Properties Of Construction Materials Research Articles

How Adding Wood Dust Affects the Properties of Composite Construction Materials

Composite materials based on wood dust are promising construction materials that have recently gained traction in the market. Their success is attributable to the benefits such materials represent for construction: they are eco-friendly and resistant to atmospheric effects; they are well-disposable and easy to machine. Utilizing wood dust is essentially recycling the waste of woodworking, furniture-making, and lumbering industries, as well as the waste associated with the use of low-grade wood. The present paper covers the processes that occur in the structure of a composite materials when using abrasive wood dust as a filler. The research team has made pilot samples of various composition; analysis revealed the composition affected such properties as density, flexural strength, and water absorption. The effects were further analyzed to attribute them to specific mixture components. Refining the production technology and the recipe is one of the key objectives of producing and applying constructional composites today. Maximizing the performance while reducing the energy costs and the production costs requires a focus on rheological properties. The properties of a composites material mainly depend on the type and properties of its organic filler. Understanding that is fundamental to optimizing the composition, i.e. to finding such filler that will provide sufficient strength at a maximum fill factor. It is also known that using fillers makes the composition significantly cheaper.

Effects of Material Properties on Seismic Vulnerability Assessment of Unreinforced Masonry Buildings

This study investigates the seismic performance of existing unreinforced masonry buildings considering the effects of different material properties selected from design codes' assumptions and experimental values. For this purpose, work was conducted to analyze a selection of existing buildings in Albania designed with typical methodologies of the past structural design codes. Experimental investigations were carried out on bricks and mortars extracted from the selected buildings, as well as a series of regular and irregular sized mortar specimens prepared in the laboratory for comparative evaluation purpose. In addition, diagonal compression tests were performed on two full-size (1.2 m × 1.2 m) masonry walls built in the laboratory, which were prepared based on the existing building's construction method and material properties. Selected typical URM buildings were analyzed with commercial program CDSWin using different masonry mechanical characteristics that were obtained from experimental work in this study. The equivalent frame method (EFM) was used for the modeling of the buildings and pushover analysis was performed to obtain their seismic capacity. To evaluate the seismic response of each case, a comparison was established between the drift ratio and maximum base shear. As a result, using the code assumptions for the mechanical properties of masonry, overly conservative results were obtained. To understand better and clarify how stresses are being distributed in the walls, it is essential to perform experimental investigations to acquire the representative masonry characteristics such that a reliable structure assessment and retrofitting could be implemented.

Features of the Technology of Construction of Road Pavements from Vacuum-Treated Asphalt Concrete Mix

When changing the structural properties of road construction materials, their compaction technologies should be improved with the choice of the best compaction means and their technological modes of operation in specific conditions of work conduction. For a mixture evacuated at an asphalt concrete plant that has increased water and frost resistance characteristics, as well as changed rheological parameters, it is also necessary to determine the technological parameters of the compaction means used, taking into account the features of its rheological characteristics. The compaction technology of vacuum-treated hot asphalt-concrete mix by pneumatic wheel roller with the determination of the necessary number of passes on the trail, speed modes along the roller passages and the magnitude of the air pressure in the tires of the roller has been developed. Using a promising rheological approach, the dynamics of accumulation of the asphalt concrete mixture layer density along the roller passages was studied by simulation modeling, and the time when the pneumatic roller was finished and the compaction work was transferred to heavy smooth rollers was determined. Changing the rheological properties of the vacuum-treated asphalt mix increases the efficiency of its compaction, reducing material costs, increasing the productivity of compaction tools while improving the quality and durability of road asphalt pavements. Keywords: hot asphalt-concrete mix, rheological properties, water and frost resistance of asphalt concrete, road roller, compaction.

Structure and nanomechanical characterization of synthetic calcium-silicate-hydrate with poly-methacrylic acid

ABSTRACT: The principal phase of hardened Portland cement pastes is calcium silicate hydrate (C-S-H), which influences the physical and mechanical properties of construction materials. In this work, calcium silicate hydrate (C-S-H) was synthesized, with the addition of poly-methacrylic acid with sodium (PMA), for the development of C-S-H/ polymer nanocomposites. Among the polymers available, PMA is indicated in the literature as one of those viable for producing C-S-H/polymer complexes. However, no consensus exists regarding the type of interaction this produces. The resulting compounds were characterized by XRD, FT-IR, TGA, carbon content (CHN), TEM, SEM and elastic modulus and hardness were measured by instrumented indentation. A significant change was verified in the nanomechanical properties of C-S-H with PMA, resulting in reduction in the elastic modulus and hardness. The set of results presented do not confirm the intercalation of PMA in the interlayer space of C-S-H, but presented evidence of the potential for intercalation, since changes in the microstructure clearly occurred.

