Non-bearing Walls Research Articles

Formation of Cellular Concrete Structures Based on Waste Glass and Liquid Glass

The use of waste in the production of building materials is one of the possible ways to solve problems related to the sustainable management of non-degradable waste and difficult-to-recycle secondary resources. In this paper, a method is proposed for the non-autoclave production of an ultra-lightweight cellular concrete based on Portland cement, glass waste and liquid glass. A mixture of sodium hexafluorosilicate and hydroxide is used as a hardening activator, an aluminum powder serves as a gas-forming agent. The setting and hardening of raw mixtures occurs under the action of exothermal heat release due to a complex of chemical reactions occurring in the system, and the resulting material does not require additional heat treatment. It is optimal to use two fractions of glass waste to achieve acceptable material strength: coarse crushed (fineness modulus Fm = 0.945) and finely ground (specific surface Ssp = 450–550 m2/kg) glass. Glass particles of the fine fraction of glass, along with Portland cement, participate in hydrolytic and structure-forming processes, while glass particles of the coarse fraction play the role of reinforcing filler. The influence of the dispersion of glass and the density of liquid glass on the density, porosity, strength, water absorption and water resistance of the resulting cellular material was determined. At an average density of cellular concrete in the dry state of 150–320 kg/m3, the following characteristics can be achieved: a compressive strength up to 2.0 MPa, bending strength up to 0.38 MPa, thermal conductivity coefficient of the material in the range 0.05–0.09 W/(K·m), and a maximum operating temperature of 800 °C. The proposed ultra-lightweight cellular concrete can be used as a non-combustible heat and sound insulation material, as well as a repairing composition; the cellular concrete blocks can be used as filling masonry and for the construction of non-bearing internal walls.

A novel bionic straw-filled concrete block: compression and heat-transfer performance

To develop economical, environmentally friendly and lightweight building materials, a novel straw-filled bionic concrete hollow block (BCHB) was designed. Compression tests were conducted to determine the compressive strength of the BCHB. Furthermore, the compressive and heat-transfer properties of these blocks were investigated with finite-element analysis, and the following results were observed. (a) The BCHB model did not easily experience local collapse. Instead, it mainly exhibited thin cracks due to shear failure, providing great cracking and collapse resistance, thereby resulting in excellent compressive performance. (b) By reducing the thickness of the short edges of the BCHB models, they exhibited great compressive and thermal insulation performance, making these the preferred BCHBs. (c) The BCHB presented herein was the simplest model of the beetle elytron plate. In contrast to a traditional hollow brick, the BCHB was proven to be a lightweight, fully enclosed brick (block) with a high hollow ratio and could be used as a new non-bearing wall material replacing the traditional type in building construction.

Wind loads tests of external walls blocks masonry of noncombustible polystyrene concrete

Introduction. Blocks of non-combustible polystyrene concrete of D300 density grade, B1 compressive strength class with normalized thermal conductivity λ0 = 0,078 W/(m·°C) and frost resistance grade not lower than F75, developed by LLC “Institute VNIIZhelezobeton”, were used in masonry with a thickness of 375 mm without special fireproof lining. Such masonry successfully passed standard fire tests for fire hazard and fire resistance, which showed the possibility of its use in external non-bearing energysaving walls of multi-storey buildings (up to 25 floors inclusive, about 75 m high).Aim. Evaluation of the strength and deformation characteristics of non-combustible wall masonry made of noncombustible polystyrene concrete blocks with a density of D300 at design wind loads at a height of about 75 m. Materials and methods. Fragments of uncoated wall masonry 375 mm thick, 2,7 m high and 1,2 m wide of noncombustible polystyrene concrete blocks mounted on a mortar with over-all dimensions of 295 × 375 × 595 mm were tested.The test procedure is in accordance with State Standard 8829-2018.Results. The destructive bending load exceeded the calculated one by an average of 4,1 times, while the deflection in the middle of the fragment was 1,9 times less than the permissible one.A methodology has been developed for calculating the strength and deformability of masonry of polystyrene concrete blocks under wind loads, taking into account the influence of horizontal and vertical masonry joints, which is scheduled to be reflected in Amendment No. 1 SP 434.1325800.2018.Conclusions. The results of wind load tests showed that for unlined masonry made of non-combustible polystyrene concrete blocks with a density of D300 and a thickness of 375 mm, the requirements for strength and deformability are met with a significant margin. The results of tests for wind and fire effects of the specified block masonry make it possible to use it in nonbearing external walls of multi-storey residential energyefficient buildings up to 75 m high in virtually all regions of Russia.

