I am a dedicated PhD student, passionate about sharing my journey and experiences.
តែសភាពធន់នឹងកម្លាំងសង្កត់របស់បេតុង geopolymer (geopolymer concrete)។
Can you guess the concrete compressive strength by just hearing the blasting sound? 30, 40, 50-60 MPa?
Fracture energy is a fundamental property that quantifies the energy absorbed by the material as a crack propagates. It plays a crucial role in the design and analysis of structures, aiding in predicting a material's behavior when subjected to stress and strain. For instance, knowing the fracture energy of a concrete mix enables engineers to design more resilient structures less susceptible to catastrophic failure.
The Wedge Splitting Test (WST) is a test method utilized to determine the fracture properties of materials, particularly concrete and similar materials. This test aims to measure the fracture energy of a material, which represents the energy required to propagate a crack through it. Understanding this parameter is crucial for assessing a material's behavior under stress and its overall toughness.
In the WST, a notched specimen is systematically split by driving a wedge into the notch. Typically, the specimen is a prismatic concrete block with a pre-cut notch where the wedge is inserted. As the wedge advances into the notch, it induces a crack that traverses through the specimen. Throughout the test, the force applied gradually to the wedge and the displacement of the crack are both monitored and recorded. Subsequently, this data is utilized to compute the fracture energy of the material.
សូមចូលរួមសោកស្តាយ និងរំលែកទុក្ខដល់គ្រួសារសពមកពីតាកែវ ដែលរងគ្រោះដោយសារការបាក់រលំអាងទឹក។មិនមែនឧប្បត្តិហេតុដូចកប៉ាល់បុកស្ពាននៅអាមេរិកទេ តែជាកំហុស។
ការងារគណនា និងសាងសង់ មិនស្រួលពេក ហើយក៏មិនពិបាកខ្លាំងរហូតដល់ថ្នាក់ដោះស្រាយមិនចេញដែរ។ម្ចាស់គម្រោង អ្នកដឹកនាំគម្រោង និងវិស្វករគណនាមិនត្រូវមើលងាយការងារកប់ក្នុងដីទេ។ការងារកប់ដីហ្នឹងពេលខ្លះគឺស្មុគស្មាញជាងអាការងារមើលឃើញនៅលើដីទៅទៀត។ពេលគណនាអាងទឹកត្រូវគិតឲ្យគ្រប់ជ្រុងជ្រោយ គិតពីនីវ៉ូទឹកក្រោមដីនៅរដូវប្រាំងនិងវស្សាដែលមានសម្ពាធលើអាងទឹក កម្លាំងដីដែលមានអំពើលើអាងទឹក កម្លាំងគ្រឿងចក្រមានសកម្មភាពជុំវិញអាងទឹកក្នុងកំឡុងពេលសាងសង់ សម្ពាធទឹកក្នុងអាង និងកម្លាអផ្សេងៗទៀត ហើយធ្វើករណីបូកឆ្លាស់រាល់កម្លាំងទាំងអស់ដែលអាចកើតឡើង ហើយមានអំពើលើអាងទឹក។
កម្លាំងដីជុំវិញអាងទឹកមានអំពើលើអាងទឹកប្រហែល៣តោនក្នុង១ម៉ែតការ៉េនៃផ្ទៃជញ្ជាំង បើអាងនេះកប់ដីជម្រៅ៣ម៉ែត ហើយបើសិនមានគ្រឿងចក្ររត់ជុំវិញទៀត អាងទឹកកានតែយ៉ាប់ហើយ។ករណីបើសង់ហើយមានទឹកពេញអាង អាចកាត់កងកមនលាំងបុកពីក្រៅអាងបានខ្លះ។
អគារ ឬសំណង់ខ្លះត្រូវការជញ្ជាំងក្រាស់ៗ មុខកាត់សសរ ឬធ្នឹមធំៗ គឺដើម្បីគិតពីសុវត្ថិភាពសំណង់ និងអ្នកសាងសង់ក្នុងកំឡុងពេលសាងសង់។
វិស្វកររៀនចប់គឺដើម្បីដោះស្រាយបញ្ហា។វិស្វករ រួមផ្សំនឹងបច្ចេកទេស ឬបច្ចេកវិទ្យាថ្មីៗ អ្វីៗអាចទៅរួច។
កុំខ្ជីខ្ជា!បំណងល្អពីអតីតវិស្វករអាងទឹកស្អាត និងទឹកស្អុយ។
Be a problem solver, not a killer!
Thanks to the advancements in high-performance concrete that play a vital role to reduce material usage and to give greater flexibility in design compared to conventional concrete. Due to the novelty of the matrix product, its application remains less explore. Today, our team investigates its interaction with post-installed anchor by conducting pull-out tests.
The pull-out test on post-installed mechanical torque-controlled expansion anchors in high-performance concrete.
1) First, we need to obtain engineering documentation and specifications from the manufacturer, indicating the material properties and specifications of the anchors. Key information includes the anchor's location, drill bit diameter, anchor embedment depth, and torque value to be applied by the wrench.
2) After tightening the anchor, we set up the pull-out test by attaching the fixture or loading frame with a hydraulic load cell and a linear variable displacement transducer (LVDT). Before applying the load, we verify the functionality of the LVDT and hydraulic systems to ensure everything is in order. After that, we begin applying the load slowly until failure occurs.
12/02/2024
Anchors installation training program offered by
Australian Engineered Fasteners and Anchors Council (AEFAC), and supported by Swinburne University of Technology.
In chemical post-installed anchors, load transfer occurs primarily through the adhesive bond between the anchor and the substrate (concrete or masonry material). The adhesive material fills the voids between the anchor and the drilled hole, creating a strong bond. Load is transferred from the anchor to the surrounding substrate through this adhesive connection.
Nevertheless, in mechanical post-installed anchors (expansion anchor, screw anchor, headed stud…), load transfer relies on the mechanical engagement of the anchor within the drilled hole. The anchor expands or creates friction with the surrounding material, securing itself in place. Load is then transferred through the mechanical interlocking or friction between the anchor and the substrate, ensuring the anchor can withstand applied forces.
Tensile performance of post-installed anchors is very sensitive to the quality assurance. For post-installed chemical/adhesive anchors, tensile performance of the anchor is significantly affected by the cleanliness and temperature of the concrete or masonry substrate. On the other hand, the tensile capacity of post-installed mechanical anchors is highly influenced by the drill hole diameter tolerance.
Note: Standards Australia, AS 5216, Design of post-installed and cast-in fastenings for use in concrete, Appendix B Clause B2 recommends the installer is competent and suitably qualified through the AEFAC Installer Certification Program and/or
a specific training program from the product supplier.
