| 1. |
T. Kawakami, Y. Sagawa, Y. Kawabata, and K. Yamada, Experimental investigation of expansion and damage due to alkali-silica reaction at low temperature, Proc. of the 16th International Congress on the Chemistry of Cement 2023, V ol.III, 2023.09. |
| 2. |
Dasar Amry, Patah Dahlia, Hamada Hidenori, Yamamoto Daisuke, Sagawa Yasutaka, Life performance of 40-year-old RC beams with different concrete covers and bar diameters in natural corrosion environments, Structures, 10.1016/j.istruc.2022.11.033, 46, 2031-2046, 2022.12. |
| 3. |
Kawabata, Yuichiro; Yamada, Kazuo; Kawakami, Takashi; Sagawa, Yasutaka, Environmental impacts on expansion of concrete due to alkali-silica reaction, MAGAZINE OF CONCRETE RESEARCH, 10.1680/jmacr.22.00158, 2023.07. |
| 4. |
Onoue, Kozo; Sagawa, Yasutaka; Atarashi, Daiki; Takayama, Yuji, Optimization of mix proportions and manufacturing conditions of fly ash-based geopolymer mortar by parameters design with dynamic characteristics, CEMENT & CONCRETE COMPOSITES, 10.1016/j.cemconcomp.2022.104645, 133, 2022.10. |
| 5. |
Shigetada Hatakeyama, Yasutaka Sagawa, Hidenori Hamada, Shinichi Hino, Mamoru Masaki, Yuji Sato, Development of Improved Loop Joint Applied for Precast PC Deck Slab, Journal of Advanced Concrete Technology, https://doi.org/10.3151/jact.19.644, 19, 6, 644-654, 2021.06. |
| 6. |
K. Yamada, T. Yamamoto, Y. Kawabata, Y. Sagawa, N. Ueda, Y. Kubo & S. Ogawa, Performance based design and maintenance strategy with controlling ASR, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations (Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan), https://doi.org/10.1201/9780429279119-352, 2579-2587, 2021.03. |
| 7. |
Y. Kawabata, K. Yamada, S. Ogawa & Y. Sagawa, Mechanisms of internal swelling reactions: Recent advances and future research needs, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations (Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan), https://doi.org/10.1201/9780429279119-355, 2599-2607, 2021.03. |
| 8. |
K. Yamada, Y. Kawabata, S. Ogawa & Y. Sagawa, A method keeping total alkali content and maximizing water supply for concrete prism test of potential expansion by ASR, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations (Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan), https://doi.org/10.1201/9780429279119-356, 2608-2612, 2021.03. |
| 9. |
T. Kawakami, Y. Sagawa, Y. Kawabata, K. Yamada & S. Ogawa, A study on ASR expansion behavior of concrete exposed to natural environment for 5 years: Experimental and numerical approaches, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations (Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan), https://doi.org/10.1201/9780429279119-360, 2637-2643, 2021.03. |
| 10. |
D. Yamamoto, H. Hamada & Y. Sagawa, An experimental discussion on bond strength reduction of ASR damaged concrete, Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations (Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan), https://doi.org/10.1201/9780429279119-361, 2644-2650, 2021.03. |
| 11. |
Dasar, A., Patah, D., Hamada, H., Sagawa, Y., Yamamoto, D., Applicability of seawater as a mixing and curing agent in 4-year-old, Construction and Building Materials, 10.1016/j.conbuildmat.2020.119692, 259, Article number 119692, 2020.10. |
| 12. |
T. KAWAKAMI, Y. KAWABATA, K. YAMADA, Y. SAGAWA, THE CONCEPT OF AN ASR MODEL ABLE TO DESCRIBE VARIOUS COMPLEX PESSIMUM EFFECTS, Proceedings of the ConMat’20, 2020.08. |
| 13. |
YEN THENG LOKE, HIDENORI HAMADA, YASUTAKA SAGAWA, DAISUKE YAMAMOTO, HIROTAKA HAZEHARA, TADAAKI NOZAWA, YUKI KOBAYASHI, COMPARATIVE STUDY ON DURABILITY OF REINFORCED CONCRETE MEMBER MADE WITH 150 MPA HIGH STRENGTH MORTAR WITH CRACKS UNDER CHLORIDE ENVIRONMENT, Proceedings of the ConMat’20, 2020.08. |
| 14. |
DAISUKE YAMAMOTO, HIDENORI HAMADA, YASUTAKA SAGAWA, MASAHIRO HARUGUCHI, HIROYUKI YAMADA, AN INVESTIGATION OF LONG-TERM RESISTANCE TO CHLORIDE PENETRATION AND STEEL CORROSION ON EXISTING CONCRETE STRUCTURE WITH SCMS, Proceedings of the ConMat’20, 2020.08. |
| 15. |
S. HATAKEYAMA, S. HINO, H. HAMADA, Y. SAGAWA, Y. SATO, S. KAWABE, M. MASAKI, RESISTANCE AGAINST FATIGUE LOADING OF PRECAST PC DECK SLAB WITH THE IMPROVED LOOP JOINT, Proceedings of the ConMat’20, 2020.08. |
| 16. |
KATSUNOBU SHINKAI, HIROKI GODA, KOJI HARADA, YASUTAKA SAGAWA, MAKOTO HIBINO, THE BASIC RESEARCH ON ASR RESISTANCE OF GEOPOLYMER, Proceedings of the ConMat’20, 2020.08. |
| 17. |
K. KAMARULZAMAN, P. ASTUTI, M.A. CARONGE, L. NGUYEN, H. HAMADA, Y. SAGAWA, D. YAMAMOTO, COMBINATION OF IMPRESSED CURRENT AND SACRIFICIAL ANODE CATHODIC PREVENTION TO IMPROVE CORROSION PREVENTION SYSTEM IN REINFORCED CONCRETE, Proceedings of the ConMat’20, 2020.08. |
| 18. |
PINTA ASTUTI, RAHMITA SARI RAFDINAL, HIDENORI HAMADA, YASUTAKA SAGAWA, DAISUKE YAMAMOTO, A STUDY ON REPAIRING SYSTEM OF SEVERELY DAMAGED RC BEAM BY CATHODIC PROTECTION USING DIFFERENT KIND OF SACRIFICIAL ANODES, Proceedings of the ConMat’20, 2020.08. |
| 19. |
YASUTAKA SAGAWA, PROPERTIES OF CONCRETE MIXED WITH GROUND GRANULATED BLAST-FURNACE SLAG AND ITS APPLICATION FOR PRESTRESSED CONCRETE, Proceedings of the ConMat’20, 2020.08. |
| 20. |
Astuti, P., Kamarulzaman, K., Rafdinal, R.S., Hamada, H., Sagawa, Y., Yamamoto, D., Influence of Rust Removal Process on the Effectiveness of Sacrificial Anode Cathodic Protection in Repair Concrete, 4th International Conference on Construction and Building Engineering and 12th Regional Conference in Civil Engineering, ICONBUILD and RCCE 2019, 10.1088/1757-899X/849/1/012088, 2020.05. |
| 21. |
P. Astuti, R. S. Rafdinal, H. Hamada, Y. Sagawa, D. Yamamoto, K. Kamarulzaman, Effectiveness of Rusted and Non-Rusted Reinforcing Bar Protected by Sacrificial Anode Cathodic Protection in Repaired Patch Concrete, International Conference on Sustainable Insfrastructure 2018, ICSI 2018
IOP Conference Series: Earth and Environmental Science, 10.1088/1755-1315/366/1/012013, 366, 1, 2019.11, This study focuses on the monitoring of rusted and non-rusted rebar protected by sacrificial anode cathodic protection until 1000 days. Three specimens of RC beam structures having a length of 580 mm and 150x100 mm cross-section are fabricated. Two reinforcing barwith the same surface condition (∼ 13 mm) were embedded in mortar parallel to each other with the intermediary distance of 40 mm and the cover depth of 30 mm in the bottom surface of the specimen. Discrete sacrificial zinc anode is connected to one rebar in patch repair section. During the investigation, the specimenswere exposed under three conditions, i.e., 20°C air curing, dry-wet cycle, and dry laboratory air. Potential of both rebar and sacrificial anode was monitored to check the condition of the cathodic protection system. The result indicates that non-rusted rebar condition in repaired patch concrete (chloride-free) is the most desirable initial condition when the sacrificial anode is applied on it to protect corroded steel bar in existing concrete (chloride contamination).. |
| 22. |
Kozo Onoue, Takeomi Iwamoto, Yasutaka Sagawa, Optimization of the design parameters of fly ash-based geopolymer using the dynamic approach of the Taguchi method, Construction and Building Materials, 10.1016/j.conbuildmat.2019.05.177, 219, 1-10, 2019.09. |
| 23. |
Pinta Astuti, Rahmita Sari Rafdinal, Hidenori Hamada, Yasutaka Sagawa, and DaisukeYamamoto, Application of sacrificial anode cathodic protection for partially repaired RC beams damaged by corrosion, Proceedings of 4th International Symposium on Concrete and Structures for Next Generation CSN2019, 284-293, 2019.06. |
| 24. |
