
not warm(moisture content).
give smooth finish(feeling).
water it should float on the surface of water for some time.


The excessive presence of silt in the sand reduces the
bonding between cement and aggregates. It increases water demand for concrete.
This reduces the strength of the concrete.
It also modifies the setting times of concrete. It can cause
cracks in hardened concrete. Hence, silt content is undesirable in the sand.
Here is a simple method to find out the silt content in sand.
The permissible limit of silt
content
The silt content should be less than 8 % by volume.
What to do if silt content is
more than the allowable limit?
The sand having silt content more than 8 %, should not be
used in concrete. However, the sand can be used after washing. It brings the
sand content below the permissible limit.
Frequency of Testing of silt
content
The silt content should be tested daily and once for each
truck at the time of unloading at sites.






The preparation of estimates represents one of the most
important functions performed in any business enterprise. In the construction
industry, the quality of performance of this function is paramount to the success
of the parties engaged in the overall management of capital expenditures for
construction projects.
The estimating process, in some form, is used as soon as the
idea for a project is conceived. Estimates are prepared and updated continually
as the project scope and definition develops and, in many cases, throughout
construction of the project or facility.
The parties engaged in delivering the project continually
ask themselves “What will it cost?” To answer this question, some type of
estimate must be developed. Obviously, the precise answer to this question cannot
be determined until the project is completed. Posing this type of question
elicits a finite answer from the estimator. This answer, or estimate,
represents only an approximation or expected value for the cost. The eventual
accuracy of this approximation depends on how closely the actual conditions and
specific details of the project match the expectations of the estimator.
Extreme care must be exercised by the estimator in the
preparation of the estimate to subjectively
weigh the potential variations in future conditions. The
estimate should convey an assessment of the
accuracy and risks.
Estimating Defined
Estimating is a complex process involving collection of
available and pertinent information relating to the scope of a project,
expected resource consumption, and future changes in resource costs. The
process involves synthesis of this information through a mental process of
visualization of the constructing process for the project. This visualization
is mentally translated into an approximation of the final cost.
Estimating at any stage of the project cycle involves
considerable effort to gather information. The estimator must collect and
review all of the detailed plans, specifications, available site data,
available resource data (labor, materials, and equipment), contract documents,
resource cost information, pertinent government regulations, and applicable
owner requirements. Information gathering is a continual process by estimators
due to the uniqueness of each project and constant changes in the industry environment.
Unlike the production from a manufacturing facility, each product of a
construction firm represents a prototype. Considerable effort in planning is
required before a cost estimate can be established. Most of the effort in
establishing the estimate revolves around determining the approximation of the
cost to produce the one-time product.
The estimator must systematically convert information into a
forecast of the component and collective costs that will be incurred in
delivering the project or facility. This synthesis of information is
accomplished by mentally building the project from the ground up. Each step of
the building process should be accounted for along with the necessary support
activities and embedded temporary work items required for completion.
The estimator must have some form of systematic approach to
ensure that all cost items have been
incorporated and that none have been duplicated. Later in
this chapter is a discussion of alternate
systematic approaches that are used.
The quality of an estimate depends on the qualifications and
abilities of the estimator. In general, an
estimator must demonstrate the following capabilities and
qualifications:
• Extensive knowledge of construction
• Knowledge of construction materials and methods
• Knowledge of construction practices and contracts
• Ability to read and write construction documents
• Ability to sketch construction details
• Ability to communicate graphically and verbally
• Strong background in business and economics
• Ability to visualize work items
• Broad background in design and code requirements

Design and Construction of Concrete Formwork
Concrete formwork serves as a mold to produce concrete
elements having a desired size and configuration. It is usually erected
for this purpose and then removed after the concrete has cured to a satisfactory
strength. In some cases, concrete forms may be left in place to become part of
the permanent structure. For satisfactory performance, formwork must be
adequately strong and stiff to carry the loads produced by the concrete,
the workers placing and finishing the concrete, and any equipment or materials
supported by the forms. For many concrete structures, the largest
single component of the cost is the formwork. To control this cost, it
is important to select and use concrete forms that are well suited for the job.
In addition to being economical, formwork must also be constructed with
sufficient quality to produce a finished concrete element that meets job
specifications for size, position, and finish. The forms must also be designed,
constructed, and used so that all safety regulations are met.
Formwork costs can exceed 50% of the total cost of the
concrete structure, and formwork cost savings should ideally begin with
the architect and engineer. They should choose the sizes and shapes of the
elements of the structure, after considering the forming requirements and
formwork costs, in addition
to the usual design requirements of appearance and strength.
