Modern Construction Materials Research Articles

Application of Hybrid Absorptive–Diffusive Panels with Variable Acoustic Characteristics Based on Wooden Overlays Designed Using Third-Degree-of-Freedom Bezier Curves

This manuscript describes the application of novel hybrid acoustic panels with variable acoustic properties that could be used in the design process. Despite the significant growth in the modern acoustic absorbing and diffusing panel sector in recent years, there is still a need for sustainable and original designs that will fit standard interior design trends. The most significant requirement is satisfying the design needs of variable acoustic venues. The availability of acoustic panels with variable properties is minimal, as most designs are based on textiles in the form of rolling banners; therefore, there is no market diversity. The current paper presents an original solution for a novel perforated wooden panel based on third-degree-of-freedom curves. Due to the possibility of exchanging the front panel, the acoustic surface can be varied and adjusted to the room considering different requirements for the acoustic climate, for example, by modifying the attenuation range from low to mid–high frequencies. The novel panels have unique esthetic properties with functional acoustic features regarding sound diffusion and absorption. In this paper, sound absorption and diffusion measurements will be presented for the different variants of the panels, presenting the option to modify the parameters to adjust the panel’s features to the room’s needs. In situ acoustic measurements in a laboratory were conducted to test the variable acoustic panels’ influence on the room’s acoustic parameters, such as T30 and C80. In summary, the advantages of this kind of design will be discussed, alongside the possible impact on modern construction materials’ utilization in architecture.

Перспективи застосування жорсткого дорожнього одягу під час будування автомобільних доріг та удосконалення підходів до його конструювання і розрахування

Introduction. This article examines the issue of improving the methods of designing and calculating rigid road surfaces, outlined in the DSTU project “Guidelines for the Design of Rigid Road Surfaces” (hereinafter referred to as the DSTU project). The specified methods were developed on the basis of domestic and global experience in the design of highways with rigid road surfaces, analysis of current legal acts, regulatory documents, technical literature related to the object of standardization, taking into account the availability of modern road construction materials and technologies. density of traffic flow, diversity of subsoil, including in complex engineering and geological conditions, peculiarities of road and climatic regions of Ukraine, etc. Problem statement. The need for improvement and a unified approach to the design of rigid road clothing, taking into account the peculiarities of its operation, with the determination of the appropriate parameters depending on the initial data and the effective use of material and technical resources.

Knowledge, Preparedness, and Practices of Lanna People for Earthquake-Resistant Housing in Active Fault Zones of Northern Thailand

An earthquake shakes the earth’s surface, causing structural damage to buildings, houses, bridges, and highways. Analyzing the earthquake resistance of buildings and Lanna traditional houses in Northern Thailand's active fault zones can mitigate these consequences. This study aimed to: 1) assess the earthquake resistance of buildings and Lanna traditional houses in these zones, and 2) examine the knowledge, preparedness, and practices of Lanna people regarding earthquake-resistant housing. The results revealed that 1.80% of buildings and Lanna traditional houses were not strong enough to withstand earthquakes. However, Lanna people in active fault zones demonstrated a high level of knowledge, preparedness, and practice in earthquake-resistant housing. Lanna traditional houses often use locally available materials like wood, leaves, stone, and bamboo, which are flexible and resilient during earthquakes. These materials are more sustainable than modern construction materials due to their lower environmental impact and cost-effectiveness. Engineers play a crucial role in ensuring homes are earthquake-resistant while preserving the cultural and historical essence of Lanna Thai architecture. By integrating modern engineering practices with traditional design elements, they create homes that are both safe and culturally significant.

Features of the structure and properties of stone mastic asphalt

AbstractThe purpose of this study is to investigate the features and properties of stone mastic asphalt in the context of its potential for practical application in road repair works, aiming to create a high‐quality road surface and replace outdated structural materials with newer alternatives. The leading approach combines a systematic analysis of the issues submitted for consideration and an experimental study of the properties of stone mastic asphalt, which are important in the context of the practical use of this building material to ensure high quality parameters of the roadway and the timeliness of its repair, if necessary. Within the framework of this study, results were obtained that indicate a significant variety of approaches to determining the characteristics and properties of the material under consideration, clearly demonstrating current solutions to the problem of improving the performance of stone mastic asphalt by introducing special admixtures into its composition. The findings and conclusions of this research are valuable for road service employees and developers of modern construction materials, aiding in high‐quality road surface repair and creating durable asphalt for safe road use in the future.

