배합조건 및 다짐하중에 따른 포러스 콘크리트의 특성에 관한 실험적 연구

임서형 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.3

포러스 콘크리트는 시멘트, 물 그리고 굵은골재로 구성되어 있으며, 공기 및 물의 투과 그리고 흡음 등 지구 환경부하를 저감시키기 위 해 사용되어 왔다. 그러나 포러스 콘크리트의 물리적, 역학적 성상은 시공시 이루어지는 다짐하중에 의해 변한다. 따라서 본 연구에서는 결 합재 종류, 물-결합재비, 목표공극율에 따른 포러스 콘크리트의 물리적, 역학적 성상을 파악하였으며 특히, 다짐하중에 따른 포러스 콘크리 트의 공극율, 강도, 투수계수의 물성변화를 파악하였다. 본 연구에서 사용한 골재는 부순자갈 생산과정에서 발생되는 부산물로서 최대크기 는 13mm이다. 연구결과, 포러스 콘크리트의 목표 공극율, 투수계수, 압축강도는 공극율과 밀접한 상관성을 지니고 있으며, 공극율은 포러 스 콘크리트의 배합설계로 제시할 수 있는 가능성이 있는 것으로 판단되다. 포러스 콘크리트의 압축강도는 팽창재 치환율 5%에서 가장 높 게 나타났으며, 실리카 흄 치환율 10%에서 치환하지 않은 콘크리트보다 32% 높게 나타났다. 그리고 다짐하중을 변화시킨 본 연구결과 압 축강도는 하중 15kN부터 증가하였고, 공극율은 하중 0.8kN부터, 투수계수는 하중 35kN부터 각각 감소하는 것으로 나타났다. Porous concrete consists of cement, water and coarse aggregate and has been used for the purpose of decreasing the earth environmental load such as air and water permeability, sound absorption, etc. However, the physical and mechanical properties of porous concrete changes due to compaction load during construction. For such a reason, the purpose of this study is to investigate the physical and mechanical properties of porous concrete according to the kinds of binder, the ratio of water to binder and target void ratio. In particular, this study has been carried out to investigate the influence of compaction load on the void ratio, strength and coefficient of permeability. Aggregate used in this study are by-products generated during production of crushed gravel with a maximum size of 13mm. The results of this study showed that the target void ratio, the coefficient of permeability and compressive strength of porous concrete had a close relationship with the void ratio, and it will be possible that the void ratio is suggested by the mix design of porous concrete. The compressive strength of porous concrete was the highest at the content of the expansive admixture of 5% and compared to non-mixture, 10% mixture of silica fume improved compressive strength about 32%. And in the result of the study to change the compaction load, the compressive strength increased from the load of 15kN, the void ratio decreased from the load of 0.8kN, the coefficient of permeability decreased from the load 35kN, respectively.

하악 구치부에 식립한 sintered porous surfaced implants의 후향적 다기관 연구

김우성(Woo-Sung Kim),안경미(Kyung Mi An),손동석(Dong-Seok Sohn),정희승(Heui-Seung Jung),신임희(Im-Hee Shin) 대한치과의사협회 2009 대한치과의사협회지 Vol.47 No.12

