Floor Construction Research Articles

Construction and technical examination of wooden structures (on the example of a wooden country house)

In practice, the construction of wooden buildings of low-rise residential construction is carried out based on the experience and knowledge of the builders, and does not agree with the legal framework of the construction industry. Therefore, many low-rise and garden houses are typical, unequal spacing of the beams, overestimated the distance between the bearing walls, the construction of attic floors without regard to bearing loads of the lower floors, uneven box joints timber, use of faulty material or materials from different batches with different parameters and characteristics. All these violations in the construction and operation of objects made of wooden structures lead to civil disputes in the framework of which it is necessary to conduct construction and technical expertise.

Verification of Thermo-Technical Characteristics of Selected Floor Constructions for Dairy Cows (Pilot Study)

Abstract The purpose of this study was to theoretically and practically investigate the thermo-technical properties of two bedding surface materials under real farm conditions during the hot summer period. The study was focused on the research of cubicles with water mattresses and straw bedding for dairy cows. The results of thermal-technical calculations showed that straw belongs to the category of warm floors, the thermal effusivity value of cubicle with straw is b = 173.55 W·s1/2·m−2·K−1; the heat transfer coefficient is U = 0.36 W·m−2·K−1. Water mattress belongs to the category of cold floors with the thermal effusivity value b = 572.46 W·s1/2·m−2·K−1 and the heat transfer coefficient U = 4.504 W·m−2·K−1. On the basis of calculations, the results showed that U was 12.5 higher for water mattresses than for straw, and b was 3.3 times higher for water mattresses than for straw. Based on thermographic measurements under field conditions of dairy farm, it was observed that the surface temperature of the water mattresses after one hour of lying was lower by 4.95 ±1.88 °C in comparison to chopped straw. In practice, suitability of the material structure of water mattresses was verified on the basis of physical properties for summer period.

Low-frequency impact sound of timber floors: A finite element–based study of conceptual designs

Traditionally, product development concerning acoustics in the building industry is measurement oriented. For lightweight floors, frequencies that are lower than the frequency range for heavy concrete floors are an issue. The frequency range of from 50 Hz down to 20 Hz influences the human perception of impact sound in multi-story apartment buildings with lightweight floor constructions, such as timber floors, for example. It is well known that a lower frequency range of interest makes finite element simulations more feasible. Strategies for reducing impact sound tend to be less straightforward for timber floors because they have a larger variation of designs when compared to concrete floors. This implies that reliable finite element simulations of impact sound can save time and money for the building industry. This study researches the impact sound transmission of lightweight timber floors. Frequency response functions, from forces on excitation points to sound pressure in the receiving cavity below, are calculated. By using fluid elements connected to reflection-free boundary elements under the floors in the models, the transmission and insulation can be studied without involving reverberation. A floor model with a hard screed surface will have a larger impact force than a softer floor, although this issue seems less pronounced at the lowest frequencies. To characterize floor surfaces, the point mobilities of the impact points are also calculated and presented. The vibration and sound transmission levels are dependent on the selection of the excitation points.

Evolution of Floor Construction System in Beirut (1840-1940)

This article is going to deal with the evolution of floor structural systems; traditional structural systems during the late Ottoman period and the concrete structural systems during the French mandate period in Beirut. Beyond this, natural constraint timber materials used in the late nineteenth century and the available concrete materials used in the early twentieth century can direct influence the evolution of the floor structural systems which became an integral part of architectural design and typology. Structural principles of traditional floor construction techniques will be characterized and assessed in eight case studies tracing its structural systems in terms of their evolution. The subject matter will be approached in a descriptive manner for floor structural systems and the determination of mechanical properties of timber.

Strength Prediction of Mass-Timber Panel Concrete-Composite Connection with Inclined Screws and a Gap

AbstractMass timber panels (MTPs) are a new generation of engineered wood panels that are available in large plane dimensions to facilitate fast floor construction with the obvious environmental be...

