Floor Slabs Research Articles

Оценка несущей способности железобетонной плиты пола цеха на армированном грунтовом основании

A method for calculating the floor structure of an industrial building on a compensatory soil cushion on a base reinforced with vertical elements is considered. The foundation is composed of weak soils and reinforced with driven reinforced concrete piles. The compensation cushion is made of sandy soils compacted to the required deformation modulus. The calculation was performed using the numerical method in the SCAD software package. Information was obtained on the stress-strain state of piles, pad soil and floor slab. The soil of the compensation cushion was tested to meet the strength conditions of A.I. Botkin. The possibility of using a reinforced concrete floor slab of an industrial building has been determined.

Equations for early-stage design embodied carbon estimation for concrete floors of varying loading and strength

Building designers are increasingly tasked with tracking and reducing the embodied carbon of structural systems, including concrete floor slabs. Design decisions that affect both the structural performance and the embodied carbon of a concrete floor are often made in the early design stages without complete structural analyses and life cycle assessments, which are commonly finalized in later stages. In this study, we employ polynomial regression models to estimate the embodied carbon for ten concrete floors to guide practitioners toward environmentally-informed design decisions. Six reinforced concrete (RC) and four post-tensioned (PT) floors are evaluated with varying five structural parameters including the span length, concrete strength, live and dead loads, and deflection limit, equating to 41,328 design scenarios for the RC systems and 27,552 design scenarios for the PT systems, while also considering 32,440 different concrete mix Environmental Product Declarations. The analytical equations are deployed in a web-app intended for practitioners to quickly evaluate and compare different design scenarios and floors. By estimating the embodied carbon of concrete floors while accounting for design and material uncertainty, these equations are ready for immediate use to reduce the carbon footprint of future buildings.

Experimental Determination of the Bearing Capacity of a Reinforced Concrete Floor Slab

Purpose of research. Experimental determination and analysis of the bearing capacity, deformability and crack resistance of a reinforced concrete floor slab supported on three sidesMethods. Testing a specimen of a reinforced concrete floor slab supported on three sides (loggia floor) by a controlled load simulating the operational one. Measurement of deflections. Analysis and justification of test resultsResults. The slab was loaded to a level of 325 kN or 20.1 kPa. This load exceeded the control load by a factor of 1.64 with a safety factor of 1.6, exceeded the design load by a factor of 2.64, and exceeded the standard load by a factor of 3.08. The maximum recorded deflection at maximum load was 3.01 mm in or in span fractions of 0.0009, which is 7.41 times less than the allowable deflection from the standard load - 0.00667 of the span length. The testing has been terminated for safety reasons.Conclusion. The points that could allow the developing of more economical building structures are: refinement of the design scheme for the operation of structures, the optimal choice of a finite element in the calculation, as well as the gradual inclusion in the sets of rules of methods for calculating building structures based on the theory of structural systems with distributed parameters at critical energy levels.

Half-precast “crossbar-slab-column” frame joint

Introduction. Half-precast frames embodied the positive properties of both precast and cast-in-situ structures. These structural systems are difficult to introduce due to their low level of knowledge, lack of experimental data, and an almost complete absence of a regulatory and technical framework for a design. This stimulates a need to improve and develop new joints with high operational reliability and manufacturability.Aim. To identify the causes of the frame joint destruction.Materials and methods. The frame joint is provided by the hidden cast-in-situ column cantilever in the grooves of crossbars and half-precast floor slab with the installation of additional longitudinal and transverse reinforcement. Precast and cast-in-situ elements interact mainly by reinforcement starter bars. The destruction of frame joints was considered using the example of a half-precast frame with the main spans of 9 and 12 m in a two-storey building according to the results of a full-scale survey during the construction period.Results. At the joints of most crossbars with columns, inclined cracks were detected in the support zones along the lateral surfaces with an opening width of 0.1–5 mm. In addition, cracks were observed along the contact area of the support crossbar groove with the column grouting concrete. An opening revealed them spreading into the body of the groove grouting concrete along the column edge. No adhesion between the walls of a crossbar groove with the joint grouting concrete is observed. The crack formation pattern indicates the determined contour of the floor slab punching above the column.Conclusion. The cause for the destruction of half-precast frame joints involves the insufficient bearing capacity of the section for the action of transverse forces due to the ductility of precast and cast-in-situ elements.