Purpose: The aim of this study was to evaluate the survival rate of sintered porous-surfaced implants placed in the edentulous posterior mandibles, in relation to implant length and diameter, crown-to-implant ratio, and types of prostheses, for a maximum of eight years of functioning. Material and Methods: The study group consisted of 43 partially edentulous patients who visited Catholic University Hospital of Daegu and one private dental clinic. A total of 122 sintered porous-surfaced implants - Endopore<SUP>R</SUP> (Innova Life Sciences, Toronto, Ontario, Canada) - were placed in the edentulous posterior mandibles. Two diameter sizes (4.1 ㎜ and 5.0㎜) and four lengths (5.0㎜, 7.0㎜, 9.0㎜, and 12.0㎜) were used. One hundred and three implants were splinted and 21 implants were non-splinted. The survival rates of the implants in relation to length, diameter, crown-to-implant ratio, and types of prostheses were investigated. Statistical data were analyzed using SPSS Win. Ver 14.0 software with the Chi-square test. Results: The survival rate of the 4.1㎜ diameter implants was 100% and 91.2%) for the 5.0㎜ diameter implants. The survival rates of the implants of differing diameters were found to be statistically different (p=0.005). The survival rates of both the 5.0㎜ and 7.0㎜ length implants were 100%. The survival rate of the 9.0㎜ length implants was 97.9% and for the 12.0㎜ length implants was 95.1%. There was no statistical difference in survival rates for the differing lengths of implants. Of the 103 prostheses that were splinted, the survival rate was 98.0%. The survival rate of splinted prostheses was higher than that of the non-splinted prostheses, but was found to be not statistically different. There were no failed cases when the crown-to-implant ratio was under 1.0. When the crown-to-implant ratio was between 1.0 and 1.5, the failure rate of the implants was 6.7%. No failure was recorded with the ratio range of 1.5 to 2.0. Relative to the crown-to-implant ratio of 1.0, the failure rates were statistically different (p=0.048). Discussion and Conclusion: The cumulative survival rate of the porous-surfaced implants placed in the edentulous posterior mandibles was 97.5%. Short porous-surfaced implants showed satisfactory results after a maximum of nine years of functioning in the edentulous posterior mandibles.

황토를 포함한 다공성 식생콘크리트의 역학적 특성 및 내약품성에 미치는 보강섬유의 효과

이진형(Lee Jin-Hyung),박찬기(Park Chan-Gi),박종식(Park Jong-Sik) 대한토목학회 2011 대한토목학회논문집 A Vol.31 No.2A

본 연구는 보강섬유의 종류(마섬유, 펄프섬유, PVA섬유, 나이론섬유) 및 혼입률(0.0%, 0.1%, 0.2%, 0.3%)이 다공성 식생콘크리트의 역학적 특성과 내약품성에 미치는 효과를 평가하였다. 시험은 섬유의 종류 및 혼입률의 변화에 따른 다공성 식생콘크리트의 압축강도, 공극률, pH, 휨강도 및 내약품성 특성을 분석하기 위하여 수행하였다. 섬유의 종류 및 혼입률은 다공성 식생콘크리트의 압축강도, 공극률 및 내약품성에 영향을 미쳤다. 섬유의 혼입률이 증가할수록 압축강도, 휨강도 및 공극률은 증가하였다. 그렇지만 다공성 식생콘크리트의 pH 값과 내약품성은 섬유의 종류 및 혼입률의 변화에 큰 영향이 없었다. This study evaluated the effects of fibers on the mechanical properties and chemical solution resistance of porous concrete with fiber type (jute, pulp, PVA and nylon fiber) and fiber volume fraction (0.0%, 0.1%, 0.2%, 0.3%). The tests that were carried out to analysis the properties of porous concrete included compressive strength, void ratio, pH value, and chemical solution exposure with varying type and volume fraction of fiber were conducted. The type and volume fraction of fiber also affected the void ratio, compressive strength, flexural strength and chemical solution exposure. Increased volume fractions of fiber resulted in improved properties of the compressive strength, flexural strength and void ratio. However, the difference between the measured pH value and chemical resistance of porous concrete with fiber type and volume fraction was not significant.