Compositional Characterization and Chronology of Roman Mortars from the Archaeological Site of Arroyo De La Dehesa De Velasco (Burgo De Osma- Ciudad De Osma, Soria, Spain)

This study characterises the mortar materials used in the construction of walls and floors at the Arroyo de la Dehesa de Velasco site, located near the Roman city of Uxama Argaela (the modern Burgo de Osma—Ciudad de Osma, Soria, Spain). Multilayer mortars have been characterised by petrographic, mineralogical (X-ray diffraction and scanning electron microscopy with energy dispersive analyses and geochemical analysis (X-ray fluorescence). Additionally, radiocarbon dating of the mortar binder fraction was performed in order to establish the chronology of the building in the absence of other archaeological chronological records. The results showed that similar siliceous aggregates and lime binders were used in the fabrication of multilayer system mortars. Some multilayer wall mortars show ceramic fragments or brick powder to produce hydraulic mortars and improve the resistance to moisture. The raw materials used for the construction of the site were of local origin and the construction was built during the first century BC, according to radiocarbon dating.

Measurement of Radioactivity in Some Commercial Porcelain Samples by Using HPGe Detector

Estimations of specific activity concentrations in eight commercial porcelain tiles made in different countries were performed by the use of HPGe detector. We have found that the highest specific activity concentrations for 238U, 40K were equal to (21.120 Bq/kg) and (283.862 Bq/kg) respectively, Iranian origin, while the highest specific activity concentration for 232Th was found to be equal to (29.292 Bq/kg), Iraqi origin; all of which were less than their corresponding recommended values given by (UNSCEAR, 2000). The radiation hazard indices [Iɣ , Hin ,Hex , Raeq ,DƔ , (AEDE) in and (AEDE) out] were also studied and their values were less than the allowed values determined by (UNSCEAR, 2000). Therefore, all the studied tiles of commercial porcelain are safe when used, for example, in floor constructions.

Low- carbon design strategies for new residential buildings – lessons from architectural practice

ABSTRACT This study presents the environmental life cycle assessment of four low carbon design strategies applied in Danish, architectural practice. The subject of analysis is a set of five buildings erected within the same constrictions in terms of floor area, energy performance and construction costs. The tested design strategies were: use of recycled materials, design for extended durability of components, adaptable design, and design for reduction of operational energy demand. The results of the five buildings are compared with a reference building (i.e. a typical, Danish single-family dwelling). Results show that the recycling/upcycling strategy is the most effective in reducing the embodied carbon. The use of structural wood in the same design furthermore points to the use of wood as a viable low-carbon strategy. In combination, these two strategies result in an approximate 40% saving of life cycle embodied carbon compared to the reference. Using durable materials yields up to 30% lower embodied carbon compared to the reference, whereas a design for adaptability results in 17% lower embodied carbon. However, these results are sensitive to the scenarios made for the service lives of materials and the implemented disassembly solutions. In a life cycle carbon perspective, the emissions from energy use prove to be of importance, although depending on the modelling approaches of the energy mix. With the shrinking, global carbon budgets in mind, there is justified reason to holistically optimize the design of new buildings by integrating various design aspects addressing the whole life cycle of the building.

공동주택 바닥 공사 공정별 바닥충격음 특성 분석

공동주택 바닥 공사 공정별 바닥충격음 특성 분석

An accurate higher order plate theory for vibrations of cross-laminated timber panels

In this contribution, bending vibrations of cross-laminated timber (CLT) panels are addressed. The focus is on the low to mid audio frequency range in view of the sound radiation properties of CLT. To this end, a plate theory recently proposed by the authors is adapted by introducing a deformation ansatz for the transverse displacement and neglecting insignificant terms, yielding a theory with six degrees of freedom. From the governing equations of motion, dispersion relations for the propagation of bending wave are derived, which also allow to compute the natural frequencies and mode shapes of bounded plates. The weak formulation of the equations of motion is presented. The accuracy of the proposed theory is validated for a simply supported rectangular CLT panel for which an analytical solution is available. The results are compared with first order shear deformation theory, revealing the limitations of this simplified theory in the present context. Finally, finite element solutions for the rectangular plate with non-classical boundary conditions are presented, as well as incorporating a floating floor construction, underlining the importance of numerical solutions for the practical application of this plate theory.

