A5066320048- Fire effects on concrete materials
- Innovative concrete reinforcement materials
- Concrete Properties and Behavior
- Structural Behavior of Reinforced Concrete
- Engineering and Material Science Research
- Concrete and Cement Materials Research
- Structural Response to Dynamic Loads
- Fire dynamics and safety research
- Concrete Corrosion and Durability
- Structural Load-Bearing Analysis
- Rock Mechanics and Modeling
- Botanical Research and Chemistry
- Educational Robotics and Engineering
- Non-Invasive Vital Sign Monitoring
- Animal Genetics and Reproduction
- High-Velocity Impact and Material Behavior
- Cardiovascular Health and Disease Prevention
- Structural Health Monitoring Techniques
- Plant Toxicity and Pharmacological Properties
- melanin and skin pigmentation
- Coal Combustion and Slurry Processing
- Geotechnical Engineering and Analysis
- Mediterranean and Iberian flora and fauna
- Structural mechanics and materials
- Agriculture and Biological Studies
Gunma University
2013-2025
Kiryu University
2013-2016
Kindai University
2016
Gifu University
2011-2012
Purpose The behavior of high-performance concrete (HPC) at high temperatures is very complex and also affects the global heated HPC-based structures. Researchers have reported how various types fibers affected mechanical properties cement-based materials temperatures. This study aims to discuss effects on compressive strength elastic modulus HPC with polypropylene (PP) jute fiber. Design/methodology/approach Adding synthetic fiber (especially PP type) a widely used effective method...
This paper investigates the relationship between spalling behavior and weight loss for ultra-high-strength fiber-reinforced concrete (UFC) containing different types short fibers (jute, PP, WSPVA) in high-temperature environments at 400, 600 800 °C. The explosive that occurred under these conditions caused severe damage to control specimen but only slight with jute fiber. It was therefore inferred adding 0.19% by volume of natural (length: 12 mm) UFC is effective prevention spalling-related damage.
This paper reports on an experimental study regarding the behavior of restrained high-strength concrete in response to type extreme heating associated with fire. The was intended support estimation thermal stress from strain a restraining steel ring and vapor pressure under conditions RABT 30 rapid curve. size specimens φ300 X 100 mm, results showed that explosive spalling occurred between 4 10 minutes terms time. It also observed greater than value 0.1 MPa at point mm heated surface 5...
In this study, we examined the relationship between spalling behaviour and ratio of UFC with three kinds short fibers (jute, polypropylene, water-soluble polyvinyl alcohol) at high temperature. The heating temperatures were 400 °C 600 °C. Although specimen jute fiber dosage 0.19% by volume was occurred explosive spalling, damage slightly small. It appears that addition to is effective for preventing spalling.
This paper reports on an experimental study regarding the behavior of steel ring-restrained concrete in response to fire exposure. The was conducted enable estimation thermal stress based ring strain such under conditions a RABT 30 heating curve. specimens used were made from high-strength (Fc: 80 MPa) restrained using rings with thicknesses 0.5, 8 and 18 mm.
High-strength concrete (HSC) is widely used to construct high-rise buildings, bridges and other heavy structures in the world. However, best way reduce spalling risk of HSC when exposed high temperature, such as fire still ongoing. According researches, thermal stress vapour pressure are major factors that cause at temperatures. In addition, Japan Concrete Institute Technical Committee previously examined potential performance high-temperature conditions (ref. JCI-TC154A), proposed ring...
Urticaria is induced by the histamine released from mast cells which develops wheals (edema) as a visual feature. In clinical practice, second-generation H
Ultra-high-strength-fiber-reinforced concrete (UFC) can help in reducing the labor required for construction work and extend service life of structures owing to its high compressive strength durability. Furthermore, reinforcing fiber suppresses crack width provides bending toughness. However, explosive fire spalling tends occur when UFC is exposed temperature, load bearing capacity structure drastically deteriorates. The fundamental mechanism remains unclear, but it known that compounding...
Prestressed concrete (PC) structures have the advantage of resisting tensile stress and prevent cracking because their initial compressive stress. Thus, it contributes to large-scale structures. However, PC are more prone fire spalling compared reinforced (RC) prestressing force introduced in beams. Recent studies reported two major theories spalling: thermal theory, vapor pressure combination. reducing using synthetic fibers, such as PP fibers. On other hand, our research group investigated...
本論文では,高温環境下での高強度コンクリートの耐爆裂性評価における爆裂発生指標を提案した.すなわち,拘束リングにコンクリートを打設した供試体の一面加熱試験を実施した.この試験により,拘束条件下のコンクリートの爆裂規模を評価できた.拘束リングの円周方向ひずみの計測値から,円筒モデルよりコンクリートの拘束応力分布を推定した.その結果,加熱面からの断面深さ方向の温度分布に比例した応力分布が得られた.爆裂発生指標では,引張破壊のひずみ限界値を用いたひずみ破壊指数と爆裂破壊指数を提案した.本論文では,ひずみ破壊指数に着目した.試験で得られた爆裂進行深さの経時変化とひずみ破壊指数で評価した爆裂進行深さを比較した.その結果,爆裂開始時間と爆裂進行過程を評価可能であることがわかった.
The physical and chemical transformations that take place when concrete is exposed to high temperatures result in the deterioration of its mechanical properties.As a these changes, gradually or quickly loses strength durability.The effects high-temperature exposure manifest themselves form surface cracks, spalling disintegration, which render structures unserviceable.To identify depth at concreate change qualities, phenolphthalein solution sprayed cores taken from construction.Also, method...
本研究では仕事量一定則に着目し、膨張コンクリートによる導入応力算定の基礎的な資料を得るために、20℃、30℃、50℃の温度履歴を与え、膨張モルタルの一軸拘束試験を実施した。さらに、各材齢で熱分析・SEM観察を行い、膨張性能と水和生成物の生成状況との比較検討を行った。その結果、膨張性能に温度依存性が示唆され、高温環境下では膨張性能の低下が確認された。また、熱分析・SEM観察から20℃、30℃においては膨張の要因となるエトリンガイトの生成が確認されたが、50℃においてはエトリンガイトが減少する可能性が示唆された。これは、本研究では昇温速度が大きかったことが影響していると考えられ、温度依存性は水和生成物の生成のタイミングに影響することが示唆された。