Composite Building Research Articles

Analisis Kekuatan Mekanik Komposit Polimer Diperkuat Serbuk Kulit Kerang

In recent decades, the development of composite material technology has continued to increase rapidly and has been used for various applications as an alternative material to replace metal. In line with growing environmental issues, the utilization of natural materials which are abundant in nature and easy to find is the main priority for composite building materials. In this study, shell powder was used as a reinforcing material for epoxy polymer composites. The aims of this study were to obtain the average compressive, tensile, and flexural strength of shell powder-reinforced polymer composite materials, to calculate the distribution of test results using the PDF method, and to calculate the contribution of shell powder to the mechanical properties mentioned using the ANOVA method. The tensile, compressive, and flexural test specimens follow the test specimen standards of ASTM D638, ASTM D7264, and ASTM D695 respectively. The composition of shell powder consists of 10%, 30%, and 50%. Testing of these mechanical properties using a UTM-type hydraulic test equipment model WEW-300D with a capacity of 300 kN. The test results show an increase in the mechanical properties of the material. The increase occurred in compressive and flexural strength where the composition was given up to 30% and 50%, namely between 120 – 125 MPa. However, increasing the composition of shell powder at 30% and 50% actually resulted in a decrease in tensile strength between 12 – 9 MPa. Finally, based on the results of ANOVA analysis, it was shown that the addition of shell powder as a reinforcement for polymer composites significantly improved their mechanical properties.

ECNU-13: A High-Silica Zeolite with Three-Dimensional and High-Connectivity Multi-Pore Structures for Selective Alkene Cracking.

A high-silica zeolite ECNU-13 (Si/Al=23) with a new three-dimensional (3D) pore system and a nanosized morphology has been developed, consisting of multitudes of 10-membered ring (10-R) medium pores and one set of 8-R small pores. A phase-discrimination strategy was proposed to synthesize ECNU-13 by regulating the gel compositions and nucleation processes that were used for preparing 12-R large-pore germanosilicate IM-20 with the known UWY topology. The crystallization was directed towards forming one set of single four-ring (s4r) composite building units together with one set of double four-ring (d4r) rather than two different types of d4r units in IM-20. The electron crystallographic investigations elucidated that the ECNU-13 structure was composed of two kinds of polymorphs as a result of distinct atomic positionings in s4r units. In catalytic cracking of 1-butene, ECNU-13 exhibited high propene selectivity (55.6 %) and propene to ethylene molar ratio (>4.7) superior to well-studied conventional ZSM-5 zeolite catalyst.

ECNU‐13: A High‐Silica Zeolite with Three‐Dimensional and High‐Connectivity Multi‐Pore Structures for Selective Alkene Cracking

AbstractA high‐silica zeolite ECNU‐13 (Si/Al=23) with a new three‐dimensional (3D) pore system and a nanosized morphology has been developed, consisting of multitudes of 10‐membered ring (10‐R) medium pores and one set of 8‐R small pores. A phase‐discrimination strategy was proposed to synthesize ECNU‐13 by regulating the gel compositions and nucleation processes that were used for preparing 12‐R large‐pore germanosilicate IM‐20 with the known UWY topology. The crystallization was directed towards forming one set of single four‐ring (s4r) composite building units together with one set of double four‐ring (d4r) rather than two different types of d4r units in IM‐20. The electron crystallographic investigations elucidated that the ECNU‐13 structure was composed of two kinds of polymorphs as a result of distinct atomic positionings in s4r units. In catalytic cracking of 1‐butene, ECNU‐13 exhibited high propene selectivity (55.6 %) and propene to ethylene molar ratio (>4.7) superior to well‐studied conventional ZSM‐5 zeolite catalyst.