Experimental investigation of transition composite connections in historic style buildings

Historic timber buildings possess immense historical, artistic, and scientific value, but a few of them have survived after thousands of years of natural disasters and wars. Historic style buildings with modern construction material, imitating historic timber buildings forms, have emerged to inherit and promote traditional culture. To investigate the seismic performance of transition columns commonly used in historic style buildings, two full-scaled composite column transition (CCT) connections between steel reinforced concrete (SRC) square column and reinforced concrete (RC) circular column were designed and tested under invariable axial load and cyclic lateral load. Both failure patterns and force mechanism were studied based on the test process of the CCT connections. Then, the influence of axial compressive ratio on the mechanical behaviour of the CCT connections was assessed by looking at the hysteretic curves, backbone curves, characteristic loads, ductility, energy dissipation capacity and strength degradation. The results demonstrated that the failure patterns of the CCT connections were typical flexural failure, with the failure zone occurring at the upper column-root. The CCT connections exhibited excellent capacities of deformation and energy dissipation. As axial compression ratio increases, the failure of the CCT connection becomes more severe, leading to enhanced energy dissipation capacity. However, the strength and ductility of the CCT connection decrease. Based on the experimental results, an equation for calculating the lateral stiffness of CCT connections between SRC square column and RC circular column in historic style buildings was proposed, and verified to be accurate. The findings can provide necessary basis for the rational design and widespread application of historic style buildings.

Investigating the Impact of Carbon Fiber as a Wheelchair Frame Material on Its Ability to Dissipate Kinetic Energy and Reduce Vibrations.

Using a wheelchair over uneven terrain generates vibrations of the human body. These vibrations result from mechanical energy impulses transferred from the ground through the wheelchair components to the user's body, which may negatively affect the quality of the wheelchair use and the user's health. This energy can be dissipated through the structure of the wheelchair frame, such as polymer and carbon fiber composites. This article aims to compare a wheelchair with an aluminum alloy frame and a carbon fiber frame in terms of reducing kinematic excitation acting on the user's body. Three wheelchairs were used in the study, one with an aluminum alloy frame (reference) and two innovative ones with composite frames. The user was sitting in the tested wheelchairs and had an accelerometer attached to their forehead. The vibrations were generated by applying impulses to the rear wheels of the wheelchair. The obtained results were analyzed and compared, especially regarding differences in the damping decrement. The research shows that using modern materials in the wheelchair frame has a beneficial effect on vibration damping. Although the frame structure and material did not significantly impact the reduction in the acceleration vector, the material and geometry had a beneficial effect on the short dissipation time of the mechanical energy generated by the kinematic excitation. Research has shown that modern construction materials, especially carbon fiber-reinforced composites, may be an alternative to traditional wheelchair suspension modules, effectively damping vibrations.

ENCAUSTIC AS AN ANCIENT PAINTING TECHNIQUE: A FAILING TRADITION

The article highlights the peculiarities of the encaustic painting technique and the main problems of preserving this unique technique in the modern art of Ukraine. The meaning of the concept of “encaustic” is revealed. Considerable attention is paid to the technological varieties of encaustic as an ancient pictorial art. Thus, ancient authors wrote about the expressiveness and beauty of the encaustic technique, but, at the same time, “wax painting of the ancients” turned out to be one of the mysterious techniques. First of all, this is due to the fact that very few encaustic works have survived, and the description of technologies was almost absent. Thus, after studying the “Fayum portraits” found in 1887 in Middle Egypt (the Fayum oasis), it was possible to determine that the funerary masks were made in the encaustic technique. Mentions of encaustic works date back to the ancient literature of the times of imperial Rome. During the Renaissance, even Leonardo da Vinci tried to unravel the mystery of encaustic painting, but even he had very little information about this technology. According to the descriptions, it was necessary to solve a complex technological process, so the masters collected information piece by piece and experimentally implemented this technique. These were the first stages of the revival of encaustic painting, which is also called wax painting, because the basis of encaustic paints was wax. The stability of this painting technique was ensured, in particular, by the presence of various resins, linseed oil and dyes of natural origin in the composition of encaustic paints. These paints were applied layer by layer on special soils under high temperature. The exceptional artistic value of the encaustic technique made it possible to preserve it and gave the prospect of revival thanks to the creative searches of artists of the 1970-1995 years of the 20th century. Painting with wax paints meets all the requirements of modern monumental art along with frescoes and mosaics. Modern construction technologies and materials provide ample opportunities for monumental artists to solve various artistic and plastic tasks related to the application of the encaustic technique. The article also considers the role of encaustic in modern easel and monumental art. The work of modern masters of Ukraine who worked in the encaustic technique is analyzed.

