• 한국가구학회지
• /
• 제27권2호
• /
• pp.137-144
• /
• 2016

Wood plastic composite (WPC) is a green composite made of wood flour and thermoplastics to provide better performance by removing the defects of both wood and plastics. However, relatively low thermal stability and poor fire resistance of wood and plastics included in WPC have been still issues in using WPC as a building material for interior applications. This study investigated the effect of environmentally-friendly flame retardants (EFFRs) on the mechanical, thermal, morphological, and water absorption properties of wood flour (WF)/talc/polypropylene (PP) composites in comparison with neat PP. The whole EFFRs-filled WF/talc/PP composites showed higher values in flexural strength, flexural modulus, and impact strength compared to neat PP. In thermal properties, aluminum hydroxide (AH)-filled composite showed a $36^{\circ}C$ reduction in maximum thermal decomposition temperature ($T_{max}$) compared to neat PP, but magnesium hydroxide (MH) played an important role in improving thermal stability of filled composite by showing the highest $T_{max}$. From this research, it can be said that MH has potentials in reinforcing PP-based WPCs with improvement of thermal stability.

• 한국농공학회논문집
• /
• 제51권1호
• /
• pp.21-26
• /
• 2009

This study was performed to evaluate the physical and mechanical properties of concrete using waste activated carbon. Materials used were ordinary portlant cement, crushed coarse aggregate, natural fine aggregate, waste activated carbon, and superplasticizer. The substitution ratios of waste activated carbon were 0,1,2,3,4,5,6,7,8,9 and 10%. The unit weight was decreased and water absorption ratio was increased with increasing the waste activated carbon content, respectively. When the substitution ratio of waste activated carbon was 3%, compressive strength, flexural strength and dynamic modulus of elastisity were more higher than that of the ordinary portland cement (OPC), and it was decreased with increasing the waste activated carbon content, respectively. The most effective contents of waste activated carbon was 2% in performance and 4% in practical use Accordingly, waste activated carbon can be used for concrete material.

• 한국의류학회지
• /
• 제22권6호
• /
• pp.609-609
• /
• 1998

This paper surveys the effect of rice straw ash solution to the physical properties of Sappan Wood dyeing fabrics. In the quantitative analysis of rice straw ash solution, the quantities of absorbed ingredients in fabrics were increased by bath pull treatment but the amount of absorption(K/S value) was increased by bath pH4.5 treatment. This is related to the metal ion. Among the metal ion, effect of Fe iou and Al ion were related. In case added extracted dye solution to mordants, the color dye solution became dark and increased reddish. The changes of mechanical properties of fabrics tensile resilience, bending rigidity(B), compressional resilience(RC) were increased. Generally mechanical properties were increased by rice straw ash solution treatment, specially bath pH9 treatment. Rice straw ash solution treatment of dyeing fabrics made the improvement in tensile strength and elongation and in the amount of absorption, dye ability, color fastness, mechanical properties, tensile strength, elongation.

• 한국의류학회지
• /
• 제22권6호
• /
• pp.699-705
• /
• 1998

This paper surveys the effect of rice straw ash solution to the physical properties of Sappan Wood dyeing fabrics. In the quantitative analysis of rice straw ash solution, the quantities of absorbed ingredients in fabrics were increased by bath pull treatment but the amount of absorption(K/S value) was increased by bath pH4.5 treatment. This is related to the metal ion. Among the metal ion, effect of Fe iou and Al ion were related. In case added extracted dye solution to mordants, the color dye solution became dark and increased reddish. The changes of mechanical properties of fabrics tensile resilience, bending rigidity(B), compressional resilience(RC) were increased. Generally mechanical properties were increased by rice straw ash solution treatment, specially bath pH9 treatment. Rice straw ash solution treatment of dyeing fabrics made the improvement in tensile strength and elongation and in the amount of absorption, dye ability, color fastness, mechanical properties, tensile strength, elongation.

• 한국농공학회지
• /
• 제45권6호
• /
• pp.128-135
• /
• 2003

This study is performed to examine the physical and mechanical properties of concrete using recycled aggregate and industrial by-products. The test results show that the unit weight, compressive and flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity are decreased with increasing the content of recycled aggregate. But, the absorption ratio is increased with increasing the content of recycled aggregate. The unit weight is 2,237∼2,307 kg/$\textrm{m}^3$, the absorption ratio is 2.96∼4.12%, the compressive strength is 415∼532 kgf/$\textrm{cm}^2$, the flexural strength is 75∼96 kgf/$\textrm{cm}^2$, the ultrasonic pulse velocity is 4,350∼4,949 m/s and the dynamic modulus of elasticity is $390\times10^3\;∼\;465\times10^3$ kg f/$\textrm{cm}^2$, respectively These recycled aggregate concrete can be used for high strength concrete.