Yuichiro Kawabata, Kazuo Yamada, Yasutaka Sagawa, Shoichi Ogawa, Alkali-Wrapped Concrete Prism Test (AW-CPT) - New testing protocol toward a performance test against alkali-silica reaction-, Journal of Advanced Concrete Technology, 10.3151/jact.16.441, 16, 9, 441-460, 2018.09, A new testing protocol, Alkali-Wrapped Concrete Prism Test (AW-CPT), is proposed to avoid alkali leaching and drying, which considerably influence expansion behavior of concrete affected by alkali-silica reaction (ASR). The approach used in this test is that a concrete specimen is wrapped by wet cloth containing alkali solution mimicking the alkalinity of the concrete pore solution. The proposed testing protocol was validated through laboratory and field-exposure measurements, with a focus on expansion, alkali mass balance, and mass change. The test results clearly showed that alkali leaching and drying were significantly reduced by using the AW-CPT method. AW-CPT gives a conservative threshold total alkali content, while conventional CPT overestimates it. The test results also highlighted that there may be an optimum condition of temperature and level of alkali boosting for each reactive aggregate.. |
| 25. |
Rita Irmawaty, Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Performance of pre-stressed concrete sheet pile after long-term exposure in the marine splash environments, 1st International Symposium on Transportation Studies for Developing Countries, ISTSDC 2017
MATEC Web of Conferences, 10.1051/matecconf/201818111004, 181, 2018.07, Pre-stressed concrete (PC) sheet piles are commonly used for river revetment, retaining wall, etc. However, it has not been used in port and harbor structure due to corrosive environmental conditions, which is severe for steel corrosion in concrete structure. Performances of PC sheet piles were evaluated after 12 years exposure in the marine splash environment. An evaluation of mechanical properties, carbonation depth, porosity, chloride content and PC steel condition were carried out. Overall, all specimens showed satisfactory performance: only a few concrete corner and edge chips, low chloride content and low rate of corrosion were observed. Investigation results indicated that BS5 (B = GGBFS, S = steam curing, and cover thickness of 5 cm) showed the best performance (more durable), even though its strength was lower than the other.. |
| 26. |
Yuichiro Kawabata, Kazuo Yamada, Go Igarashi, Yasutaka Sagawa, Effects of Soak Solution Type on Alkali Release from Volcanic Aggregates - Is Alkali Release Really Responsible for Accelerating ASR Expansion? -, Journal of Advanced Concrete Technology, 10.3151/jact.16.61, 16, 1, 61-74, 2018.01, Alkali release from aggregates is considered to cause expansion due to the alkali-silica reaction (ASR), owing to the increase in the hydroxide ion concentration (namely pH) of the pore solution. However, a direct validation of this assertion has not yet been made. In this research, the effects of the type of soak solution, which might better mimic the composition of the pore solution, on the behavior of alkali release from aggregates are investigated through immersion tests of aggregates. More importantly, accompanying ions dissolved from the aggregates are also measured in order to determine the mechanism for the increase in hydroxide ion concentration of the pore solution. The test results show that this increase can barely be observed, despite a considerable amount of alkalis being released. The results critically question the conventional view that alkali released from an aggregate serves to accelerate the ASR.. |
| 27. |
Yuichiro Kawabata, Kazuo Yamada, Go Igarashi, Yasutaka Sagawa, Effects of Soak Solution Type on Alkali Release from Volcanic Aggre-gates − Is Alkali Release Really Responsible for Accelerating ASR Expansion? −, Journal of Advanced Concrete Technology, https://doi.org/10.3151/jact.16.61, 16, 9, 61-74, 2018.01. |
| 28. |
Adiwijaya, Hidenori Hamada, Yasutaka Sagawa, D. Yamamoto, Influence of seawater mixing and curing on strength characteristics and porosity of ground granulated blast-furnace slag concrete, Global Congress on Construction, Material and Structural Engineering 2017, GCoMSE 2017
IOP Conference Series: Materials Science and Engineering, 10.1088/1757-899X/271/1/012070, 271, 1, 2017.12, Generally, in the concrete industry, several billion tons of fresh water are annually used for mixing water, curing water and cleaning water. Nevertheless, the utilization of seawater in the concrete industry is prohibited, because it increases the risk of corrosion of steel bars in concrete. This study presents strength characteristics and porosity of seawater mixed concrete and tap water mixed concrete incorporating Ground Granulated Blast-Furnace Slag (GGBS) with water-binder ratio (W/B) of 40%, 50% and 60%. The influence of seawater mixing, GGBS and curing conditions such as tap water curing (TC), seawater curing (SC) and air curing (AC) on the strength and porosity of concrete were evaluated. Based on investigation result, it was shown that there is no significant influence of seawater mixing in improving strength of GGBS concrete up to 365 days in TC and SC. Effectiveness of seawater-mixing on strength enhancement of GGBS concrete is larger in air curing than in water curing. Porosity of seawater-mixed concrete is decreased compared to tap water-mixed concrete in all curing conditions.. |
| 29. |
Isneini Mohd, Yasutaka Sagawa, Hidenori Hamada, Daisuke Yamamoto, An experimental study on mitigating alkali silica reaction by using lithium hydroxide monohydrate, 3rd International Conference on Construction and Building Engineering: Smart Construction Towards Global Challenges, ICONBUILD 2017
Proceedings of the 3rd International Conference on Construction and Building Engineering, ICONBUILD 2017
Smart Construction Towards Global Challenges, 10.1063/1.5011512, 1903, 2017.11, The ASR suppression effect of lithium hydroxide monohydrate (LiOH·H2O) in mitigating ASR was evaluated by both mortar bar and concrete prism test. JIS A 1146 was used to make mortar bars. Meanwhile, RILEM AAR-3 was used for casting concrete prisms. Reactive aggregates were used in pessimum proportion for mortar and concrete mixtures. The results showed that concrete (L1) used reactive aggregates were immersed in 4M/l LiOH·H2O solution can reduce expansion. Then, concrete (L3) with reactive aggregates were covered with cement paste made with 4M/l LiOH·H2O and were immersed in 4M/l LiOH·H2O solution can reduce expansion. Treatment of reactive aggregates with 4M/l LiOH·H2O the controlled room at 80°C for 5 days can reduce expansion for andesite-1, and at 80°C for 10 days can reduce expansion for andesite-2. The LiOH·H2O results showed that maximum absorption LiOH·H2O of coarse aggregates used andesite-2 = 1.75 mol/l at temperature 80°C. Then, the effective immersing period for passivation of aggregates was at day 7.. |
| 30. |
Isneini Mohd, Sagawa Yasutaka, Hamada Hidenori and Daisuke Yamamoto, An experimental study on mitigating alkali silica reaction by using lithium hydroxide monohydrate, AIP Conference Proceedings 1903, 030005 (2017), https://doi.org/10.1063/1.5011512, 2017.11. |
| 31. |
Amry Dasar, Hidenori Hamada, Yasutaka Sagawa, Daisuke Yamamoto, Deterioration progress and performance reduction of 40-year-old reinforced concrete beams in natural corrosion environments, Construction and Building Materials, 10.1016/j.conbuildmat.2017.05.162, 149, 690-704, 2017.09, Deterioration progress and performance reduction were experimentally evaluated in 40-year-old corroded reinforced concrete (RC) beams. The corrosion process was natural, without acceleration by current application, admixture inclusion, or exposure to an artificial chloride environment. The mechanical performance of the beams was evaluated through a four-point bending test. The corroded steel reinforcing bars were extracted for corrosion evaluation and tensile testing. A good correlation was established between crack width and cross-section loss, as well as between cross-section loss and ultimate capacity loss. Furthermore, the relationship between deterioration progress and performance degradation with the exposure period for each deterioration stage was elucidated.. |