Numerical studies on the seismic response of a three-storey low-damage steel framed structure incorporating seismic friction connections

A 9 m high, near full scale three-storey configurable steel frame composite floor building incorporating friction-based connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China, as part of the RObust BUilding SysTem (ROBUST) project. A total of nine structural configurations are designed and detailed. To have a better understanding of the expected system behaviour, as well as effects of other structural and non-structural elements (NSEs) on the overall system response, experimental testing at component level has been conducted prior to the shake table testing. This paper presents an introduction to the ROBUST project, followed by a numerical study on one of the nine configurations of the structure, having Moment Resisting Steel Frame (MRSF) in the longitudinal direction and Concentrically Braced Frame (CBF) in the transverse direction. Hysteretic properties employed in the numerical models are validated against component test results. The predictions of the building's seismic response under selected base excitations are presented indicating the likely low damage performance of the structure.

A Review of the Environmental Benefits of Using Wood Waste and Magnesium Oxychloride Cement as a Composite Building Material

There is an increasing awareness of the negative environmental impact produced by human activity worldwide. The scope of this paper is to analyze the possibilities of the further use of wood waste as a composite building material with magnesium oxychloride cement (MOC), and to identify the environmental benefits offered by this solution. The environmental impact of improper wood waste disposal affects both aquatic and terrestrial ecosystems. Moreover, burning wood waste releases greenhouse gases into the atmosphere, causing various health problems. The interest in studying the possibilities of reusing wood waste increased significantly in recent years. The focus of the researcher shifts from considering wood waste as a burning fuel to generate heat or energy, to considering it as a component of new building materials. Combining MOC cement with wood opens the possibility of creating new composite building materials that can incorporate the environmental benefits offered by the two materials.

Brown sugar enhancing strength of corn stalk biomass bricks

In order to enhance the strength of corn stalk biomass brick, corn stalk fiber, calcium hydroxide, and brown sugar water solution were mixed and moulded into biomass brick. The corn stalk fiber content was 15 wt% and the calcium hydroxide content was 85 wt% in bricks. Brown sugar water was added to calcium hydroxide at 1 wt% of the calcium hydroxide content. Compressive strength and flexural strength increased with the increasing concentration of brown sugar water solution. Moisture content, density, and drying shrinkage rates were not affected significantly by the concentration of brown sugar water solution. But compressive strength, flexural strength, and tensile strength were affected significantly by the concentration of brown sugar water solution. Compared with the control brick, the compressive strength increased by 51.03%; flexural strength increased by 64.24%; tensile strength increased by 40.91%. Therefore, brown sugar could significantly enhance the compressive strength, flexural strength, and tensile strength of biomass brick. The reason was that brown sugar promoted calcium hydroxide to form more calcium carbonate. The presence of brown sugar helped CO2 diffuse inside the bricks because slow carbonation of the brick surface significantly delayed pore plugging around the surface of the bricks. The research results provided the scientific base for brown sugar enhancing the strength of corn stalk biomass brick and it was interesting to use corn stalk effectively. It was of great significance to the application of sugar adhesives and the research and development of organic/inorganic composite building materials.

The structure-directing role of heterologous seeds in the synthesis of zeolite

Zeolites have been widely used as catalysts, ion-exchangers, and adsorbents in chemical industries, detergent industry, steel industry, glass industry, ceramic industry, medical and health field, and environmental field, and recently applied in energy storage. Seed-assisted synthesis is a very effective approach in promoting the crystallization of zeolites. In some cases, the target zeolite cannot be formed in the absence of seed zeolite. In homologous seed-assisted synthesis, the structure of the seed zeolite is the same to that of the target zeolite, while the structure of the seed zeolite is different to that of the target zeolite in the heterologous seed-assisted synthesis. In this review, we briefly summarized the heterologous seed-assisted syntheses of zeolites and analyzed the structure-directing effect of heterologous seeds and surveyed the “common composite building units (CBUs) hypothesis” and the “common secondary building units (SBUs) hypothesis”. However, both hypotheses cannot explain all observations on the heterologous seed-assisted syntheses. Finally, we proposed that the formation of the target zeolite does need nuclei with the structure of target zeolite and the formation of the nuclei of the target zeolite can be promoted by either the undissolved seed crystals with the same CBUs or SBUs to the target zeolite or by the facilitated appropriate distribution of the specific building units due to the presence of the heterologous seed that does not have any common CBUs and SBUs with the target zeolite.

