Hybrid Road Barrier Design As Aesthetic Safety Feature and Urban Furniture

Abstract— There are various types of road barriers such as steel W beam, steel cable, concrete and wooden (timber) that have been used all over the World. They all have some advantages and disadvantages from different kinds of aspects such as construction time, ease of installation, low-cost, proven effectiveness, impact resistance, durability, service life, maintenance, etc. but to attain a more pleasant drive especially in historical and natural urban roads or scenic highways, installing wooden (timber) barriers can be considered as a more aesthetically pleasing alternative. In addition to aesthetic, wooden barriers can be preferred for their impact energy and sound absorption capabilities especially in urban roads. With the design, it is also estimated that light effect of oncoming traffic will be blocked. The main idea is to use hybrid barriers for both aesthetic safety feature in scenic or historical roads and urban furniture. This paper also summarizes comparisons among conventional road barrier systems considering the European standard EN 1317, Road Restraint Systems and provides a discussion of future designs.   Index Terms—road restraint system, timber barrier, hybrid barrier, road barrier, urban furnitur

Effects of factors on direct screw withdrawal resistance in medium density fiberboard and particleboard

An increase in demand on solid wood that is insufficient supply to meet in the world necessarily directed to other engineering materials that could be an alternative to the solid wood. In this context, instead of using solid wood in furniture and construction industry, wood-based panels such as medium density fiberboard (MDF) and particleboard (PB) have become widely used as construction material. Limited research has been done in the field of fastener performance as mechanical properties with different parameters in the joints constructed with these panels. Therefore, in this study, the parameters of screw type, pilot hole, screw orientation, water treatment and adhesives were investigated in MDF and PB. The results indicated that the highest direct screw withdrawal (DSW) resistance was observed in the test blocks applied with PU and the lowest DSW resistance was in the test blocks without a pilot hole drilled in both materials. In addition, MDF in general had better DSW resistance than PB in almost all combinations of the parameters. The treatment of water into MDF and PB test blocks negatively affects the DSW resistance. The DSW resistance in the face orientation was found to be higher than the corresponding ones in the side orientation in both materials

Utjecaj starenja na neka fizikalna i mehanička svojstva škotske borovine upotrebljavane za gradnju povijesnih kuća u Safranbolu

Wood has been a favourite construction material since the ancient times because of its natural beauty and excellent properties, such as high specific strength, heat insulation and ease of handling and processing. It was also used in Safranbolu, where Turkish Ottoman civil architectural samples have been carefully protected and preserved without losing their originality. It was inscribed to “The World Heritage List” by UNESCO in 1994. In this study, density, Brinell hardness and compression strength perpendicular to the grain of Scotch pine (Pinus Sylvestris Lipsky.) wood, from the fl oor joist of 10 different demolished historical Safranbolu houses for 10 different years, were determined and compared with those of wood from freshly cut trees. The highest decrease in compression strength perpendicular to the grain of salvaged Scotch pine wood used as floor joist for 210 years was nearly 27 percent lower than those of wood from freshly cut Scotch pine. The results indicate that the physical properties, Brinell hardness and compression strength perpendicular to the grain of the Scotch pine wood were significantly affected by the 210-year service life.Drvo je još od antičkih vremena zbog svoje prirodne ljepote i izvrsnih svojstava kao što su velika specifična čvrstoća, toplinska izolacija i jednostavnost rukovanja i obrade često upotrebljavano kao građevni materijal. Ono je za tu namjenu iskorištavano i u Safranbolu, gdje su tursko-osmanski civilni arhitektonski primjerci pažljivo zaštićeni i očuvani bez narušavanja njihova originalnog izgleda. Ta je kulturna baština 1994. godine upisana u Popis svjetske baštine UNESCO-a. U ovom su istraživanju prikazani rezultati mjerenja gustoće, tvrdoće prema Brinellu i tlačne čvrstoće okomito na vlakanca na uzorcima drva škotskog bora (Pinus sylvestris Lipsky.) napravljenima od podnih greda iz deset različitih demoliranih povijesnih kuća iz Safranbola iz deset različitih godina. Te su vrijednosti uspoređene s vrijednostima izmjerenima na uzorcima od drva svježe srušenih stabala škotskog bora. Najveće smanjenje tlačne čvrstoće okomito na vlakanca izmjereno je na uzorcima od škotske borovine koja je 210 godina služila kao podna greda. Ta je tlačna čvrstoća bila gotovo 27 % manja od tlačne čvrstoće drva svježe srušenih stabala škotskoga bora. Rezultati pokazuju da je na fizikalna svojstva škotske borovine, tvrdoću prema Brinellu i čvrstoću okomito na vlakanca znatno utjecalo 210 uporabnih godina