Keeping constant dimensions from floor to floor, using dimensions that
match standard material sizes, and avoiding complex shapes for elements in
order to save concrete are some examples of how the architect and structural
engineer can reduce forming costs.



Foundation Engineering is an important subject in civil engineering covering soil investigation, bearing capacity, settlement, shallow foundations, deep foundations, piles, and related topics.
Below is a sample question paper suitable for civil engineering students and interview/exam preparation.
Subject: Foundation Engineering
Time: 3 Hours
Maximum Marks: 100
10 × 2 = 20 Marks
Answer all questions.
5 × 8 = 40 Marks
Answer any five.
2 × 20 = 40 Marks
Answer any two.
A square footing is proposed at a certain depth below ground level.
Given:
Using an appropriate bearing-capacity theory, determine the ultimate and allowable bearing capacity.
Clearly state the factors and assumptions used.
Explain the different components of foundation settlement.
Discuss:
Explain how excessive settlement can affect a building.
Explain the design principles and construction procedure of a pile foundation.
Discuss:
Explain the complete procedure for a foundation soil investigation.
Your answer should cover:
For students preparing for examinations or interviews, these are particularly important:
| Topic | Key Point |
|---|---|
| Foundation | Transfers structural loads to soil |
| Shallow foundation | Transfers load at relatively shallow depth |
| Deep foundation | Transfers load through deeper soil/rock |
| Bearing capacity | Soil's capacity to support foundation loads |
| Settlement | Downward movement of foundation/soil |
| Differential settlement | Unequal settlement between parts of a structure |
| SPT | In-situ soil resistance test |
| Pile | Deep foundation member |
| Pile cap | Connects pile group to the supported structure |
| Raft | Large foundation supporting several columns/walls |
Q: Why is soil investigation necessary?
A: To determine subsurface conditions and obtain information required for safe and economical foundation design.
Q: Which is better, shallow or deep foundation?
A: Neither is universally better. The appropriate foundation depends on soil conditions, loads, groundwater, settlement requirements, site constraints, and project economics.
Q: What causes differential settlement?
A: Differences in soil conditions, foundation loading, foundation dimensions, groundwater conditions, construction sequence, or variations in soil stiffness can contribute to differential settlement.
Q: What is the purpose of a pile cap?
A: A pile cap connects a group of piles and transfers structural loads from the supported member into the pile group.
Q: Why are piles used?
A: Piles may be used when near-surface soils cannot safely or economically support the required loads, or when settlement, uplift, lateral loads, or other site conditions make deep foundations appropriate.

The construction industry includes companies involved in buildings, highways, bridges, airports, railways, tunnels, energy projects, industrial facilities, and major infrastructure.
Because there is no single definition of “top,” companies can be ranked by construction revenue, international presence, project size, or specialist expertise. ENR's 2026 Top 400 Contractors, for example, ranks U.S. contractors by 2025 construction revenue.
Country: China
CSCEC is one of the world's largest construction and engineering groups. Its activities cover building construction, infrastructure, investment, design and other construction-related services.
It has been widely recognized as one of the world's largest construction companies by revenue. (ConstructionPlacements)
Country: United States
Bechtel is a major engineering, construction and project-management company involved in large infrastructure, energy, mining, manufacturing and transportation projects.
In ENR's 2026 Top 400 U.S. contractors ranking, Bechtel was ranked #2 by 2025 construction revenue.
Country: United States
Turner Construction is a major building contractor known for large commercial, healthcare, sports, education and infrastructure projects.
It ranked #1 in ENR's 2026 Top 400 Contractors based on 2025 construction revenue.
Country: France
VINCI is a major international infrastructure and construction group involved in areas such as:
Transportation infrastructure
Roads
Airports
Energy
Building construction
Concessions
Country: France
Bouygues Construction works on major building and infrastructure projects internationally.
Its activities include:
Buildings
Civil works
Infrastructure
Sustainable construction
Country: Spain
ACS is a major international construction and infrastructure group involved in:
Civil engineering
Transportation
Energy
Mining
Industrial projects
Infrastructure services
Country: India
Larsen & Toubro is one of India's best-known engineering and construction groups.
Its activities include:
Infrastructure
Buildings
Transportation
Heavy civil engineering
Energy
Water and effluent treatment
Industrial projects
L&T is frequently included among the leading construction companies in India. (MagicBricks)
Country: India
Shapoorji Pallonji is one of India's long-established construction and engineering groups.
Its work includes:
Buildings
Infrastructure
Industrial facilities
Water projects
Real estate
Country: India
Tata Projects works on major infrastructure and urban development projects.
