scholarly journals Study on behaviors of wave-dissipating concrete blocks of submerged breakwater around the Fukui Port using GPS

2008 ◽  
Vol 55 ◽  
pp. 966-969
Author(s):  
Hiroshi YOSHINAGA ◽  
Yoshiyuki OOSHITA ◽  
Tadashi WATANABE ◽  
Yasutaka TAKAMOTO ◽  
Takemitsu TAKANO
1964 ◽  
Vol 1 (9) ◽  
pp. 38
Author(s):  
Duarte Abecasis

The urgent necessity for providing a system of protective works of the harbour of Leixoes with complementary works to improve the poor con ditions of the shelter in the basin and to protect ships entering the port became evident in 193^* In fact, the frequency of disaster to trawlers and to other ships within the basin during southwestern gales as well as the very dangerous conditions at the entrance under such gales were incompatible with the increasing economic importance of Oporto and its hinterland. These bad conditions culminated in the foundering of the 9000 T Dutch steamship "Orania" at anchor in the basin colliding on the 19th December 193^ with the steamship "Luanda" when entering the harbour under severe hurricane. The construction of the 1000 m long new breakwater was started wit a 15 m wide vertical wall to be set partly on rocky bottom and partly o a sandy bottom. Before leaving the rocky bottom the upper part of the wall was destroyed by a strong gale (Fig. l). For the advancement of t work the contractor and an official commission recommended the adoption of the Casablanca type of slope work. For economical reasons and on those of the sure possibility of its conversion into a conventional type of work, would it become convenient it was decided, at the author's suggestion, and after model study at Lausanne School of Engineer's Laboratory, to adopt a new type of submerged work, to replace the unsuccessful vertical type or the type of Casablanca proposed by the contractor (Fig. 2). The section adopted coi prised a rubble mound core of stones to 1• with the crest at level (-9m00), and berms of rubble to kF, 12 m wide to the sea side and 10 m wide to the port side (Fig. l). T The top and slopes of the mound were protected by an armour of 90 concrete blocks with the corners cut for best accommodation. The cost of the work could be reduced to half of that corresponding to the last of these types of breakwaters and its maintenance charge greatly reducec The estimated cost of the works would be reduced from JL 1.770.000 to £. 880.000 and the maintenance charges foreseen reduced from £ 35*^00 yearly to £ 2.800 yearly (comparison with the Casablanca type).


2020 ◽  
pp. 49-52
Author(s):  
S.E. YANUTINA ◽  

The relevance of research in the factory laboratory of JSC «198 KZHI», which is part of the HC GVSU «Center», is dictated by the need to dispose of foam polystyrene waste that occurs in large quantities when producing the precast concrete. In the production of three-layer external wall panels, polystyrene heatinsulating plates of the PPS 17-R-A brand are used as an effective insulation material. The secondary use of PPS 17-R-A for its intended purpose, as a heater, is not possible. The volume of foam polystyrene produced varies from 25 to 45 m3 per month. Utilization (disposal) of foam polystyrene waste is an expensive undertaking. Its use as a filler in the production of expanded polystyrene blocks was tested in the factory’s laboratory to produce foam polystyrene concrete with specified physical and mechanical characteristics. The results of testing of expanded polystyrene concrete of classes B2.5 and B 7.5 are presented. It is shown that under the conditions of the reinforced concrete factory technology, the production of polystyrene concrete blocks is possible with the achievement of the design strength. The information presented in the article is aimed at motivating specialists who produce recast concrete to the possibility of using foam polystyrene waste for low-rise construction. Keywords: foam polystyrene, ecology, energy efficiency, foam polystyrene concrete, foam polystyrene heat insulation plates, precast concrete.


2017 ◽  
Vol 1 (2) ◽  
pp. 34
Author(s):  
Zulkarnain Zulkarnain ◽  
Nadjadji Anwar

The Research Center and Development of Water (Puslitbang) is currently developing the Submerged Breakwater in shallow sea area (PEGAR). The author is interested to examine the material that easily obtained in the field of RCP concrete cylinder. The observation is how it to be ability in function as submerged breakwater an go green and low cost. The physical model of wave transmission test is how the response to the structure in ability to damping of wave as the breakwater function. In this research breakwater used is submerged breakwater type by using concrete cylinder (buis beton). The purpose from this research is to know how the response of breakwater structure to the waves through it, with some variation of the structure by creating a structure with three variations of the arrangement and freeboard that is the relative depth with the crest width is constant. The wave generated test in this study is using regular waves in wave flume at FTSP Civil Engineering Department of Institute Technology Ten November. From the analysis of the effect of the installation of submerged breakwater by using concrete cylinder to the wave damping value, it can be concluded that the factors that are very influential is the freeboard and the composition of concrete cylinder. Scenario A (rigid vertical massive) is capable of producing the smallest value of kt is 0.33. As for scenario B (rigid horyzontal massive) with a damping value of 0.5, while the scenario C (rigid permeable) is only able to produce kt value of 0.71. Scenario A is better than scenario B and C Because the position of arrangement of A is very good used to damp wave in small or big freeboard conditions.