Main characteristics of 11th -15th centuries bricks from monumental buildings of the Pechersk monastery in Kyiv

The relevance of the proposed work lies in the fact that the powerful collection of building materials has been assembled in the scientific funds of the National Preserve „Kyiv-Pechersk Lavra” over a 100-year history of archaeological research into architectural monuments from the 11th-15thcenturies (the Dormition Cathedral, chapel of St. John the Baptist, Trinity Gatech church, a brick refectory, and a stonewall from the 12thcentury). It consists of bricks (plinthois), ceramic tiles and stone floor slabs, roof tiles, glass hutters, frescoes, mosaics, samples of stones and solutions, marble decorative elements, etc. Among the most massive and informative materials is a plinthoi. The study of its characteristics and historical and cultural significance is aimed at acquiring a body of knowledge about building materials. M. Kholostenko, G. Ivakin, O. Syromyatnikov, and D. Jolshin were engaged in the study of bricks from the Pechersk monastery. However, no generalizing work on construction materials of the 11th-15th centuries of these monuments of ancient Kyiv has been carried out till now.

Floor slab composite action effects on hysteresis behaviors of steel-framed-tube structures with shear links

The utilization of spandrel beams with a low span-to-depth ratio in a Steel-Framed Tube (SFT) structure can potentially diminish its ductility and energy dissipation characteristics. Conversely, integrating an SFT with end-plate-connected, replaceable low-yield-point steel shear links (SFT-RLYPSL) may significantly enhance its seismic response. This study introduces a prototype SFT-RLYPSL configuration designed to mitigate the premature separation of a reinforced concrete (RC) slab from the spandrel beams, a phenomenon observed in prior research. A series of finite element (FE) models were established, utilizing the prototype structure as a basis, to systematically investigate the impact of various parameters, including the presence and thickness of the RC slab, concrete strength, shear link length, and initial spandrel beam stiffness, on the cyclic behavior of an SFT-RLYPSL substructure module. Additionally, the failure mechanisms of the substructure module were assessed. The findings of this study reveal that the utilization of T-shaped connectors can effectively delay the pull-out of studs from the RC slab, especially under substantial vertical displacement of the spandrel beam. The initial elastic stiffness and load-carrying capacity of the substructure module can be significantly enhanced through the promotion of RC slab composite action. An optimal shear link length ratio falls within the range of 0.95 to 1.25, and given the assumption of LYP225 steel shear links with length ratios of 0.95 to 1.25 in the SFT-RLYPSL, the recommended minimum thickness and concrete grade for the RC slab, based on numerical simulation results, are 120 mm and C30, respectively. It is further recommended to employ C30 concrete for an RC slab with a thickness of 120 mm. Finally, a restoring force model is proposed, accurately reflecting the observed mechanical behaviors of the SFT-RLYPSL substructure module.

PERENCANAAN GEDUNG RAWAT INAP RS MM DUNDA MENGUNAKAN SOFTWARE SAP 2000

This research aims to analyze the structural analysis of a building using software Since computerization is used to complete every building plan or design, the development of technology and information, especially computerization in the world of construction, cannot be separated anymore and is not a new phenomenon. The decision to use a computer to complete construction plans was based on the fact that computers have the advantage of not only being able to finish quickly but also having accuracy, effectiveness, and ease of use (Dwi Deshariyanto, Anita Intan Nura Diana 2021). The following findings have been achieved based on the final results of the development of this final report. using the SAP 2000 version 22 program to calculate reinforcement in columns, beams, and floor slabs, Using earthquake response spectrum design analysis, earthquake load calculations refer to SNI 1726: 2019 (Procedures for Planning Earthquake Resistance for Buildings and Non-Buildings), The design of this building is based on the type of reinforced concrete structure and the Unique Moment Resisting Frame System (SRPMK). The floor difference is in accordance with the relevant SNI criteria

Seismic behavior of a new fabricated concrete grating composite wall structure in rural residences: Shaking table test and finite element analysis

To promote the application of prefabricated concrete structures in the field of rural residences, this paper proposes a new fully fabricated concrete grating composite wall structure (FFCGCW). A 2:3 scaled single-story model with door and window openings was designed, and a shaking table test was carried out to study the seismic performance of the FFCGCW structure. Three types of seismic waves were selected to analyze the failure modes, dynamic response, displacement response, strain response, and acceleration response of the structure under four peak ground accelerations (PGAs). The experimental results indicated that the FFCGCW structure had a large stiffness and could work in an elastic state at PGA = 0.4 g. At PGA = 0.8 g, the maximum inter-story drift was 1/600, and the natural frequency decreased by 9.4 %. The structure just entered a plastic state, and no overall failure occurred when loaded to 0.8 g. The cracks mainly occurred on the concealed beam at the upper end of the window, the corner of the door opening, the floor slab, and the column base, but they did not continue to develop and no collapse occurred. Compared to cast-in-situ concrete structures, FFCGCW structural components use bolt-connected keyed joints, which are convenient for construction and have similar seismic performance. During the earthquake, the bolt gaskets constantly deformed, the pre-tightening force of the bolt decreased, and the keyed joints allowed for mutual displacement between structural components to dissipate energy. Meanwhile, a simplified shell-element finite element (FE) simulation method was proposed for the grating wall, and the experimental data was verified by the FE analysis, with errors within 10 %.

