Study of Bond Strength of Concrete Using Recycled Aggregates

Paratibha Aggarwal, Associate Professor, Babita Saini, Assistant Professor, Sarvesh Tripathi, M.Tech student, Deptt. of Civil Engg., N.I.T. Kurukshetra

Introduction

Concrete has been the leading building material since it was first used and is bound to maintain its significant role in the upcoming future due to its durability, maintenance free service life, adaptability to any shape and size, wide range of structural properties plus cost effectiveness. The concrete is the most important construction material which is manufactured at the site. It is the composite product obtained by mixing cement, water and an inert matrix of sand and gravel or crushed stone. It undergoes a number of operations such as transportation, placing, compaction and curing. The distinguishing property of concrete is the ability to harden under water. The ingredients can be classified into two groups namely active and inactive. The active group consists of cement and water, whereas the inactive group consists of fine and coarse aggregates. The inactive group is sometimes also called inert matrix. Concrete has high compressive strength but its tensile strength is very low. In situations where tensile stresses are developed the concrete is strengthened by using steel bars or short randomly distributed fibres forming a composite material called reinforced cement concrete (RCC) or fibre reinforced concrete. The resistance of concrete to the slipping of reinforcing bars embedded in concrete is called bond strength. The bond strength is provided by adhesion of hardened cement paste and by the friction between concrete and reinforcement. It is also affected by the shrinkage of concrete relative to steel. On an average bond strength is taken approximately as 10% of the compressive strength. The roughness of the steel surface, water, the chemical composition of cement and steel bar diameter are the factors that affect the bond strength of concrete. In pull-out tests on plain bars, the maximum load generally represents the bond strength that can be developed between the concrete and steel. With plain bars the maximum load is not very different from the load at the first visible slip, but in the case of the deformed bar, the maximum load may correspond to a large slip which may not in fact be obtained in practice before other types of failure occur. The load shall be applied to the reinforcing bar at a rate not greater than 2250 kg/mm, or at no-load speed of the testing machine head of not greater than 1.25 mm/min, depending on the type of testing machine used and the means provided for ascertaining or controlling speeds. The maximum load for each type of failure shall be recorded. The new replaces the old and same follows with the buildings. Older buildings require reconstruction for better and higher economic gains and on account of obsolescence on structural or functional grounds and also due to the damages inflicted on them by natural disasters and wars. The rate of demolition showed an upward trend which in turn increased the dumping costs due to unavailability of appropriate sites nearby. Thus efficient use of the demolished concrete would reduce the costs and definitely lead to conservation of the invaluable non-renewable sources of energy and hence must be given due importance. The demolished concrete could be used as aggregate for concrete resulting in large consumption of the material. Recycling is the act of processing the used material for use in creating new product. The usage of natural aggregate is getting more intense with the development in infrastructure area. In order to reduce the usage of natural aggregate, recycled aggregate can be used as the replacement materials. Recycled aggregate are comprised crushed, graded inorganic particles obtained from the materials that have been used in the constructions and demolition debris. These materials are generally from buildings, roads, bridges, and sometimes even from catastrophes, such as wars and earthquakes.
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.
NBM&CW October 2012

No comments yet, Be the first one to comment on this.

Advancing Concrete Durability in Coastal and Aggressive Environments

Advancing Concrete Durability in Coastal and Aggressive Environments

Professor (Dr.) S B Hegde provides a thorough examination of the challenges faced by concrete infrastructure in India’s coastal and harsh environments; the impact of salt, humidity, pollution, and extreme weather on concrete durability

Read more ...

Concrete Distress Maintenance & Repair Techniques

Concrete Distress Maintenance & Repair Techniques

Concrete structures deteriorate over time due to environmental factors, leading to issues like cracks and corrosion. Effective repair and maintenance are vital for restoring strength and durability. In this article, Sasanka Dey

Read more ...

Durability and Sustainability of Hardened Concrete

Durability and Sustainability of Hardened Concrete

Concrete is widely used in construction, yet its longevity and sustainability often go unnoticed until signs of premature deterioration appear. To truly understand how to extend its service life, it is crucial to explore the factors

Read more ...

Role of Chemical Admixtures in Enhancing Construction Durability

Role of Chemical Admixtures in Enhancing Construction Durability

“In modern construction, the integration of chemical admixtures is not just an enhancement—it's a necessity. By improving durability, performance, and sustainability, these innovations are shaping the future of infrastructure.

Read more ...

ICrete by Amazecrete: A Game-changer Concrete Additive

ICrete by Amazecrete: A Game-changer Concrete Additive

With the introduction of ICrete, we are pushing the boundaries of concrete technology with solutions that address both performance and environmental challenges. Kowshika V R, Executive Director, Amazecrete

Read more ...