• Computers and Concrete
• /
• 제22권4호
• /
• pp.407-417
• /
• 2018

Over the past three decades, self-compacting concrete (SCC), which is characterized by its superior rheological properties, has been gradually used in construction industry. It is now recognized that the application of SCC using supplementary cementitious materials (SCM) is highly attractive and promising technology reducing the environmental impact of the construction industry and reducing the higher materials costs. This paper presents an experimental study that investigated the mechanical and durability properties of SCCs manufactured with blended binders including fly ash, slag, and micro-silica. A total of 8 batches of SCCs were manufactured. As series of tests were conducted to establish the rheological properties, compressive strength, and durability properties including the water absorption, water permeability, rapid chloride permeability and initial surface absorption of the SCCs. The influences of the SCC strength grade, blended types and content on the properties of the SCCs are investigated. Unified reactive indices are proposed based on the mix proportion and the chemical composition of the corresponding binders are used to assess the compressive strength and strength development of the SCCs. The results also indicate the differences in the underlying mechanisms to drive the durability properties of the SCC at the different strength grades.

• 한국세라믹학회지
• /
• 제46권6호
• /
• pp.633-638
• /
• 2009

Lightweight materials were fabricated using glass abrasive sludge, bottom ash and slag powder in this study. This study tried to draw the correlation between physical properties and internal pore of lightweight material. The content of bottom ash and slag powder was from 10% to 50% and firing temperature from $760{^{\circ}C}\;to\;800{^{\circ}C}$ in rotary kiln. The lightweight material containing bottom ash or slag powder had a specific gravity of $0.21{\sim}0.70$ at particle size $2{\sim}4$ mm. Replacement ratio of the admixture increasing with specific gravity increased. Fracture strength of panel made with various lightweight materials was $32{\sim}55\;kgf/cm^2$ and flexural strength was $11{\sim}18\;kgf/cm^2$. Fracture strength increased by 72% and flexural strength was 63% compared with reference. Thermal conductivities of panel was $0.07{\sim}0.11W/m{\cdot}k$. The water absorption ratios of panel with lightweight materials containing bottom ash were $1.8{\sim}2.8$% and slag powder were $2.65{\sim}2.8$%. Excellent results on resistant of water absorption.

• International Journal of Ocean System Engineering
• /
• 제1권3호
• /
• pp.148-154
• /
• 2011

Generally, strength degradation is caused by the absorption of moisture in composites. For this reason, a fracture is generated in the composites and traces of glass fiber degrade human health and physical damage is generated. Therefore, in this research, we studied the mechanical properties change of composites by moistureabsorption. The composites were manufactured with and without the Gel-coating process and were immersed in a moisture absorption device at $80^{\circ}C$ for more than 100 days. The mechanical properties of the moistureabsorption composites and the composites which dry after moisture-absorption were compared. The mechanical properties degradation of basalt fiber composites according to the result of the measurement of moistureabsorption was smaller than that of glass fiber composites by about 20%. In addition, the coefficient of moisture absorption was lower for the case of Gel-coating processing than the composites without the Gel-coating process by about 2% and it was deduced that Gel-coating did not have a significant effect on the mechanical properties.

• Journal of the Korean Wood Science and Technology
• /
• 제17권4호
• /
• pp.26-34
• /
• 1989

This study was carried out to manufacture bark board from oak bark by new processes and to examine the physical and mechanical properties of the board. This process with no addition of adhesive used higher pressure and temperature than the conventional one and was applied with or without paraformaldehyde. The results are as follows: 1. The new manufacturing process allowed a good bark board with high absorption coefficient. 2. The best manufacturing process for the mechanical properties of bark board was paraformaldehyde 10%-$250^{\circ}C$-100kg/$cm^2$-3 minutes, (bending strength 40kg/$cm^2$, internal bonding strength 2kg/$cm^2$) and the best manufacturing process for both the mechanical properties of bark board and economic point of view was $250^{\circ}C$-100kg/$cm^2$-3 minutes (bending strength 28kg/$cm^2$, internal bonding strength 1.52kg/$cm^2$). 3. Bark board showed specific gravities from 0.94 to 1.03 and air dried moisture content 9.2% to 11.7%, but Bark board needed paraffin wax emusion treatment. 4. The absorption coefficient of bark boards had two peaks along with frequency; one in 200-400 cps, the other 1200-2000 cps. The former was low but the latter great.

• 폴리머
• /
• 제37권1호
• /
• pp.113-120
• /
• 2013

Pilot scale에서의 나노복합체의 상용화를 위해 용융 삽입법을 적용하고 이축 압출기로 제조한 polyamide/MMT 나노복합체의 흡습 특성을 연구한 결과, MMT 도입으로 수분 흡수율이 감소되었으며 그에 따라 치수 안정성이 향상되었다. 굴곡강도 및 탄성률은 수분 흡수율이 증가함에 따라 저하되었으며, 이로부터 MMT의 도입은 강도 향상효과와 함께 흡습방지를 통한 강도 저하 억제효과도 보이는 것으로 조사되었다.