ANALISIS PERHITUNGAN SISA TULANGAN (WASTE), KEBUTUHAN SERTA BIAYA TULANGAN PADA PROYEK RUMAH SAKIT BUNDA THAMRIN MEDAN

In the implementation of construction, there is such thing as a residual use of material which is commonly referred to as Waste Construction. Errors in the supervision and calculation of materials can have a major impact on the budget spent on project implementation, one of which is the use of reinforcing iron material. The use of reinforcing iron material is very important to be considered and calculated carefully and precisely so that it has very little material remnants. Therefore, the purpose of this research is to find out the amount of reinforcement needed and the required cost along with the reinforcement waste. The method used in this calculation is the Bar Bending Schedule method with the Microsoft Excel program to calculate reinforcement waste and calculate reinforcement requirements for column, beam and floor slab structure work along with the percentage comparison between reinforcement waste and reinforcement requirements. Based on the results of data processing, the need for reinforcement needed for the work of Foundations, Columns, Beams, Floor Plates and Stairs is 183380.233 kg. A lot of waste reinforcement for the work of Foundations, Columns, Beams, Floor Plates and Stairs as much as 26673.281 kg. The percentage of waste reinforcement for Foundations, Columns, Beams, Floor Plates and Stairs is 12.52% and the total cost required is Rp. 2,887,099,791.84.

Comparative life cycle assessment of traditional timber jack arch slab refurbishment solutions: Eco-efficient proposal versus conventional ones

Abstract Purpose In the context of worldwide efforts to reduce plastic waste, the authors of this document patented a cement mortar floor slab interjoist prefab vault incorporating recycled plastic. This piece was designed to be used for the refurbishment of Spanish traditional timber jack arch floor slabs. Taking into account nowadays context, it is essential to assess the environmental benefits of this product. Methods A cradle to gate LCA has been performed following ISO 14044 and ISO 15804 recommendations. Thus, the aim of this research is both to provide a measure of the environmental improvement that this material adds to the building process and to compare it with current most used construction elements used for the same function. It is stressed that this study is based mainly on primary data obtained from Spanish producers. Results The results obtained show that the reference scenario, corresponding to the new patented vault, is the system with lower impacts in six out of the seven categories assessed. Furthermore, when adding the LCA normalisation step, the conducted analysis show that for the most influential impact categories, GWP100a and AD fossil fuels, the reference scenario bears the lowest scores. Conclusions It can be concluded that the new patented vault has a better environmental performance than the assessed commercial vaults. Therefore, in this research, the benefits for the construction sector to incorporate recycled plastics are shown. Furthermore, these results can encourage the research on construction products that include recycled plastics in their composition. Bearing in mind that this study assesses the impacts corresponding to the production of a prototype of the newly vault, it is considered that there is room for further improvement through the optimisation of the production process.

Reconstruct the 3D load redistribution paths of framed structures subjected to local column failure and multi-floor fire

Considering the slabs in the global response of steel framed buildings in fires is important, as deflected floor slabs could redistribute the load to columns leading to column failure and even progressive collapses. Floor slab systems also experience tensile membrane action after deflection, which differs from the behaviour observed using 2D structural fire models. This paper focuses on unfolding the load redistribution mechanisms using 3D steel-concrete composite structure models, while multi-floor spreading fires and local failure of columns are considered. A framed structural model based on the Cardington building is designed and modelled, in which the composite slabs at different floors are simulated using the recently developed high-efficiency slab model to address the slab effect to the global load redistribution. Four hazard scenarios representing different states of the central column (i.e., fully protected, partially protected or failed) are given as the initiating local failure. The analyses with the 3D structural models show that the slabs can effectively pull up the failed column and the vertical loads are transferred to the adjacent columns. The worst scenario has been identified as the case experiencing column failure both at the upper floor and the lower floor, which leads to the middle floor without pulling action and causes significantly large deflection. This may be a scenario that local column failure triggers progressive collapse of a real building and should be prevented.