| 32. |
Nurazuwa Md Noor, Daisuke Yamamoto, Hidenori Hamada, Yasutaka SAGAWA, Study on Chloride Ion Penetration Resistance of Rubberized Concrete Under Steady State Condition, MATEC Web of Conferences, Volume 47, 2016 (The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES 2015)), http://dx.doi.org/10.1051/matecconf/20164701004, 47, 2016.04. |
| 33. |
Nurazuwa Md Noor, Daisuke Yamamoto, Hidenori Hamada, Yasutaka SAGAWA, Rubberized Concrete Durability Against Abrasion, MATEC Web of Conferences, Volume 47, 2016 (The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES 2015)), http://dx.doi.org/10.1051/matecconf/20164701006, 47, 2016.04. |
| 34. |
Mohd Isneini, Yasutaka SAGAWA, Hidenori Hamada, Daisuke Yamamoto, An Experimental Study on Mitigating Alkali Silica Reaction by Using Fly Ash (FA) in Combination with Silica Fume and Expanded Perlite Powder (EPP), MATEC Web of Conferences, Volume 47, 2016 (The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES 2015)), http://dx.doi.org/10.1051/matecconf/20164701014, 47, 2016.04. |
| 35. |
Amry Dasar, Rita Irmawaty, Hidenori Hamada, Yasutaka SAGAWA, Daisuke Yamamoto, Prestress Loss and Bending Capacity of Pre-cracked 40 Year-Old PC Beams Exposed to Marine Environment, MATEC Web of Conferences, Volume 47, 2016 (The 3rd International Conference on Civil and Environmental Engineering for Sustainability (IConCEES 2015)), http://dx.doi.org/10.1051/matecconf/20164702008, 47, 2016.04. |
| 36. |
Mohd Isneini, Yasutaka Sagawa, Hidenori Hamada, Daisuke Yamamoto, An experimental study on mitigating alkali silica reaction by using fly ash (FA) in combination with silica fume and expanded perlite powder (EPP), 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164701014, 47, 2016.04, ASR suppression by FA, SF, EPP, FA in combination with SF and EPP were evaluated by both mortar bar and concrete prism test. Mortar bars were made based on JIS A 1146, meanwhile concrete prism bars were casted in accordance with Rilem AAR-3. Both specimens were stored in 40°C 100% R.H. controlled room. Mortar and concrete mixtures used reactive aggregate in pessimum proportion. The results indicated that FA in combination with SF and EPP showed smaller expansion compared to FA. The best of concrete mixtures in reducing expansion is combination of FA with SF (FA15SF10).. |
| 37. |
Nurazuwa Md Noor, Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Erratum to
Study on chloride ion penetration resistance of rubberized concrete under steady state condition (MATEC Web of Conferences (2016) 47 (01004) DOI: 10.1051/matecconf/20164701004), 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164701021, 47, 2016.04, Original article: MATEC Web of Conferences 47, 01004 (2016), DOI: 10.1051/matecconf/20164701004 The abstract of the article should be replaced by the abstract below: In this paper, the effect of crumb rubber, CR as fine aggregate in the concrete to enhance concrete durability against chloride ion diffusion was studied. Chloride ion diffusion in rubberized concrete was tested by migration test under steady state condition. Concrete specimen with water-to-cement ratio of 0.50 was prepared to study the CR effectiveness in comparison with lower water-to-cement ratio. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against chloride ion diffusion. Results showed that chloride transport characteristics were improved by the increasing amount of CR in all mixed due to the fact that CR has the ability to repel water. Meanwhile, rubberized concrete with w/c = 0.35 gave better resistance against chloride ion penetration compared to w/c = 0.50. This was much improved with combination of CR and SF.. |
| 38. |
Amry Dasar, Rita Irmawaty, Hidenori Hamada, Yasutaka Sagawa, Daisuke Yamamoto, Prestress loss and bending capacity of pre-cracked 40 year-old PC beams exposed to marine environment, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164702008, 47, 2016.04, Six prestressed concrete beams (PC beam) were used for evaluation, consist of four post-tension beams (PC-O) and two pre-tension beams (PC-R). In order to investigate the effect of crack on prestress loss and bending capacity after long-term exposed, prestressed concrete beams were pre-crack and then exposed to marine environment. Experimental work was carried out to evaluate PC beams performance after long-term exposed. In addition, visual observations and load bearing capacity test was carried out. Furthermore, evaluation of prestress loss conducted using three-point loading bending test and the remaining tendon forces in the beam were determined using Crack Re-opening Method. The experimental results revealed that prestress loss was increased due to corrosion of strand/wire which affected by the pre-crack on the prestressed beams. Approximately a prestress loss around 26% and 30% was recorded for post-tension and pre-tension beams respectively.. |
| 39. |
Nurazuwa Md Noor, Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Rubberized concrete durability against abrasion, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164701006, 47, 2016.04, Durability performance of rubberized concrete against abrasion is presented in this paper. Surface depth loss was measured when abrasion load was constantly applied on concrete surface at each 500 interval rotation. Specimen with water-to cement ratio of 0.50 and 0.35 was prepared and tested at 28 days of curing age. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against wear when added with crumb rubber. Results showed that crumb rubber shows good potential in providing abrasion resistance to concrete mix. However, in the case of rubberized concrete with silica fume, abrasion resistance was found to be slightly decreased with compressive strength more than 50N/mm2 due to the lack of low elastic modulus of CR particles to accommodate with denser cement matrix.. |
| 40. |
Nurazuwa Md Noor, Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Study on chloride ion penetration resistance of rubberized concrete under steady state condition, 3rd International Conference on Civil and Environmental Engineering for Sustainability, IConCEES 2015
MATEC Web of Conferences, 10.1051/matecconf/20164701004, 47, 2016.04, Foamed concrete is a controlled low density ranging from 400kg/m3 to 1800kg/m3, and hence suitable for the construction of buildings and infrastructures. The uniqueness of foamed concrete is does not use aggregates in order to retain low density. Foamed concrete contains only cement, sand, water and foam agent. Therefore, the consumption of cement is higher in producing a good quality and strength of foamed concrete. Without the present of aggregates, the compressive strength of foamed concrete can only achieve as high as 15MPa. Therefore, this study aims to introduce the pelletized coconut fibre aggregate to reduce the consumption of cement but able to enhance the compressive strength. In the experimental study, forty-five (45) cube samples of foamed concrete with density 1600kg/m3 were prepared with different volume fractions of pelletized coconut fibre aggregate. All cube samples were tested using the compression test to obtain compressive strength. The results showed that the compressive strength of foamed concrete containing 5%, 10%, 15% and 20% of pelletized coconut fibre aggregate are 9.6MPa, 11.4MPa, 14.6MPa and 13.4MPa respectively. It is in fact higher than the controlled foamed concrete that only achieves 9MPa. It is found that the pelletized coconut fibre aggregate indicates a good potential to enhance the compressive strength of foamed concrete.. |