Its areas include:
Metro systems
Roads
Buildings
Industrial infrastructure
Water projects
Power-related infrastructure
Country: South Korea
Hyundai E&C is a major Korean construction company with international experience in:
Buildings
Highways
Bridges
Tunnels
Power plants
Industrial facilities
Overseas infrastructure
For readers interested in the Gulf construction market, companies operating in the region are particularly relevant.
Country: Qatar
UCC Holding was ranked #1 in Forbes Middle East's 2026 Top 10 Construction Companies. The company operates internationally and has participated in major projects in the Middle East and other markets. (Forbes ME)
Other major construction and engineering companies active across the Gulf include companies such as:
Consolidated Contractors Company (CCC)
QD-SBG Construction
HBK Contracting
Midmac
Redco Construction – Al Mana
Larsen & Toubro
Samsung C&T
Hyundai Engineering & Construction
Some well-known companies in India's construction and infrastructure sector include:
| Company | Major Areas |
|---|---|
| Larsen & Toubro | Infrastructure, buildings, heavy civil |
| Tata Projects | Infrastructure, urban projects |
| Shapoorji Pallonji | Buildings, infrastructure |
| Afcons Infrastructure | Marine, bridges, roads, metro |
| Hindustan Construction Company | Infrastructure, tunnels, dams |
| NCC | Infrastructure and construction |
| GMR Group | Airports and infrastructure |
| Welspun Enterprises | Roads, water and infrastructure |
Several of these companies appear in current Indian construction-company lists. (MagicBricks)
Large construction companies are responsible for delivering some of the world's most complex infrastructure.
Their projects can include:
Skyscrapers
Hospitals
Hotels
Shopping malls
Residential towers
Highways
Bridges
Airports
Metro systems
Railways
Tunnels
Dams
Water-treatment plants
Drainage systems
Irrigation projects
Oil and gas facilities
Power plants
Manufacturing plants
Industrial buildings
Large construction companies employ professionals in many disciplines:
Civil Engineers
Structural Engineers
Planning Engineers
QA/QC Engineers
Quantity Surveyors
Cost Engineers
MEP Engineers
HSE Engineers
Surveyors
Project Managers
Construction Managers
For civil engineers looking for international opportunities, companies with large infrastructure portfolios can offer experience in roads, bridges, buildings, airports, metro systems, utilities and major infrastructure projects.
The world's construction industry includes thousands of contractors, engineering companies and infrastructure groups. Companies such as CSCEC, Bechtel, Turner, VINCI, Bouygues, ACS, L&T, Shapoorji Pallonji, Tata Projects and Hyundai E&C are examples of major players.
However, “top” does not necessarily mean “best.” A company's ranking may depend on the measurement used, such as revenue, geographical presence, project type or specialist capability.
For a Civil Boss article, it is better to state the ranking methodology and year rather than presenting a list as an absolute ranking. ENR's 2026 ranking, for example, is based on construction revenue.
Ready-mix concrete (RMC) is concrete that is produced in a batching or mixing plant according to a specified mix design and delivered to the construction site in a fresh condition, usually using transit mixer trucks.
Unlike concrete mixed manually or in small site mixers, ready-mix concrete is produced under controlled conditions and supplied to the project when required.
RMC is widely used for buildings, bridges, highways, foundations, slabs, columns, industrial structures, and infrastructure projects.
The typical RMC process is:
Raw Materials → Batching → Mixing → Transportation → Site Testing → Placement → Compaction → Finishing → Curing
The main ingredients are:
Cementitious materials
Fine aggregate
Coarse aggregate
Water
Admixtures, where required
The quantities are controlled according to the approved concrete mix design.
RMC can be supplied in different forms depending on how it is produced and transported.
All ingredients are mixed at a central batching plant before being transported to the site.
The ingredients are partially or fully mixed in a truck mixer during transportation, depending on the production system.
The concrete is partially mixed at the central plant and mixing is completed in the truck mixer.
The actual production method depends on the batching plant and project requirements.
RMC is produced using controlled batching and mixing procedures.
This can provide more consistent concrete quality than uncontrolled manual mixing.
Modern batching plants can accurately measure materials such as:
Cementitious materials
Aggregates
Water
Admixtures
This helps maintain the specified mix proportions.
Large quantities of concrete can be delivered continuously to the site.
This is particularly useful for:
Large slabs
Foundations
Columns
Bridges
High-rise buildings
Because concrete is produced at a batching plant, less labour is required for on-site material measuring and mixing.
RMC plants can have controlled processes for:
Material storage
Batching
Mixing
Testing
Production records
Concrete can also be sampled and tested at the project site according to the applicable specification.
RMC is especially useful when a project requires a large quantity of concrete within a relatively short period.