Structural Reliability Assessment Including Variability of Reinforcement Cover Based on Measurements on Selected Buildings

Abstract This article presents the results of reinforcement cover thickness measurements carried out in several buildings erected in 2022 in Rzeszów. The results of the measurements are presented in two variants depending on the reinforcement cover thickness assumed by the designer: the first variant contains all the results and the second contains results only from places where the designed cover thickness was 25 mm. For both variants, a histogram of the percentage deviation from the design value was determined and mean values, standard deviation, coefficient of variation and maximum values of negative and positive deviation were calculated. The obtained reinforcement cover thickness distributions were used to determine the reliability of a floor slab with a simply supported beam static scheme. Analyses were carried out for 4 slabs differing in span, thickness and selected reinforcement. Using the FORM analytical method, values for the reliability index and probability of failure were determined. The reliability index values obtained were compared with the values required by EC 1990 and ISO 2394. The results obtained did not meet the standard requirements.

Sound insulation of slabs in dwellings

The well-being and sleeping quality of people in dwellings depends on appropriate sound insulation efficiency of building structures. In individual apartments, airborne sound is produced by people talking and music playing, and impact sound is produced by people walking and falling of various objects on the floor. The inter floor slab separating the individual dwellings is intended for airborne and impact noise insulation, so special attention is paid to its design and installation. Since the composition of this structure is primarily determined by the structural requirements, the improvement of the sound insulation performance is mainly carried out by developing the damping interlayer materials. The stone wool plate has been modified reducing the fiber intertwining to obtain a more uniform fiber directivity, thus reducing its dynamic stiffness. Therefore, the aim of this study was to investigate the sound insulation efficiency of inter floor slabs with a new modification of stone wool damping interlayer in comparison with currently used mineral wool products. The experimental measurements in 50-5000 Hz frequency range were performed in construction site (real structures), the single-number quantities – weighted standardized level difference (DnTw) and weighted normalized impact sound pressure level (L‘nW) with living adaption term (C) were determined and compared. The research results demonstrated that the modified stone wool with reduced fiber intertwining and lover organic content used for damping interlayer enables to improve living sound insulation of inter floor slab comparing with existing stone wool materials.

Moisture transport properties of concrete with SCMs – descriptions, test methods and some applications

AbstractMoisture transport properties of concrete are rarely determined, simply because it is difficult and time‐consuming. Most studies in literature are limited to cement paste and mortar. Translation of these properties to concrete are not straight‐forward. Recently, however, a few measurements are done, also on concretes with supplementary cementitious materials.An overview is given on various ways of theoretically describing the moisture transport properties of concrete, with different “moisture transport coefficients” and their interrelations. Methods of determining those properties are shown and their advantages and drawbacks are discussed. Available data in literature are summarized and compared. A recently developed test method, the tin‐can method, is described. New results are shown for concretes with SCMs. The method's possibilities to be used for short‐term tests of aging concrete are discussed.A few important applications where the moisture transport properties are decisive are presented: applying moisture‐sensitive flooring materials on concrete floor slabs and carbonation‐initiated reinforcement corrosion under varying climatic conditions.

Cyclic behavior and numerical study of PRC coupling beam with steel truss floor slab

The coupling beam with small span-to-depth ratio is prone to brittle shear failure under the action of earthquake, so it can not play its role as the first line of defense against earthquake. Therefore, this paper proposes a method for calculating the shear bearing capacity of PRC-connected beams with reinforced truss floor plates. A more rational calculation model should be adopted based on its mechanical mechanism. In this study, ABAQUS finite element software is utilized to explore the parameters of PRC-connected beams with steel truss plates, including the span-to-height ratio, reinforcement ratio of the internal steel plate, diameter of upper and lower chord bars, and diameter of abdominal bars. The analysis shows that the span-to-height ratio, steel plate ratio and concrete compressive strength have a significant effect on the seismic behavior of PRC coupling beams with steel truss floor slab. Based on the softened tension-compression bar model combined with the multi-strip model, the theoretical calculation method of the shear capacity of PRC connected beams with steel truss bearing plates is derived. The results of comparison test and simulation verify the accuracy of the calculation results, and provide a design basis for the engineering application of PRC connected beams with steel truss floor plates.