2020 ◽  
Vol 1 (1) ◽  
pp. 19-23
Author(s):  
Diah Willis L ◽  
Thomas Priyasmanu ◽  
Wahyu Panji A ◽  
D. H. Praswanto ◽  
E. Y. Setyawan

Development in the current development sector has grown rapidly, in this development we can see a good potential to be developed, namely the development of bricks with good quality compared to using red bricks which production takes a long time. Batako is an alternative that can be used in the construction of a building, because currently the price of red brick is quite high because the production cost is quite expensive. Besides, the price of firewood used for cooking red brick is getting difficult. Meanwhile, the demand for brick gradually increased because brick was one of the main components in building construction. So it needs to be developed in making brick blocks because the time is relatively short in the drying process. Therefore the community service team made a brick making machine with a vibration system for compaction and a faster production process in brick making using a machine that has been made, so that it can increase partner income, who previously produced 120 pieces with a manual system using a machine that could produce 500 pieces of brick per day.


2021 ◽  
Vol 323 ◽  
pp. 112657
Author(s):  
Juan Rafael Filgueira Guerra ◽  
Antonio Luiz Pereira de Siqueira Campos ◽  
Humberto Dionísio de Andrade

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4174
Author(s):  
André M. Santos ◽  
Ângelo J. Costa e Silva ◽  
João M. F. Mota ◽  
João M. P. Q. Delgado ◽  
Fernando A. N. Silva ◽  
...  

The understanding of the mechanical fixation behavior of coatings is crucial for a better comprehension of the bonding systems, especially at the interface between the mortar and the substrate. Physical adherence is related, among other things, to the contents of the materials used in the roughcast and mortar coatings, due to the colloidal water penetration into the pores of the substrate. This work evaluated the influence of different lime solution additions replacing the kneading water in the preparation of roughcast and mortar coatings. Two types of substrates were investigated:ceramic bricks and concrete blocks. Three wall masonry panels were constructed, with dimensions of 220 × 180 cm2, one of concrete block and two of ceramic bricks, followed by the application of roughcast and mortar coating with an average thickness of 5 mm and 20 mm, respectively. Direct tensile bond strength tests were performed and the results, with a 95% confidence level, showed that substrate ceramic and treatment in the roughcast exhibited a better behavior regarding the distribution of the tensile bond strength of the tested specimens. However, no significant differences of the amount of addition used (0%, 5%, 10% and 15%) on the tensile bond strength were observed.


2021 ◽  
Vol 11 (11) ◽  
pp. 5008
Author(s):  
Juan José del Coz-Díaz ◽  
Felipe Pedro Álvarez-Rabanal ◽  
Mar Alonso-Martínez ◽  
Juan Enrique Martínez-Martínez

The thermal inertia properties of construction elements have gained a great deal of importance in building design over the last few years. Many investigations have shown that this is the key factor to improve energy efficiency and obtain optimal comfort conditions in buildings. However, experimental tests are expensive and time consuming and the development of new products requires shorter analysis times. In this sense, the goal of this research is to analyze the thermal behavior of a wall made up of lightweight concrete blocks covered with layers of insulating materials in steady- and transient-state conditions. For this, numerical and experimental studies were done, taking outdoor temperature and relative humidity as a function of time into account. Furthermore, multi-criteria optimization based on the design of the experimental methodology is used to minimize errors in thermal material properties and to understand the main parameters that influence the numerical simulation of thermal inertia. Numerical Finite Element Models (FEM) will take conduction, convection and radiation phenomena in the recesses of lightweight concrete blocks into account, as well as the film conditions established in the UNE-EN ISO 6946 standard. Finally, the numerical ISO-13786 standard and the experimental results are compared in terms of wall thermal transmittance, thermal flux, and temperature evolution, as well as the dynamic thermal inertia parameters, showing a good agreement in some cases, allowing builders, architects, and engineers to develop new construction elements in a short time with the new proposed methodology.


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