Related Experiment Video
Updated: Nov 24, 2025
05:26
Determination of the Mechanical Properties of Flexible Connectors for Use in Insulated Concrete Wall Panels
Published on: October 19, 2022
1.9K
Eco-UHPC as Repair Material-Bond Strength, Interfacial Transition Zone and Effects of Formwork Type
Ankit Kothari1, Magdalena Rajczakowska1, Thanyarat Buasiri1
1Building Materials, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187 Luleå, Sweden.
Materials (Basel, Switzerland)
|December 22, 2020
Summary
Eco-Ultra High Performance Concrete (Eco-UHPC) effectively repairs deteriorated concrete structures, enhancing mechanical properties and extending service life. This sustainable repair method improves structural integrity and promotes circular economy principles in civil engineering.
Area of Science:
- Civil Engineering
- Materials Science
- Sustainable Construction
Background:
- Circular economy principles in civil engineering emphasize reduced carbon footprint and extended structural service life.
- Deteriorated concrete structures require effective repair materials to maintain functionality and sustainability.
- Eco-Ultra High Performance Concrete (Eco-UHPC) offers a potential solution for concrete repair and rehabilitation.
Purpose of the Study:
- To evaluate the interfacial bond properties between deteriorated normal strength concrete (NSC) and a novel Eco-UHPC overlay.
- To assess the influence of different formwork types on the bond characteristics and microcracking behavior.
- To investigate the mechanical performance and durability enhancement provided by the Eco-UHPC repair.
Main Methods:
- Surface preparation of NSC elements using water jets to simulate degradation.
- Casting of Eco-UHPC overlays using untreated rough plywood and surface-treated shuttering plywood.
- Analysis using Ultrasonic Pulse Velocity (UPV), pull-off bond tests, Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometry (EDS).
Main Results:
- Eco-UHPC repaired elements exhibited significantly improved mechanical properties compared to reference NSC.
- Bond strength ranged from 2 to 2.7 MPa, with a narrow interfacial transition zone and minimal porosity.
- Untreated plywood limited microcracking via surface friction, while treated plywood led to more cracking, though none penetrated the overlay.
- Partial self-healing of microcracks was observed with water treatment.
Conclusions:
- Eco-UHPC is a viable and effective material for repairing deteriorated concrete structures.
- The application of Eco-UHPC can significantly extend the lifespan of concrete structures, contributing to sustainability.
- Formwork surface characteristics influence shrinkage-induced microcracking, but overall repair integrity is maintained.
Keywords:
Eco-UHPCITZNSC (normal strength concrete)SEM-EDSUPVbond test (pull-off)formworkself-healingMore Related Videos
07:15A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli
Published on: December 11, 2014
14.0K
09:06The Effect of Construction and Demolition Waste Plastic Fractions on Wood-Polymer Composite Properties
Published on: June 7, 2020
8.3K
Related Concept Videos
01:28Transition Zone
232
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...
232
01:17Mortar Properties
286
Mortar properties encompass a range of characteristics crucial for construction and masonry work, including workability, water retention, bond strength, durability, compressive strength, volume change, and appearance. Workability refers to mortar's ability to be easily applied and manipulated without sagging or falling off surfaces, which is important for efficient masonry unit placement and alignment. Water retention is essential to prevent the mortar from losing moisture too quickly to...
286
01:12Bonding and Strength of Aggregate
322
The bond between aggregate particles and the cement matrix is significantly influenced by the shape and surface texture of the aggregates. High-strength concretes benefit from a rougher texture, which leads to stronger bonding due to greater adhesion. Angular aggregates with larger surface areas also enhance this bond. The bonding quality, however, is complex to assess as no universally accepted test exists. Good bonding is indicated when a crushed concrete specimen shows some aggregate...
322
01:25Workability of Concrete
245
The workability of concrete is a crucial property that affects its handling, placing, and finishing during construction. It describes the ease with which concrete can be mixed, placed, compacted, and finished. Workability is primarily concerned with the concrete's movement and its ability to resist internal friction and external resistance from molds and reinforcements during the application process.
Concrete's workability is determined by its resistance to internal forces that arise...
Concrete's workability is determined by its resistance to internal forces that arise...
245
01:21Types of Cement I
249
Portland cement comes in several types, each with distinct properties and applications based on their chemical composition and hydration characteristics:
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
249
01:15Reinforced Brick Masonry
1.4K
Reinforced brick masonry is an advanced construction technique that enhances the structural integrity of brick walls by incorporating steel reinforcements. These reinforcements are either placed within the hollow cores of bricks or sandwiched between two layers of masonry, known as wythes, and are then secured in place with grout. Grout is a fluid mixture composed of Portland cement, aggregate, and water, providing the necessary bonding agent for the steel and brick.
To fortify brick walls...
To fortify brick walls...
1.4K