtech is proud to be a part of numerous projects across India, providing quality and satisfaction, thanks to our team with more than 46 years of expertise in the construction field.

Segmental construction, prestress precast I & box girders, steel composite girders, and balanced cantilever structures are among our specialties.