Dr. K.M. Soni, Superintending Engineer, CPWD, Bhopal

Black cotton soil, a cohesive soil, is considered a problematic soil for civil engineers. It has characteristics of swelling during rains and shrinking during summer. In both the conditions, it poses problems. During swelling, structure has uplift pressure and produces heave in the foundations, plinth beams, bottom of floors of buildings and canals, roads surfaces etc. and on shrinkage, cracks develop in walls, slabs, plinth protection, floors etc. Though, local construction technology has been developed traditionally in most of the places where such type of soil is found, still cracks are observed in many structures as sufficient precautions are not taken during the construction and maintenance period of the buildings.

Index Properties

Black cotton soil of India has a liquid limit between 60-90%, plastic limit between 30-50% and shrinkage limit about 8-18% as given in Table 1.

Black cotton soils having high plasticity index more than 23 described as critical and severe having free swell more than 100% are to be taken special care to avoid cracks in the structures.

In Situ Properties

Black cotton soil is very hard on drying but becomes slippery and slushy during rains. Its density varies along the depth. On the surface, density is about 1.6 g/cc and reduces to about 1.4 g/cc in dry state along the depth while on saturation, it is almost constant along the depth. When soil is dry, shear strength is quite high on the surface and it reduces marginally along the depth while during rains shear strength reduces and is very low near the surface. Thus, saturated state also has effect on its shear strength. However, properties change up to a certain depth only and then become constant.

Black cotton soil consists of montmorillonite which has swelling characteristics. On its surface and internal layers, it has an electric charge. When the particles come into contact with water, a film is formed around clay particles and the water reaching into layers uplifts the layers and produces heave into the soil. If heave is prevented, say by floorings, it produces uplift pressure. Therefore, to avoid uplift pressure, important consideration is to avoid water coming into contact with black cotton soil.

Remedial Measures to Prevent Damages

Damages to Buildings

Various types of damages can occur in the buildings due to up lift forces and settlement caused by the expansive soils such as:
  1. Diagonal and vertical cracks in smaller direction of slab.
    This is a premium article available exclusively for our subscribers.
    If you are already a subscriber, please Login
    If not, subscribe now and get access to well researched articles & reports on infrastructure construction, equipment & machinery, innovations & technology, project reports, case studies, and more. All this by simply paying just ₹200/- for a month of complete portal access, or a discounted rate of ₹1000/- for a full year of access.
Dynapac Machines Deployed on Prestigious Palkhi Marg Project in Maharashtra
The Palkhi Marg holds deep significance as a pathway of faith for devotees of Lord Vitthal. Every year, thousands of ‘warkaris’ embark on a spiritual journey to the temple town of Pandharpur in Maharashtra. With the vision to create a Bhakti Marg and ensure

Read more ...

Delhi Vadodara Expressway Package-1 An overview
The Delhi-Vadodara Expressway is a part of the most anxiously awaited Delhi-Mumbai Expressway - the foundation stone for which was laid on March 8th 2019. Also referred to as the Delhi-Mumbai Industrial Corridor, it is planned as part of the Bharatmala

Read more ...

Bonded Rigid Pavement - A New Edge Concrete Pavement
The exponential growth of the highway infrastructure in the past two decades has increased demand for long-lasting, durable pavements. Rigid pavements are suitable for heavily trafficked areas and are found to be performing satisfactorily with minimum

Read more ...

BRO Builds ‘Zero Fatality Corridors’ in Arunachal Pradesh
Through its unwavering commitment to road safety, eco-conscious practices, and visionary solutions, the Border Roads Organisation is elevating the standard of road infrastructure development in India. In Arunachal Pradesh, its contributions

Read more ...

Engineering Measures for Pothole Prevention
Roads, pavements, and other paved surfaces have depressions in them called potholes which are caused by a variety of conditions. They not only present a serious risk to traffic and pedestrians, but also necessitate expensive repairs by local governments and

Read more ...

Pavement Marking Essential For Road Safety
Vivek Singh, Founder, BuildStreet delves into the significance of pavement marking, its objective, and importance, with a focus on Hot Applied Thermoplastic paint - the predominant choice for road markings in India, its technical aspects, application methodology

Read more ...