THE EFFECT OF HOLLOW STRUCTURE PARAMETER ON THE 3D-PRINTED WALL BEARING CAPACITY. EXPERIMENTAL MODEL

We present the results of experimental studies and modelling of the evaluation of the bearing capacity of hollow 3D-printed walls with the printed shell performing bearing functions. The bearing capacity of hollow 3D-printed walls was experimentally assessed depending on the ratio of the void areas and casting layers in the wall structure. It was established that in case of central loading, a 3D-printed wall with bearing casting layers can serve as a bearing wall similar to traditional types of masonry construction without filling voids with structural concrete and reinforcement. We established the value of strength reduction of hollow 3D-printed walls, which amounted to ~0.1 – 0.25 MPa per 1 % of the increased area of voids. The limit value of the hollow structure parameter was determined, which must not exceed K = 0.75 in order to ensure the bearing capacity of self-bearing and non-bearing 3D-printed walls. We obtained an experimental model of the relationship between the hollow structure parameter and the bearing capacity, which allowed predicting the bearing capacity of a 3D-printed wall under central loading. It was suggested to take into account the hollow structure parameter K when calculating the elements of unreinforced 3D-printed walls under central compression according to the first group of limit states.

Heavy and light masonry walls impact on medium height reinforced concrete frames buildings

The paper studies the influence of light weight aerated autoclaved concrete (AAC) partitioning walls to a medium height reinforced concrete structure, in Bucharest (Romania). The building is designed as a framed structure with non-bearing AAC walls placed in certain bays. There is a bearing full bricks masonry wall in one of the bays. Full bricks are used because of its high strength compared to AAC. The aim is to determine the importance of the masonry walls placement, both full bricks and AAC, for the building’s behavior. The analysis points out the structure’s elastic and plastic behavior and also the efforts developed in the non-bearing walls. The bearing masonry wall’s behavior is very important, because the structure is built in a high seismic area. To extend the study, the full bricks wall is replaced with a reinforced concrete one. This is done to see how it impacts the building’s behavior, for both the elastic and plastic stage. The paper concludes that AAC, full bricks and concrete walls placements have a significant influence on the structure.

Green Organic Partition Board from Waste Materials as Soundproof Material

Walls are vital in the structure, and give security to the host. Wall as part of structure in industrialised Building System (IBS). Walls can be made a plunge two bearing and non-bearing walls. Non-bearing walls are made of delicate parcel boards. Segment board ought to be, areas of strength for light have great Noise Reduction Coefficient (NRC). This' exploration will likely make another segment board from squandered material to deliver ecologically protected and less expensive board from the current board. The principal material is coconut shell and paper. Each board is made in various extents to pick the board with best NRC. Commotion impact framework chamber is utilized to test the capacity of sound proof of the new sheets. The perusing of the sound level meter was taken in various good ways from the sound source and changing the level of the sound recurrence and sound power. The outcome showed that the new parcel board which produced using 80% coconut shell, 15% concrete, 5% paper can diminish the clamor better compared to the other sheets. This board has NRC is 21%, 21%, 24%, and 12% for the different sound level tests. This can be an option IBS parcel board.