Development of the Construction of City Buses in Terms of Reducing the Curb Weight of the Vehicle

Modern city buses are made of various construction materials and the share of material groups has changed over the decades. By replacing heavy materials for structural elements or bus components with their lighter counterparts, the kerb weight of the bus can be reduced by up to several hundred kilograms. This article presents the issues of the development of city bus design in terms of passenger space comfort and bus structure in the context of reducing the vehicle's own weight since the 1970s. The main changes in vehicle design allowing for reducing the weight of structural elements of bodies and chassis as well as the main assemblies in city buses are presented as well as research on body types in terms of aerodynamics, safety and travel comfort. It has been shown that reducing the weight of the bus does not negatively affect its load capacity and the new bus designs are equipped with safety and comfort systems, including ABS (Anti-lock Braking System), ASR (Automatic Stability Regulation), ESP (Electronic Stability Program) and air conditioning in the passenger space. Thanks to modern light construction materials, we gain the opportunity to improve safety and comfort without losing the transport capabilities developed as a result of the development of city buses over the years.

Building and living in Tlemcen (Algeria). From the traditional house to the colonial villa

Domestic architecture in the city of Tlemcen knew changes in architectural design and construction techniques over time, from prehistoric times, through the succession of Islamic dynasties, the colonial era and the current period. Individual housing during the colonial period was marked by the transition from the traditional patio house to suburban housing and individual villas with courtyards and gardens. A comparative study was carried out of a traditional Ottoman house in Bab El Hadid and a colonial villa in the avenue Allée des Pins. It reveals two architectural styles from two different eras, designed for two populations with different lifestyles, and highlights the traditional and modern construction techniques and materials used.

Localised Web Bearing Behaviour of Cold-Formed Austenitic Stainless-Steel Channels: Review of Design Rules and New Insight under Interior Loading

Stainless steels are modern high-performance construction materials exhibiting excellent corrosion resistance, recyclability, ductility, and durability which make them appealing to use in the construction industry. However, when used as structural sections, they are subjected to localised failure in the web. This study aims to examine the structural behaviour of cold-formed low-carbon content standard austenitic 304L and 316L stainless steel channels under localised interior bearing loads. The results of 21 tests on unlipped channels with different cross-section sizes and thicknesses are presented. A nonlinear quasi-static Finite Element (FE) model is then developed. The FE model is validated against experimental test results and demonstrated good agreement in terms of bearing strength and failure modes. In addition, the experimental and FE results are used to compare the results against the results predicted in accordance with the American specification SEI/ASCE 8:2002 and European Standard EN 1993-1-4:2006. It is found that the current design equations are unreliable and too unconservative to use for cold-formed austenitic stainless steel unlipped channels, especially when compared to SEI/ASCE 8:2002, as much as 41%.

Experimental and numerical study on structural behavior of reactive powder concrete corbels without stirrups

This paper presents a study that explores the application of reactive powder concrete (RPC), a modern construction material, to corbels without stirrups. The focus of the research is to investigate the shear behaviors of RPC corbels under vertical loading through experimental and numerical methods. Three RPC corbels with different shear span-to-effective depth ratios (av/d) of 0.6, 1.1, and 1.6 were tested. A commercial finite element method (FEM) code was utilized for the numerical analysis, and its accuracy was verified against the experimental results. A parametric study was conducted to evaluate the influence of various factors, including RPC compressive strength, RPC tensile strength, amount of main reinforcement, yield strength of main reinforcement, and stress-strain model of main reinforcement. Additionally, the shear strengths obtained from the tests were compared with the predicted values based on design codes, including ACI 318–14 and NF P18–710. The findings reveal that the av/d ratio significantly affected the load-deflection behaviors and failure modes of the RPC corbel specimens. The numerical model demonstrates good agreement with the experimental results. The RPC compressive strength emerges as the primary factor influencing the peak load of RPC corbels. Comparing various predictions, the Strut-and-Tie models recommended by the NF code exhibit the highest accuracy and safety in estimating the shear strengths of the RPC corbels.

