Revista Ingeniería de Construcción

Brick dust and fly ash as subgrade stabilizer for Low Traffic Volume Roads: laboratory and test track evaluation

2024-05-17T17:26:00+00:00

Currently, there are materials from industry that, under certain physical conditions, can contribute to the improvement of soils mechanical properties. Materials such as brick dust (BD) and fly ash (FA) have high SiO₂ and Al₂O₃ contents, which denote pozzolanic activity. In addition, it has been shown that these materials can be activated when combined with lime. This generates internal cementation processes when the particle size is 0.075 mm. Rural roads in Colombia have one of the highest percentages of the entire road infrastructure, and only about 7% are in good condition. Difficult access conditions, soil susceptibility, the financial impossibility of intervening in this entire network and the need to implement circular economy processes, make these materials attractive in terms of stabilization to improve traffic conditions. BD and FA were applied in dosages of 0%, 3%, 6%, 9%, 12% and 24% in finogranular soils (silt and clay) and sandy soils, compaction was evaluated, and a factorial experimental design was carried out to evaluate the influence of the material on the variable unconfined compressive strength (UCS), through an ANOVA analysis. To evaluate the performance of BD and FA, a test track was made on a low traffic volume road in northern Colombia, which had a sandy soil. BD and FA were added at 12% and activated with lime, in 30 m long cells. To establish a comparative pattern, other cells were made in the same geometric conditions with materials that are usually used in this type of application, such as cement. These cells were evaluated over a period of 16 months. Characteristics such as resilient modulus, international roughness index (IRI) and slip resistance coefficient were measured during this period. The results indicate that when these materials are added to finogranular soils (silts and clays), the UCS increases by 150% with respect to the unstabilized soil, while for sandy soils the strength increases from 70% to 125%. During the evaluation period, the BD and the FA were able to increases of over 50% in the resilient modulus with respect to the unstabilized soil. However, the FA showed comparable results with respect to the cement-stabilized cell. In addition, although the sections deteriorated over time, they maintained their roughness index within the admissible ranges indicative of a good serviceability index.

Experimental Study of the Semicircular Bending Test for Estimating the Flexural Strength of Concrete Mixtures for Pavements

2024-05-14T16:29:33+00:00

The feasibility of using the Semicircular Bending (SCB) test to control the quality of concrete for application in pavements was investigated. Two concrete mixtures incorporating high-strength cement with specified compressive strengths of 30 MPa and 40 MPa were manufactured. The results of the SCB test were correlated with those of the flexural strength of standardized beams and the compressive strength of cylinders. A statistical analysis of the goodness of fit of all the empirical models obtained was conducted to study the degree of association between the variables. Power models were the most appropriate to relate the mechanical properties studied, with Pearson's correlation coefficients higher than 0.93. These equations can feed the database of levels 1 and 2 of the Mechanistic-Empirical (ME) design method for concrete pavements. Models with unique values that allow quick calculations with good precision were also found. The results show that the SCB test is a promising option when estimating the flexural strength of concrete for use in pavement, as well as carrying out its control and quality assurance.

Risk Management in Construction Projects in Palestine: Contractors' Perspective

2023-07-19T14:11:09+00:00

This study is conducted to identify the main risks in construction projects in Palestine from contractors’ perspective. Questionnaire survey is the tool used to achieve the objectives of the study. 41 critical risk factors in projects associated with project duration were identified and classified as external and internal factors. The risk map for the investigated causes created based on their perceived severity and frequency of occurrence. The findings revealed 29 causes in the red zone of the risk map, 11 in the yellow zone and 1 in the green zone. The top severe risk factors are: delayed payments by the owner, closure and siege by the authorities, poor site supervision, segmentation of the Palestinian governorates, late payments to subcontractors, change orders by frequent adjustments of the owner, lack of qualified labors, unrealistic completion date of projects, weather conditions, and rework due to noncompliance with contract documents.

Consequences in cost and time in construction projects due to the low level of BIM methodology use

2024-06-19T16:42:44+00:00

BIM (Building Information Modeling) methodology has established itself as an essential tool in the construction industry. Despite this, in Ecuador the implementation of BIM is lagging behind, and although there are some initiatives in private companies, its use is still limited. The purpose of this research is to identify the consequences in cost and time in construction projects due to the low level of use of BIM methodology in 30 projects of private companies in Ecuador. In order to achieve this, the BUA (BIM Use Assessment) tool was used to evaluate the level of BIM use in each project during the planning and design phases. Subsequently, cost and schedule data were collected for the evaluated projects. The results show that the main consequences of the low level of BIM usage are associated with the increase in cost and schedule. It is concluded that promoting the use of BIM is essential to improve the performance of the construction industry in Ecuador.

