Investigation of the influence of different surface regularization methods for cylindrical concrete specimens in axial compression tests
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2017-06-01 |
| Journal | Revista IBRACON de Estruturas e Materiais |
| Authors | Rennan Medeiros, Beatriz Anselmo Pereira, Gustavo Sipp, T. DELFINO |
| Institutions | Universidade do Sul de Santa Catarina |
| Citations | 3 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation & Analysis: Diamond Abrasive Performance in High-Strength Concrete Testing
Section titled â6CCVD Technical Documentation & Analysis: Diamond Abrasive Performance in High-Strength Concrete TestingâExecutive Summary
Section titled âExecutive SummaryâThis research paper, investigating end-face regularization methods for concrete compression specimens, validates the critical role of high-purity MPCVD diamond material in achieving reliable, standards-compliant mechanical testing results, particularly for High Strength Concrete (HSC).
- Superior Performance: The mechanical wear method using a diamond abrasive grinding wheel (established by NBR 5738) proved to be the most effective surface preparation technique.
- Key Achievement: Diamond grinding achieved the highest mean rupture stress (up to 78.30 MPa) and demonstrated the lowest dispersion (coefficient of variation) across all concrete mixes (C20 to C80).
- Precision Requirement: Successful compression testing mandates a surface irregularity limit of < 0.05 mm, a precision reliably achieved only through diamond mechanical wear systems.
- Tooling Efficacy: The efficacy of the grinding method hinges on the quality and durability of the diamond abrasive wheels, highlighting the necessity of utilizing robust, high-consistency Polycrystalline Diamond (PCD) substrates in tool manufacturing.
- Research Implication: The study confirms that inadequate surface preparationâsuch as using low-performing diamond saws or inconsistent sulfur capsâcan lead to sample rejection or erroneous strength reporting, underscoring the demand for certified diamond tooling material.
Technical Specifications
Section titled âTechnical SpecificationsâData extracted from the comparative analysis focusing on test parameters and key results.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Concrete Strength Range (Tested) | C20 to C80 | MPa | Four mixes assessed, covering Normal and High Strength Concrete groups. |
| Specimen Dimensions (Nominal) | 100 x 200 | mm | Diameter x Height of cylindrical specimens. |
| Required Surface Irregularity Limit | < 0.05 | mm | Mandated planeness and perpendicularity requirement (ASTM C617, C39). |
| Standard Grinding Wheel Specification | Diamond Abrasive | N/A | Essential media for mechanical wear method (NBR 5738). |
| Maximum $f_{cm}$ Achieved (Mix 4, 28d) | 78.30 | MPa | Highest average compressive strength achieved, resulting from diamond grinding. |
| Lowest Coefficient of Variation (Metric) | Reduced dispersion | % | Key performance metric achieved by NBR 5738 grinding method across all strengths. |
| Axial Load Application Rate | ~ 0.5 | MPa / s | Standardized continuous loading rate during compression test. |
| Curing Conditions | 23 ± 2 °C, RH > 95 | N/A | Standardized curing environment (NBR 5738). |
Key Methodologies
Section titled âKey MethodologiesâThe experimental design compared four surface preparation methods. The most successful methods relied directly on advanced diamond materials provided by specialized CVD synthesis.
- Concrete Molding: Specimens (100 mm x 200 mm) were cast across four strength mixes (C20, C40, C60, C80) and cured for 7 and 28 days.
- Surface Preparation (Standard Reference Method): Mechanical wear using a grinding machine equipped with a diamond abrasive wheel was applied to the specimen ends to correct irregularities and ensure surfaces met the < 0.05 mm planeness limit (NBR 5738).
- Surface Preparation (Alternative Mechanical Method): Specimens were prepared using a diamond saw cutting technique, utilizing a special diamond wheel to remove a thin layer and achieve a flat, smooth surface (NM 77).
- Compression Testing: Specimens were axially compressed on an EMIC PCE 150 tf machine at a continuous rate of 0.5 MPa/s, with results analyzed statistically (ANOVA) based on mean strength and coefficient of variation.