Mies van der Rohe “건축술(Baukunst)”의 현상학적 특성 분석 : 재료의 감각 지각 및 인지를 중심으로

Purpose: Mies van der Rohe is one of the most important figures in modernist architecture He emphasized the poetic experience induced in the process of material construction(bauen). This study is to identify the phenomenological characters in the Mies’s spaces according to his concept of “Building Art(Baukunst). It is specifically focused on how sensational perception/cognition occurs. Method: Mies’s texts are selected with literature and images to identify ideas and usage of material properties. The research was processed by identifying the meaning of Baukunst and its relation with material, and then examining the sensational aspects of perception and cognition in Mies’s build works at structural/ non-bearing member. Result: (1) The phenomenological characteristics of Mies van der Rohe are divided into structural members and non-bearing members, especially non-bearing walls. (2) He tried to realize the objective and absolute essence of architecture in structural members. Accordingly, the perceptual elements of structural members in his architecture utilize traditional and customary perceptual qualitative elements, that is, the physical properties of materials we so-called stereotypes. This is similar to Merleau-Ponty

КОНСТРУКТИВНАЯ СИСТЕМА БЫСТРОВОЗВОДИМОГО ЗДАНИЯ ИЗ ИНДУСТРИАЛЬНЫХ ПАНЕЛЬНО-РАМНЫХ ЭЛЕМЕНТОВ

The paper presents a new structural solution of the precast-monolithic frame for prefabricated residential and civil buildings of various storeys manufactured from prefabricated industrial reinforced concrete elements. The precast frame structures include L-shaped and inverted U-shaped precast elements, installed in the longitudinal and transverse directions and forming a frame, hollow-core slabs and bracing perforated beams of the outer contour, on which fencing non-bearing wall structures are supported within each storey. The computational model of the precast-monolithic building frame was developed using different degrees of discretization at different stages of the analysis. This allowed to obtain both a general picture of structural system deformation in the limiting and over limit states caused by special and emergency actions, and a detailed picture of the stressed state in concrete and reinforcement of structural elements before and after cracking. The paper provides the results of the comparative analysis of the effectiveness of application of the proposed structural system in the mass construction as compared with the applied constructions of large-panel buildings. It has been shown that the application of the proposed structures of panel-frame elements allows considerably reduce the material capacity, cost and transportation expenses of the reinforced concrete frame by up to 30 %, ensuring the mechanical safety of the building.

Sludge-based baking-free brick prepared by sewage sludge with high moisture content: Influence of process parameters and environmental risk assessment

The high-water content and difficult dehydration of sewage sludge are the main factors restricting its disposal and application in China. In the paper, the sludge-based baking-free brick (SBFB) was made from sludge and fly ash - carbide slag - desulfurization gypsum with a certain amount of aggregate using compaction forming technology. The influence of process parameters (e.g., sludge content, aggregate content, molding pressure, curing method and curing temperature) on the properties of SBFB were investigated. Additionally, the environmental risk assessment of heavy metals and organic pollution of SBFB samples were carried out. The results indicated that when the sludge content was less than 30 %, the SBFB strength reaches 13.7 MPa under wet-heat cycle curing, which can meet the national standard of nonbearing wall for building bricks. According to the analysis of SEM and XRD, mullite and silicalite crystals were needle-like structures, which made the sludge particles closely linked with solid waste and compact structure. The appearance of these crystal structures was the internal driving force for the later strength of SBFB. Values of risk assessment criteria decreased through solidification treatment, in which Cd decreased to no risk, As, Pb, Zn decreased to low risk, Cu, Ni had moderate risk. All heavy metals were within China standards (GB5085.3–2007). Compared with sludge, the degradability of protein under curing conditions was greater than 77.35 % because of the decomposition of proteins in gel reaction system.