Improving the effectiveness of project scheduling by using Earned Value Management and Artificial Neural Network

2024-07-01T00:30:56+00:00

During construction, uncontrolled resources impact project performance. Earned Value Management (EVM) is a widespread method used for project management based on time and cost control. Advances in Information Technology (IT) provide options to improve the EVM method. The EVM is a project-level method that excludes detailing the behavior of project parameters at the level of construction operations, they are handled in aggregated economic terms over time. Thus, this work studies the improvement of EVM using IT to express the handling of operational variables. This article uses a road construction project as a case study, to evaluate three approaches (i.e., Bayesian Network (BN), Artificial Neural Network (ANN), and Hybrid EVM-ANN) as improvement options for the EVM method. It was found that the ANN provides the best improvement of EVM results. The use of ANN and project parameters improves the handling of EVM. By mayor forecast effectiveness, is expected to improve the quality and availability of data for decision making, a condition which in turn may improve agility and adaptability of the project as-built outcomes. The model EVM-ANN uses parameters that influence project implementation completion, making it easier to assess project time performance based on various conditions in the field so that the project can obtain the best strategy to ensure project completion on time.

Seismic performance of a multipurpose hall building using nonlinear static analysis

2024-05-31T23:18:42+00:00

The nonlinear static analysis method has facilitated models closer to the structural response for strong seismic movements. Therefore, an evaluation of the seismic performance of a multipurpose room building located in a public national university in Chiclayo-Peru was developed by applying nonlinear static analysis, which contains two similar modules of 3 levels each with irregular floors. The structural system of the building is made of bearing walls, it was built in 2010 and was designed according to E.030 (Peruvian earthquake resistant norm) and with the seismic microzoning of Peru. For practical purposes, taking into consideration the symmetry of the global structure, one of the modules was evaluated using nonlinear methods that can simulate the effect of earthquakes on the building using distributed loads on each of the levels. This development included the application of a linear analysis to establish the response spectra and from there implement the nonlinear Pushover analysis. With the results of the analysis, the plastic ball joints of the structural elements of the building were evaluated for both directions. Based on the results, the performance in both directions was determined taking into account the performance levels of HAZUS and VISION2000. The results show a performance of "Life safety" and "Close to collapse" in the X and Y direction respectively, in addition to that, drifts also show a close relation with performance data because HAZUS shows that Y drifts are not favorable, therefore, it is necessary to execute a reinforcement.

Evaluation of seismic performance of an educational institution using nonlinear dynamic analysis

2024-05-31T23:50:01+00:00

Currently, there are a large number of old educational institutions that are still in operation and have been built without taking into account seismic-resistant criteria. Since these buildings are considered essential, they must maintain their operability during and after a seismic stress. In this research, two two-story modules with regular floor plans belonging to an educational institution built in 1994 were analyzed, which are characterized by having a reinforced concrete portal frame system in the X direction and a confined masonry system in the Y direction. These modules were analyzed by applying the linear parameters of NTP. E.030 and nonlinear methodologies such as ADNL, where the structures were subjected to three seismic events that occurred in Peru, which were corrected, scaled and made compatible with the response spectrum by means of the Seismosignal and Seismomatch software. The ETABS software was used for the modeling and following the guidelines of ASCE 41-17 and FEMA 356, the response of the seismic records in the north-south and east-west directions was evaluated, obtaining the shear and displacement vs. time drifts and graphs. Based on the results, the seismic performance for both directions was obtained, taking into account the performance levels given by HAZUS99, determining that in the X direction it presents a performance of "Complete structural damage" and in Y of "Slight structural damage", concluding that for this type of buildings a structural reinforcement in the X direction is necessary to improve such performance.

Mechanical Response of Steel Sheets with Perforations for Composite Floor Systems with Reinforced Concrete and the Application of Emitted Magnetic Signals as an Approximate Tool for Structural Monitoring.

2024-05-31T22:37:24+00:00

Recently composite flooring systems have been widely accepted as a construction solution, due to their various constructive advantages, Among them mainly the savings during construction which results in lower costs. This calls for a continuous study to improve said flooring system. In the present research, the flexural capacity of a series of composite flooring prototypes (made of concrete plus a steel deck with a surface modification into a vented deck), helped in comparing the mechanical response (maximum load and deflection) with classical composite steel deck systems. At the same time as monitoring deflection (as the load changed), one sensor reported the surface magnetic flux at a nearby area. It was possible to see a strong correlation between larger changes in deflection and the emanated magnetic flux at the surface of the steel deck. Three stages are available to see as the test continued: i) complete elastic behavior, ii) rise in tensile demand on the steel deck, iii) loosening of the composite behavior and ultimately collapse. Mechanical results show almost no difference between those composite flooring systems made with continuous steel decks when compared to those with vented decks.

COVID-19 opportunities in construction projects: the case of Peru

2024-05-27T19:32:36+00:00

The Covid pandemic has been an unprecedented event in the construction sector, which has generated a series of impacts, for which many researchers have developed studies to identify them. However, many of these studies have focused on the negative impacts and have not focused on collecting the opportunities generated. For this reason, the following study aims to identify the opportunities generated in the medium term because of the COVID-19 pandemic in construction projects, considering the case of the Peruvian construction sector. To this end, the study begins with a literature review where the main opportunities are identified, which are validated by expert judgment. In the next stage, Peruvian professionals were surveyed; the results were processed and categorized using the RII (Relative Importance Index), and finally, the results were discussed. The main opportunities generated by COVID-19 are greater emphasis on hygiene programs, the use of remote work technology, and the acceleration of digitalization in projects. This research will help professionals in the construction sector to exploit the opportunities of disruptive events like COVID-19 that may arise in the future.