cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14307269.v1
title: Development of Brazilian highway live load model for unlimited fatigue life

description: Abstract This work studies the fatigue live load model used in Brazil for highway bridges. Using the unlimited fatigue life approach, the current live load model is evaluated in relation to the actual traffic and a new fatigue live load model is proposed. Weigh-in-motion (WIM) stations data on two important Brazilian highways are used. The main structural analysis performed in this paper consider the bridges as box girders or multiple girders. The ratio between real traffic and the live load model load effect (bias factor) are determined for single and continuous spans in terms of bending moment and shear force. It is found that the bias factor of the current live load can vary a lot and may not ensure unlimited fatigue life. The proposed model, on the other hand, presents more uniform bias factors and is in accordance with the unlimited fatigue life approach for the WIM data.
DOI: 10.6084/m9.figshare.14307267.v1
title: Proposition of a simplified analytical design procedure for lattice girder slabs with shuttering in cold-formed steel lipped channel section

description: ABSTRACT This paper presents an analytical procedure to determine the resistance of a new composite ribbed lattice slab system, composed by a lipped channel cold-formed steel (CFS) profile in minor bending fastened to a lattice girder by plastic connectors, as well as light filling elements and additional rebar. Motivated by the lack of standardized procedures for such system, this paper combines slab design prescriptions to create a computational tool that estimates load capacity and required propping during construction, serving as a basis for a design catalogue. Finally, a strong limitation of unpropped construction due to the low performance of the cold-formed profile under minor axis bending was observed, being the system able to reach spans up to 1.5 m between props in general.
DOI: 10.6084/m9.figshare.14307266.v1
title: Three-dimensional modelling of wall-beam interaction in structural masonry buildings

description: ABSTRACT: Wall-beam interaction (wall-beam system) is a phenomenon that requires further investigation in order to be consistently incorporated into structural building analysis. Researchers such as Wood, Rosenhaupt, Burhouse, Stafford Smith, Navaratnarajah, Davies, Riddington and Armed conducted tests on specimens to develop simplified analysis models, emphasizing the behavior of walls without openings under one span beams. The present study performed computational analysis using an specific equivalent frame model in order to study the behavior of the wall-beam system in more complex wall and beam arrangements. The examples considered the linear elastic behavior of materials and consisted of assessing stress distribution and displacements on support beams, in addition to stresses at the bottom of the walls, for panels in a real structural masonry building. Two- and three-dimensional analyses were used and the results showed the importance of three-dimensional analysis of wall interconnections. The effects of eccentricity between the vertical plane of the wall and horizontal support beam axis were also evaluated, showing the strong influence of twisting moments in support beam design.
DOI: 10.6084/m9.figshare.14307264.v1
title: Performance of concrete with the incorporation of waste from the process of stoning and polishing of glass as partial replacement of cement

description: Abstract The incorporation of waste glass as a partial replacement for cement in concrete can provide an alternative destination for the waste, reduce the consumption of cement (minimizing CO2 emissions and consumption of natural resources), and improve the concrete performance. Thus, this research evaluated the performance of concrete incorporating waste glass sludge (GS), resulting from the process of stoning and polishing of soda-lime flat glass, as a supplementary cementing material. Mechanical strength and durability properties were assessed through compressive strength, alkali-silica reactivity, electrical resistivity and chloride permeability, diffusivity and migration tests. Mixtures containing metakaolin (ME) were also evaluated. The results indicated that the use of the waste ground to an adequate size can replace up to 20% of cement. At this content, it caused a reduction of chloride penetration of over 80%, reduced ASR and conserved compressive strength. The combination of waste with metakaolin replacing 20% of cement also improved all the concrete properties, increasing the compressive strength up to 12% at 28 days.
DOI: 10.6084/m9.figshare.14307263.v1
title: Early-age behavior of blast-furnace slag cement pastes produced with carbon nanotubes grown directly on clinker

description: Abstract Carbon nanotubes are a promising material to solve the low tensile strength and ductility of Portland cement-based materials. Carbon nanotubes (CNTs) synthesized directly on cement clinker particles can also reduce production costs and help dispersion. In this scenario, this paper analyzes the fresh state rheological behavior, as well as the initial hydration period of blast-furnace slag (Brazilian CP III 40 RS) cement pastes produced with CNTs grown directly on clinker. CP III 40 RS was selected since it is one of the most used cement by the construction industry in Brazil. Cement pastes containing 0.1% and 0.3% of CNTs with respect to cement content were compared with CNT-free pastes. No chemical admixtures were used as a dispersant in all cases. The yield stress, plastic viscosity, temperature profile and evolved accumulated heat during the initial hydration period as well as setting times are the properties investigated. The results show that the addition of CNTs does not alter the rheological behavior of the cement pastes considering the employed concentrations, although the yield stress values were larger. The presence of CNTs in the cement pastes did not change the evolved accumulated heat during the first 72 hours of the hydration period.
DOI: 10.6084/m9.figshare.14307260.v1
title: Effects of alkali-silica reaction on mechanical behavior of four-pile caps