Mechanical properties and interface improvement of bamboo cellulose nanofibers reinforced autoclaved aerated concrete

Autoclaved aerated concrete (AAC) has low density, suitable compressive strength, and excellent thermal and sound insulation capacity for building non-bearing walls. However, porous AAC blocks usually have low flexural strength and thus are prone to cracking during service life. Herein, bamboo cellulose nanofibers (BCNF) were incorporated into AAC matrix to enhance mechanical strengths. The BCNF was further modified by 3-mercaptopropyl-trimethoxysilane (KH590) to improve the interfacial bonding between BCNF and AAC matrix. Results showed that the AAC with the addition of 0.3 wt% KH590-modified BCNF had 49.2% and 20.7% higher flexural strength and compressive strength than those without BCNF, respectively. AAC slurry belongs to a pseudoplastic fluid with a yield value, which can be described by Bingham rheological model. With the increase of shear rate, the stress of AAC slurry increased and the viscosity decreased exponentially. The interfacial bonding of BCNF/AAC-matrix was characterized by FTIR, XPS, NMR, and SEM analyses. It was confirmed that the siloxane groups of KH590 react with the hydroxyl groups of BCNF, thus grafting the BCNF with hydrophobic moieties and improving their interfacial adhesion with AAC matrix. In addition, granite powders collected from stone processing mill were utilized as a main component of AAC matrix. This study provides a feasible way of utilizing renewable materials and solid waste in preparing high-performance AAC as green building materials.

Evaluation of Data Extracted from Floor Plans for Apartment Complex Remodeling

South Korea has witnessed an increasing social demand for housing supply due to rapid urban population growth from the 1950s through the 1970s. At least two million houses have been in use for 30 years or more since the implementation of policies related to the mass production of apartment houses 20–30 years ago. Methods for improving the aging of domestic apartment houses and their living environment are reconstruction and remodeling, and the government has been encouraging remodeling by easing laws and regulations related to it. During the early stages of a typical remodeling project, many candidate floor plans arise in the process of finalizing the floor plan, resulting in significant time consumption in the iterative process for reviews and revisions. Extracting quantitative indicators by comparing floor plans before and after remodeling at the initial design stage and comparing the indicators of the target complex with the existing case can facilitate a more time‐efficient and economical decision‐making process. In this study, quantitative indicators were extracted from floor plans by applying a structural evaluation program for remodeling of apartment housing at five existing domestic apartment complexes (nine buildings in total), and a detailed comparative analysis was conducted. Evaluated indices included variations of floor area, load‐bearing wall, nonbearing wall, slab, weight, area moment of inertia, torsional resistance, and visualization of removed, remaining, and new bearing walls. The proposed method can continuously accumulate data from domestic apartment house remodeling projects and accelerate the process by shortening the time required for final decision‐making in future remodeling projects.

Influence of production on hemp concrete hygrothermal properties: sorption, water vapour permeability and water absorption

Hemp concrete is considered to be a carbon negative material. Hemp absorbs CO2 during the growth and lime needs CO2 for carbonation. The material, which has good thermal insulation properties, is used as a non-bearing wall material or plaster. For such use the hygrothermal properties of a material must be well known especially when indoor insulation is in focus. In the current study hemp concrete produced in two different ways was in focus and following the hygrothermal properties of hemp concrete as a building material were studied: water absorption (EN 1015-18), water vapour sorption (EN 12571), water vapour permeability (EN 12572) and thermal conductivity (EN 12667). The results of the study can be used in hygrotheramal calculations and modelling.

