Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Porous pavement applications, which is environmentally friendly, especially for residential areas, allow rainwater to remain clean and to feed groundwater through infiltration. Porous asphalt pavements, in which are among the pavement types used in porous pavements systems, also reduce environmental noise pollution. On the other hand, there is a need to improve the performance of these asphalt pavement mixtures, which have a short service life due to their porous structure. It has been considered to improve the performance of the pavement mixtures by using basalt fiber without compromising the hydraulic permeability level. The waste slag material released during the ferrochrome production process was used as aggregate in the porous asphalt mixture design. Thus, it is aimed to benefit from the economic and environmental aspects with the recycling of ferrochrome slag in an area suitable for its properties. In the study, the design performances of porous asphalt mixtures were determined with tests such as volume analysis, permeability, Cantabro particle loss, indirect tensile strength, and moisture susceptibility. Basalt fiber was added at 0.2%, 0.4%, 0.6% and 0.8% of the mixture weight. It has been determined that the mixtures of basalt fibers at 0.2% significantly improve the mechanical performance.

Tunnel entrances are among the most likely places for rock fall events. For this reason, concrete tubes are constructed before tunnel entrances against rock falls. In this study, the normal stress and the deformation in both horizontal and vertical directions occurred by crashing rock on concrete tunnel tubes were investigated using finite element method in three dimensional conditions. Different velocities and masses of falling rock analyzed to demonstrate effect of velocity on normal stress and deformations. It was observed that deformations on the concrete tube increased as the impact energy increased due to increasing velocity and mass. The mass of crashed rock, M, is changes from 3 kN to 200 kN and peak deformations could reach approximately 150 cm when the mass of falling rock was M=200 kN and V = 30 m/s. When the velocity of rock V=10 m/s just before the impact, the ratios of deformations to rock mass of 3 kN, 25 kN, and 200 kN were approximately 0.00066 m/kN, 0.0014 m/kN and 0.00175 m/kN, respectively.

The objective of this study is to examine the seismic performance of exterior and interior types of an emulative precast beam to column connection, constructed with grouted steel dowel bar and cast-in-situ concrete under quasi-static reversed cyclic loading. The dowel bar connection between the precast structural elements is achieved by inserting the dowel bar into the column corbel's holes and the precast portion of the beam. To secure the dowel bar's anchorage, these holes are packed with non-shrinkage grout and then cast-in-situ concreting is done in the joint core and the entire upper segment of the precast beam. In the past, particularly after an earthquake in the Emilia-Romagna region of Italy in May 2012 (Ercolino, Magliulo, & Manfredi, 2016), witnessed damage to precast reinforced concrete structures was more likely to occur in the precast beam-column joint section. Hence, it’s essential to improve the performance of the beam-column joint to withstand all possible lateral load combinations, which are to be included in the design and detailing of the precast structural components. This study analyzed an eight-story RC frame building for earthquake loading using Staad.Pro software. The exterior and interior types of proposed beam-column connections were designed and detailed using the design forces and moments computed by the Staad.Pro analysis, in accordance with the Indian standard codes (IS 456, 2000), (IS 1893, 2016)and (IS 13920, 2016). The beam-column joint behavior under quasi-static cyclic loading was studied using one-third scaled-down test specimens, i.e., monolithic (MBC-EJ & MBC-IJ) and emulative beam-column (EBC-EJ & EBC-IJ) exterior and interior joints. In that proposed emulative connection, the structural continuity and compatibility between the precast elements were achieved through the corbel with the dowel bar and cast-in-situ concreting. The test specimen’s ultimate and yield load carrying capacity, energy dissipation capacity, stiffness degradation, and ductility parameters were determined based on the obtained load-displacement hysteresis relationship. Based on the findings, the precast exterior joint specimens (EBC-EJ) were found to be 14.36% more ductile and 13.23% more energy dissipative than monolithic exterior joint specimens (MBC-EJ). Similarly, precast interior joint specimens (EBC-IJ) outperformed monolithic interior joint specimens (MBC-IJ) by 6.27% more ductility and 16.86% more energy dissipation. Therefore, the experimental results confirmed that using grouted dowel bars and wet concreting in the joint area enhances rigidity and structural continuity, as well as improves the ultimate strength of precast connections to a level that closely resembles typical monolithic beam-column joints.

The current study aimed to analyse the viability of incorporating the post cryogenic discarded rubber and the air-cooled slag as an aggregate in partial replacement of stone dust in fly ash bricks production. A range of mechanical, non-destructive, and microstructural tests was performed on bricks thus produced by incorporating rubber and slag aggregates in various dosages (i.e., 5, 10, 15, 20 and 25% by stone dust weight).  The result revealed that the compressive strength dropped from 71 to 43 % in the case of rubber aggregate replacement. Morphology study confirms that the rubber aggregates resulted in the porous microstructure of the bricks and leads to lesser unit weight and lighter structure. The rubber may be used as a lightweight aggregate in the brick possibly as it reduces the density of the final product. However, the use of rubber in bricks needs to be cautiously designed to get hold of productive solutions at the end. The findings demonstrate that the copper slag substitution of up to 15%, found to be enhanced the strength properties and it will be a better choice for low-cost construction as a promising alternative construction material.