솔-젤법에 의한 다공성 실리카 세라믹스의 제조-$H_2O/TEOS$ 몰비의 영향-

이진휘,김화중,이준,Lee, Jin-Hui,Kim, Wha-Jung,Lee, Joon 한국세라믹학회 1997 한국세라믹학회지 Vol.34 No.2

TEOS와 에탄올의 양을 고정하고 H2O/TEOS의 몰비가 2.6-59.0이 되는 범위에서 염산촉매를 사용하여 다공성 실리카 세라믹을 제조하였다. 서로 다른 조성의 솔 9종을 만든 후 젤화시간 측정, TG/DTA에 의한 건조시료의 열분석 및 FT-IR과 X-ray diffractometer에 의한 중간생성물의 특성분석을 수행하였고 50$0^{\circ}C$까지 열처리한 시료의 FT-IR에 의한 SiO2폴리머 분석, N2-adsorption isotherm을 이용한 비표면적과 기공크기분포 조사 및 TEM에 의한 SiO2폴리머의 형태와 기공의 변화를 조사하였다. 적용된 조성 및 촉매의 농도에서 최소 젤화반응시간은 TEOS1몰달 물의 양이 약 11몰에서, 가장 높은 중합도는 약 8-18몰에서, 그리고 가장 큰 비표면적값은 약 11몰에서 보였다. 이것은 물의 양이 약 11몰일 때 중합반응이 가장 빠르게 진행하였음을 의미한다. 결론적으로, 물의 양이 증가함에 따라서 약 11몰까지는 반응이 빠르게 진행되나 그 이상의 물이 사용될 경우 과잉의 물이 반응저해요인으로 작용하여 젤화시간의 지연 및 비표면적의 감소를 보인다. Porous silica ceramics were prepared(with HCI catalyst) using H2O/TEOS molar ratios of 2.6~59.0, with the EtOH/TEOS ratio fixed. After preparing 9 kinds of sol, the followings were investigated; measurement of the gelation time, thermal analyses by TG/DTA, property analyses of the intermediates by FT-IR and X-ray diffractometry with dried samples, analyses of SiO2 polymer by FT-IR, the investigation of specific sur-face area and pore size distribution by N2-adsorption isotherm, and structural change of SiO2 polymer and pore morphology by TEM observation, with samples heat-treated to 50$0^{\circ}C$. In the concentrations of in-vestigated compositions and catalyst, gelation time showed a minimum at ca. 11 moles of water per one mole of TEOS, the highest degree of polymerization at ca. 8-18 moles, and the largest specific surface area at ca. 11 moles, which means that the polymerization proceeded fastest at ca. 11 moles of water. In con-clusion, the more water used, the faster the polymerization reaction up to ca. 11 moles, but more than ca. 11 moles of water caused retardation of gelation and resultant reduction of specific surface area.

반복 융해 수분 처리에 따른 다공성 아스팔트의 동탄성계수 변화

유재원(Yoo, Jaewon),Tan Hung Nguyen,안재훈(Ahn, Jaehun) 한국방재학회 2019 한국방재학회논문집 Vol.19 No.7

다공성 아스팔트는 투수성이 높기 때문에, 도로의 안전성 향상 및 우수 관리에 효과적이다. 하지만 표면 배수층으로 물에 자주 노출되기 때문에 수분에 의한 영향을 받는다. 본 연구에서는 공극율이 7.7%, 8.3%인 다공성 아스팔트 혼합물의 건조 및 수분 처리 과정을 실시하고, 동탄성계수 시험을 수행하였다. 각 1회의 수분 처리 과정은 60 °C의 항온수조에 24 시간 수침 후 25 °C의 다른 항온수조에서 추가로 2 시간 수침하였다. 기존의 연구결과와 비교하였을 때, 다공성 아스팔트 혼합물의 낮은 공극율에서 동탄성계수는 더 높게 나타났고, 1회의 수분 처리 과정 후 동탄성계수는 전체적으로 증가하는 경향을 나타났다. 하지만 2회의 수분 처리 과정 후에는 다공성 아스팔트 혼합물에서 손상이 발생하여 오히려 감소하였다. 동탄성계수 비를 이용하여 온도 및 하중재하 주기에 대한 영향을 분석한 결과, 다공성 아스팔트의 동탄성계수는 하중재하 주기보다 온도변화에 따라 더 민감하게 나타났다. Porous asphalt has been used for permeable pavements to improve the safety of roadways and the effectiveness of storm-water management. As a surface drainage that is frequently exposed to water, it is affected by moisture. In this study, dynamic modulus tests were performed on both unconditioned and moisture-conditioned specimens with air-void contents of 7.7% and 8.3% to investigate the viscoelastic properties. One cycle of the moisture-conditioning procedure included placing the specimens in a water tank at 60 °C for 24 h, and subsequently in a water tank at 25 °C for additional 2 h. The results showed that the specimens with lower air-void content exhibited higher values of dynamic modulus. After one cycle of moisture conditioning, the dynamic modulus of the porous-asphalt mixture overall increased. However, the dynamic modulus was reduced by damage after two conditioning cycles. On the basis of the results of the effect of temperature and load frequency on the dynamic-modulus ratio, we can conclude that the dynamic modulus of porous asphalt is more sensitive to temperature than to frequency.