description: ABSTRACT: The structural behavior resulting from alkali-aggregate reactions on four-pile caps was numerically studied using software based on the Finite Element Method. The cracking was analyzed in terms of reduction rates in the mechanical properties of the concrete (compressive strength, tensile strength and modulus of elasticity) as a consequence of the expansion induced by the alkali-aggregate reaction (AAR) referred to in the literature. One option for dealing with changes in mechanical properties, reported as influenced by the reactive aggregate type, environmental conditions and stress state, is to directly use the value of the properties of the material tested in the analysis, an approach adopted in the study and implemented in the analysis. From the results found in the analysis program the three main effects of AAR could be better understood: expansion, cracking and degradation of mechanical properties of concrete.
DOI: 10.6084/m9.figshare.14307258.v1
title: From numerical prototypes to real models: a progressive study of aerodynamic parameters of nonconventional concrete structures with Computational Fluid Dynamics

description: Abstract The practical evaluation of aerodynamic coefficients in unconventional concrete structures requires specific studies, which are small-scale models evaluated in wind tunnels. Sophisticated facilities and special sensors are needed, and the tendency is for modern and slender constructions to arise with specific demands on their interaction with the wind. On the other hand, the advances obtained in modern multi-core processors emerge as an alternative for the construction of sophisticated computational models, where the Navier-Stokes differential equations are solved for fluid flow using numerical methods. Computations of this kind require specialized theoretical knowledge, efficient computer programs, and high-performance computers for large-scale calculations. This paper presents recent results involving two real-world applications in concrete structures, where the aerodynamic parameters were estimated with the aid of computational fluid dynamics. Conventional quad-core computers were applied in simulations with the Finite Volume Method and a progressive methodology is presented, highlighting the main aspects of the simulation and allowing its generalization to other types of problems. The results confirm that the proposed methodology is promising in terms of computational cost, drag coefficient estimation and versatility of simulation parameters. These results also indicate that mid-performance computers can be applied for preliminary studies of aerodynamic parameters in design offices.
DOI: 10.6084/m9.figshare.14307255.v1
title: Incorporation of recycled aggregates from construction and demolition waste in paver blocks

description: ABSTRACT: The consumption of natural resources and energy increased proportionally with the growth of the world population and its economic level. There was an increasing exponential consumption of natural resources, which implied an increase in environmental impacts. The construction sector is responsible for a very significant production of construction and demolition waste (CDW). Thus, there is a concern in search of a more sustainable final disposal. Many studies have been investigated the development of new materials with the incorporation of recycled aggregates from CDW. This paper presents a study of performance evaluation of concrete blocks produced with CDW. For that purpose, an experimental campaign was performed, including a characterization of the aggregates used. The incorporation of 100% of fine and coarse recycled aggregates. The mixtures were designed according to the condition of the aggregate (dry, washed or saturated). The performance of these blocks was evaluated in terms of mechanical strength and water absorption. Some additional tests were also performed to deeper analyze of the microstructure of these blocks. To assess the durability of the concrete blocks, a full-scale road was built. The results were very positive, since there were no significant differences between the modified concrete blocks and the reference sample (0% of the CDW). The modified block with fine aggregate presented the best performance of all the blocks, concerning mechanical strength. In addition, the performance of concrete blocks with washed recycled aggregates had a better performance compared to the others. The results obtained were satisfactory for the application of the blocks in the streets with low movement and low load.
DOI: 10.6084/m9.figshare.14307254.v1
title: Evaluation of external sulfate attack (Na2SO4 and MgSO4): Portland cement mortars containing fillers

description: Abstract Sulfate attack is a term used to describe a series of chemical reactions between sulfate ions and hydrated compounds of the hardened cement paste. The present study aims to evaluate the physical (linear expansion, flexural and compressive strength) and mineralogical properties (X-ray diffraction) of three different mortar compositions (Portland Cement CPV-ARI with limestone filler and, with a quartz filler, in both cases with 10% replacement of the cement by weight) against sodium and magnesium sulfate attack (concentration of SO4 2- equal to 0.7 molar). The data collected indicate that the replacing the cement by the two fillers generate different results, the quartz filler presented a mitigating behaviour towards the sulfate, and the limestone filler was harmful to Portland cement mortars, in both physical and chemical characteristics.
DOI: 10.6084/m9.figshare.14307251.v1
title: Influence of the cementitious matrix on the behavior of fiber reinforced concrete

