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

Urbanization and modern development of expanding infrastructure have resulted in large construction activities. With the expeditious growth in the construction industry, the rate of demolition has also increased. This is causing considerable increase in Construction and Demolition (C&D) waste all around the globe. To minimize its impact on society and environment, preventive measures are required to be taken on urgent basis, and for this reason construction industry has proposed the use of recycle concrete aggregates in different applications and there is dire need to investigate experimentally the properties of concrete products made using Recycled Aggregate Concrete (RAC). In this regard, this study focused to investigate the mechanical properties of 100% RAC bricks prepared with two different compositions with respect to coarse to fine aggregates ratio (i.e., 70:30 and 60:40), cement dosage (i.e., 10% and 15% by weight of total aggregates) and casting pressure (i.e., 25 MPa and 35 MPa). Recycled concrete aggregates required for this study were produced by crushing tested concrete samples having compressive strength of 21 MPa to 28 MPa. Mechanical tests were performed on bricks to determine their compressive strength, flexural strength, shear strength, impact energy in compression and flexure. In addition to these destructive tests, non-destructive (rebound hammer and ultra-sonic pulse velocity) tests were also performed. To draft a comparison, Natural Aggregate Concrete (NAC) bricks and first class burnt clay bricks were also tested. The results indicated that the compressive strength of NAC bricks was about 30% higher than the compressive strength of RAC bricks. However, RAC bricks exhibited higher compressive strength as compared to burnt-clay bricks. The flexural strength of RAC bricks containing 60% coarse aggregates and 40% fine aggregates and RAC bricks containing 70% coarse aggregates and 30% fine aggregates was found to be almost similar but their flexure strength was 37.3% and 20.7% lesser than their corresponding NAC bricks. Flexure strength of RAC bricks and burnt clay bricks was found to be almost same. Qualitative assessment by ultrasonic pulse velocity (UPV) tests showed that the NAC and RAC bricks were of good quality as per the standard criteria. The findings of this study indicated that RAC bricks satisfied the strength requirements as stated by local and international standards. Further, RAC bricks performed better than commonly used first class burnt clay bricks. Production and use of RAC bricks in masonry structures will not only help to conserve the depleting resources of natural aggregates and clay but also help to protect our environment from pollution by reducing CO2 emission caused by the coal-burning as fuel in kilns for the manufacturing of burnt-clay bricks.

While Fibre-Reinforced Plastics are lightweight, show a high tensile strength, and have no issue with corrosion, they are unfortunately brittle and perform poorly against temperature. Therefore, it is important to know the time and magnitude of the temperature reaching the bars in the high-temperature effect of FRPs produced in the form of bar in reinforced concrete structural elements in concrete. This study set out to examine the time and temperature values of glass fiber reinforced polymer (GFRP) reinforced concrete under high-temperatures. The effects of concrete cover thickness and concrete strength on temperature transfer were researched experimentally. GFRP bars were placed in specimens prepared in three concrete strengths and three different concrete cover thicknesses (20-40-60 mm) exposed to temperature, and temperature-time graphs were created by measuring bar temperature, concrete surface temperature and ambient temperature. The critical time to a glass transition temperature, and optimum cover thickness of GFRPs according to concrete strength and concrete cover thickness were discussed. The study results appeared to indicate that the thickness of the concrete cover is very effective in protecting the bar against temperature in reinforced concrete structural elements, as concrete strength, itself, has only a limited effect.

Today, environmental health needs more attention than in the past. Objects consisting of plastic materials such as bottles take many years to decompose. Therefore, in the recent years, a lot of research has been done to reuse them and one of which is use in the concrete mixes. In previous research, very low percentages of these materials (between 0.5% and 1.5%) has been used as fine aggregate substitutes in the concrete and evaluations have more focused on the flexural strength. In this research, Polyethylene terephthalate (PET) as a substitute for sand and Polypropylene fibers (PP) as an additive material are used in the concrete mixes. 14 concrete beams in both reinforced and unreinforced states have been evaluated. The replacement percentage of the PET is 10, 30 and 60% and additive percentage of the PP is 0.5, 1.5 and 3% of the total weight of concrete. The dimensions of the beams have been chosen in such a way to categorized in the deep beams. So, rectangular cross-section has been considered (width = 100mm and height = 400mm). Shear strength and ductility are two important parameters that have been evaluated in this research.