| 41. |
Muhammad Akbar Caronge, Hidenori Hamada, Rita Irmawaty, Yasutaka SAGAWA, Daisuke Yamamoto, Application of Sacrificial Point Anode for Prevention of Steel Corrosion in Cracked Concrete, Journal of Advanced Concrete Technology, 13, 10, 479-488, 2015.10. |
| 42. |
Muhammad Akbar Caronge, Hidenori Hamada, Rita Irmawaty, Yasutaka Sagawa, Daisuke Yamamoto, Application of sacrificial point anode for prevention of steel corrosion in cracked concrete, Journal of Advanced Concrete Technology, 10.3151/jact.13.479, 13, 10, 465-478, 2015.10, The effectiveness of a commercially available sacrificial point anode for corrosion prevention of steel in cracked concrete is presented. Reinforced concrete prisms with dimensions of 150 mm x 150 mm x 500 mm were prepared with a water to cement ratio (W/C) of 0.4 showing crack widths ranging from 0.1 to 0.4 mm obtained by pre-cracking. These specimens were exposed to three conditions: (1) laboratory air (temperature of 202C and relative humidity of 60%); (2) immersed in 3% NaCl solution; and (3) dry/wet cycles of above mentioned conditions. Measurements included the free corrosion potential, polarization behavior of the sacrificial point anode, anodic-cathodic polarization curve of the reinforcement steel and visual observation. The test results show that the sacrificial point anode was effective to prevent the embedded steel from corrosion in cracked concrete. Specimens exposed to dry/wet cycles or immersed in 3% NaCl solution demonstrated a better protection than those exposed to laboratory air due to the high moisture condition. Thus, a sacrificial point anode becomes active to protect the steel bars even in cracked concrete.. |
| 43. |
Adiwijaya, Hidenori HAMADA, Yasutaka SAGAWA, Daisuke YAMAMOTO, EFFECT OF MINERAL ADMIXTURES ON CARBONATION OF SEAWATER MIXED CONCRETE, Proceedings of the 2nd Makassar International Conference on Civil Engineering (MICCE 2015), 153-162, 2015.08, This study presents carbonation of seawater mixed concrete and tap water mixed concrete incorporating
mineral admixtures such as Fly Ash (FA) and Ground Granulated Blast-Furnace Slag (GGBS) with W/B of 40%, 50%
and 60% in tap water curing (TC), seawater curing (SC) and air curing (AC). The effect of seawater mixing, mineral
admixtures, water-binder ratio, curing conditions and exposure condition on carbonation process of concrete were
evaluated. Concrete prism specimens using tap water and seawater as mixing water were prepared. At 24 hours after
casting, specimens were de-molded and followed by distinct curing conditions such as tap water curing, seawater curing
and air curing. After curing until 28 days, specimens were exposed in air during 4 weeks before they were brought into
accelerated chamber for carbonation and natural outdoor exposure. Based on experimental result, it was shown that
carbonation depth of seawater-mixed concrete with and without mineral admixtures in AC was lower compared to tap
water mixed concrete in both accelerated and natural exposure carbonation. Moreover, mineral admixtures increased
carbonation rate of seawater mixed concrete in all curing condition. Besides, the carbonation rate of seawater-mixed
concrete with and without mineral admixtures in SC was smaller than that of in TC. In addition, accelerated carbonation
depth of seawater mixed or tap water mixed FA and GGBS concrete was seven times larger than natural exposure
carbonation.. |
| 44. |
M. A. Caronge, Hidenori HAMADA, Yasutaka SAGAWA, Daisuke YAMAMOTO, APPLICATION OF SACRIFICIAL ANODE TO PREVENT MACROCELL CORROSION IN REPAIRED RC MEMBER, Proceedings of the 2nd Makassar International Conference on Civil Engineering (MICCE 2015), 163-170, 2015.08, This paper presents results of an experimental investigation on the effectiveness of sacrificial anode to
prevent macrocell corrosion of steel in repaired RC member. Experimental tests were carried out in reinforced concrete
beams with sizes of 150 mm x 150 mm x 500 mm and cover thickness of 30 mm. Each specimen consisted of plain
steel bar (PS), plain steel bar with sacrificial anode (PSCP) and epoxy coated steel bar (PSE). Mix proportion was
divided into two categories; firstly, existing concrete (EC) with 4 kg/m3 and 10 kg/m3 of chloride and W/C ratio of
53.5% and 40% were placed, namely N53.5, N40 and BB40. For BB40, replacement of cement with 50% of blast
furnace slag (BFS) was added. Secondly, concrete with 47% of W/C ratio without chloride was placed as repaired
concrete (RPC). The potential value of steel, depolarization tests, anodic-cathodic polarization curve, polarization
behavior of sacrificial anode, and visual observation were evaluated after one-year exposure. From the test results,
PSCP showed good passivation film and little corrosion than PS in RPC. It means sacrificial anode is effective to delay
macrocell corrosion repaired section. Also, replacement of cement by 50% BFS can raise the resistance to penetration
of chloride ions into repaired concrete.. |
| 45. |
Yasutaka SAGAWA, Kazuo YAMADA, Shoichi OGAWA, Yuichiro KAWABATA, Masahiro OSAKO, The Effect on Expansion of Wrapping Concrete Prisms with Cloth Saturated with Alkali Hydroxide, Proceeding of 27th Biennial National Conference of the Concrete Institute of Australia in conjunction with the 69th RILEM Week, 822-831, 2015.08. |
| 46. |
Kazuo YAMADA, Shoichi OGAWA, Yuichiro KAWABATA, Yasutaka SAGAWA, Masahiro OSAKO, Takamasa Ochiai, A Study on the Estimation of ASR Expansion Based on CPT, Proceeding of 27th Biennial National Conference of the Concrete Institute of Australia in conjunction with the 69th RILEM Week, 1465-1471, 2015.08, Concrete prism tests (CPT) were performed on samples having various alkali content and at
various temperature. Assuming the shape of the expansion curve, three parameters describing expansion
were obtained by data fitting. Then the dependence of these parameters on alkali amount and
temperature were calculated. By using the basic information, expansion behavior measured in field
exposure test was reproduced. There are some necessities to modify some parameters, so that
appropriate ASR estimation in arbitrary condition becomes possible. The effect of SCMs can be taken into
account with the decrease in alkali amount due to their substitution to cement. |
| 47. |
Yasutaka SAGAWA, Shu OTA, Koji HARADA, Takeyoshi NISHIZAKI, Hiroki GODA, Utilization of Fly Ash with Higher Loss on Ignition for Geopolymer Mortar, Advanced Materials Research, 10.4028/www.scientific.net/AMR.1129.614, 1129, 614-620, 2015.08. |
| 48. |
Rahmita Sari RAFDINAL, 濵田 秀則, 佐川 康貴, 山本 大介, EFFECTIVE LENGTH OF CATHODIC PROTECTION EMBEDDED STEEL WITH SACRIFICIAL ANODE UNDER NON-HOMOGENEOUS CHLORIDE ENVIRONMENT, コンクリート工学年次論文集, 37, 1, 955-960, 2015.07, This study was carried out to identify the effective length of embedded segmented steel element with sacrificial anode exposed to non-homogeneous chloride environment against macro-cell corrosion. Four concrete specimens which consist of chloride contaminated and non-chloride contaminated concrete were evaluated. Results show that sacrificial anode can protect embedded steel in the boundary of non-homogeneous chloride environment with the effective length is about 120 mm until 200 mm from edge of the boundary.. |
| 49. |