Organizational and technological reliability of construction in Iraq

Introduction. Capital construction of buildings and structures in the Republic of Iraq is one of the most important areas of production activity, it is the basis for the development of all sectors in the country’s economy. The modern construction complex of Iraq is constantly developing and improving, modern construction materials, technologies, methods of organization and management of construction are being introduced, which makes it possible to implement construction projects of almost unlimited complexity. However, in modern conditions that have been formed in the Republic of Iraq from the end of the 20th century to the present, a special problem has become the need for full and timely provision of construction with all types of resources, which, in the conditions of the Iraqi construction market, is an unsolved scientific and practical task, due to the high influence of negative factors different nature, thereby reducing the organizational and technological reliability of the construction of buildings. Materials and methods. To solve this problem, 7 stages of developing a system of indicators for the sustainable development of resource infrastructure, which will improve the organizational and technological reliability of construction in Iraq are proposed. In addition, a model for calculating generalized criteria for the organizational and technological reliability of construction was developed. To determine the significance of indicators of organizational and technological reliability, it is proposed to use the method of expert evaluation. Results. A system of indicators for the sustainable development of resource infrastructure has been developed, consisting of seven stages. The indicators of organizational and technological reliability of construction are singled out and their significance is determined. Discussion and conclusions. Taking into account the influence of the factors studied by us predetermines the use of the concept of risk as a quantitative measure of the implementation of a negative scenario of the construction progress under the influence of various factors, which allows further research using the apparatus of risk theory. On the basis of the proposed research method, we can calculate the effectiveness of indicators of resource provision for construction in Iraq.

Current directions of development of domestic regulatory and technical documentation in the field of timber construction considering foreign experience

Introduction. The concentration of a huge amount of forest resources on the territory of the Russian Federation allows to expand significantly the usage of wood in the construction of both low-rise and high-rise buildings and structures. The main directions of development of normative and technical documentation (NTD) in the field of wooden construction, demanded by the professional community, are presented.
 
 Materials and methods. A survey of wooden house building market participants was conducted to identify the most urgent problems in the field of wood application in the construction industry. The NTD of the USA, Canada and EU countries regulating the usage of wood in the construction industry were reviewed. The best practices implemented in foreign NTD and capable of serving as a reference point in the process of modernization of the domestic regulatory framework in the subject area under study have been identified. The questions of fire safety, earthquake resistance, as well as modern construction materials and products based on wood, used in the market of building wooden structures (WS) are considered. The composition and structure of NTD of the Russian Federation in the field of wood construction have been analyzed.
 
 Results. The analysis of domestic and foreign NTD has revealed a significant deficit in the part of normative and methodological support of construction from materials and products based on wood. Recommendations on updating, cancellation or revision of domestic normative-technical documents have been developed.
 
 Conclusions. The necessity of intensification of applied scientific researches for updating of NTD, in particular normative-methodical manuals and recommendations is formulated and substantiated. Proposals for structuring the system of NTD RF in the field of construction of wooden structures have been developed. The system of state standards in this area should cover technical specifications for individual materials and wood products describing their physical and mechanical properties and design characteristics. The proposed structure of NTD in the field of wooden construction has the possibility of dynamic development taking into account the development of the nomenclature of materials, calculation methods and applied technologies.

Evolution and Current State of Building Materials, Construction Methods, and Building Regulations in the U.K.: Implications for Sustainable Building Practices

This study presents a comprehensive review of building materials, construction methods, and building regulations on the U.K. mainland. This provides valuable insights into the historical progression and transformation of the construction industry through a comprehensive analysis of both traditional and modern building construction materials and methods and categorising their evolutionary trajectory. Current building regulations in England, Wales, and Scotland are compared, highlighting differences in fire safety, noise safety, energy conservation, and sustainability. For example, fire safety regulations are analysed in detail, including fire resistance duration, wall cladding combustibility, and limitations on unprotected areas. Advances in knowledge and technology have led to increasingly sophisticated and energy-dependent methods, materials, and regulations. This study showcases the vast array of building construction materials spanning centuries, each possessing unique properties and performances. The selected methods and materials represent those currently employed or widely utilised in the U.K. construction industry, affirming their relevance and applicability in modern construction practices. Limitations in construction practices primarily stem from a lack of knowledge and tools rather than material scarcity. Enhancing knowledge and access to advanced tools is crucial to overcoming these limitations and driving advancements in the field. This study provides insights into the evolution of building materials, construction methods, and building regulations that can inform future developments in sustainable building practices. The findings have significant implications for policymakers, building designers, and constructors, particularly in terms of adopting sustainable materials and construction methods that comply with building regulations while reducing the environmental impact of the built environment.