Development of a Model for OTTV and RTTV based on BIMVPL to Optimize the Envelope Thermal Performance

The thermal performance of a building has a profound effect on sustaining the conditions of indoor environments, and it is critical in obtaining any energy-efficient design. Choosing an appropriate construction material is one of the most effective methods to prevent excessive energy consumption in the building, to minimize heat flows, and sustain a comfortable temperature for occupants. The majority of the existing buildings in Malaysia are mostly constructed using bricks for their outer walls; many studies nominated these materials as the producer of heat. This study is focusing on evaluating the thermal performance of construction materials in a tropical climate, with the involvement of manual calculation methods for Overall Thermal Transfer Value (OTTV) of walls and roof. Therefore, this study proposes integrating Building Information Model (BIM) and visual programming language (VPL) for supporting the calculation of OTTV based on MS1525:2014. The expected result of the proposed system will support designers on calculating OTTV coefficient comparable with the manual calculation, which is considered promising in minimizing time-consuming and human error when optimizing envelope performance during building design. This study proposed a model to access and extract construction materials properties from BIM library using VPL to estimate OTTV value using a real-time calculation tool.

АНАЛИЗ МЕТОДИКИ АНАЛИТИЧЕСКОГО РАСЧЕТА СДВИГОВЫХ СВЯЗЕЙ НА СЕЙСМИЧЕСКИЕ И ЭКСТРЕМАЛЬНЫЕ НАГРУЗКИ

Introduction: This paper reviews the analytical method of assessing the seismic and extreme load resistance of buildings with a complex macrostructure that includes elastic-plastic inserts operating in shear. Methods: We analyze a number of studies that rationalize the choice of models for simulating complex elastic-plastic deformation in a mechanical system with several degrees of freedom, as well as studies that review the durability and resilience of buildings with a complex macrostructure based on non-linear shear links when subjected to dynamic and extreme impact. We also consider the methods of structural analysis regarding buildings with elastic-plastic inserts, accounting for the plastic hinged joints of metal frames. Results: We apply the analytical method to linear and non-linear systems with n degrees of freedom. We propose a mathematical equation that describes the nature of shear link response to seismic and extreme loads. Our method makes it possible to obtain an analytical solution for structures with proportionate and disproportionate damping by using the direct integration algorithm. Discussion: Most structures with a broad range of construction material properties require a disproportionate damping model. In this study, we solve equations by using the direct integration algorithm based on disproportionate damping. Under high dynamic load, the reinforcement of shear inserts operates in a plastic state.

Properties and material models for construction materials post exposure to elevated temperatures

Temperature rise, as in the case of fire, severely damages the properties of construction materials and imposes temperature-induced degradations that alter their microstructure and characteristics. As such, practitioners often struggle when assessing residual state of a fire-damaged structure especially due to the lack of insights into residual (post-fire) properties of construction materials. With the hope of narrowing this knowledge gap, this study presents an approach to derive residual material models for a variety of construction materials such as normal strength concrete (NSC), high strength concrete (HSC), ultra-high performance concrete (UHPC), mild steel (MS), high strength steel (HSS), cold formed steel (CFS), stainless steel (SS), glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP). This approach leverages a hybrid combination of two machine learning (ML) techniques (artificial neural networks (ANN) and genetic algorithms (GA)) to derive specifically tailored material models capable of tracing the post-fire behavior of construction materials. When implemented, the proposed material models could enable proper and unified assessment of fire-damaged structures.

Probabilistic method and FEM analysis in the design and analysis of cracks widths

The probability method of cracking estimation allows for taking all collected information about the properties of construction material, assumed loads and performance precisions into account. The article shows the results of the probability analysis in relation to the reinforcement area of the cylindrical tank walls calculated in tension zone. On the basis of the method proposed in PN-EN 1992-3 and PN-EN 1992-1-1, this reinforcement was calculated due to the uncontrolled development of cracking. The article also presents FEM analysis carried out for the tank using GID and ATENA Static software.