H. Hamada, D. Yamamoto, Y. Sagawa, T. Ikeda, An experimental study on relationship between chloride content in mortar and passivity condition of embedded steel bar, 4th International Symposium on Life-Cycle Civil Engineering, IALCCE 2014
Life-Cycle of Structural Systems
Design, Assessment, Maintenance and Management - Proceedings of the 4th International Symposium on Life-Cycle Civil Engineering, IALCCE 2014, 10.1201/b17618-219, 1479-1484, 2015, In this study, properties related to corrosion of embedded steel in mortar, which contains chloride around threshold chloride content for steel corrosion, were discussed. Half-cell potential, polarization resistance and polarization curve of embedded steel were measured. Half-cell potential showed a linear relationship with chloride content in mortar. Polarization resistance and grade of passivity judged by polarization curve quickly decreased at the chloride content around 0.3 - 0.4% mass percent versus unit cement mass. This indicates that the destruction of passivity film on steel surface is occurred around this chloride level, which is believed presently to be threshold chloride content for steel corrosion initiation.. |
| 50. |
Nurazuwa Md Noor, H. Hamada, Y. Sagawa, D. Yamamoto, Effect of crumb rubber on concrete strength and chloride ion penetration resistance, Jurnal Teknologi, 10.11113/jt.v77.7004, 77, 32, 171-178, 2015, This paper present the effect of crumb rubber on its ability to produce concrete with structural strength when it was used directly from the plant without any treatment process. Crumb rubber was added as fine aggregates at 0%, 10%, 15% and 20% of sand volume meanwhile silica fume was added at 10% by cement weight. Three main series of concrete namely rubberized concrete with water-to-cement ratio of 50% and 35% was design and development of compressive strength was observed from day 7 until 91 days. Also, effectiveness of crumb rubber under flexural strength and splitting tensile strength was studied at 28 days curing age. Effect of crumb rubber on durability performance was done on chloride ion penetration resistance performance by migration test and by immersion in salt water. Chloride ion diffusion in rubberized concrete by migration test was carried out under steady state condition using effective diffusion coefficient, De meanwhile, immersion test in salt water was conducted under non-steady state condition using apparent diffusion coefficient, Da. Results showed that compressive strength was decrease with the increasing of crumb rubber in the mixture. Even though the strength were reducing with the inclusion of crumb rubber, the reduction were less than 50% and it achieved acceptable structural strength. Chloride transport characteristics were improved by increasing amount of CR and rubberized concrete with w/c = 0.35 gave better resistance against chloride ion compared to w/c = 0.50 with more than 50% difference. Silica fume provide slightly strength increment compared to normal rubberized concrete and the same behavior was observed during chloride ion diffusion test.. |
| 51. |
Isneini Mohd, Yasutaka SAGAWA, Daisuke YAMAMOTO, Hidenori HAMADA, An Experimental Study on Mitigating ASR Using Fly Ash and Silica Fume, 土木構造・材料論文集, 30, 149-156, 2014.12. |
| 52. |
Muhammad Akbar Caronge, Hidenori Hamada, Yasutaka Sagawa, Daisuke Yamamoto, Rahmita Sari Rafdinal, POTENTIAL PERFORMANCE OF SACRIFICIAL ANODE TO PREVENT CORROSION OF STEEL IN REPAIRED RC MEMBER , Proceedings of the 6th International Conference of Asian Concrete Federation, 1327-1332, 2014.09. |
| 53. |
Adiwijaya, Hidenori Hamada, Yasutaka Sagawa, Daisuke Yamamoto, EFFECTS OF MINERAL ADMIXTURES ON STRENGTH CHARACTERISTICS OF CONCRETE MIXED WITH SEAWATER, Proceedings of the 6th International Conference of Asian Concrete Federation, 925-930, 2014.09. |
| 54. |
Kazuo Yamada, Shinya Karasuda, Shoichi Ogawa, Yasutaka Sagawa, Masahiro Osako, Hidenori Hamada, Mohd Isneini, CPT as an evaluation method of concrete mixture for ASR expansion, Construction and Building Materials, 10.1016/j.conbuildmat.2014.04.034, 64, 184-191, 2014.08, Highly reactive andesite aggregates including opal or tridymite were evaluated by concrete prism test (CPT) in two ways and the suitable conditions of CPT were discussed. 18 concrete mixtures were used to examine the effect of the type and content of aggregate, the type of cementitious material. Two methods for detecting for ASR reactivity were used; RILEM AAR-4 and JASS 5N, and the latter one is of which authors revised few points. As the results, different performances of andesite depending on the size and the different required amounts of fly ash suppressing ASR depending on the mixture proportion were well demonstrated by CPT that is difficult for mortar bar test. As a curing method to avoid alkali leaching, wrapping with wet paper showed much less leaching than curing in a sealed box. From the viewpoint of easiness of operation, small size 75 × 75 × 250 mm is suitable than large size 100 × 100 × 400 mm.. |
| 55. |
Nurazuwa MD NOOR, 濵田 秀則, 佐川 康貴, 山本 大介, STRENGTH CHARACTERISTICS AND EFFECTIVE CHLORIDE DIFFUSION COEFFICIENT OF RUBBERIZED CONCRETE, コンクリート工学年次論文集, 36, 1, 1864-1869, 2014.07, In this study, crumb rubber was used as fine aggregate at 10%, 15% and 20% sand volume replacement to produce rubberized concrete with satisfied compressive strength. Rubberized concrete was tested on its fresh properties, mechanical strength and effective diffusion coefficient of chloride ion. In addition, silica fume as 10% of cement was added to investigate the effect on the strength and resistance against chloride penetration. Results shows mechanical strength reached to the acceptable value for satisfied strength as structural concrete and chloride ion resistance was improved with silica fume.. |
| 56. |
Muhammad Akbar CARONGE, 濵田 秀則, 佐川 康貴, 山本 大介, EFFECT OF CURING AND CRACK WIDTH ON POTENTIAL PERFORMANCE OF STEEL WITH SACRIFICIAL ANODE IN CRACKED CONCRETE, コンクリート工学年次論文集, 36, 1, 1204-1209, 2014.07, The effectiveness of sacrificial anode to protect embedded steel in cracked concrete under different curing conditions; air curing, immersion in a 3% NaCl solution and dry/wet cycle is presented. Reinforced concrete prism in size of 150x150x500 mm3 with water-to-cement ratio of 0.4 and pre-crack of 0.1 to 0.4 mm in width was evaluated. The result showed that sacrificial anode was effective to protect the embedded steel in cracked concrete. Also, crack width significantly influences the corrosion rate.. |
| 57. |
Nurazuwa Md Noor, 山本 大介, 合田 寛基, 濵田 秀則, 佐川 康貴, Strength and Surface Abrasion Resistance of Crumb Rubber Mixed Mortar, 土木構造・材料論文集, 29, 91-96, 2013.12. |
| 58. |
Adiwijaya, 山本 大介, Amry DASAR, 濵田 秀則, 佐川 康貴, Effects of Seawater Mixing and Curing on Strength and Carbonation of Fly Ash Concrete, 土木構造・材料論文集, 29, 97-103, 2013.12. |
| 59. |
Daisuke YAMAMOTO, Hidenori Hamada, Yasutaka SAGAWA, Nurazuwa Md Noor, DIAGNOSIS OF LOAD BEARING CAPACITY OF SEWAGE PIPES DETERIORATED BY SULFATE ATTACK, Proceedings of Seventh International Conference on Concrete under Severe Conditions – Environment and Loading, 1, 1280-1288, 2013.09, It has been frequently reported that concrete sewage facilities has deteriorated in short term
than expected service life time of 50 years. This is serious problem in durability and
maintenance of the sewage facilities. It is clear that this deterioration originates from sulfuric
acid generated by the micro-organism activity in the sewage, thus nowadays a routine
corrosion inspection of the sewage pipes is carried out. However, deterioration in sewage pipe
has not well verified by current checking techniques, thus to ensure the required performance
during service period is difficult.