Hydration, Strength and pH Properties of Porous Concrete Using Rice Husk Ash

Kim, Young-Ik,Sung, Chan-Yong The Korean Society of Agricultural Engineers 2007 한국농공학회논문집 Vol.49 No.3

This study was performed to evaluate void ratio, compressive and flexural strengths, and pH properties according to the content ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with content of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash for the weight of cement formed more C-S-H hydrates due to the $SiO_2$ of rice husk ash. In the XRD test, cement mortar with a 5% rice husk ash for the weight of cement registered a higher peak point of approximately $2{\theta}=20{\sim}25^{\circ}$ compared to cement mortar without rice husk ash. According to the results of the XRD and SEM tests, the $SiO_2$ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with rice husk ash decreased with increasing content ratio of rice husk ash. In addition, the void ratio of porous concrete with rice husk ash decreased compared to porous concrete without rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% content ratio of rice husk ash slightly increased compared to concrete without rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. However, the pH value was nearly the same regardless of neutral treatment time in 28 curing days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels (less than 9.5) in all mixtures for planting at 28 curing days.

식생 적용을 위한 왕겨재와 순환골재를 활용한 포러스 콘크리트의 공극률 및 강도 특성

김영익(Young-Ik Kim),성찬용(Chan-Yong Sung) 충남대학교 농업과학연구소 2006 Korean Journal of Agricultural Science Vol.33 No.2

This study was performed to evaluate void ratio, compressive and flexural strength, and pH properties according to the admixture ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with an admixture of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash admixture for the weight of cement formed more C-S-H hydrates due to the SiO₂ present in the applied rice husk ash. According to the results of the SEM test, the SiO₂ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with an admixture of rice husk ash decreased with increasing admixture ratio of rice husk ash. In addition, the void ratio of porous concrete with an admixture of rice husk ash decreased compared to porous concrete with no admixture of rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% admixture ratio of rice husk ash slightly increased compared to concrete with no admixture of rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels(less than 9.5) in all mixtures for planting at 28 curing days.

식생 적용을 위한 왕겨재와 순환골재를 활용한 포러스 콘크리트의 공극률 및 강도 특성

김영익(Young-Ik Kim),성찬용(Chan-Yong Sung) 충남대학교 농업과학연구소 2006 농업과학연구 Vol.33 No.2

This study was performed to evaluate void ratio, compressive and flexural strength, and pH properties according to the admixture ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with an admixture of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash admixture for the weight of cement formed more C-S-H hydrates due to the SiO₂ present in the applied rice husk ash. According to the results of the SEM test, the SiO₂ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with an admixture of rice husk ash decreased with increasing admixture ratio of rice husk ash. In addition, the void ratio of porous concrete with an admixture of rice husk ash decreased compared to porous concrete with no admixture of rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% admixture ratio of rice husk ash slightly increased compared to concrete with no admixture of rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels(less than 9.5) in all mixtures for planting at 28 curing days.

