Enhanced Bond Reinforcing Steel Bars with Surface Texturing
Bond strength between reinforcing steel and concrete directly impacts structural performance, with conventional smooth bars achieving bond strengths of 2-4 MPa, while surface-modified bars can reach 8-12 MPa. Recent field measurements show that inadequate bonding contributes to approximately 40% of early-age concrete failures, particularly in high-stress applications where load transfer between steel and concrete is critical.
The fundamental challenge lies in creating surface modifications that maximize mechanical interlock without compromising the bar's core structural properties or introducing stress concentrations that could lead to premature failure.
This page brings together solutions from recent research—including multi-scale textured surfaces, helical wound configurations with circumferential indents, and tapered geometries with specialized coatings. These and other approaches focus on practical implementation strategies that enhance bond strength while maintaining constructability and long-term durability of reinforced concrete structures.
1. Steel Fibers with Silane Coating and Silica Composite Treatment for Enhanced Fiber-Matrix Interface
UNIV WUHAN, 2024
Surface-modified steel fibers for ultra-high performance concrete that enhance bonding and mechanical properties. The fibers are modified through a silane coating process followed by a silica composite treatment, which improves fiber-matrix interface and mechanical performance. The modified fibers achieve improved flexural and compressive strength compared to conventional fibers, enabling enhanced durability and performance in high-performance concrete applications.
2. Reinforced Concrete Structure with Helical Short Fiber Bars Featuring Circumferential Indents
REFORCETECH LTD, 2023
A reinforced concrete structure comprising short fiber bars with enhanced bonding properties. The bars are made from continuous, parallel fibers embedded in a cured matrix, with an average length of 20 mm to 200 mm and an average diameter of 0.3 mm to 3 mm. Each bar features a helical wound configuration with indents extending circumferentially, providing improved bonding characteristics through controlled fiber alignment and surface texture. The bars can be used for repairing cracked concrete structures, where conventional steel reinforcement is insufficient due to cracking. The reinforced structure maintains its post-cracking strength compared to conventional reinforced concrete.
3. Steel Fibers with Orthosilicic Acid-Derived Surface Film for Enhanced Fiber-Matrix Interface in Reinforced Concrete
GANSU TRANSPORTATION PLANNING SURVEY & DESIGN INSTITUTE CO LTD, 2023
Modified steel fibers for reinforced concrete that enhance its mechanical performance by improving fiber-matrix interface properties. The fibers are modified by coating them with a surface film derived from the reaction of steel fiber surface hydroxide with orthosilicic acid in an alkaline solution. This film, which forms during the fiber oxidation process, significantly increases the fiber-matrix interface area and enhances fiber bonding strength. The modified fibers exhibit improved tensile properties compared to conventional fibers, particularly under high-stress conditions, due to their enhanced mechanical interlock with the cement matrix.
4. Concrete-Filled Steel Tube Arch Frame with Multi-Scale Textured Surface and Protruding Members for Enhanced Bonding
UNIV SHANDONG SCIENCE & TECH, 2023
Concrete-filled steel tube arch frame with enhanced structural integrity through multi-scale textured surface reinforcement. The frame features strategically positioned protruding members that integrate with the steel pipe arch and concrete, creating a multi-scale textured surface. The protruding members are specifically designed to provide enhanced bonding between the arch and concrete, while the steel pipe arch itself is reinforced with a surface roughened finish. The multi-scale textured surface configuration enables improved load transfer between the arch and concrete, significantly enhancing the structural integrity of the concrete-filled steel tube arch frame.
5. Steel Fiber for Concrete Reinforcement with Longitudinal Streaked Surface Pattern
THE REGENTS OF THE UNIVERSITY OF MICHIGAN, 2022
Concrete reinforcement comprising a steel fiber with a surface featuring a streaked pattern. The streaks are arranged in a specific pattern along the fiber's longitudinal axis, with the longitudinal axis remaining unchanged. This unique surface treatment enhances the fiber's bond with the concrete matrix while maintaining the fiber's original longitudinal orientation.
6. Concrete Column with Convex Grain Surface for Enhanced Steel Reinforcement Bonding
CHINA RAILWAY NO.4 ENGINERING GROUP CO LTD, THE FIFTH CONSTRUCTION CO LTD OF CHINA TIESIJU CIVIL ENGINEERING GROUP, 中铁四局集团第五工程有限公司, 2021
Concrete column with a unique surface grain pattern that enhances bonding between steel reinforcement and concrete. The column's surface features a convex grain structure that creates a more effective interface between the steel reinforcement and concrete, significantly improving the bond strength compared to conventional profiles. This unique surface pattern enables enhanced stress transfer between the steel and concrete, enabling improved structural performance in reinforced concrete columns.