In this paper, the method for deterioration diagnosis for sewage pipes is investigated. As a
result, the degree of deterioration can be examined, and methodology for estimation of service
life with satisfy required performance of sewage pipe is proposed.. |
| 60. |
Takanori IKEDA, Hidenori Hamada, Yasutaka SAGAWA, M. Funahashi, EXPERIMENTAL INVESTIGATION OF AIR VOID FORMED AROUND STEEL BAR USING X-RAY CT SCANNING, Proceedings of Seventh International Conference on Concrete under Severe Conditions – Environment and Loading, 1, 742-748, 2013.09, Corrosion of Steel bar is affected by several factors such as chloride ion concentration,
oxygen and water supply. Interfacial zone between concrete and steel bar is also important
factor on steel corrosion. It is well known that air void formed around steel bar accelerates
corrosion, however air void structure such as size and distribution were not fully understood.
This study presents the observation results of three dimensional structure of air void
around steel bar obtained by X-ray CT (Computed Tomography) scanning. Mortar specimens
with height of 500mm and cross section of 150×150mm are prepared. Water to cement ratio
of mortars are varied 3 types to change bleeding ratio. Aluminum bar are used as alternative
material for steel bar because X-ray can not transmit in steel. Two bars with different height,
30mm from top and bottom, are embedded in each specimen. One month after casting,
observation using X-ray CT scanning is carried out. As a result, 2~5mm of thickness of air
void is formed around top bar. On the other hands, the average thickness of air void around
bottom bar is 0.1~0.3mm. However, several air voids with mm-ordered size are detected on
bottom bar which can cause macro-cell corrosion. Air void size around top bar depended on
water to cement ratio, larger void is formed in specimen with higher water to cement ratio.
Using X-ray CT scanning is effective to evaluate air void structure quantitatively.. |
| 61. |
Yasutaka SAGAWA, Daisuke YAMAMOTO, Yoshikazu Henzan, Properties of concrete with GGBS and its applications for bridge superstructures, Proceedings of 3rd International Conference on Sustainable Construction Materials and Technologies (SCMT3), 2013.08. |
| 62. |
Amry DASAR, Hidenori Hamada, Yasutaka SAGAWA, Takanori IKEDA, Durability of marine concrete with mineral admixture and marine aquatic organism layer, Proceedings of 3rd International Conference on Sustainable Construction Materials and Technologies (SCMT3), 2013.08. |
| 63. |
Rita IRMAWATY, Daisuke YAMAMOTO, Hidenori Hamada, Yasutaka SAGAWA, Deterioration of prestressed concrete beams due to combined effects of carbonation and chloride attack, Proceedings of 3rd International Conference on Sustainable Construction Materials and Technologies (SCMT3), 2013.08. |
| 64. |
Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Toshiumi Hiromitsu, Evaluation of compressive strength of concrete using small diameter core, 3rd International Conference on Sustainable Construction Materials and Technologies, SCMT 2013
Sustainable Construction Materials and Technologies, 2013-August, 2013.01, In Japan, large number of concrete structures were constructed in the high economic growth period (60's~70's), and they are entering a period over the designed service life, therefore the proper life cycle management for life extension of these structures is becoming necessary. The use of small diameter core specimen for compressive strength test in conducting the maintenance procedures for existing structures is desirable technology because it gives minor damage to the structure and less risk to cut off reinforcements when the core sampling is done. However, it is known that the variance of compressive strength test result by a small diameter core becomes large and it is difficult to evaluate precisely the compressive strength. From this background, the research described in this paper focused on development of the compressive strength test method by using small diameter core.. |
| 65. |
Yasutaka Sagawa, Daisuke Yamamoto, Yoshikazu Henzan, Properties of concrete with GGBS and its applications for bridge superstructures, 3rd International Conference on Sustainable Construction Materials and Technologies, SCMT 2013
Sustainable Construction Materials and Technologies, 2013-August, 2013.01, Chloride diffusion coefficient of the concrete mixed with ground granulated blast-furnace slag (GGBS) was investigated. As the results, GGBS reduced the effective diffusion coefficient of chloride ion by from 1/5 to 1/10. Also, GGBS with specific surface area of 6000 cm2/g improved the chloride resistance of concrete when water to binder ratio (W/B) was was smaller than 45%. In addition, GGBS with specific surface area of 6000 cm2/g was applied to prestressed concrete bridge. The effective diffusion coefficient of the concrete used for bridge superstructure showed the lower value. As the results of simple simulation by using Fick's second low, it is expected that steel bars in concrete will not occur corrosion for 100 years.. |
| 66. |
M. W. Tjaronge, H. Hamada, R. Irmawaty, Y. Sagawa, Influence of the curing method on comprssive strength and porosity of concrete mixed with sea water, marine sand and fly ash, 7th International Conference on Asian and Pacific Coasts, APAC 2013
Proceedings of the 7th International Conference on Asian and Pacific Coasts, APAC 2013, 798-801, 2013.01, There many archipelagic state such as Japan, Indonesia and other countries. Indonesia consists of thousands of islands where many peoples live in the low land area, the distant and isolated islands that lack of clean water or fresh water and mountain sand or river sand.Transporting the fresh water or clean water and mountain aggregates or river aggregates for concrete production to the low land area, the distant and isolated islands will make the price of concrete work becomes more expensive. In order to overcome the problem of shortage of clean water and fine aggregate in the low land area, the distant island, and saving the fresh water over the world, this research seeks to use sea water and sea sand to produce concrete. In order to overcoming the continuous dumping of waste material, this research also uses semen containing wasted material such as fly ash. This research is a part of ongoing investigation that focuses to study the mix design), mechanical properties (compressive strength-modulus elasticity), porosity, and curing method in order to achieve an optimum correlation between sea water, marine sand, cement, river or mountain coarse aggregate in production of high performance concrete. Furthermore, it is important to conduct research on utilization of sea water, whose percentage is 97% of the total water on the earth, as an effort for improving the technology of saving fresh water.. |
| 67. |
Amry Dasar, Hidenori Hamada, Yasutaka Sagawa, Takanori Ikeda, Durability of marine concrete with mineral admixture and marine aquatic organism layer, 3rd International Conference on Sustainable Construction Materials and Technologies, SCMT 2013