The main aim of the current study is to search the impact of variable matrix phase features on fly ash based lightweight geopolymer mortars (LWGM). Another scope of the study is to obtain performance oriented optimum mixture proportions through response surface method (RSM). In order to have low unit weight for LWGMs, pumice aggregate was utilized as a part of the aggregate. The investigated engineering properties are water absorption, drying shrinkage and thermal conductivity. By performing optimization analysis, it was aimed to obtain the best numerical models representing the experimental results depending on the input variables. The decrease of liquid (alkali activators) to powder (fly ash) ratio, Na2SiO3 solution to NaOH solution ratio and increase of sodium hydroxide molarity led to improvement of compressive strength. Dry thermal conductivity values in dry state were observed to be less than those of saturated ones. Moreover, the higher sodium hydroxide molarity and lower Na2SiO3 solution to NaOH solution ratios, and liquid to powder ratios resulted in further shrinkage reduction. Depending on the goals of maximum compressive strength, minimum water absorption, and drying shrinkage, optimum values for molarity, SS/SH, and l/p factors were determined as 14 M, 1.586, and 0.45, respectively.

Decision-making regarding building performance in all construction project phases is a complex task. This article addresses the challenge of managing building performance information throughout construction project phases. It proposes a tool that assists in verifying the building performance requirements for different stakeholders and supports the integration of this information within the BIM process. The developed tool allows the launch, monitoring, and creation of a database with information about the project, the work, and the stakeholders. A practical study was chosen to test this tool. Its result is particularly meaningful to all stakeholders, as it prioritizes the information and underlying activities for the collaborative project development among the participants. In summary, the information integration related to the requirements to guarantee the building performance, co-related to the construction project development phases, is essential for improving internal processes. It is worth mentioning that managing this information is not a simple process and requires contextual knowledge, leadership, and management and communication skills.

Engineers prefer reduced beam section (RBS) connections in steel moment frames built in earthquake zones due to their many benefits. The RBS shape design significantly affects joint behavior. This paper examines the effect of RBS geometry on joint behavior and seismic performance using ANSYS finite element analysis software. RBS connections are investigated using European profiles and steel grades due to the limited number of studies using European profiles in the literature. The simulation study is carried out in three stages. In the first stage, an experimental study in the literature is simulated, and the reliability of the created finite element model is checked. In the second stage, geometric changes are made to the verified numerical model, and the obtained new models are examined under monotonic loading to observe the effect of RBS geometry on moment-rotation behavior. In the third stage, the effect of the change in the RBS geometry on the seismic performance is investigated under cyclic loading. As a result of the study, the effects of various changes made in the RBS geometry on the joint behavior and seismic performance are presented graphically. By using the results of the analysis under monotonic loading, the regression analysis is carried out, and the formulas giving the elastic-plastic stiffness, elastic moment capacity, and elastic rotation angle of the support are derived. Besides, simulation models show that the RBS joints' seismic performance met the minimum criteria specified in the earthquake code (AISC/ANSI 341-16) when European steel profiles and quality are applied.

This study focused on whether industrial iron chips waste can be recycled by using them in the production of reinforced concrete cantilever beams. The amount of aggregate in the range of 0-4 mm in the concrete used in the production of cantilever beams was determined. And this amount was reduced by 10%, 20%, and 40% and replaced with iron chips. Cantilever beams have been produced in two different ways as under-reinforcement and over-reinforcement by changing the diameters of the tension reinforcement. Thanks to the experimental setup, the cantilever beams were loaded at their endpoints. In the experimental study, the load-displacement curves of the cantilever beams were obtained. According to the findings obtained in the study, under-reinforced cantilever beams behaved more ductile than over-reinforced cantilever beams. Cantilever beams with 40% iron chip additive reached the highest strength and exhibited the most brittle fracture examples. Cantilever beams containing 10% and 20% iron chip additives increased their ductility values up to 14.54% and decreased ​​their strength up to %17.27 compared to reference cantilever beams.

The objective of this study was to improve the performance of flexible pavement through suitable aggregate gradation. Thus, initially, the dynamic modulus of asphalt mixtures |E*| for different aggregate gradations were predicted, and suitable aggregate gradation was determined. Then the performance of three different pavement structures for two aggregate gradations (Mid and Suitable), using AASHTOWare Pavement ME Design 2.5. 5, were evaluated for local conditions of Izmir, Turkey. The analysis result revealed that using suitable values compared to middle values increased the |E*| and improved the rutting and fatigue resistance of all pavement structures for any traffic levels. The output of this study can be used as a guide for hot mixed asphalt mix design and pavement design based on Mechanistic-Empirical Pavement Design Guide as well.

In this study, the capacity and ultimate behavior of Reinforced Concrete (RC) and Steel Fiber Reinforced Concrete (SFRC) beams are evaluated. Nonlinear Finite Element Analysis (NLFEA) and the inverse analysis technique were used to model its structural response using the ATENA finite element software. The smeared crack approach, the crack band model, and advanced constitutive models were used to reproduce concrete fracture. The analyzed beams were subjected to rupture in a four-point bending test setup. The relationship between the shear span and the depth of the beams was 1.5. Four scenarios were analyzed, RC beams with and without stirrups, and SFRC beams without stirrups with volumes of 0.57% and 0.76%. The results obtained in the modeling are discussed in terms of the ability of the models to numerically reproduce the relationships: load versus displacement, load versus strain, crack patterns, and failure modes. The analysis techniques allowed to reproduce the experimental response of the beams with good agreement. They show great potential to solve structural engineering problems.