scholarly journals EXPERIMENTAL STUDIES OF SPECIALLY SHAPED CONCRETE BLOCKS FOR ABSORBING WAVE ENERGY

2011 ◽  
Vol 1 (7) ◽  
pp. 35
Author(s):  
Shoshichiro Nagai
Keyword(s):  
Wave Energy ◽  
Experimental Studies ◽  
Concrete Block ◽  
Breaking Waves ◽  
The Body ◽  
Concrete Blocks ◽  
Cast Concrete ◽  
Protective Cover ◽  
Run Up ◽  
Energy Absorbing

Laboratory tests were performed to determine wave energy absorbing ability of and stability characteristics against breaking waves of various shaped pre-cast concrete armor units used for protective cover layers on the seaward slopes of rubblemound breakwaters and for parallel dykes placed the offshore sides of seawalls. A new shape of armor units, a hollow tetrahedron concrete block with a porosity of 25 percentages in the body was proved to have better characteristics for wave energy absorbing ability and attenuation of wave run-up, as well as for stability against breaking waves also than tetrapod or other armor units used up-to-date.

scholarly journals Numerical Modeling of Failure Mechanisms in Articulated Concrete Block Mattress as a Sustainable Coastal Protection Structure

2021 ◽  
Vol 13 (22) ◽  
pp. 12794
Author(s):  
Ramin Safari Ghaleh ◽  
Omid Aminoroayaie Yamini ◽  
S. Hooman Mousavi ◽  
Mohammad Reza Kavianpour
Keyword(s):  
Numerical Modeling ◽  
Concrete Block ◽  
Breaking Waves ◽  
Physical Models ◽  
Coastal Protection ◽  
Similarity Parameter ◽  
Environmental Friendliness ◽  
Shoreline Protection ◽  
Concrete Blocks ◽  
Run Up

Shoreline protection remains a global priority. Typically, coastal areas are protected by armoring them with hard, non-native, and non-sustainable materials such as limestone. To increase the execution speed and environmental friendliness and reduce the weight of individual concrete blocks and reinforcements, concrete blocks can be designed and implemented as Articulated Concrete Block Mattress (ACB Mat). These structures act as an integral part and can be used as a revetment on the breakwater body or shoreline protection. Physical models are one of the key tools for estimating and investigating the phenomena in coastal structures. However, it does have limitations and obstacles; consequently, in this study, numerical modeling of waves on these structures has been utilized to simulate wave propagation on the breakwater, via Flow-3D software with VOF. Among the factors affecting the instability of ACB Mat are breaking waves as well as the shaking of the revetment and the displacement of the armor due to the uplift force resulting from the failure. The most important purpose of the present study is to investigate the ability of numerical Flow-3D model to simulate hydrodynamic parameters in coastal revetment. The run-up values of the waves on the concrete block armoring will multiply with increasing break parameter (0.5<ξm−1,0<3.3) due to the existence of plunging waves until it (Ru2%Hm0=1.6) reaches maximum. Hence, by increasing the breaker parameter and changing breaking waves (ξm−1,0>3.3) type to collapsing waves/surging waves, the trend of relative wave run-up changes on concrete block revetment increases gradually. By increasing the breaker index (surf similarity parameter) in the case of plunging waves (0.5<ξm−1,0<3.3), the low values on the relative wave run-down are greatly reduced. Additionally, in the transition region, the change of breaking waves from plunging waves to collapsing/surging (3.3<ξm−1,0<5.0), the relative run-down process occurs with less intensity.

scholarly journals The Influence of Lime Solution in Kneading Water Substitution on Cement Roughcast and Mortar Coating

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 ◽  
...  
Keyword(s):  
Bond Strength ◽  
Concrete Block ◽  
Tensile Bond Strength ◽  
Water Penetration ◽  
Strength Tests ◽  
Lime Solution ◽  
Concrete Blocks ◽  
Materials Used ◽  
Bonding Systems ◽  
Direct Tensile

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.

scholarly journals Thermal Inertia Characterization of Multilayer Lightweight Walls: Numerical Analysis and Experimental Validation

2021 ◽  
Vol 11 (11) ◽  
pp. 5008
Author(s):  
Juan José del Coz-Díaz ◽  
Felipe Pedro Álvarez-Rabanal ◽  
Mar Alonso-Martínez ◽  
Juan Enrique Martínez-Martínez
Keyword(s):  
Lightweight Concrete ◽  
Thermal Flux ◽  
Experimental Studies ◽  
Thermal Inertia ◽  
Transient State ◽  
Experimental Tests ◽  
Building Design ◽  
Experimental Methodology ◽  
Improve Energy Efficiency ◽  
Concrete Blocks

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.

scholarly journals Geotechnical Approach to Early-Stage Site Characterisation of Shallow Wave Energy Sites

2021 ◽  
Vol 9 (6) ◽  
pp. 605
Author(s):  
Craig Heatherington ◽  
Alistair Grinham ◽  
Irene Penesis ◽  
Scott Hunter ◽  
Remo Cossu
Keyword(s):  
Wave Energy ◽  
Early Stage ◽  
Breaking Waves ◽  
Time Frame ◽  
High Energy ◽  
Specific Information ◽  
Terrain Analysis ◽  
Site Suitability ◽  
Site Characterisation ◽  
A Site