Pengaruh Salinitas Pasir Terhadap Kuat Tekan Bata

The development of technology, especially in the construction field, in manufacturing bricks is increasingly rapid and varied, one of which is lightweight brick. The light brick is a composite building material made of sand, cement, limestone, gypsum, water, and aluminum powder. In general, lightweight bricks have two types, Autoclaved Aerated Concrete (AAC) and Cellular Lightweight Concrete (CLC). Light bricks were created to lighten the structural load of a construction building, speed up construction, and minimize material waste during the wall installation process. Sand is a staple in the construction process. In addition, sand material cannot be separated from its use in the industrial world. The Taguchi method is a methodology in engineering that aims to improve the quality of products and processes and can reduce costs and resources to a minimum. The compressive strength of the concrete load is the magnitude of the load per unit area, which causes the concrete specimen to collapse when loaded with a specific compressive force, which is generated by the press machine; the compressive strength of the concrete will increase with increasing age of the concrete, where the compressive strength of the concrete will increase rapidly (linearly). Salinity is the salt content dissolved in water which is one of the physical parameters that can affect the quality of water, soil and sand.

Evaluation of Seismic Response of Composite Buildings under Near-Field Earthquakes

This paper represents the effectiveness of the bracing system concerning the seismic performance of steel-concrete composite buildings by comparing 5-storey composite buildings with and without bracings subject to extreme earthquake loads. The nonlinear time history analysis (NTHA) is carried out on the specific building models considered for this study. The seismic response is obtained in terms of different seismic response parameters which are further compared to determine the effect of the bracing system. The results obtained by applying real earthquake records of different near-field & far-field earthquakes were compared for three earthquake response parameters which include base shear, inter-storey drifts, and storey displacements. The bracing system is very effective in resisting the seismic force when subjected to extreme earthquakes as it increases the overall stiffness of the building. The bracing system improves the overall performance of the composite building by reducing the inter-storey drifts and maximum storey displacement under extreme earthquakes.

ADVANCED ANALYSIS OF STEEL‐CONCRETE COMPOSITE BUILDINGS

AbstractThis paper presents a nonlinear simulation method for composite framing systems constituted from concrete‐filled steel tubular columns (CFST) and composite beam systems. A force‐based fibre beam‐column element in OpenSees was adopted. This element was capable of accurately capturing the local buckling of steel and the confining effect of concrete using the modified stress‐strain relationships of the steel and concrete fibres. A source code for the connection element was also developed in OpenSees to capture the semi‐rigid behaviour of the beam‐to‐column connections of the composite buildings. Through the verification with numerous experiments, the model has shown its capability of accurately simulating composite frames with simplicity and less computational cost. An extensive parametric study was conducted to examine the effect of the bracing systems and the rigidity of the connections on the behaviour and instability of the whole composite buildings.

Vibration control of seismic forces using viscous dampers and buckling restrained braces in irregular composite buildings

This study addresses the effectiveness of buckling restrained braces (BRBs) and viscous dampers (VDs) in dissipating seismic energy and increasing the seismic performance of irregular composite buildings during earthquake events. The seismic response of steel-concrete composite moment resisting frames of 15 stories with concrete filled steel tubes (CFST) as columns and composite beams was examined with and without seismic protection devices by employing ETABS software using the response spectrum method as per IS 1893:2016 for seismic zone V. Regular and irregular plans characterised the structures. The plan irregular buildings include C and L-shaped buildings. The BRBs and VDs were installed on all the buildings in two configurations: corner bays and centre bays throughout the height. The results showed BRBs and VDs excellent energy dissipation capabilities. VDs contributions were 5%-8% more than BRBs and, therefore, more efficient. Centre bays placement of VDs was most efficient for regular buildings reducing time-period by 60%, maximum story displacement by 57%, base shear by 37%, and maximum interstory drift ratio by 70%. Corner bays placement of VDs was most efficient for C and L-shaped buildings reducing time-period by 55%-60%, maximum story displacement by 63%-65%, base shear by 30% and 13%, and maximum interstory drift ratio by 78%-80%, respectively, making viscous dampers an excellent choice for midrise composite buildings.