- Statistical Finding: The diamond grinding method consistently achieved superior results (higher mean strength, lower result dispersion) compared to diamond saw, neoprene pads, and sulfur capping.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe documented research underscores the critical need for highly consistent, durable diamond material in manufacturing high-precision abrasive tools for advanced material testing (HSC). 6CCVD provides the foundation for the most reliable methods identified in this study.
| Applicability Focus | 6CCVD Material/Capability | Engineering Value Proposition |
|---|---|---|
| High-Precision Abrasive Tools | Polycrystalline Diamond (PCD) Wafers | We supply the bulk PCD necessary to fabricate the segments for the high-performance diamond abrasive grinding wheels that adhere to the strict NBR 5738 standard, ensuring optimal material removal and surface geometry for concrete strengths up to 80 MPa and beyond. |
| Thickness & Durability | PCD Thicknesses from 0.1 ”m up to 500 ”m | Thicker, high-consistency PCD layers dramatically increase the lifespan and performance stability of abrasive tools, crucial for maintaining the calibrated wear limit mentioned in Section 1.2 and ensuring low test dispersion. |
| Material Preparation & Shaping | Custom Dimensions (up to 125 mm PCD) and Laser Cutting | Abrasive wheel manufacturers require specific geometries. 6CCVD offers precision laser cutting and shaping of PCD and SCD plates to create perfectly dimensioned segments for industrial diamond saws and grinding wheels. |
| Surface Finish Consistency | High-Fidelity Polishing (Ra < 5 nm on Inch-size PCD) | Our in-house polishing capabilities ensure that even large-area PCD substrates used for specialized tools maintain extremely tight surface tolerances, critical for manufacturing tools that guarantee concrete planeness < 0.05 mm. |
| Shipping & Logistics | Global Shipping (DDU default, DDP available) | Ensure rapid and reliable delivery of custom diamond tooling substrates worldwide to meet demanding industrial production schedules. |
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend the grinding and sawing applications described, 6CCVD recommends:
- Industrial Grade Polycrystalline Diamond (PCD): Ideal for abrasive tools requiring high wear resistance, maximum material removal rate, and consistent performance across large contact areas.
- Single Crystal Diamond (SCD) Substrates: For ultra-high precision tools where homogeneity and extreme hardness are required for the most durable segments.
Customization Potential
Section titled âCustomization PotentialâThe diamond abrasive tools shown in Figures 3 and 4 are specialized equipment. 6CCVD offers comprehensive services to support tool manufacturers:
- Custom Dimensions: We supply PCD wafers and plates up to 125 mm, allowing for the creation of large-diameter abrasive discs and wheel segments.
- Metalization Services: We offer custom metalization (Au, Ti, W, Cu, etc.) to enhance bonding between the diamond segment and the tool holder, improving the stability and heat dissipation of the grinding wheels used in high-intensity applications.
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team provides expert consultation on material selection. We specialize in tailoring MPCVD diamond specifications (grain size, purity, and thermal conductivity) to optimize performance for extreme industrial wear applications, particularly those involving hard materials like High Strength Concrete or other ceramic composites.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
ABSTRACT This study was conducted with the aim of evaluating the influence of different methods for end surface preparation of compressive strength test specimens. Four different methods were compared: a mechanical wear method through grinding using a diamond wheel established by NBR 5738; a mechanical wear method using a diamond saw which is established by NM 77; an unbonded system using neoprene pads in metal retainer rings established by C1231 and a bonded capping method with sulfur mortar established by NBR 5738 and by NM 77. To develop this research, 4 concrete mixes were determined with different strength levels, 2 of group 1 and 2 of group 2 strength levels established by NBR 8953. Group 1 consists of classes C20 to C50, 5 in 5MPa, also known as normal strength concrete. Group 2 is comprised of class C55, C60 to C100, 10 in 10 MPa, also known as high strength concrete. Compression tests were carried out at 7 and 28 days for the 4 surface preparation methods. The results of this study indicate that the method established by NBR 5738 is the most effective among the 4 strengths considered, once it presents lower dispersion of values obtained from the tests, measured by the coefficient of variation and, in almost all cases, it demonstrates the highest mean of rupture test. The method described by NBR 5738 achieved the expected strength level in all tests.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
Section titled âReferencesâ- 2011 - ResistĂȘncia MecĂąnica do Concreto