Ultra-disperse modifying zeolite-based additive for gypsum concretes

Under modern construction conditions it is important to find the ways of cost reduction without deteriorating physical&mechanical properties of construction materials and their environmental properties. That is why the construction materials on the basis of the gypsum binder remain competitive and the increase of their operation properties is one of the relevant today tasks. In this paper the authors presented a way of increasing water resistance and strength of gypsum concrete by adding ultra-disperse modifying zeolite-based additive from available raw materials. The authors find out zeolite grindability and its chemical composition. The ultra-disperse modifying zeolite-based additive is a paste dispersed in water and added into a concrete mix as water solution. When 14% of the additive is included in gypsum paste the softening factor grows from 0.31 to 0.84 while the grade strength increases by 30%, the ultimate compression strength of dry samples - by 2.5 times and amounts to 30 MPa. Studying physical&mechanical properties and the micro-structure of gypsum&concrete samples proves the efficiency of using the developed ultra-disperse modifying zeolite-based additive.

Heat engineering properties of energy-efficient material based on plant additives (dried hogweed)

Introduction. The articlecompares the heat engineering properties of construction materials: high-strength concrete, ordinary concrete, and two concrete samples containing a vegetable additive, dried stem fragments of hogweed (Heracleum sosnowskyi). The first sample contains the additive in the crushed form, while the second contains the additive in the form of tubes. The research to estimate heat conduction in the four samples under unsteady conditions.
 Materials and methods. The thermal diffusivity of two samples with plant additive is determined using a comparative physical experiment. When determining the thermal properties, the accumulating component of the enclosure is taken into account what leads to a long delay in the temperature variation over time. DS18B20 digital temperature sensors connected to an Arduino Uno board were used to measure the temperature. The experiment was carried out in the Challenge 250 chamber at an initial temperature of 20 ºС. Then the chamber temperature was lowered to 0 ºС within 30 minutes. In the next period, the temperature dropped from 0 ºС to –10 ºС. The data obtained are of interest for improving the energy efficiency of buildings.
 Results. The experiments showed that the tubular-hogweed sample is close to high-strength concrete by its heat engineering properties. The material thermal diffusivity affects the amplitude of temperature fluctuations and the accumulating capacity of the wall.
 Conclusions. It is established experimentally that at lower thermal diffusivity of a hogweed-containing sample, the amplitude of temperature fluctuations increases. This indicates a greater time lag, just as in the case of a high-strength concrete sample. When using the hogweed as an additive, we obtain a heat-resistant minimum-cost material for enclosures. Considering an issue of the energy efficiency in construction and existing additives to concrete, the researchers have reached the conclusion that it is efficient to use the dried hogweed as the plant additive.

Study of micromycete destructive power in gypsum and polymeric binding composite construction materials

Analyzing fungus resistance of gypsum and organic composites is extremely important since fungi may both lead to deterioration in mechanical and operational properties of construction materials and adversely affect people’s health, including development of chronic diseases. We study fungus resistance and fungicidity characteristics of popular finishing gypsum and organic (epoxy- and polyester-based) composites. Plaster materials get exposed to micromycete biocorrosion faster than the ones based on a polymeric binding. Micromycetes adapt on plaster samples quicker than on epoxy and polyester samples. During their metabolism, micromycetes intensively allocate acid products on plaster samples, their high enzymatic activity is also noticed on polymeric materials.

The Carbonate-Hardening Lime Construction Material Properties Formation during their Long-Term Storage and Use under Normal Conditions

This paper presents the lime binding forced carbonate-hardening materials properties formation study and determins the stability of these properties during long-term storage and use under normal conditions. The tests showed these materials stability properties over time, confirming the strength and density growth of the test samples after long storage due to the calcium hydroxide recrystallization completion into calcium carbonate processes. Also, the results of the samples carbonate hardening study under natural conditions during 18 months are presented. An efficiency assessment of forced carbonate hardening as one of the methods of recycling technogenic CO2 in order to reduce its emissions in the atmosphere, and, in the result, to obtain high-quality construction materials has been made.

Test methods for characterizing concrete properties at elevated temperature

SummaryFire resistance of structural members is dependent on the thermal and mechanical properties of constituent materials and these properties vary as a function of temperature. Currently, there are limited standardized test procedures for evaluating thermal and mechanical properties of construction materials at elevated temperatures. This paper provides a review and assessment of test methods and procedures for evaluating high temperature thermal and mechanical properties of concrete. The drawbacks and variations in currently available test procedures and methods in standards are discussed. Recommendations on the most suitable methods and procedures for measuring thermal and mechanical properties at elevated temperature is presented. In addition, applicability of the proposed high temperature test methods and procedures is illustrated through a case study on conventional concrete specimens. Further, the need for developing standards by organizations such as American Society for Testing and Materials (ASTM), with standardized specifications and test procedures for measuring high temperature properties of construction materials, is laid out.