7. Steel Fiber with Multi-Anchor Point Structure for Concrete Reinforcement
浙江博恩金属制品有限公司, ZHEJIANG BOEN METAL PRODUCTS CO LTD, 2021
A multi-anchor point steel fiber for concrete reinforcement that enhances bonding between the fiber and concrete matrix while preventing fiber pull-out. The fiber features a unique multi-anchor point structure that provides multiple points of attachment to the concrete, thereby preventing fiber displacement during curing and load application. This design enables improved anchorage and cohesiveness between the fiber and concrete, while maintaining fiber orientation and distribution for enhanced mechanical properties.
8. Steel Fiber with Dual Curved Hook Ends for Enhanced Fiber-Matrix Bonding in Concrete
UNIV SOUTHWEST PETROLEUM, 2019
A steel fiber for ultra-high performance concrete that enhances tensile strength and durability through improved fiber-matrix bonding. The steel fiber features a curved hook structure at both ends, which significantly increases the surface area of the fiber while maintaining its structural integrity. This design enables enhanced anchoring of the fiber to the concrete matrix, thereby improving the bond strength and ultimate tensile performance of the concrete. The curved hook shape also enables more efficient fiber alignment, particularly in conventional fiber-reinforced concrete applications where traditional hook shapes may lead to reduced bonding efficiency.
9. Steel Fiber with Tapered Ends and Corrosion-Resistant Coating for Reinforcement in Ultra-High Performance Concrete
Shanghai Urban Construction Design & Research Institute (Group) Co., Ltd., SHANGHAI URBAN CONSTRUCTION DESIGN AND RESEARCH INSTITUTE CO LTD, 2019
Steel fiber for ultra-high performance concrete that combines enhanced tensile strength, improved anchoring, and enhanced corrosion resistance. The steel fibers feature a unique rebar design with tapered ends, where the diameter increases by one to three times from the middle section to the ends, providing optimal reinforcement while maintaining structural integrity. The tapered design enables controlled fiber-matrix interaction during concrete deformation, while the corrosion-resistant surface treatment ensures durability. This innovative fiber design enables ultra-high performance concrete to achieve higher tensile strength while maintaining its bond with the reinforcing steel, with enhanced strain capacity and resistance to cracking.
10. Steel Fiber with Tapered Elliptical Cross-Section for Reinforced Concrete
SUBOTE NEW MATERIALS CO., LTD., Jiangsu Sobute New Materials Co., Ltd., 2018
An open-loop cavity steel fiber for reinforced concrete that enhances crack resistance and toughness through improved fiber anchorage. The fiber design features a unique cross-sectional shape with a tapered, elliptical profile that maximizes the bonding area with the concrete while maintaining a controlled fiber cross-sectional geometry. This design enables enhanced anchorage and distribution of stress across the fiber, particularly in critical bending points, thereby improving the overall crack resistance and toughness of reinforced concrete structures.
11. Steel Bar with Intermittent Longitudinal Ribs and Transverse Rib Configuration for Enhanced Concrete Bonding
China Construction Eighth Engineering Division Corporation, Ltd., China Construction Eighth Engineering Division Corp., Ltd., 2018
Discontinuous longitudinal ribbed steel bar with improved concrete bonding. The bar features intermittent longitudinal ribs and a unique longitudinal rib configuration that incorporates transverse ribs between the ribs. The transverse ribs are strategically positioned to enhance concrete adhesion while maintaining structural integrity. This design approach enables controlled reinforcement of reinforced concrete members through the use of discontinuous longitudinal ribs, reducing the risk of concrete damage during loading.
12. Ribbed Steel Bar with Staggered Transverse Ribs for Uniform Bonding Force Distribution
China Construction Eighth Engineering Division Corporation, Ltd., 中国建筑第八工程局有限公司, 2018
Ribbed steel bar with staggered transverse ribs that improves the distribution of bonding force between the steel surface and concrete. The bar features transverse ribs that are staggered at an angle between the transverse ribs, creating a more uniform distribution of the bonding force. This design addresses the conventional problem of uneven bonding force distribution between the steel surface and concrete, particularly in reinforced concrete structures where the lateral ribs are unevenly distributed.
13. H-Shaped Steel Column Connector with Transverse Grooved Web and Lateral Bar Reinforcement
江苏鑫乾冷拉型钢有限公司, JIANGSU XINQIAN COLD-DRAWN STEEL CO LTD, 2018
A connecting structure for H-shaped steel columns that combines structural integrity with improved concrete bonding. The structure comprises a web, upper wing, and lower wing, with the web connecting the upper and lower wings. The web features transverse grooves and lateral bars that pass through them. This design enables strong bonding between the steel sections and concrete through the web's interlocking geometry, while the grooves and bars provide additional support. The structure is particularly effective for high-strength concrete applications where conventional welding methods may compromise structural integrity.