Sustainable Construction Materials and Technologies, 2013-August, 2013.01, The high chloride ion concentration along with the presence of oxygen and water leads to accelerated corrosion process. It is fact that, durability of marine concrete depends corrosion resistance of concrete. On the other hand, addition of mineral admixture and covered marine aquatic organism layer has a potential to reduce the risk of corrosion. A total of 6 samples were prepared which had been exposed in the marine environment for 13 years. During the initial several years, marine aquatic organism layer was formed. In order to investigate the effect of mineral admixture and marine aquatic organism layer against corrosion, experimental laboratory study was carried out to measure corrosion potential and micro-pore structures related to the rate of chloride ion diffusion. Results show that mineral admixture can reduce the risk of corrosion. Moreover, marine aquatic organism layer had a positive effect to prevent the chloride ingress into concrete.. |
| 68. |
Rita Irmawaty, Daisuke Yamamoto, Hidenori Hamada, Yasutaka Sagawa, Deterioration of prestressed concrete beams due to combined effects of carbonation and chloride attack, 3rd International Conference on Sustainable Construction Materials and Technologies, SCMT 2013
Sustainable Construction Materials and Technologies, 2013-August, 2013, Performance of prestressed concrete (PC) beams subjected to both carbonation and chloride ingress has not been clarified well so far. This paper presents the evaluation results and discussion on materials deterioration and corrosion state of prestressing wire/tendons of 35 year's test PC beams. All beams were exposed to the actual marine tidal environments at the Sakata Port more than 20 years, then transferred and stored in a constant temperature over 15 years. The results indicated that all beams showed deterioration on the exterior and the whole surface of beams was carbonated. Even carbonation did not cause corrosion of reinforcement, however, it may have contributed to degradation of cover concrete. In addition, even though tendons were protected by sheath and mortar grouting, however, corrosion area on tendons reached 40%, and prestressing wires corrosion length was 50 to 73%, indicating severe corrosion conditions for PC beams with 30 mm cover depth.. |
| 69. |
Rita Irmawaty, 山本 大介, 濵田 秀則, 佐川 康貴, Performances of PC Sheet Pile after 12 Years Exposure in the Marine Tidal Environments, コンクリート工学年次論文集, 34, 1, 706-711, 2012.07. |
| 70. |
Hidenori Hamada, Yasutaka Sagawa and Daisuke Yamamoto, Some Studies on Performance Enhancement of Recycled Aggregate Concrete -2009-2011 in Japan -, Proceeedings of the 2nd UAP/SEL Seminar on Recycling of Demolished Concrete, pp.1-10, 2011.12. |
| 71. |
Hidenori Hamada, Yasutaka sagawa and Toru Yamaji, Anti-Corrosion Technologies on Bridges Affected by Marine Environment, Proceedings of the 2011 International Forum on Bridge Engineering, Taipei, Taiwan, pp.81-102, 2011.09. |
| 72. |
Rita Irmawaty, Hidenori HAMADA, Yasutaka SAGAWA and Sho Yamatoki, A DISCUSSION ON DURABILITY OF HIGH STRENGTH CONCRETE (HSC) IN VIEW POINT OF MICRO PORE STRUCTURE, Proceedings of The 3rd International Conference of European Asian Civil Engineering Forum, Yogyakarta, pp. S-49 - S-54, 2011.09. |
| 73. |
Y. Sagawa, T. Katayama, T. Tsutsumi and H. Matsushita: Development of Large-scale Precast Concrete Skew Box Culvert with Looped Joint Connection, Concrete Journal, Vol.49, No.3, pp.13-20, Mar. 2011. |
| 74. |
Yoshikazu HENZAN, Hidenori HAMADA, Yasutaka SAGAWA and Masahiro SUZUKI: Experimental Study on Shrinkage Properties of Concrete Used with Ground Granulated Blast-Furnace Slag 6000, Journal of Structures and Materials in Civil Engineering, No.26, pp.106-111, December, 2010. |
| 75. |
Classification of Probability of Deterioration of Concrete by Sulfate Attack Based on Investigation Results of Sulfate Content of Ground. |
| 76. |
Research of Reactivity Test for Aggregate Cause Late Expansive ASR. |
| 77. |
Effect of Alkali Release from Aggregate on the Expansion due to ASR. |
| 78. |
Influence that several kinds of conditions exert on electrochemical measurement result. |
| 79. |
Experimental Study on Relationship between Void under Reinforcing Bar and its Corrosion. |
| 80. |
Mingdi Gao, Hidenori Hamada, Yasutaka Sagawa, Takanori Ikeda, Evaluation on chloride diffusion coefficient of blast-furance slag cement concrete, 2nd International Conference on Durability of Concrete Structures, ICDCS 2010
Advances in Concrete Structural Durability - Proceedings of the 2nd International Conference on Durability of Concrete Structures, ICDCS 2010, 243-248, 2010.01, Blast-furnace slag cement (BB) is made by mixing granulated blast-furnace slag into Ordinary Portland cement (N). Slag cement concrete has been intensively studied because of its ability to get improved durability. However, in order to get high durability of slag ccmcnt concrete, enough wet curing condition and curing period is necessary. At present technical situation, there are not enough unified techniques to evaluate the chloride ion diffusion properity of slag cement concrete quantitatively. And the relation between various test methods and the chloride ion diffusion coefficient is also not examined thoroughly. In this study, by converting the substitution rate of slag and by changing its curing condition, compressive strength of the BB, not curcd in moisture was much lower than the other cured in wet condition. While, in longer moisture curing it can get the same strength as the N. From the results of both electro-migration test and submergence in salt water test, the higher the substitution rate of slag and the longer the moist curing period is, the smaller the diffusion coefficient is. And the influence level of cumulative pore volume on chloride diffusion property is different between N and BB.. |
| 81. |
H. Hamada, Y. Sagawa, T. Ikeda, R. Morikawa, Several factors affecting the anodic polarization curve of steel bars embedded in mortar, 6th International Conference on Concrete under Severe Conditions-Environment and Loading, CONSEC'10
Concrete under Severe Conditions
Environment and Loading - Proceedings of the 6th International Conference on Concrete under Severe Conditions, CONSEC'10, 10.1201/b10552-23, 201-208, 2010, Anodic polarization curve is measured to evaluate the condition of passivated film on steel surface. Normally, polarization curve can be adapted only to "specimen" immersed in aqueous solution in laboratory. Furthermore, a set of measurement takes about 40 minutes. It makes difficult to apply this measurement for actual structures. If these difficulties could be overcome, polarization curve measurement can be used on site to evaluate the condition of paasivated film on steel surface in concrete. In this study, at first, a new measuring method with new sensor system, which makes it possible to apply it to actual structures, was developed. And, several factors were tested to evaluate their effects on polarization curve. Finally, several conclusions could be obtained. (1) Polarization curve obtained with new sensor system is almost equal to it with ordinary system. (2) Polarization speed affects on polarization curve, as that the current flow is increased with high polarization speed. (3) With new sensor system, polarization curve measurement can be adopted to actual structures on site.. |
| 82. |
A Study on Steel Corrosion of Repaired RC Bridge under Chloride Attack Environment
Yasutaka SAGAWA, Ryota MORIKAWA and Hidenori HAMADA
Proceedings of the Concrete Structure Scenarios, JSMS, Vol.9, pp.97-102, October, 2009. |
| 83. |
Yasuhiro DAN, Takeshi IYODA, Yusuke OHTSUKA, Yasutaka SAGAWA and Hidenori HAMADA : The Relationship Between Curing Condition and Durability on Concrete Using Blast-Furnace Slag Cement, JSCE Journal of Materials, Concrete Structures and Pavements, Vol. 65, No. 4 pp.431-441, October, 2009. |
| 84. |
A study of sewege pipe diagnosis technique by using ultrasonic wave method,