Lessons from nature [Biomimicry- Construction

Two finalists in the 2022 Ray of Hope Prize have looked to nature for innovative ways to transform the sector and improve the environmental impact of urban construction, ultimately making cities more sustainable. Biomimicry plays a key role in these innovations, with both Mycocycle and Metavoxel drawing inspiration from natural processes to create new solutions for the construction industry. Metavoxel has invented new composite building materials that have taken inspiration from the cellular construction of materials such as bone, wood, and sea sponge. These programmable, cellular building materials are based on discrete assembly of modular building-block parts. By leveraging the benefits of cellular architecture, Metavoxel can address a range of performance regimes with significantly less material while offering improved performance through application-specific tunability. This means that the construction industry can cut the cost of building projects and improve structural efficiency, as Metavoxel's cellular innovations are around 98% air but maintain a high level of structural performance. Mycocycle, on the other hand, works with fungi to break down complex construction waste materials. Inspired by biomimicry, Mycocycle not only processes the waste but also recycles it into building materials that can be used in new products. This innovative approach to waste management not only addresses the growing issue of unsustainable disposal of waste materials but also provides a sustainable source of building materials.

Seismic performance of irregular composite buildings: A comparative study of the effectiveness of buckling restrained braces and viscous dampers

Seismic performance of irregular composite buildings: A comparative study of the effectiveness of buckling restrained braces and viscous dampers

Prefabricated thermally-activated fiber-polymer composite building slab P-TACS: Toward the multifunctional and pre-fabricated structural elements in buildings

The traditional sequential design of building elements, where every element performs only one dedicated function, carries significant embodied energy. Thus, modular pre-fabricated load-bearing elements could overcome the disadvantages of the current carbon-intensive construction practice and go beyond; as such, lightweight glass fiber-polymer composite profiles could be more advantageous in performance. Cellular structures of such profiles can be advantageous for adding water channels for active heating and cooling indoors and for fire protection. Therefore, the development of such a modular active building slab referred to as P-TACS (Prefabricated Thermally-Activated Fiber-Polymer Composite Slab) is explored in this work. The structural performance of a proposed P-TACS design is verified in terms of serviceability and ultimate limit states. The addition of local carbon fiber inclusions allows for an increase in the span of the slab to 10 m and a more uniform surface temperature. Thermal performance of the structurally optimized geometrical configuration is analyzed by, first of all, determining water parameters based on the 1D approach partially adopted from the standard radiant systems analysis and, secondly, by a detailed 2D thermal analysis using ANSYS Fluent numerical simulations. The hydraulic and thermal performance comparison of the novel P-TACS design with two standard radiant systems (ESS Type A and RCP) reveals that the P-TACS design outperforms the standard embedded surface system ESS Type A, both for floor heating and cooling case. In addition, the response time of P-TACS is three times faster compared to the ESS response time. The main advantage of the P-TACS is in lower mean water temperature, compared to traditional embedded radiant systems (e.g., EES type), required for conditioning the space, potentially resulting in lower operational energy use. The fire outbreak scenario is considered to complete the analysis, and the measures to switch water flow from nominal to fire scenario are proposed.

Structural robustness of composite modular buildings: The roles of CFST columns and inter-module connections

This paper explores the important roles of concrete filled steel tube (CFST) columns and inter-module connections on the structural robustness of composite modular buildings. Various numerical models were developed for concrete filled steel tube (CFST) columns, semi-rigid frames, and conventional steel buildings under column removal scenarios to verify the validation of the present study. A numerical model of a 10-storey composite modular building was then developed, in which conventional hollow steel section columns were replaced by CFST columns to improve resistance against buckling of columns. To examine the behavior and force transmission mechanism of composite modular buildings under various module removal situations, nonlinear dynamic and nonlinear static pushover analyses was conducted. The introduction of CFST columns provided resistance against buckling of columns under high axial forces. It was observed that a pin-joint inter-module connection approach is a conservative approach to model the connections between modules. It was discovered that the dynamic amplification factor (DAF) recommended by the general service administration (GSA) for the nonlinear static analysis overestimates the displacement response of the modular building structure under module loss situations. The modular building was deemed safe against progressive collapse without excessive failure of the component members. However, progressive failure of the modular building under corner module removal scenario was observed in pushover analysis due to shear failure of horizontal inter-module connections. It was observed that the corner module removal scenario is more critical as compared to the column removal scenario for modular buildings. Based on the location of module removal, the DAF values of 1.65 and 1.2 were recommended for corner module removal and internal and edge module removal, respectively.