A Comparative Study of Deterministic and Stochastic Models of Microstructure Evolution during Multi-Step Hot Deformation of Steels.

Modern construction materials, including steels, have to combine strength with good formability. In metallic materials, these features are obtained for heterogeneous multiphase microstructures. Design of such microstructures requires advanced numerical models. It has been shown in our earlier works that models based on stochastic internal variables meet this requirement. The focus of the present paper is on deterministic and stochastic approaches to modelling hot deformation of multiphase steels. The main aim was to survey recent advances in describing the evolution of dislocations and grain size accounting for the stochastic character of the recrystallization. To present a path leading to this objective, we reviewed several papers dedicated to the application of internal variables and statistical approaches to modelling recrystallization. Following this, the idea of the model with dislocation density and grain size being the stochastic internal variables is described. Experiments composed of hot compression of cylindrical samples are also included for better presentation of the utility of this approach. Firstly, an empirical data describing the loads as a function of time during compression and data needed to create histograms of the austenite grain size after the tests were collected. Using the measured data, identification and validation of the models were performed. To present possible applications of the model, it was used to produce a simulation imitating industrial hot-forming processes. Finally, calculations of the dislocation density and the grain size distribution were utilized as inputs in simulations of phase transformations during cooling. Distributions of the ferrite volume fraction and the ferrite grain size after cooling recapitulate the paper. This should give readers good overview on the application of collected equations in practice.

Experimental study on mechanical properties of M−25 grade concrete with cow dung ash and waste rubber tube pieces

In this modern era, many new technologies came into existence in generation of modern construction materials. More Over Growing population, urbanization and industrialization increased the requirement cement and natural aggregates. The production of cement lead to environmental quandaries due to emission of gaseous pollutants. The availability of materials of good quality are rare and also economically the price was very high. So,we need a material which was less expensive as well as eco friendly like cow dung ash and refused rubber tube shreds.. Further more, these aggregates have been customarily treated as inert filler in concrete but in fact, aggregates not truly inert but its physical, thermal, and chemical properties influence the concrete. Due to tremendous demand of concrete as a construction material there is need to preserve the natural coarse aggregates by using alternative materials which can obtain from recycled or unused materials. Therefore, the best management strategy preferred is recycling of rubber dregs and cowpat soot that leads to effectual utilization that minimizes environmental impact and maximize the conservation of natural resources. These materials are partially replaced by coarse aggregate and cement in manufacturing of concrete. To study the effect of adding Cow dung Ash,Waste Rubber Tube Pieces, in various percentage (0%,10%, 15%, 20%) by the weight of cement and coarse aggregate, for curing periods of 7, 14 and 28 days respectively, compressive strength, split tensile strength test on M25 grade concrete was conducted.

Potentials of Constructing Sustainable Rammed Earth Buildings in Hot-Arid Regions: Structural and Environmental Challenges

The continuous increasing in the price of cement is one of the major challenges facing the construction industry. Moreover, concrete mixtures are main sources of CO2 emissions. On the other hand, rammed earth material could be a good alternative to reduce costs and amounts of emissions. In addition, it is appropriate to be used in hot-arid regions due to its thermal mass properties. Yet, such a material has limitations in terms of durability and strength. This research aims firstly to test the suitability of rammed earth as urban modern construction material, through examining characteristics and specifications of soil, sand, and other stabilizers to improve the resistance to frost attack and avoid deterioration. Secondly, to explore the efficiency in terms of indoor environmental conditions. The research was implemented by constructing an experimental building within a university campus in Jordan, to conclude the best solutions in terms of environmental and structural challenges.