Grinding Aids as Energy Saver in Cement Production

Grinding Aids as Energy Saver in Cement Production

The benefits of using different grinding aids in cement production are improved output, decreased energy consumption, cost reduction, and minimizing the carbon footprint- all of which are steps forward in bringing greater sustainability

Read more ...

Thermax Acquires BuildTech to Expand its Footprint in Construction Chemicals

Thermax Acquires BuildTech to Expand its Footprint in Construction Chemicals

The recent acquisition of BuildTech by Thermax exemplifies a significant trend within the industry towards strategic expansion and enhanced capabilities in construction technologies.

Read more ...

Icrete By Amazecrete Enhances Strength & Durability of Concrete

Icrete By Amazecrete Enhances Strength & Durability of Concrete

Icrete has emerged as a new age material for Concrete Construction given its efficacy in increasing the strength and durability of concrete, bringing value additions and greater profitability to the users.

Read more ...

Cement Industry Targets Net Zero with 25% Emissions Reduction by 2030

Cement Industry Targets Net Zero with 25% Emissions Reduction by 2030

The Cement Industry is embarking on a Net Zero pathway, aiming for a 25% reduction in CO2 emissions by 2030 and a full decarbonization by 2050, driven by technological innovations, use of alternative raw materials, and circular economy

Read more ...

Determining Plastic Hinge Length in Precast Seismic Force-Resisting Systems

Determining Plastic Hinge Length in Precast Seismic Force-Resisting Systems

Plastic hinges form at the maximum moment region of reinforced concrete columns. A reasonable estimation of the plastic hinge length is key to successfully modeling the lateral load-drift response and conducting a proper seismic

Read more ...

Properties and Applications of Geopolymer Masonry Blocks

Properties and Applications of Geopolymer Masonry Blocks

Radhakrishna, Professor and Head, Department of Civil Engineering, RV College of Engineering, Affiliated to Visvesvaraya Technological University, Bengaluru. Block masonry is one of the oldest methods of construction. It is composed

Read more ...

Advancing LC3 Cement Technology for Sustainable Construction in India

Advancing LC3 Cement Technology for Sustainable Construction in India

Dr S B Hegde provides a deep, research-driven analysis of LC3 cement, emphasizing its chemistry, process innovations, global applicability, and success stories, and evaluates its technical advantages, performance, cost savings

Read more ...

Supplementary Cementitious Materials Improving Sustainability of Concrete

Supplementary Cementitious Materials Improving Sustainability of Concrete

Concrete is the second most consumed material after water in the world and cement is the key ingredient in making concrete. When a material becomes as integral to the structure as concrete, it is important to analyze its environmental impacts.

Read more ...

Alite & Belite in Portland Cement: A Key to Sustainability & Strength

Alite & Belite in Portland Cement: A Key to Sustainability & Strength

Dr. S B Hegde guides construction industry stakeholders on balancing cement’s early strength with long-term durability and sustainability and advocates optimized cement formulations and supplementary materials for more resilient infrastructure

Read more ...

Amazecrete: Offering Sustainable Concrete Solutions like ICRETE

Amazecrete: Offering Sustainable Concrete Solutions like ICRETE

V.R. Kowshika, Executive Director, Amazecrete, discusses the economic and environmental benefits of eco-friendly and sustainable products like ICRETE and the positive impact on the construction industry.

Read more ...

Admixture-Cement Compatibility For Self-Compacting Concrete

Admixture-Cement Compatibility For Self-Compacting Concrete

An admixture is now an essential component in any modern concrete formula and plays a significant role in sustainable development of concrete technology. Dr. Supradip Das, Consultant – Admixture, Waterproofing, Repair & Retrofitting

Read more ...

Amazecrete's Icrete: New Age Material for Concrete Construction

Amazecrete's Icrete: New Age Material for Concrete Construction

By maximizing the durability and use of supplementary cementitious materials, Icrete has emerged as a new age material for Concrete Construction V. R. Kowshika Executive Director Amazecrete

Read more ...

Nanospan’s Spanocrete® Reduces Cement & Curing Time in Fly Ash Bricks

Nanospan’s Spanocrete® Reduces Cement & Curing Time in Fly Ash Bricks

Hyderabad-based Ecotec Industries is a leading manufacturer of fly ash bricks and cement concrete blocks in South India under the trademark NUBRIK. Their products are known for their consistency and quality. Ecotec was earlier owned

Read more ...

Ready-Mix Concrete: Advancing Sustainable Construction

Ready-Mix Concrete: Advancing Sustainable Construction

A coordinated approach by the government, industry stakeholders, and regulatory bodies is needed to overcome challenges, implement necessary changes, and propel the RMC sector towards further growth such that RMC continues to play a vital

Read more ...

To get latest updates on whatsapp, Save +91 93545 87773 and send us a 'Saved' message
Click Here to Subscribe to Our eNewsletter.