Daisuke YAMAMOTO, Yasutaka SAGAWA, Hidenori HAMADA and Hiromichi MATSUSHITA
Proceedings of the Japan Concrete Institute, Vol.31，No.1，pp.2137-2142, July, 2009. |
| 85. |
ASR-Related expansion behavior of concrete incorporated fly ash,
Masayoshi NISHI, Hidenori HAMADA, Yasutaka SAGAWA and Yuichiro KAWABATA
Proceedings of the Japan Concrete Institute, Vol.31，No.1，pp.1327-1332, July, 2009. |
| 86. |
Effect of water absorbed in recycled aggregate on strength and microstructure of mortar
Hideaki MURAKAMI, Yasutaka SAGAWA, Yuichiro KAWABATA and Hiromichi MATSUSHITA
Proceedings of the Japan Concrete Institute, Vol.30，No.2，pp.397-402, July, 2008. |
| 87. |
Enegetic considerations for static compression failure process of concrete
Kouzou ONOUE, Hiromichi MATSUSHITA, Hidenori HAMADA and Yasutaka SAGAWA
Proceedings of the Japan Concrete Institute, Vol.30，No.1，pp.369-374, July, 2008. |
| 88. |
Suppressing effect of mineral admixture on DEF-related expansion of heat-cured mortar
Takanori IKEDA, Yuichiro KAWABATA, Hidenori HAMADA and Yasutaka SAGAWA
Proceedings of the Japan Concrete Institute, Vol.30，No.1，pp.135-140, July, 2008. |
| 89. |
Influence of Quality of Recycled Aggregate on Relation between Pore Volume and Strength of Mortar
Yasutaka SAGAWA, Hiromichi MATSUSHITA and Yuichiro KAWABATA
Proceedings of the Japan Concrete Institute, Vol.29，No.2，pp.385-390, July, 2007.  |
| 90. |
Study on strain measurement method in young aged concrete using embedment strain transducer
Kazumasa FUJITA, Hiromichi MATSUSHITA, Yasutaka SAGAWA and Yoshihiro FUKUZAWA
Proceedings of the Japan Concrete Institute, Vol.29，No.1，pp.597-602, July, 2007. |
| 91. |
Physical Properties of Blast-furnace Slag Melted Fly Ash and Utilization as Fine Aggregate
Katsuya TAKAHASHI, Hiromichi MATSUSHITA, Yasutaka SAGAWA and Shingo HAMAMOTO
Proceedings of the Japan Concrete Institute, Vol.29，No.1，pp.171-176, July, 2007. |
| 92. |
Application of Digital Image Correlation Method to Strain Measurement of Mortar Specimen under Uniaxial Compression
Yasutaka Sagawa, Kouzou Onoue, Masakazu Uchino and Hiromichi Matsushita
Journal of JSEM, Vol.7, No.2, pp.114-120, July, 2007. |
| 93. |
Influences of Calculating Condition on Prediction of Chloride Deterioration for Concrete Highway Bridge. |
| 94. |
A Study on Relationship between Porosity and Compressive Strength of Concrete with Recycled Aggregate. |
| 95. |
A Study on Fresh Property and Compressive Strength of Mortar Mixed with Molten Slag. |
| 96. |
Deterioration by Calcium Chloride Solution of High-Strength Concrete with Blast Furnace Slag. |
| 97. |
A Study on Rehabilitation of the Initiated Crack in Mortar. |
| 98. |
Effect of Water Contained in Cement-Based Matrial on Compressive Failure Process. |
| 99. |
The Effect of Melting Method on Chemical Composition and Physical Property of Molten Slag. |
| 100. |
A Study on LCC Evaluation of the Concrete Bridge under Salt Damage Environment. |
| 101. |
Y. SAGAWA, H. MATSUSHITA, Y. MAEDA, T. CHIKADA and S. KANEYASU, Influence of Blast-Furnace Slag on Durability of High-Strength Concrete, Proceeding of 8th CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Conrete, pp.703-720, May, 2004, 2004.05. |
| 102. |
A Study on Durability of Recycled Aggregate Concrete. |
| 103. |
Effect of Curing Condition ot High Strength Concrete with Grand Granulated Blast-furnace Slag
Kouzou ONOUE, Hiromichi MATSUSHITA, Yasutaka SAGAWA and Yoshitaka MAEDA
Proceedings of the 12th Symposium on Developments in Prestressed Concrete, pp.173-176, October 2003. |
| 104. |
An Effect of Quality of Recylcled Aggregate to Compressive Strength of Recycled Concrete
Yasutaka SAGAWA, Hiromichi MATSUSHITA, Hiroaki TSURUTA and Ryuichi KOGA
Proceedings of the Japan Concrete Institute, Vol.25, No.1, pp.1265-1270, July 2003. |
| 105. |
A Study on Physical Properties of Recycled Aggregate Crushed by Various Methods
Yasutaka SAGAWA, Hiromichi MATSUSHITA, Hiroaki TSURUTA and Yoshihiro SUE
Proceedings of the Japan Concrete Institute, Vol.24, No.1, pp.1347-1352, June 2002. |
| 106. |
The Relationship of Failure Process of PC Pier and Behavior of PC Bars
Osamu NAKAMURA, Hiroaki MATSUSHITA, Yasutaka SAGAWA and Hideo WAKISAKA
Proceedings of the Japan Concrete Institute, Vol.23, No.3, pp.721-726, July 2001. |
| 107. |
Mechanical Properties of Steel Fiber Reinforced High Strength Mortar
Yasutaka SAGAWA, Hiromichi MATSUSHITA, Hiroaki TSURUTA and Yoshihide SHIMOYAMA
Proceedings of the Japan Concrete Institute, Vol.23, No.2, pp.199-204, July 2001. |
| 108. |
Bending Properties of Steel-Concrete Composite Girders with Automatically Welded Box Dubel
Kiminori KUNO, Hiromichi MATSUSHITA and Yasutaka SAGAWA
Proceedings of the Japan Concrete Institute, Vol.23, No.1, pp.775-780, July 2001. |
| 109. |
Yasutaka SAGAWA, Hiromichi MATSUSHITA and Hiroaki TSURUTA, Anchoring Method of Carbon Fiber Sheet for Strengthening of Reinforced Concrete Beams, Proceedings of the Fifth International Conference on Fibre-reinforced Plastics for Reinforced Concrete Structures, Vol.1, pp.409-417, July 2001, 2001.06. |
| 110. |
A Study on Bond Characteristics and Improvement of Ultimate Strength in Carbon Fiber Sheet Adhesion Method
Yasutaka SAGAWA, Hiromichi MATSUSHITA and Koyo TAKEO
Journal of Materials, Concrete Structures and Pavements, Vol.V-50,No.669, pp.71-84, February 2001. |
| 111. |
Yasutaka Sagawa, Hiromichi Matsushita, Koyo Takeo and Makoto Saito, A study on a New Method of Anchorage of Carbon Fiber Sheet for Flexural Strengthening, Transactions of the Japan Concrete Institute, Vol.22, pp.237-242, February 2001, 2001.02. |
| 112. |
Yasutaka Sagawa, Hiromichi Matsushita, Koyo Takeo, Makoto Saito, Study on a new method of anchorage of carbon fiber sheet for flexural strengthening, Transactions of the Japan Concrete Institute, 22, 237-242, 2000.12, In this study, anchoring method of Carbon Fiber Sheet (CFS) bonded to tension surface for flexural strengthening of reinforced concrete (RC) beams was examined experimentally. The anchoring method proposed in this study was that CFS for anchoring with fiber direction inclined 45 degree to the longitudinal axis of the beam was bonded in U-shape. As a result of comparison with the method that fiber direction was perpendicular to axis, it was indicated that the former was more effective than the latter.. |
| 113. |
A Study on a New Method of Anchorage of Carbon Fiber Sheet for Flexural Strengthening
Yasutaka SAGAWA, Hiromichi MATSUSHITA, Koyo TAKEO and Makoto SAITO
Proceedings of the Japan Concrete Institute
Vol.22, No.1, pp.475-480, June 2000. |
| 114. |
Experiment of RC Beam Reinforced with CFRP Adhesive Method Having Variety of Shear-span Ratio
Koyo TAKEO, Hiromichi MATSUSHITA, Yasutaka SAGAWA and Toshiyuki USHIGOME
Proceedings of the Japan Concrete Institute, Vol.21, No.2, pp.205-210,June 1999. |
| 115. |
Measuring Method of Strain Using Wheatstone Bridge - (Part 2) A Proposal of a New Method for Measurement of Strain -
Haruki OKANO, Hiromichi MATSUSHITA and Yasutaka SAGAWA
Technology Reports of Kyushu University, Vol.72, No.3, pp.239-244, May 1999. |
| 116. |
Measuring Method of Strain Using Wheatstone Bridge - (Part 1) Present Status and Causes of Errors in Measurement -
Haruki OKANO, Hiromichi MATSUSHITA and Yasutaka SAGAWA
Technology Reports of Kyushu University, Vol.72, No.3, pp.231-238, May 1999. |
| 117. |
Experiment of Carbon Fiber Sheet on CFRP Adhesive Method
Koyo TAKEO, Hiromichi MATSUSHITA, Terumasa YAHARA and Yasutaka SAGAWA
Proceedings of the Japan Concrete Institute, Vol.20, No.1, pp.431-436, July 1998. |