고로슬래그시멘트를 사용한 다공성 황토콘크리트의 성능 평가

김황희,강수만,박종식,박상우,전지홍,이진형,차상선,박찬기,Kim, Hwang-Hee,Kang, Su-Man,Park, Jong-Sik,Park, Sang-Woo,Jeon, Ji-Hong,Lee, Jin-Hyung,Cha, Sang-Sun,Park, Chan-Gi 한국농공학회 2010 한국농공학회논문집 Vol.52 No.3

This study aims to evaluate a porous concrete using hwang-toh, blast furnace slag and blast furnace slag (BFS) cement instead of type I cement. The tests that were carried out to analysis the properties of porous hwang-toh BFS cement concrete included compressive strength, continuous void ratio, absorption rate, and pH value, repeated freezing and thawing test were conducted. Test results indicated that the performance in porous hwang-toh concrete are effective on the kaoline based binder materials. The pH value were shown in about 9.5 ~ 8.5. The compressive strength was increased and void ratio was decreased with increasing the kaoline based binder materials, respectively. The void ratio and compressive strength were in the range of about 21 ~ 30 %, 8 ~ 13 MPa, respectively. The increased in void ratio of more than 25 % is showed to reduce the resistance of repeated freezing and thawing. Also, the resistance of repeated freezing of thawing and the compressive strength of porous hwang-toh BFS cement concrete are independent with hwang-toh content and BFS cement amount. But, the void ratio was decreased with increasing the high volume hwang-toh contents (more than 15 %).

괴재슬래그를 이용한 포러스 콘크리트의 투수성 및 강도 특성

이경동 ( Gyeong-dong Lee ),한재익 ( Jae-ik Han ) 한국환경기술학회 2015 한국환경기술학회지 Vol.16 No.1

본 연구에서는 산업부산물인 괴재슬래그를 이용하여 배합설계를 실시한 포러스 콘크리트의 투수성, 강도특성에 미치는 영향을 파악하기 위한 실험을 실시한 결과 공극률은 20%이상이며, 연속공극은 전공극의 80%이상을 차지하고 있었다. 이때 공극률은 골재의 입경이 커짐에 따라 다소 증가하는 경향이 나타났고, 단위 시멘트량이 증가할수록 감소하였다. 그리고 포러스 콘크리트의 압축강도는 6 이상, 휨강도 및 인장강도는 압축강도의 ~ 및 ~로 보통 콘크리트에 비하여 압축강도에 대한 휨강도나 인장강도의 강도발현이 높다는 것을 알 수 있었으며, 투수계수는 골재 입경이 커지면 공극률이나 공극경도 커져서 적은 폭으로 증가한 반면에 단위 시멘트량이 증가할수록 상대적으로 큰 폭으로 감소하였다. 이상의 결과로 볼 때, 포러스 콘크리트는 용도에 따라 적절한 배합을 선택함으로써 투수콘크리트나 다공질콘크리트 제품 등에 적용할 수 있을 것으로 판단된다. n this study, some experiments are carried out to investigate the permeability and the strength properties of porous concrete(PoC) made with ground air-cooled blast furnace slag of industrial by-products. PoC specimens were made according to concrete mix design, PoC`s void ratio was over 20%, the continuous void ratio(C.V.R.) was over 80% of the total void ratio(T.V.R.). The larger size distribution of aggregate, the higher C.V.R. was exhibited. And the more unit cement content, the lower void ratio was exhibited. PoC specimens had compressive strength of more than 6 , the ratio of flexural strength to compressive strength varies from to and that of tensile strength to compressive strength varies from to . Therefore the ratio of flexural strength and tensile strength to compressive strength of PoC are higher than corresponding ratios of conventional concrete. As size distribution of aggregate increased, the void ratio and the permeability increased slightly. But, as the unit cement content increased, the permeability increased significantly. By these results, PoC can be used to produce a permeable and porous concrete products.