Effects of controls and floor construction of radiant floor heating systems for residential application with high variability of solar gains

This article discusses various reactive and predictive controllers, with and without setback, and floor construction, for radiant floor heating in a single-detached house in a cold climate, with high variability in solar gains. Heating energy to the floor and occupant comfort was evaluated. Modeling showed that in general, lower thermal mass floors performed better in cases with lower solar gains variability (lower south-facing glazing area). For high solar gains variability, floors with higher mass tended to provide better comfort, as long as the tubes were located near the surface of the floor. Temperature setback generally was found to provide modest heating energy savings and decreased overheating periods. Proportional–integral–derivative (PID) and outdoor temperature reset with indoor temperature feedback controllers were found to generally perform the best for all cases. It was found that proper selection of controller and floor construction can make a difference in heating energy demand by as much as 25%.

Low-Rise Monolithic Steel-Reinforced Concrete Houses on the Basis of the “Load-Bearing Floor” Constructive System

The load-bearing floor is a box-shaped structure consisting of monolithic floor slabs cohesive with all walls and partitions located between them [1]. The load of the bearing floor is transmitted only to the exterior walls. Thereby, the spaces within the outer walls located under the bearing floor and above it don’t require any intermediate support. The effectiveness of the load-bearing floor construction implementation is the ability to obtain freedom while making planning decisions, re-planning in the process of the operation and reducing the consumption of structural materials for creation of the building carcass compared to the existing traditional structures [2]. In [3] authors describe the technology of construction of the bearing floor and present the results of computational studies of the stress state of its elements in their different design. In this article we discuss the planning and design features of the load-bearing floor in steel-reinforced concrete structures of low-rise buildings.

Superhydrophobic wood grafted by poly(2-(perfluorooctyl)ethyl methacrylate) via ATRP with self-cleaning, abrasion resistance and anti-mold properties

Abstract Wood is a natural, abundant, renewable resource, which is easily processed, has beautiful texture and good mechanical strength, and is widely used for furniture, flooring, decor and building construction. However, wood is vulnerable to moisture and microorganisms, resulting in deformation, cracks, mold and degradation, which causes aesthetic problems and/or shortens the service life of wood products. In this paper, superhydrophobic wood (wood-F) was fabricated by grafting poly(2-(perfluorooctyl)ethyl methacrylate) (PFOEMA) onto wood by atom transfer radical polymerization (ATRP). Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with an energy-dispersive X-ray spectroscopy (EDS) showed that PFOEMA was successfully grafted onto wood. The resultant wood-F exhibited excellent water resistance with a contact angle (CA) of 156° and hysteresis of 4°. The modified wood also showed abrasion resistance, self-cleaning ability and anti-mold properties, all of which are desirable for various wood products.

Measurements behind Internal Insulation on Solid Masonry Walls with Different Orientations and Degrees of Repair in a Danish Multi-story Building

Internal insulation is used in many heritage buildings to ensure a better indoor environment and reduce energy use. This article describes measurement results from installing an internal insulation system in a Danish multi-story building. The internal insulation system consists of a fully glued vapour tight insulated plasterboard. To reduce the risk for wood decay and mould growth at the wooden beam ends in the floor construction, a 100-200 mm uninsulated gap was left above and below the floor construction. Measurements include the effect of orientation, degree of façade repair and influence of indoor moisture content. Results show in general acceptable hygrothermal conditions behind the insulation system. However, a gradual increase in relative humidity at sun-exposed walls was registered due to ‘summer condensation’. The degree of surface repair also showed an influence on relative humidity levels during this period. At the uninsulated gap above the floor, a higher moisture content indoor resulted in a higher relative humidity, though without exceeding the threshold for mould growth. However, a large temperature range was registered. The influence of the uninsulated gap on reducing the risk of wood decay and mould growth at the beam ends could therefore not unambiguously be confirmed.