Marine renewable energy is still in its infancy and poses serious challenges due to the harsh marine conditions encountered for wave or tidal installations and the survivability of devices. Geophysical and hydrodynamic initial site surveys need to be able to provide repeatable, reliable, and economical solutions. An oscillating water column wave energy converter is to be installed on the west coast of King Island, Tasmania. The location is in a high-energy nearshore environment to take advantage of sustained shoaling non-breaking waves of the Southern Ocean and required site-specific information for the deployment. We provide insight into scalable geophysical site surveys capable of capturing large amounts of data within a short time frame. This data was incorporated into a site suitability model, utilising seabed slope, sediment depth, and water depth to provide the terrain analysis needed to match deployment-specific characteristics. In addition, short-term hydrology and geotechnical work found a highly energetic seabed (near seafloor water velocities <1 m/s) with sufficient bearing capacity (6 MPa). In a highly energetic environment, care was taken to collect the relevant data needed for an assessment of critical information to an emerging technology companies primary project. This is in addition to the malleable methodology for a site suitability model that can incorporate various weighted parameters to prioritise the location for shallow wave energy sites in general.

River Soil & Sand Solidified Blocks as Ballast in Beach Protection

2013 ◽  
Vol 779-780 ◽  
pp. 323-326 ◽  
Author(s):  
Jing Min Mao ◽  
Da Feng Gao
Keyword(s):  
Yangtze River ◽  
Setting Time ◽  
Experimental Studies ◽  
Curing Agent ◽  
The Yangtze River ◽  
Environment Protection ◽  
Time Stability ◽  
Alternative Materials ◽  
Concrete Blocks ◽  
Protection Engineering

This paper deals with the feasibility of beach protection project alternative materials - the Yangtze River soil and sand, applies PCSB curing agent to solidify it and to produce beach protection blocks. Experimental studies on the performance of strength, setting time, stability and anti-erosion have been carried out to inquire into the regularity of solidification. Using soil and sand curing blocks instead of concrete blocks in the application of Yangtze River beach protection engineering has advantages of technology, economy and environment protection etc.

Experimental Studies on Diesel Engine with Piston Crown Modification Using an Optimum Alternative Fuel

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Air Gap ◽  
The Body ◽  
Injection Timing ◽  
Positive Trend ◽  
Piston Crown ◽  
Karanja Oil

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.

Late Stage Decomposition of Embalmed Cadavers

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pilar Mata Tutor ◽  
Catherine Villoria Rojas ◽  
María Benito Sánchez
Keyword(s):  
Soft Tissue ◽  
Late Stage ◽  
Good Condition ◽  
Experimental Studies ◽  
The Body ◽  
Health Law ◽  
External Appearance ◽  
Intrinsic Factors ◽  
Preservation Technique ◽  
Extrinsic And Intrinsic Factors

Decomposition is a natural process that begins approximately four minutes after death and continues until the body is degraded to simpler biochemical components which are gradually recycled back to the environment. This process is dependent on extrinsic and intrinsic factors. Embalming is a chemical preservation technique that aims to preserve the external appearance of the body in good condition for an indeterminate period. In Spain, there is a lack of experimental studies carried out to analyse the variables that affect decomposition in embalmed bodies, therefore, in accordance with the conclusions reached by previous authors, it is hypothesised that embalmed bodies show quantifiable characteristics during the late stage decomposition which distinguish them from control, unembalmed, cadavers. An anthropological and statistical analysis was performed on 14 individuals from Cementerio Sur de Madrid exhumed after ten years according to the Mortuary Health Law of the Autonomous Region of Madrid. The preliminary results obtained showed that there is a qualitative and statistically significant relationship between the variables evaluated, being the presence or absence of soft tissue the most notable difference. The mortuary or thanatopraxy treatments performed before the burial and the microenvironmental conditions of the burial positively influence the soft tissue preservation on embalmed bodies. These results contribute to the understanding about the decomposition rate of an embalmed cadavers in cemeteries, and the related extrinsic variables.

Mechanical Properties of Various Models of Interlocking Concrete Blocks under In-Plane and Out-of-Plane Loads

2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal
Keyword(s):  
Mechanical Properties ◽  
Building Material ◽  
Experimental Tests ◽  
Concrete Block ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Plane Shear ◽  
Out Of Plane ◽  
Concrete Blocks ◽  
Local Materials

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.

EVALUATION OF TOXIOLOGICAL INDICATORS OF MONTHMORRILLONITE CLAY FOR THE PURPOSE OF USING THEM AS ALUMOSILICATE SOBENT AGAINST THE NEGATIVE EFFECT OF MYCOTOXINS ON THE BODY OF ANIMALS AND BIRDS

2021 ◽  
Vol 1 (1) ◽  
pp. 72-78
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Montmorillonite Clay ◽  
Test Substance ◽  
Negative Effects ◽  
Experimental Animals ◽  
Eyelid Edema ◽  
White Rats ◽  
Mucous Membranes ◽  
Negative Effect

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.

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