Urban design strategies for summer and winter outdoor thermal comfort in arid regions: The case of historical, contemporary and modern urban areas in Mashhad, Iran

There is an increasing demand for urban planning and design strategies to decrease air temperatures in present and future cities. In this study, the outdoor thermal comfort (OTC) in Mashhad, Iran, is examined during summer and winter days by investigating the impact of urban form on pedestrian thermal comfort in three neighborhoods (historical - HA, contemporary - CA, and modern - MA) and focusing on the effects of such urban factors as height-to-width (H/W) ratio, canyon orientation (N-S, E-W, NNE-SSW, and EES-WWN), trees, and building materials. The analysis is conducted with the ENVI-met and Rayman models, which together provide reasonable estimates of OTC. The results are as follows. (1) OTC is improved in HA and CA by the presence of both trees and mid H/W ratios (H/W=1.5), particularly in E-W- and EES-WWN-oriented canyons. (2) During both summer and winter, the mean radiant temperature (MRT) is the most effective climatic factor. In winter, when MRT is high, the Physiological Equivalent Temperature (PET) is closer to the comfort range. The reverse is valid for the summer. (3) The Sky View Factor (SVF) has more significant effects in the summer than in the winter. (4) Wind velocity is the second most important factor influencing OTC. (5) The latent heat effect is less prominent in the HA and CA, which use indigenous materials (brick), than in the MA, where modern construction materials with lighter colors are more common. In winter, on the other hand, MA has a relatively lower PET in comparison to the other two neighborhoods. Lower H/W ratios, material properties (stone) and dominant wind directions are the main reasons for this poor OTC situation in the MA, with N-S canyons with low H/W ratios experiencing the worst cold stress values (<18°C). When considering both winter and summer, the results show that using indigenous materials and planting a combination of windbreaker and deciduous trees in shallow canyons will help urban planners and designers improve OTC.

Applications of Smart Material to Enhance Daylighting as a tool to Improve Sustainability of Atriums

Applications for smart building materials include making them more environmentally friendly, better able to suit user needs, and less likely to cause environmental issues. This kind of material has been suggested recently, following great scientific advancements and novel sustainable architecture techniques, as smart materials that allow controlled transmission of light and heat into the building and remove some of the traditional limitations in window application, smart material technologies are key feature competitiveness of the twenty-first century. Modern construction materials are capable of achieving great levels of utility, “Smart materials” will play a crucial role in building technology development; These materials that are part of an intelligent structural system, have the ability to sense its environment, so smart materials can function like living systems, An important element of an architectural design strategy that is environmentally sustainable is the use of daylight as part of an integrated, controlled lighting strategy. For well-designed structures, the atrium could be a significant source of daylight. It also offers other environmental advantages such as solar energy gain, reduced energy loss, and natural ventilation. The major elements of the atrium for the daylight design are a system of skylights and windows to provide daylight levels in the spaces adjacent to the atrium.

Numerical modelling of the poto-poto by coupling of finite elements and boundary elements for acoustic characterization

Sustainable development encourages the construction of buildings based from local raw materials because they are ecological, renewable, available, low energy consumption, less costly, low pollution, and therefore without risk to human health. The poto-poto is a widespread material, made of soil material and bamboo, two natural materials widely used in construction throughout the world and particularly in Central African countries, due to their affordable cost or the low technical requirements for their implementation. This material (poto-poto) although widely used, remains very insufficiently explored as well from the point of view of its mechanical characteristics as from the normative point of view necessary for its modernization. This is why, given the extent and large scale of its use, we considered it important to explore it by establishing its physical characteristics. In this paper, we have chosen to continue the characterization of poto-poto already started in the previous paper by also addressing its acoustic characteristics.Indeed, the effects of climate change are manifested by abnormal variations in temperature against seasons. Hence the urgency to master the physical properties in order to make the most of it both in terms of acoustic implementation and/or thermal insulation as regards its use as a green and modern construction material. In this work, we have, on the basis of the Biot model, carried out a 2D numerical modelling of a poto-poto wall by coupling finite elements method (FEM) and boundary elements method (BEM). The MATLAB software was used to obtain the sound absorption curves of our model. We then made several specimens of our eco-material (3 cm, 4 cm and 5 cm) dosed with 2%, 4% and 6% of bamboo fibers, on which Kundt tube measurements were performed to determine the experimental sound absorption curves. The comparison of these curves with those of the model showed acceptable standard deviations and above all allowed us to conclude that the poto-poto presents an acoustic absorption in the range of frequencies 500–1250 Hz and can thus be effectively used for the acoustic implementation of the walls and certain rooms of the buildings.