Utilization of Waste Polyethylene and its Effects on Physical and Mechanical Properties of Oriented Strand Board

The effect of adding waste polyethylene (WPE) was investigated at various ratios on some physical and mechanical properties of oriented strand board (OSB) panels. All of the test panels were bonded with 6% phenol-formaldehyde resin in three layers. The manufacturing parameters was 0/100, 10/90, 20/80, 30/70, 40/60, and 50/50 by weight% of WPE/wood strand. All the boards were manufactured to achieve targeted specific gravity of 0.65 g/cm3. Polyethylene improved the water resistance of the OSB panels because of its hydrophobicity. Based on the results of this study, thickness swelling, humidity, dimensional stability, water absorption, and screw withdrawal resistance of the samples were improved significantly. However, MOE, MOR, and internal bond strength values of the samples decreased with increasing WPE in the panels when compared to the control panels but met minimum requirements in EN 300 (type 1-2-3-4) control panels. The conclusion was reached that waste polyethylene can be used in the manufacture of OSB panels, resulting in the enhancement of above mentioned physical and mechanical properties, as well as a safe disposal and economical utilization

Simulating Strength Behaviors of Corner Joints of Wood Constructions by Using Finite Element Method

Using finite element method (FEM) has become wide spread in the field of wood mechanics for analyzing difficult problems instead of conventional methods. The objective of this study is to determine the strength properties of wood corner joints using FEM. For this purpose, diagonal compression and diagonal tension experiments were carried out using dowel, mortise and tenon elements. Corner joints (L-type) were prepared with Scotch pine (Pinus sylvestris L.) and Beech (Fagus orientalis Lipsky) woods. Data obtained experimentally were used in FEM computer modeling to determine structural specifications of wood materials. The amount of deformation as a result of compression-tension in the corner joints was determined and then simulated with a computer program using FEM (ANSYS Multiphysics/LS-DYNA). As a result, the amount of deformation obtained from experiments was consistent with the FEM computer modeling with 90 to 97 \%. It is suggested that strength properties of joints can be forecast by using FEM computer modeling instead of physical experiments that may cause loss of time, increase of cost and destruction of materials

Effects of factors on direct screw withdrawal resistance in medium density fiberboard and particle board

An increase in demand on solid wood that is insufficient supply to meet in the world necessarily directed to other engineering materials that could be an alternative to the solid wood. In this context, instead of using solid wood in furniture and construction industry, wood-based panels such as medium density fiberboard (MDF) and particleboard (PB) have become widely used as construction material. Limited research has been done in the field of fastener performance as mechanical properties with different parameters in the joints constructed with these panels. Therefore, in this study, the parameters of screw type, pilot hole, screw orientation, water treatment and adhesives were investigated in MDF and PB. The results indicated that the highest direct screw withdrawal (DSW) resistance was observed in the test blocks applied with PU and the lowest DSW resistance was in the test blocks without a pilot hole drilled in both materials. In addition, MDF in general had better DSW resistance than PB in almost all combinations of the parameters. The treatment of water into MDF and PB test blocks negatively affects the DSW resistance. The DSW resistance in the face orientation was found to be higher than the corresponding ones in the side orientation in both material

Renewable Hybrid Roadside Barrier: Optimization of Timber Thickness

Researchers have recently focused on new and original roadside barriers that prioritize aesthetic, and environmental concerns by employing natural materials. In this study, the safety performance (Acceleration Severity Index (ASI), Theorical Head Impact Velocity (THIV)), structural performance (Working Width (W), Exit Angle (α)), and failure analysis (visual deformation) of a newly developed Renewable Hybrid Barrier (RHB) system at different timber thicknesses were tried to be determined by pendulum crash test and Finite Element (FE) models. The FE models were calibrated and validated based on pendulum crash test results, and then the most suitable timber thickness in terms of safety and structural performance was determined via FE analyses. The results revealed that as the timber thickness decreased, the safety parameters, such as ASI and THIV, decreased, thus the barrier safety increased. However, it was observed that the deflection and deformations in the barrier increased as the timber thickness decreased. In this sense, the safest and the most structurally durable barrier was determined through conducting virtual optimization tests. Studies on diversification of the usage areas of natural/renewable materials should be increased in the future