Geotechnical Site Investigation and Evaluation of 20 March 2019 Mw 5.5 Acıpayam (Denizli) Earthquake

An earthquake with a magnitude of (Mw) 5.5 occurred in Yenikoy village of Acipayam district (Denizli) on 20 Mart 2019 caused heavy damages on masonary structures in Acipayam basin. Groundwater level from ground surface in the basin varies between 1m and 11m, and soil structure of the basin is made up of silty, gravely and sandy clay. Soil liquefaction was not observed in the basin after the earthquake. The main reasons of the heavy damage on the structures are mainly, high value of soil amplification, use of clayey adobe bricks and hollow bricks for building masonary houses, unpermitted construction of roof floors by using hollow bricks.

Application of fiber-reinforced concrete in high-rise construction

In this research, we study the use of fiber-reinforced concrete, including steel fiber-reinforced concrete in the construction of outrigger floors of a high-rise building. The definition and classification of fiber-reinforced concrete as a construction material, the methodology for calculating high-rise buildings using fiber-reinforced concrete, the advantages and disadvantages of this composite material, and the specifics of its use are formulated. The domestic and foreign experience in use of fiber-reinforced concrete is analyzed. The rationale for its use on the experience of construction of residential building in seismically active regions is given. A comparative analysis of concrete and fiber concrete use in the outrigger floors’ construction is carried out.

Swine House Floor Durability Enhancement Using Pozzolan-Containing Concrete Mix Designs

HighlightsThe CSF-FA floors performed better than the non-CFH and CFH floors, especially under spallation conditions. It thus makes economic sense for small- and industrial-scale swine farms to switch to CSF-FA floors due to longer durability and better investment return, in comparison with non-CFH and CFH floors.The statistical analysis indicated that the pozzolanic materials significantly improved the performance metrics of concrete mix designs (p<0.05), compared with the conventional non-CFH mix (control).The research findings are expected to be beneficial for civil engineers in the construction of concrete structures that are prone to acid corrosion or in areas with acidic soil.ABSTRACT. This research investigates the effect of pozzolanic materials on the performance of swine house concrete floor. The experimental pozzolans are fly ash (FA) and silica fume (SF), and the performance metrics are compressive strength, abrasion resistance, and resistance to lactic and sulfuric acids. There are nine experimental concrete mix designs: concrete without floor hardener (conventional concrete or non-CFH), concrete with floor hardener (CFH), concrete with 15%, 30%, 45% fly ash, and concrete with silica fume and fly ash (CSF4FA26, CSF6FA24, CSF8FA22, CSF10FA20). In acid resistance tests, a groove was cut across the specimen surface to simulate floor spallation. The results showed that the CFH floor had the highest abrasion and acid resistance but suffered from severe acid damage under spallation conditions. Meanwhile, the CSF10FA20 floor had the highest compressive strength and acid resistance under spallation conditions. The statistical analysis indicated that the pozzolanic materials significantly improved the performance metrics of concrete mix designs (p<0.05), compared with the non-CFH mix design (control). The construction costs of CSF-FA floors (THB 118 – 121) and non-CFH floor (THB 116) were comparable, but they were considerably lower than that of CFH floor (THB 196). The acid resistance of CSF-FA floors was higher than that of non-CFH and CFH floors. As a result, the CSF-FA concrete mix designs should be adopted for the construction of swine house floor due to longer durability and better investment return, in comparison with non-CFH and CFH floors which are commonly used in small- and industrial-scale swine farms. Keywords: Acid resistance, Concrete material, Durability, Farm buildings, Swine flooring.