Seismic Performance Comparison of a Building Made with Old Masonry Bayburt Stone According to Old and New TBDY

Turkey is home of a very rich geography and cultural heritage which is seen in the contemplation of its history. As in every society, efforts are being made to protect the existing cultural heritage in our country. It is our responsibility to protect, maintain and strengthen this heritage. Most of the buildings representing the richness of our culture are masonry structures. In the performance examination of these structures, there are difficulties in determining and interpreting their performances due to the properties’ variabilities of materials used in their construction. In this study, a masonry building located in Bayburt a western city of Turkey built between 1941-1942 using Bayburt stone was examined, information about construction technique, soil properties and material properties as well as existing problems of the structure were compiled and observed. The values obtained as a result of a survey study performed on the structure were moved to AutoCAD program and modelled with StatiCAD-Masonry Program. It was aimed to compare the earthquake performance analysis of the structure according to Old Turkey Building Earthquake Regulation (TBDY-2007) and New Turkey Building Earthquake Regulation (TBDY-2018). In the light of the analyses, the structural performance of Bayburt stone was examined and analysed according to regulations. Keywords: Performance Analysis, StatiCAD- Masonry, Masonry Building, Earthquake Regulation DOI: 10.7176/JSTR/5-11-04

Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Wind-induced damage during the construction process and the evolution of damage over time are important reasons for the wind-induced destruction of large cooling towers. In fact, wind vibration coefficient and stability performance will evolve with the construction height and material properties over time. However, the existing studies generally ignore the impact of wind load and structural performance during the construction period. In this study, we built the 3D physical model separately for all eight construction stages a super large cooling tower which is being currently constructed and stands 210 m. The dynamic characteristics of the cooling tower were analyzed in each stage. First, the flow field information and 3D time history of aerodynamic forces were obtained for the whole construction process using large eddy simulation (LES). Full transient dynamic finite element analysis was used to calculate the dynamic responses of the tower under the real-time changes of wind loads during the whole construction process. Five calculation methods were used to trace the evolution of wind vibration coefficient during the whole construction process of the super large cooling tower. Then the formula for wind vibration coefficient changing with the construction height was fitted. The differential values of wind vibration coefficient during the whole construction process of the cooling tower were discussed by taking the meridional axial force as the objective function. On this basis, the influence and working mechanism of wind vibration coefficient, concrete age, construction load, geometric nonlinearity, internal suction force on buckling stability, and ultimate bearing capacity of the cooling towers were investigated. This research provides an enhanced understanding on the evolution of wind-induced stability performance in super large cooling towers and a methodology to prevent wind-induced damage during the construction process.

Impact Analysis of Water Quality on the Development of Construction Materials

This research dealt with the impact of the quality of the water source on the mechanical properties of construction materials. The mechanical properties of construction materials include compressive, tensile, and flexural strength. Water samples were collected from different resources, these samples were then synthetically investigated to identify and compare their quality parameters. After a detailed chemical analysis of water samples from three sources—wastewater, surface or canal water, and ground water—construction concrete material samples were prepared. The construction materials were developed with the same water–cement ratio, i.e., 0.60 for each concrete mix sample at two mix ratios—M1 (1:2:4) and M2 (1:1.5:3). Slump cone and compacting factor tests were conducted on the fresh concrete to determine its workability prior to its hardening. Then, at 7, 14, 21, and 28 days for each mix, tests for mechanical properties were carried out to determine the compressive, tensile, and flexure strengths. Results showed that the mechanical properties of the concrete made by utilizing wastewater and surface water were more noteworthy as compared to the concrete made by groundwater. This study will help in the production of concrete which depends on waste and surface canal water, even for large projects like rigid pavement construction and water-related structures.