GAEPL Achieves Record Paving of 100 lane-km in 100 hours
Ghaziabad Aligarh Expressway Private Limited (GAEPL), under the guidance of Cube Highways, has set an example of speedy, safe, and sustainable road construction through research, integration of advanced technology, following best international practices

Read more ...

Indian Companies Delivering Projects Overseas
External affairs minister S. Jaishankar during his visit interacted with the workers and the senior staff, and lauded the role of Indian infra companies, saying that he was “impressed by their enthusiasm”. “Strong economics will complement shared values in taking

Read more ...

NHAI awards 6,003 km of highway projects in FY23
According to Motilal Oswal Financial Services, the infra project awarding activity picked up and gathered pace in Q4 of FY23, with NHAI awarding total projects of 6,003 km in FY23, much below its FY23 target of 6,500 km. The total value of projects awarded

Read more ...

Is the Indian Road Sector Navigating a Smooth Journey?
This report covers the current state of the Indian Road Sector, performance of road projects under Hybrid Annuity Model, financial performance of major road developers, and the outlook for FY24. CareEdge Ratings analysed 235 HAM projects awarded between

Read more ...

Balanced Mix Design for Bituminous Mixes
As more than 90% of the roads in India have bituminous surfacing, a proper bituminous mix design also assumes significance for better performance of the bituminous roads. India is currently witnessing huge investments by the Indian Government towards

Read more ...

Sustainable Road Construction in Hilly Region
Siksha Swaroopa Kar, Principal Scientist, Amit Kumar, Technical Officer, Krishan, Technician, Flexible Pavement Division, CSIR-CRRI, New Delhi, discuss mechanized laying of cold bituminous layer, the mixer and paver that have been fabricated, and the effectiveness

Read more ...

Implementation of Road Maintenance Management System - Benefits & Technologies
The maintenance of road pavements is essential to ensure the safety, reliability, and sustainability of road networks. A road maintenance management system (RMMS) involves effective management of resources to optimize the life cycle of roads, reduce maintenance

Read more ...

Replacement of Steel Reinforcement with  Synthetic Fibre for Concrete Pavement & Floor
Manoj Didwania, Adani Total Gas Ltd, Dharamsinh Desai University (DDU-Nadiad), Cept University, presents a paper on the use of Macro Synthetic Reinforcement Fibre (MSRF) as full or partial replacement of Steel Reinforcement for Concrete Pavement

Read more ...

GTI® Reinforced Soil Slope System
GTI® is involved in developing environmentally friendly construction products and systems, which are critical for achieving infrastructure growth in a sustainable manner. The company’s GTI® Sloping Fascia Unit and the new system GTI® Reinforced Soil Slopes

Read more ...

CRISIL: Debt to rise for road developers amid strong revenue growth
Sizeable equity commitments in under-construction projects and rising working capital requirement will increase the debt burden of road developers, though revenue growth will also be high in the next two fiscals driven by strong awarding and execution

Read more ...

Indian Toll Roads to witness moderation in growth to high single digits in FY2024 after a stellar 17-20% growth in FY2023: ICRA
WPI for December 2022 is significantly lower at 5.0% against WPI of 14.27% in December 2021. ICRA Ratings expects the toll road projects growth to moderate to high single digit in FY2024 after a 17-20% growth witnessed in FY2023 with moderation in the

Read more ...

Road Over Umling-La Pass at 19,024 Feet
Construction of World’s Highest Motorable Road Chismule – Demchok In Eastern Ladakh Using Non-Frost Susceptible Sub-Base. Union Territory of Ladakh is located at approx 11,000 feet above Mean Sea Level (MSL). The area experiences extreme cold

Read more ...

BRO Uses Eco-Friendly Steel Slag For Road Construction
Steel slag, a by-product of steel making, is produced during the separation of the molten steel from impurities in steelmaking furnaces. This process generates slag as a molten liquid melt and is a complex solution of silicates and oxides that solidifies

Read more ...

Potholes to become history breakthrough by Zydex
Vadodara-based Zydex Industries has developed a new technology in road construction that enables roads to resist cracking under heavy traffic loads and cyclic weather variations. The speciality chemicals company has been at the forefront of R&D and implementation

Read more ...