14. Structural Insert Members with Textured Powder Coating and Functionalized Fillers for Concrete Bonding
VALSPAR SOURCING INC., 2017
Coated structural insert members for reinforced concrete that enhance bonding and durability through textured surface treatments. The coated members incorporate a textured powder coating composition with functionalized fillers, which provides improved adhesion to concrete while maintaining corrosion resistance. The textured surface creates a continuous interface between the rebar and concrete, preventing water penetration and promoting mechanical interlocking. The textured coating can be applied over a corrosion-resistant base layer, enabling the use of standard uncoated rebar in reinforced concrete applications where high tensile strength is not required.
15. Reinforcing Bar with Deformed Geometry and Surface Ribs for Controlled Expansion and Bonding
SHENGFA YAO, 2017
Reinforcing bar for concrete that enhances its mechanical properties through controlled expansion and surface treatment. The reinforcing bar incorporates a deformed geometry that creates a mechanical interface with the surrounding concrete, while the surface is processed with ribs to improve bonding. The bar's expansion characteristics are tailored to match the concrete's thermal expansion rate, ensuring minimal stress generation and preventing cracking. The reinforced concrete structure achieves improved durability through the protective passivation layer formed on the steel surface by the alkaline environment of the concrete.
16. Steel Bar with Intermittent Longitudinal Ribs and Variable Interval Spacing
CHINA CONSTRUCTION EIGHTH ENGINEERING DIVISION CORPORATION LTD, China Construction Eighth Engineering Division Corp., Ltd., 2017
A discontinuous longitudinal ribbed steel bar with intermittent longitudinal ribs that enhances the cohesive force between the steel and concrete. The bar features a conventional longitudinal rib configuration interrupted by intermittent longitudinal ribs, where the ribs are spaced at intervals that vary between 0.5 to 2.5 mm. This intermittent rib pattern creates a more uniform distribution of stress across the bar, particularly in areas where the concrete is most susceptible to damage. The intermittent ribs also provide a more controlled release of stress, reducing the likelihood of premature concrete cracking. The bar's unique rib pattern enables improved bond between the steel and concrete, resulting in enhanced durability and reduced maintenance requirements.
17. Reinforced Concrete Structure with Periodic Profile Featuring Unique Cross-Sectional Shape for Enhanced Rib Distribution
BEDAREV VLADIMIR VASILEVICH, BEDAREV VLADIMIR VASILYEVICH, 2016
A reinforced concrete structure with improved anchoring performance through a novel periodic profile design. The profile features a unique cross-sectional shape that optimizes the distribution of transverse reinforcement ribs while maintaining adequate support for the concrete. The profile's geometry ensures that the longitudinal ribs maintain their structural integrity even when the concrete reaches its ultimate strength, while the transverse ribs maintain their mechanical properties throughout the concrete's working stages. This design addresses the conventional limitations of periodic profiles by balancing the reinforcement's distribution across the concrete's cross-sections.
18. Reinforcing Bars with Dual Tapered Sections for Enhanced Thread Engagement and Adhesion
MAGNETUDE, 2016
High-adhesion reinforcing bars for concrete reinforcement that utilize a unique tapered design. The bars feature a core with a tapered section that extends beyond the conventional bar end, followed by a second tapered section that engages with the bar's base section. This tapered design enables optimal thread engagement in concrete while maintaining the high adhesion properties of conventional reinforcing bars. The tapered sections are designed to ensure proper seating of the threads on the concrete, preventing upsetting during installation.
19. Concrete Matrix with Multi-Anchor Bellows-Type Steel Fibers and Perpendicular Groove Pattern
China Nuclear Concrete Co., Ltd., China Nuclear Construction Concrete Co., Ltd., 2016
High-performance concrete with improved fiber reinforcement through optimized fiber arrangement. The invention comprises a multi-anchor concrete with strategically engineered steel fibers that incorporate a bellows type flexible steel fiber with uniform groove marks on both upper and lower surfaces. The engineered fibers have engraved groove marks that create a specific fiber orientation pattern, with each notch groove perpendicular to the direction of the groove at the notch. This unique fiber arrangement enables controlled fiber dispersion and distribution within the concrete matrix, while maintaining optimal fiber orientation for enhanced mechanical anchorage and toughening.
20. Reinforcement for Concrete Structures with Angled Node Cross-Section and Uniform Cross-Sectional Area
FOUNDATION SOONGSIL UNIV INDUSTRY COOPERATION, 2016
Adhesion-enhanced release reinforcement for concrete structures that significantly improves bond strength throughout the length of the reinforcement. The reinforcement features a unique cross-sectional design with strategically angled nodes that distribute stress evenly across the reinforcement. The nodes are formed by ribs that divide the cross-section into upper and lower sections, with each section having a uniform cross-sectional area. This design ensures consistent bond strength across the reinforcement, particularly in areas where conventional reinforcement joints are prone to stress concentration. The nodes also feature a controlled angle of 15 degrees between the reinforcement shaft and the node, which helps to distribute stresses more evenly. The reinforcement maintains a constant cross-sectional area throughout its length, ensuring consistent bond strength across the entire length of the reinforcement.
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