Meso-mechanical investigations on the overall elastic properties of multi-phase construction materials using finite element method

Many construction materials are multi-phase composites in mesoscale, and therefore their overall mechanical properties strongly depend upon those of each component. Elastic properties are critical parameters in the overall performance and analysis of composites, and they are also of practical importance in design. Owning to randomness in the particle locations of each component, the overall performance of a multi-phase material also is not a deterministic value. As a result, prediction of the elastic properties of a multi-phase material is a challenging task. In the present study, a numerical simulation algorithm was proposed to investigate fully the overall elastic properties of composite samples. Finite element models, coupled with Monte Carlo simulations, subsequently were used to predict the overall modulus and Poisson’s ratio. Specifically, two typical types of construction materials were considered; soil-rock mixtures and concrete. For validation, the numerical simulation results of elastic moduli were compared with experimental test results and the comparison gave good agreement between numerical and the test results. Moreover, the influence of parameters, such as the elastic modulus of each phase, particle shape, size distribution and porosity, on the overall elastic modulus, were considered via parametric studies. Finally, the proposed numerical simulation algorithm was compared with some existing empirical models and the comparison results underscored the importance of the numerical model developed in this study.

Thermal and mechanical properties of fired clay bricks made by using grapevine shoots as pore forming agent. Influence of particle size and percentage of replacement

For decades, the construction industry has focused on developing new materials to minimise environmental impact and improve building insulation envelopes. The use of certain wastes as additives for construction materials (e.g. concrete, clay, steel) has been shown to be a feasible alternative that may improve both the current waste management strategy and the properties of construction materials. Among others, the fired clay brick (FCB) industry has been highlighted as an optimal sector for incorporating such residues, due to the large amount of mass flow involved, the use of firing temperatures above 900 °C and the observed positive effects of FCB thermal conductivity (TC) when organic residues are added. Although the properties of fired clay are closely related to the firing curves and the mineral and chemical composition of raw materials, the effect of particle size is also a key factor that directly impacts on the economic and technical feasibility. This paper therefore assesses the addition of wood chips from pruned grapevine shoots as an additive for manufacturing FCBs, and considers three particle sizes (up to 0.5 mm, above 1.5 mm and between 0.5 and 1.5 mm) and variations in the added percentage on a dry basis. Several samples were tested in order to determine the mechanical and thermal behaviour of FCBs, and it was concluded that the maximum of 10% wood chip content is limited by both the compressive strength values and the water absorption. At this percentage, TC is reduced by up to 50%. The particle size seems to have no effect on the thermal properties, but gives rise to significant variations in terms of the mechanical response.

UTILIZATION OF PUMICE OF BURDUR REGION AND ZEOLITE OF BIGADIC, BALIKESIR REGION AS FINE AGGREGATE IN CONSTRUCTION MATERIALS

Volcanic originated pumice and zeolite aggregates have low density owing to their considerable porous structure. Porosity is usually correlated with insulation properties. In order to examine the effects of this lightweight aggregates on dead load of structure and insulation properties of standard construction materials, samples were produced by using pumice and zeolite at varying percentages by volume and control samples were manufactured with crushed sand. The samples were exposed to normal (standard) curing, hot water curing and steam curing to observe the effect of different curing regimes on their behavior. Bulk density and thermal conductivity tests were carried out on samples. Both bulk density and thermal conductivity values of the lightweight mortar samples were smaller than those of control sample. Besides, chemical compositions of aggregates and cement, analyses were also performed. Silica content of pumice and zeolite were %54,09 and %75,14 by mass respectively.

Simulation two storey house of masonry wall under the earthquake load

The masonry wall building systems have high sensitivity against earthquakes and the fact that this system of construction is widespread in Iraq, especially condominiums. Iraq subjected to many earthquakes in recent years and is expected to be subjected to more intensities of earthquakes in the future engendered an urgent need to investigate the behavior of this type of construction under the influence of earthquakes. The analysis of two-storey house in this research paper was performed by the finite element package program ABAQUS. Model simulation with dimensions (5 * 20 m) from the common one and two-storey house models in Iraq. The compressive strength of bricks (17MPa) type A and compressive strength of mortar(15MPa) with mixing ratio 1:3 was used to represented of the properties of construction materials in Iraq. The nonlinearity behavior of the materials is considered in this research paper. The model is subjected to PGA(0.5g) from EL-Centro Earthquake (1940 N-S ) as input ground motion to determine its seismic performance compared the maximum displacement, drift and base shear for models with the seismic demand of Iraq. Through the analysis of the results, the models proved efficient and stable against the effect of earthquakes, especially when the load applied in the Z long direction, more than the load applied in the X short direction for all models