Production of Lightweight Concrete by Using Polystyrene (cork) waste

There are two important subjects in the local and global areas, the first is the environmental pollution and the second is economic advantages of recycling and reusing of industrial materials. One of the most important industrial materials is cork waste. Because of many good properties of cork, like compressibility and a good ability to mould according to human needs, this material become as an important material in several life categories. This research work includes production of new type of light weight concrete and studies the mechanical and thermal properties. Several proportions of raw materials were used to produce this type of concrete. This study is intended to produce light weight concrete with low thermal conductivity so that it can be used for concrete masonry units. Polystyrene aggregate was added as percentages by weight of cement to improve the thermal properties of this type of concrete. Mechanical, and thermal tests with difference ages were made in this work. For polystyrene concrete with polystyrene cement ratio (p/c) of (2.67 – 6)%, the 28-day compressive strength range is from (4.31 – 2.67)MPa, flexural strength range is from (3.05-1.719) MPa, density range is from (1493-1213) kg/m3, and thermal conductivity range is from (0.91-0.782)% as a percentage by that of reference mix. The study show suitability of this type of concrete to be used in concrete masonry units of non-bearing walls.

Design and manufacture of insulation panels based on recycled lignocellulosic waste

This paper has been focused on the properties of construction material based on cellulose. More specifically, their use as non-bearing walls, coating-panels and/or anti-humidity panels. It has been obtained from the recycling of urban waste, such as paper and paperboard. The performance of this material has been evaluated in relation to five parameters: dimensional stability against humidity, fire action, decay resistance front fungal degradation, and, their behavior as temperature and acoustics isolation. The performance of manufactured materials has been verified considering environmental factors, and simulating the condition of the material in service. This yielded satisfactory results in relation to all the agents mentioned, which allows concluding that the material fulfills the desired function. It has been concluded that the designed and manufactured panels have the necessary characteristics to replace insulating materials or Gypsum plasterboard type enclosure, extending the range of materials for this function, through the incorporation of a new option based on recycled raw material, low-cost manufacture and minimal energy resources used. • The objective was the development of a new material based on cellulose and water. • New material obtained from the recycling of urban waste (paper and paperboard). • Insulating panels based on cellulose and water have been design and development. • They could be use as non-bearing walls, coating-panels and/or anti-humidity panels. • This new option with low-cost manufacture and minimal energy resources.

Nonbearing Wall infill Under Seismic Impacts In Terms Of Non-Linear Static Analysis

The presence of wall infill during seismic impacts is one of the key factors that significantly affect the seismic stability of buildings. Also, irregularity of configuration in plan and height can often lead to more serious damage comparing to regular buildings, due to torsional oscillations and stress concentration on individual elements. The purpose of this article is to study the behavior of various irregularities in the shape of buildings under seismic impacts in terms of non-linear static analysis, taking into account the non-bearing wall infill. For this purpose, five typical geometric shapes of the building plan used in Ukraine and abroad (rectangular, + shape, L-shaped, T-shaped and 4-shaped) were adopted.The calculations were performed using the Pushover Analysis (nonlinear static analysis) method in CAD Lira-SAPR 2019. The main parameter that forms the basis for seismic stability analysis is the story drift under seismic impacts. Obtained results indicate the need to take into account the effect of wall infill, as this can lead to an increase in the seismic stability of the building and stress concentration on individual elements, which can lead to their collapse.

Experimental Study on Basic Mechanical Properties of Core-Column Non-mortar Aerated Concrete Block Masonry

Autoclaved aerated concrete (AAC) block masonry has been widely used for bearing walls of multi-story buildings or non-bearing walls of high-rise buildings because of its unique advantages, such as lightweight, low pollution output, and excellent thermal insulation performance. However, traditional AAC block masonry has the disadvantages of high water absorption, poor adhesion to mortar, and low construction efficiency. In order to improve the performance of traditional AAC masonry, this paper proposed a new kind of mortar-free AAC block masonry with concrete core-columns. Fundamental mechanical properties of compression and shear were studied. We divided a total of 16 compression specimens into four groups according to different hollow ratios and strength grades of the block, and eight shear specimens into two groups based on different hollow ratios. Each specimen consists of three-layer blocks with two core columns at the point of quadri-section. The diameters of columns were, respectively, 100 mm and 80 mm. The specimens were loaded at a constant speed to evaluate their bearing capacity, displacement response, crack development, and damage state. The formula of the average values and design values of the compressive and shear strength of masonry were obtained statistically. The stress–strain constitutive relation of masonry expressed by a three-stage curve was presented. Furthermore, the result of numerical analysis using the ABAQUS finite element program aligned well with the experimental results. The compressive strength and shear strength of the new type of masonry are no less than traditional AAC masonry, and new masonry has higher construction efficiency and more stable strength.