Features of work of retaining walls made of bored piles in flowing sandy loams

The customers usually try to avoid areas with a high groundwater level in the process of choosing a site for construction. The presence of groundwater significantly increases the cost of construction, if there is necessity of the construction of underground floors. But construction in the conditions of modern megacities is increasingly challenging geotechnical engineers, because of the need not only to build on lands with difficult engineering and geological conditions, and not only to develop reliable foundation`s decisions, but also because of the need to more effectively design the underground spaces with its subsequent operation as underground premises for various purposes.The process of water level reducing is not only technologically complex, but also leads to a changes in the physical and mechanical characteristics of soils, which are difficult to predict.This paper shows the features of numerical modeling of walls in water-saturated soils.The effect of the ability to filter water through walls on the stress-strain state of the system of retaining structures – soil mass is demonstrated.The calculations were performed using numerical modeling, since this approach allows engineers to see (predict) the formation of dangerous processes. Numerical modeling also allows to take into account the change in the physical and mechanical characteristics of the soil during drainage of the pit and take into account the process of water level reduction and the effect of water reduction on the formation of the stress-strain state of the system restraining structures – soil mass.In the framework of design process, there is always appear the opportunity to consider various technical decisions for walls and choose the most effective among those considered.In this paper, the construction of walls with the possibility to use the soil berms to temporarily reduce the free height of walls is considered. In addition, the operation of anchor fasteners in soft (weak) soils is shown. Also, elements of the building frame were used to reduce horizontal movements.It is important to understand that not all measures (the construction decisions) are possible in certain conditions, especially when it is a tight environment of dense urban development.

Māori Councils Act 1900: suspending floors

A recent review of the evolution of sub-floor moisture management (Isaacs "Evolution of Sub-Floor Moisture Management Requirements" pp. 366-394) found the first New Zealand legislative requirement for raised floors was in 1902 in by-laws made under the Māori Councils Act 1900. No similar requirements have been found in contemporaneous European building by-laws until those recommended by the Department of Public Health, Hospitals and Charitable Aid in 1912, which dealt with suspended floor durability.
 Although the use of well-made, well-drained earth floors used in Māori housing in pre-European times was in some sectors of Māori society looked back on with nostalgia, the use of suspended timber floors provided a drier, if airier, and healthier option. The Young Māori Party, with the support of the government, created a model by-law with two approaches to raise sitting and/or sleeping above ground. These required either the construction of suspended floor, or the use of a couch or bedstead at least 1 ft (0.3m) above the ground. As well as the ability to fix a time limit for compliance, it also provided the ability to levy fines if the household refused or neglected to comply with the notice. There was little variation in the implementation of the model by-law in the 24 districts established under the Act over nine years (1901 to 1910), except for the raised floor requirement (and associated penalty for non-compliance) which was not implemented in seven (30%) districts. It is concluded that unlike the durability concern of European suspended floor building by-laws, the Māori District by-laws were solely concerned with improvement of the health of the occupants.

Determination of resistance to radon entry of underground walling at stage of construction design

The dose from radon and its progeny is a controlled component of the radiation load on the population, and therefore can be reduced by the use of appropriate construction technologies. The article shows that the convective flow can be reduced to zero by choosing the appropriate floor construction, whereas the diffusion cannot be completely excluded, and the diffusion radon flux can only be reduced to a certain level. An approach to the assessment of the required radon-protective characteristics of the building is proposed under the assumption that there is no convective radon entry. As a radon load on the underground part of the building, the radon potential of the soil, determined by the results of gamma-spectrometric analysis of the soil from the construction site, was used. The procedure for calculating the geometric characteristics of layers with high resistance to radon permeability based on the required radon concentration in the ground floor premises of the building after its construction and the radiation characteristics of the soil on the construction site is shown.