description: Abstract One of the main purposes of the addition of fibers to the concrete is the control of the plastic shrinkage cracking in the fresh state and the increase of the post-crack resistance in the hardened state. The cementitious matrix is one of the factors that influences the performance of fiber reinforced concrete, interfering in the fluidity of the mixture and in the adhesion between fiber and matrix. In this context, the present paper evaluates the behavior of two concrete, one of conventional strength and another of high-strength, without fiber and with a content of 1%, by volume, of fiber, being used steel fiber and macro-polymeric fiber. For this, the mechanical properties of the concrete were evaluated in the hardened state by the tests of compressive strength, Barcelona, flexure of prisms and punching of plates. From the experimental results, statistically analyzed, there were significant changes in toughness and residual strength due to change in the cementitious matrix. Finally, an equivalence of performance between the fibers as to the toughness was observed, with the change of the cementitious matrix.
DOI: 10.6084/m9.figshare.14307248.v1
title: Experimental analysis of longitudinal shear of composite slabs

description: Abstract The composite concrete slab systems with steel-deck incorporated has become an alternative to conventional slab models, since it often does not require the use of shoring, promoting several constructive practices, beyond operation of the reinforcement as a positive moment. The procedure of verification of composite slabs is based on the semi-empirical method m and k. The purpose of this paper was to investigate the application of the "m-k method" in a group of slabs with alternative dimensions as the usually adopted in the tests, even as to correlate the values obtained with the results found when testing the models as proposed by the ANSI 2011 test standard, since the normative method is costly and expensive. Therefore, four-point flexural tests were performed on slab models considering only one deck module, varying two spans, the same procedure was repeated in slabs with usual construction dimensions (normative models). The linear regression method was applied to the data found in order to obtain the parameters that would be analyzed. The main results show that the alternative model with the adopted dimensions does not present values that can be applied directly to the normative models, since the increase of the shear span reduces in a significant way the theoretical resistance of the slabs. Nevertheless, the values for the m and k obtained of both alternative and normative models can be adopted confidently as part of the sizing process of the respective models. The deviations between theoretical and experimental resistance satisfy the specifications of the ANSI 2011 standard for both models helped in the confirmation of the previous statement. The expectation of this paper is to assist in the search for new procedures for determining parameters m and k.
DOI: 10.6084/m9.figshare.14307246.v1
title: Wind load effect on the lateral instability of precast beams on elastomeric bearing supports

description: Abstract The behavior of slender precast beams related to lateral stability in the transitional and in service phases is worrying. The presence of geometric imperfections aggravates and makes the problems of instability more susceptible. The main objective of this work is to evaluate the behavior of concrete beams on elastomeric bearings and to analyze the influence of variables such as: concrete strength, wind load and bearing compression stiffness. For the numerical nonlinear analysis the software ANSYS based on the Finite Element Method was used. The analyses show that the influence of the strength of the concrete is significant in the lateral stability of the beam. The wind load represents a considerable decrease in the contact (lift off) between the beam and the bearing. Finally, the combination of these factors can result in a critical stress situation in the beam, and it is not possible to have equilibrium, causing its toppling.
DOI: 10.6084/m9.figshare.14307243.v1
title: Lightweight concrete with coarse aggregate from ceramic waste at high temperatures

description: Abstract With the increasing use of recycled materials from civil construction, mainly as substitute for some aggregates in concrete mixtures, it is necessary to obtain technical information on the performance of these new mixtures. National and international research on the use of ceramic waste in concrete production highlight good results of this new material’s mechanical performance in environmental situations. However, little is known about its behavior at high temperatures. In this context, we sought to verify the performance of concrete mixtures produced with aggregates from ceramic block waste at high temperatures, with evaluation of their residual mechanical strength, axial compressive strength and elastic modulus, and also their tendency to spalling in fire situations. The RILEM-129 MHT method [1] was used for the assessment of residual mechanical strength, and the tendency to spalling was evaluated according to the procedure suggested by Souza and Moreno [2]. In both these evaluations, there is no national standard, and, in the case of spalling, not even an international standard. Three concrete mixtures were used, one prepared with natural coarse basalt aggregate (reference) and the other two by replacing part of this natural aggregate with aggregate from ceramic block waste (40% and 100% of substitution in volume). In the end, it is concluded that the substitution of natural coarse aggregate for lightweight aggregate from ceramic block waste can be an excellent alternative to increase the resistance of concrete to fire. Thus, the results of mechanical strength and spalling in a fire situation, unprecedented in our country, can greatly support the decision-making about the use of this alternative material in the national construction industry.
DOI: 10.6084/m9.figshare.14307242.v1
title: Experimental and numerical characterization of the interface between concrete masonry block and mortar