Jute fiber-reinforced mortars: mechanical response and thermal performance

Enhancing energy efficiency and structural capacity are the main objectives of masonry retrofitting. However, a combined enhancement of both aspects is hardly achievable, as they are related to the relevant geometric and physical parameters in a somewhat “competitive” fashion. Therefore, the main focus of this research is to achieve the dual positive effect by improving both thermal insulation properties and structural behavior of composite building materials, also with an eye to sustainability. In this context, jute fibers composite mortars were fabricated by using three different fiber lengths (5 mm,10 mm and 30 mm) and four different fiber percentages (0.5%,1%,1.5% and 2%) with respect to the mortar masses. Unreinforced mortar samples showed fragile collapse during the flexural and compression (with hour-glass shape) tests. Whereas the fiber reinforced mortar samples exhibited higher ductility and strain energy but lower strength. These composite samples present also higher thermal resistance as the fiber percentage increases. Samples with longer fibers (30 mm, in all fiber percentage category) can dissipate more mechanical energy, whereas the samples with shorter fibers (5 mm, in all fiber percentage category) have lower thermal conductivity values, which leads to improving the insulation capacity of the composite samples.

Будівельні композитні матеріали на основі деревини: оцінка безпеки в Україні та система технічного регулювання в ЄС

Abstract. Composite building materials based on wood (further ‒ wood plastics) remain a key object of sanitary and hygienic research as an important source of marker air pollutants in residential premises. Aim. Generalization of the results of sanitary and hygienic studies of wood plastics that are in circulation on the market of Ukraine; comparative analysis of individual provisions of the system of technical regulation of the specified products in the EU and Ukraine. Materials and Methods. Directives of EU countries in the field of technical regulation of chemically hazardous construction materials and sanitary legislation of Ukraine; data of sanitary-hygienic researches of the air of residential premises based on complaints of residents of the city of Kyiv, carried out by the "Kyiv City Center for Disease Control and Prevention of the Ministry of Health of Ukraine" (2010-2019); the results of chamber studies of samples (N=4859) of building products based on wood plastics and furniture, performed in the polymer hygiene laboratory of the State Enterprise "L.I. Medved’s Research Center of Preventive Toxicology, Food and Chemical Safety of the Ministry of Health of Ukraine" (2010-2019). Statistical analysis ‒ Microsoft Excel 2019. Results. According to the research data of wood-plastic samples, a high level of their compliance with technical requirements and quality parameters and hygienic standards of Ukraine was established, so over the 10 years of research, the average deviations were: glued plywood, veneered panels, other laminated wood materials - 3.59% (n=1234); fiberboard boards made of wood or other wood materials with or without the addition of resins or other substances ‒ 1.36% (n=1512); chipboard boards, with oriented chips and similar boards (for example, wafer boards) ‒ 1.73% (n=1441); furniture samp-les – 1.6% (n=672). At the same time, an increase in the number of cases of exceeding the concentration of phenol and formaldehyde in relation to the MPC average daily in the air of residential premises of multi-apartment buildings during the same period was found: phenol by 2.86 times (R2=0.764), formaldehyde by 2.7 times (R2=0.529). The difference between wood-plastic samples sent for sanitary-hygienic research and those products that enter residential premises is not excluded, and cases of wood-plastic use in residential premises that are not intended are also found. Fundamental differences in the approaches of the EU and Ukraine to the assessment of the safety of composite building materials still remain unsettled. Difficulties in adapting the product safety regulatory system in the EU for introduction in Ukraine are due to the methodology of risk assessment for human health as a key tool for substantiating product and commodity safety standards. The main distinguishing feature of the EU legal framework on this issue is the recognition of product safety based on the absence of unacceptable risk, and the methodology that was implemented in the Soviet period (more than 30-40 years ago) is based on the principle of "zero risk". Conclusions. There is a need to harmonize the EU system of technical regulation and safety for construction products based on wood with the approaches that are in force in Ukraine, which will contribute to updating the national sanitary legislation, methodology, criteria, and methodical approaches to ensure the safety of a wide range of construction products for the population. An effective tool on this path can be the development and implementation of a targeted interdisciplinary state program. Key Words: wood plastics, risk assessment, technical regulation.