This study employs rice husk ash and pozzolan cement as additional soil stabilization materials. This study aims to evaluate the bearing capacity of the soil to be used as embankment soil for subgrade pavement materials. The soil samples were collected from two different areas in the Yogyakarta region, Indonesia, namely the Wates and Imogiri regions. This study consists of experimental approach that defines a soil embankment for road subgrade with a trapezoid-shaped with top dimension of 10 cm x 20 cm, a base dimension of (20 cm x 40 cm), and a height of 10 cm. In addition, the specimens in this study were divided into two groups: the embankment with a 1 cm-thick sand base and the embankment without a sand base. The USCS classified the samples from Wates as OH-type or organic clays with moderate to high plasticity and by AASTHO as group of A-7-5 (22). The soil from Imogiri was categorized as inorganic silt or fine diatoms sand with OH clumps or AASTHO classified this soil as group A-7-5 (11). The addition of rice husk ash and pozzolan cement as stabilizing soil materials has a moderate effect on the engineering properties of the soil, particularly the bearing capacity and bearing capacity ratio of soil. This soil stabilization also demonstrates that the engineering properties of the stabilized soil significantly improved compared to the original soil without stabilization.

In this work, aspects related to academic, organizational and social issues from engineering students are exhibited in order to evaluate the virtuality influence on their higher studies. In particular, a questionnaire was carried out using a random sample of 102 argentinian engineering students. This tool allowed collecting data related to accessibility, socioeconomic context and academic performance. It was observed that students found the virtual courses unfavorable, in spite of their academic performance. In addition, the inclusion of students is less privileged in this situation, which requires immediate actions by the university community.

This paper represents a theoretical and statistical review of the current state of Mexican psychology researchers who belong to the National System of Researchers (SNI). Data for the investigation were obtained from databases provided by CONACYT. Our goal is to characterize and make visible the scientific production of these researchers. To achieve our purpose, the review and description of these researchers was established through variables such as: sex, level to which they belong, institution of belonging, research area, number of published articles, Mexico geographical distribution, Mexican psychology journals where they publish and -in general- the used media to communicate their results both nationally and internationally.  

Although Chile reports an increase in its coverage in higher education, expansion is limited by student social origin. Seeking equity and inclusion, the educational reform has promoted improvements in the centralized admission process. Thus, this essay seeks to analyze the Ranking and the information system as one of the possibilities and challenges of equity and inclusion in the Chilean reform. The analysis shows that the prioritization of university selection tests and the lack of coordination of the system represent challenges that urgently be faced to promote an inclusive paradigm, especially for students who are doubly excluded.

This study answers a question about how young people who try to enter public education and are not admitted configured their personal and educational trajectories. Through processes of young people journeys trajectories studies, trying to enter public universities in two national contexts are contrasted, that is, Nuevo León, Mexico and Havana, Cuba. In both cases, it is possible to recognize that youth trajectories are transverse by conditions of the educational systems, restrictions relative to university institutions, access policies, and personal and family resources.

This article presents the results of a case study of the Universidad Intercultural del Estado de México (UIEM), pioneer of the 12 Indigenous-serving institutions created by the Mexican government starting in 2003. Through interviews with graduates and program coordinators, the article seeks to answer the following question: To what degree do the intercultural universities break with the coloniality of power, being and knowledge? The article concludes that the epistemic frictions and contradictions between the intercultural utopia and institutional practice limit the university´s transformative potential, with implications for the intercultural system as a whole.

The Covid-19 pandemic has caused several problems and effects on higher education in Latin America and the Caribbean. Given this, the work objective is to reflect on the themes, effects, and challenges that the current health conjuncture has left for the debate on higher education in this region. The study is a critical reflection based on a literature analysis. Ten topics are identified to analyze Latin American universities and some challenges arising in this context are reflected. It is concluded that, being on an exploratory level, the research gives rise to a new research agenda.