description: Abstract Masonry is a construction system that has been used since the beginning of civilization and is still used throughout the world. The finite element method is a recent development that allows complex problems, including structural masonry problems, to be solved. A vast amount of literature exists on finite element modeling, using software such as ABAQUS, to represent experimental masonry models. Based on this established pattern, an experimental and analytical research program was designed and implemented. Thus, a set of tests was conducted to determine the compressive and tensile strengths of the masonry components, i.e., block, mortar, and grout. Bond wrench tests, diagonal tension tests, and horizontal joint shear tests were conducted to characterize the interface between the blocks and the mortar. A finite element model was then developed to represent the physical models and the general conclusion is that the finite element model was able to represent reasonably well the physical models.
DOI: 10.6084/m9.figshare.14307240.v1
title: Assessment of the dynamic structural behaviour of footbridges based on experimental monitoring and numerical analysis

description: Abstract This research work aims to investigate the dynamic structural behaviour and assess the human comfort of footbridges, when subjected to pedestrian walking, based on experimental tests and tuning of finite element model. Therefore, the investigated structure is associated to a real pedestrian footbridge, spanning 24.4m, located at the campus of the State University of Rio de Janeiro (UERJ), Rio de Janeiro, Brazil. Initially, an experimental modal testing was conducted using two data acquisition strategies. After that the experimental forced vibration tests were performed on the footbridge, considering the pedestrians walking with different step frequencies. In sequence of the study, a finite element model was developed based on the ANSYS computational program. The experimental footbridge tests were used for the calibration of results on the numerical model. Finally, a human comfort assessment was performed, based on the comparisons between the results (peak accelerations), of the dynamic experimental monitoring and the recommendations provided by design guides SÉTRA, HIVOSS and AISC.
DOI: 10.6084/m9.figshare.14307239.v1
title: Evaluation of the GPR (1.2 GHz) technique in the characterization of masonry shells of the Theatro Municipal do Rio de Janeiro

description: Abstract The geometric characterization and evaluation of structural integrity are challenges for the preservation of historical buildings. The challenges are associated to the lack of constructive records, material diversity, access and contact restrictions, and sample extraction. Non-destructive tests are indicated in these cases. The objective of this paper is to evaluate the Ground Penetrating Radar (GPR) technique with 1.2 GHz antenna in the study of the determination of material thickness and discontinuities in the masonry shells of the Theatro Municipal do Rio de Janeiro, a heritage built in early 20th century, with high historical and cultural value. With paintings by renowned artists on their intrados, the domes and vault of brick masonry were at risk of collapse in the 1970s due to differential settlements in the supports and moisture, compromising their paintings. A strengthening intervention was carried out in 1976. Considering the masonry of bricks the main component, the electromagnetic wave propagation velocity was determined as 0,15 m/ns in one of the support walls, allowing to estimate the thicknesses of the elements ranging between 20 and 31 cm. Materials incorporated into the structure were identified: reinforcement, metal inserts and bricks. However, the frequency of the antenna did not allow the detection of damages. The application of the GPR to the characterization of materials and investigation of the integrity of the domes of the Theatro Municipal highlights the potential of this technology to study heritage and other constructions.
DOI: 10.6084/m9.figshare.14307237.v1
title: Use of ornamental rock waste as a partial substitute for binder in the production of structural concrete

description: Abstract Due to the population increase, to the improvement of life conditions, to the elevation of levels of consumption and the growing industrialization of developing countries, it is estimated that the production of concrete will present significant increase in the next decades. The process of producing cement is responsible for approximately 5 % of the emissions of CO2, an expressive environment pollutant. In this context, this work presents an evaluation of the influence of partial substitution of cement by ornamental rock waste (ORW) on the physical and mechanical properties of concrete. ORW from a local marble and granite processing company was used. The waste was mineralogically characterized through X-ray diffraction (XRD) essays, energy-dispersive X-ray (EDX) microanalysis, and physically characterized through laser granulometry and specific mass. For this, was adopted a concrete trace as reference, produced with CP V-ARI cement (similar to ASTM Type III), from IPT dosage. Waste was used in proportions of 5 %, 7.5 %, 10 % and 12.5 % of substitution of cement by mass. Results were treated with ANOVA and multiple comparison of means, indicating a possibility of substitution of until 10% of cement by ORW, creating a concrete with proper resistance to Brazilian regulations regarding the classification as structural.