Seismic Capacity Estimation for Composite Multi-storeyed RC buildings

Seismic hazard happens to be one of the most devastative natural hazards to be faced by mankind. In view of urbanization and knowledge gained from past natural hazards, several urban cities have seen a transformation in building their habitats. These range from regular, irregular multistoried Reinforced Concrete (RC) buildings to several composite multi storeyed RC buildings due to certain inherent functional benefits (viz., ventilation, parking space, ease of construction etc.,). The existing seismic code regulations provided by BIS (Bureau of Indian Standards) do not specify any approach to arrive at appropriate design seismic forces and capacity for composite multi storeyed buildings. Therefore, it is imminent to assess the structural behaviour of these multistoried composite RC buildings under earthquake forces at the site location to provide a safe and functional configuration. Hence an attempt has been made in this study to analytically compare regular and composite RC building models having similar Plan and Height. The multistoried RC building configurations considered in this study comprises of regular RC building as well as RC building frame coupled with steel joists at certain locations to represent a composite structural system. These models are further analyzed to arrive at inherent nonlinear seismic capacity, ductility and design seismic forces necessary to be considered during design of RC building structure. Hence, a typical hypothetical G+5 regular and composite multistoried buildings were modelled and analysed using the nonlinear static (pushover analysis) approach. The outcomes of these analyses clearly portrays the variation in dynamic characteristics of the building frames represented in terms of its time period, inelastic capacity and response reduction factor (R). Moreover, the present study emphasizes to analytically evaluate the design seismic forces necessary for earthquake resistant design of composite buildings in any urban environment albeit the changes in structural configurations.

Comparative Study on Seismic Performance of Steel Building & Composite Building with CFT & CFST Column

In this paper a comparative study is done on Steel building & Composite building with CFT, CFT with stiffeners, CFDST Hollow & CFDST column. Seismic Analysis of (B+G+9) building is done in both Equivalent Static method & Response Spectrum method using ETABS software & Optimum Composite column is obtained from Parameter 1 (Steel Ratio, Buckling Load, Plastic Resistance, H/T Ratio), Parameter 2 (Displacement, Story Drift, Base Shear, Overturning Moment, Story Stiffness), Parameter3 (Moment of Inertia, C/S Area, Total Weight, Total Tonnage).

Sequence effect on the self-assembly of discrete amphiphilic co-oligomers with fluorene-azobenzene semirigid backbones.

Sequences can have a dramatic impact on the unique properties and self-assembly in natural macromolecules, which has received increasing interest. Herein, we report a series of discrete amphiphilic co-oligomers with the same composition but different building blocks in a semirigid backbone. These sequence-defined oligomers possess two primary amine groups on the side chain of the azobenzene building block, and hence, they become amphipathic due to quaternization of the amine groups when protonated in acidic aqueous solution. These oligomer isomers assembled into different nanoparticles, including nanofibers, hollow vesicles and spherical micellar complexes, in a THF/water/HCl mixture under the same conditions. UV-vis absorption spectra, differential scanning calorimetry (DSC) and X-ray scattering (XRD) experiments combined with theoretical calculations reveal that the sequence-controlled co-oligomers induce different molecular packing conformations and arrangement modes of building blocks in self-assembly. Furthermore, these self-assembled nanoparticles demonstrate photoresponsive morphological transformation and fluorescence emission under UV light irradiation due to trans-to-cis photoisomerization of azobenzene. This work demonstrates that customizing functional nanoparticles can be achieved by controlling the sequence structure in synthetic co-oligomers.