Experimental investigation of hysteretic behaviour of non-structural dry gypsum infill walls

Studies carried out concerning the non-bearing partition wall systems used in buildings have increased in recent years. A very limited number of studies about the behaviour of gypsum wallboard systems under cyclic repeated loads have been found in the literature. An experimental study was carried out under earthquake loads to investigate the properties of gypsum wallboard systems, such as general load–displacement behaviour, stiffness, displacement ductility ratios and energy dissipation capacities. Ten different non-bearing wall specimens were produced. Four of these wall specimens consisted of different gypsum wallboard infill walls and the remaining six consisted of plastered and non-plastered infill wall specimens built with clay bricks, light concrete briquettes and aerated concrete blocks. As a result of this study, the performance levels and general behaviours of dry gypsum infill wall systems under the effect of horizontal cyclic reversible loading were determined by comparing with other infill wall systems. Although the initial stiffness and ultimate load capacity values of the dry gypsum infill wall systems were lower compared to a masonry infill wall and lightweight concrete brick walls, it was determined that they performed very successfully in terms of displacement ductility ratio and energy dissipation capacity.

Finite Element Analytical Study of Steel Plate and Dowel Bar Systems Designed for Damage Reduction of Non-Bearing Walls

Finite Element Analytical Study of Steel Plate and Dowel Bar Systems Designed for Damage Reduction of Non-Bearing Walls

Finite element analysis of a thin-shell concrete sandwich panel under eccentric loading

This paper presents finite element (FE) analysis of the structural behavior of a concrete sandwich panel that is 210 mm thick. The analyzed section is composed of two concrete layers that are 70 mm thick, and a thermal polystyrene insulation layer that is 70 mm thick placed in between. This wall section is commonly used as a precast non-bearing external wall. However, the intent of this study is to investigate the structural performance of such a sandwich panel as a load-bearing element under eccentric axial loading. A nonlinear FE model for a concrete sandwich panel was developed for this purpose using ABAQUS commercial software, implementing a displacement-controlled analysis to trigger failure of the wall element. The composite action of the sandwich panel resulted in a ductile failure mode instead of sudden crushing, and its ultimate capacity exceeded the design load expected for a typical G+2 residential building. The load vs axial displacement response of the panel exhibited a linear behavior up to 70% of the ultimate capacity in which the two concrete layers displayed equal lateral displacements. However, different lateral displacements were encountered along the height of the two concrete layers during the nonlinear stage, starting from the top and continuing to grow down to separate the two layers. First and second modes of buckling were observed at the linear and nonlinear stages, respectively.

Finite element modelling for the dynamic analysis of hollow-core concrete floors in buildings

Precast hollow-core concrete (HC) slabs are widely used in construction, especially in Nordic countries. The combination of prestressing and low self-weight due to the voids makes it possible to build long-span floors. However, this also implies that the floors become more sensitive to vibrations from human activities, and consequently a finite element model of the floor is often necessary in order to perform a dynamic analysis. However, there are no guidelines or recommendations to implement such finite element models for HC floors. In this paper, six in-situ dynamic experiments performed in 4 buildings are presented. For each case, several finite element models have been implemented and tested. These analyses show that the orthotropic shell model for the HC floor proposed by the authors in a previous publication gives good results in all the studies. The results also indicate that the concrete walls or the steel beams and columns surrounding the floor should be incorporated in the finite element model in order to get accurate results. Besides, in some cases, the floors below and above must be modelled in order to catch all the eigenmodes. The influence of the non-bearing internal walls is also discussed.