Heavy-weight floor impact sound in the state of coupled vibration of floor slab and girder of a pure framed structure

Examples of poor heavy-weight floor impact sound insulation performance of pure framed structures with reinforced concrete were observed relative to the floor slab thickness. To investigate the cause of the poor performance, the floor vibration characteristics of actual pure framed structures were measured during heavy-weight impact. As a result, the floor vibration characteristics of the displacement of girders and the coupled vibration of the girders and floor slabs not seen in conventional floor structures surrounded by girders with reinforced concrete walls were observed. The propagation of the vibration of the floor slab was observed in more than the range surrounded by girders and in the next slab beyond the girders owing to the vibration of the girder itself. It was confirmed that these physical phenomena can be evaluated using a numerical calculation method. The effect of the changes in girder depth on the coupled vibration of the girder and floor slab was also investigated analytically. As a result, the coupled vibration of the girder and floor slab specific to pure framed structures that contribute to heavy-weight floor impact sound insulation performance was clarified physically.

Study of Simple Prediction Method for Road Traffic Vibration from viaducts

On Prediction of Road Traffic Vibration of INCE/J Technical Subcommittees, we are studying the creation of prediction formulas for vibration from embankments and cuts and vibration from bridges. This paper presents the concept of a simplified method for predicting road traffic vibration from viaducts. When large vehicle runs on viaduct, vibration occurs in the floor slab and propagates from the piers and foundation to the ground. Here, the reference waveform at the bottom of the pier is used as the reference point unit pattern, and the vibration propagates from the bottom of each pier on the plane to the ground surface, and a method of calculating the combined value at the prediction point is considered, and the establishment of a prediction method is examined. bottom. In addition, we will report on the results of an attempt to predict the vibration propagation situation to the surroundings for a large vehicle test run and compare it with the actual measurement value. In addition, we examined the calculation procedure assuming traffic flow conditions in this model.

Optimum design of TMDs for reduction of floor vibration using evolutionary computation

Perceptible floor vibration can arise due to human activities such as walking, especially in steel-framed buildings. A general strategy to reduce floor vibration is to install tuned mass dampers (TMDs) between the floor slab and a raised OA floor. For the TMDs to act effectively, two parameters must be designed properly depending on the dynamic characteristics of the target floor: eigenfrequency and damping ratio. Conventionally, even when installing multiple TMDs in a floor, design has been carried out using fixed-point theory, which was originally used to design a single TMD. With the purpose of improving the performance of multiple-TMD installations, this paper describes the use of evolutionary computation (EC), a mathematical optimization method, to design the parameters for multiple TMDs. The new technique is first verified by implementing a numerical simulation using the spectral element method, a high-efficiency numerical analysis method. TMDs designed with EC are shown to suppress floor vibration more efficiently than those designed with fixed-point theory. Next, in experiments with an actual steel-framed building, sufficient vibration suppression performance is achieved with fewer EC-designed TMDs.

Evaluation of noise reduction performance of new steel noise barrier for Shinkansen

Since Shinkansen viaducts are aged, a large-scale renovation project has been planned. In this project, aged noise barriers are scheduled to be removed and replaced. In this background, it is required to develop a new noise barrier with high constructability and high effectiveness in noise reduction. Therefore, the authors have developed a steel noise barrier without the decrease of noise barrier performance, of which weight is about 1/3 of existing concrete noise barriers. It is expected that the load on floor slabs by the developed noise barrier is more reduced, and no crane truck is basically needed for installation work. One of the features of the developed noise barrier is that all the surfaces on track side are consisted of sound absorbing materials with steel plates with small holes on it. The sound absorbing material used in the developed noise barriers has suitable sound absorbability for the frequency characteristics of the noise generated during train running. In order to evaluate the noise reduction performance, the developed noise barrier was tested on the Shinkansen track and noise measurement was conducted at the place with certain distance from the Shinkansen viaduct. As a result, the noise generated from the lower part of cars was significantly reduced on the overall level.

Study on Heavy Weight Impact Sound Insulation of CLT Floor Slab and Reduction Performance with Floor Structure

Strategies and challenge for carbon neutrality by 2050 had become important issues all over the world. In South Korea, as a move toward carbon neutrality, interest in wooden buildings is growing continuously. In order to spread the wooden buildings, especially wooden multi-residential buildings, high floor impact sound insulation performance is required. In this study, we investigated the floor impact sound insulation performance of floor slabs with cross laminated timber (CLT) panels produced in South Korea. Moreover, laboratory measurements were conducted to grasp the reduction effect by floor covering. As a result, the heavy-weight impact sound insulation performance of CLT bare slab of its thickness of 150 mm is almost 17 dB lower than that of RC slab according to ISO717-2. Concrete topping and damping material are found to be effective to both heavy and light weight floor impact sound insulation.