Examples include:
Raft foundations
Large floor slabs
Bridge decks
Piles
Large retaining structures
A project does not necessarily need to store large quantities of cement and aggregate at the construction site for every concrete pour.
This can reduce site congestion and improve material management.
Controlled production and batching can help reduce material wastage when properly managed.
RMC can improve overall construction productivity by integrating:
Batching plant + Transit mixers + Concrete pumps + Placing crew
This allows large concrete operations to be organized efficiently.
RMC must be transported from the batching plant to the construction site.
Traffic congestion, road conditions, and excessive travel time can affect delivery.
Fresh concrete has a limited usable time.
Delays can affect:
Workability
Placement
Finishing
Concrete quality
The applicable specification should define requirements for delivery and placing time.
If the batching plant experiences:
Mechanical failure
Power failure
Material shortage
Operational problems
concrete delivery may be interrupted.
Transit mixer trucks require suitable access to the project.
Small or congested sites can create logistical difficulties.
For small quantities, RMC may not always be economical because of:
Minimum order quantities
Transportation charges
Delivery charges
Pumping charges where applicable
The overall cost should be compared with the available alternatives.
If the estimated quantity is incorrect or site operations are delayed, unused concrete may become waste.
Good planning and accurate quantity estimation are therefore important.
| Feature | Ready-Mix Concrete | Site-Mixed Concrete |
|---|---|---|
| Production | Batching plant | Construction site |
| Quality control | Generally more controlled | Depends heavily on site procedures |
| Batching accuracy | Usually high | Depends on equipment and method |
| Labour requirement | Lower at site | Higher |
| Large pours | Very suitable | More difficult |
| Transportation | Required | Minimal |
| Site storage | Lower for concrete ingredients | More storage required |
| Small quantities | May be less economical | Can be convenient |
| Production consistency | Generally better | Can vary without proper control |
Before placing concrete, site personnel should verify the applicable requirements, which may include:
Check:
Concrete grade
Mix designation
Batch number
Production time
Truck identification
Quantity
Required admixtures or mix characteristics
Depending on the project specification:
Slump or other workability test
Concrete temperature
Sampling for strength specimens
Visual inspection
Confirm:
Formwork is ready
Reinforcement is correctly positioned
Concrete cover is adequate
Embedded items are installed
Construction joints are prepared
Access and placing equipment are ready
A typical operation is:
Batching Plant
↓
Transit Mixer
↓
Site Inspection
↓
Concrete Pump / Direct Discharge
↓
Placement
↓
Compaction
↓
Finishing
↓
Curing
Good coordination between the batching plant, transporters, site team, QA/QC team, and placing crew is essential.
One common site problem is adding water to a concrete truck to increase workability.
This should not be done simply at the discretion of site workers.
Any adjustment must comply with the approved mix design, project specification, and applicable procedures. Unauthorized water addition can change the water-cementitious ratio and adversely affect concrete performance.
Where permitted, workability adjustments may be made using approved procedures and materials such as specified admixtures.
RMC is widely used for:
Foundations
Columns
Beams
Slabs
Shear walls
Bridges
Highways
Tunnels
Culverts
Dams
Water-treatment facilities
Factory structures
Equipment foundations
Warehouses
Industrial floors
Before ordering concrete, confirm:
Required concrete grade
Mix design approval
Required quantity
Required workability
Maximum aggregate size
Exposure/durability requirements
Delivery location
Pumping requirements
Required testing
Concrete placement sequence
RMC = Ready-Mix Concrete.
Not automatically.
Strength depends on the mix design, materials, batching accuracy, water content, placement, compaction, curing, and quality control.
RMC generally provides better production control, but good site-mixed concrete can also achieve the required performance when properly designed and controlled.
There is no single universal time limit that applies to every project. Requirements depend on the concrete specification, admixtures, temperature, transportation conditions, and applicable standard.
Yes. RMC is commonly used for:
Isolated footings
Combined footings
Raft foundations
Pile foundations
Pile caps
provided the concrete meets the specified design and construction requirements.
Ready-mix concrete is concrete manufactured under controlled conditions at a batching plant and delivered to the construction site in a fresh condition.
Its major advantages include consistent production, accurate batching, reduced site labour, faster construction, and suitability for large concrete pours.
Its disadvantages include transportation requirements, delivery logistics, limited fresh-concrete working time, dependence on the batching plant, and potential cost disadvantages for very small quantities.
For large construction projects, RMC can significantly improve productivity, quality control, and construction efficiency when properly planned and managed.
Good RMC performance depends not only on the batching plant, but also on transportation, site testing, placement, compaction, finishing, and curing.