Abstract

The objective of this study was to evaluate the effect of six different types of treatment on mosso bamboo biomass (Phyllostachys pubescens) in order to verify its compatibility with Portland cement. The treatments adopted for mosso bamboo were: immersion in different solutions as to know: cold water, hot water, sodium hydroxide, sodium silicate, silane and calcium chloride. The degree of compatibility was determined through the study of the hydration heat rates in the first 24 hours and the compressive strength after 7 days of the bamboo-cement composites. The influence of the crystallinity of the fibers was analyzed using X-Ray Diffractometry. Results indicated that the addition of 4% calcium chloride to the blend is the most efficient treatment to decrease the species inhibitory capacity, while treating the raw material with sodium hydroxide adversely affected to the binder. The treatment with cold water presented the highest composite compressive strength and the treatment with silane presented the highest fiber crystallinity index.

Abstract

The world has developed different methodologies for the design of asphalt mixtures; each of which is intended to optimise and find the optimal combination of materials that allow them to be resistant under specific travel, climate and structural support conditions. This article presents the results of an investigation which utilised coal tar as a binding agent for road surface mixtures and carried out a comparison of results of the physical and mechanical properties of sample bituminous mixtures produced by two distinct methodologies, Marshall and Ramcodes. Finally, an analysis was carried out on the suitability of tar as a binding agent and on utilising the Ramcodes methodology when designing mixtures.

Abstract

The traffic flux is a complex phenomenon in which the dynamic behavior is generally badly defined, indeed all laws and models reflect from idealizations and empirical approximations. For this reason we develop in this paper a methodological approach for a macroscopic modeling of the traffic. The approach is based on the probabilistic aspect of the phenomenon, with the method exploitation, the base data and Agbartchenkov works results, in order to describe the basic phenomena caused by traffic. The major interest is the description of such system using a probabilistic model, which links all the factors influencing the highway traffic and the safety of the bridges, limiting speeds, density and the minimum distance between two moving objects of road traffic on a bridge.

Abstract

This study aimed to characterize and evaluate the performance of the Amazonian plant fiber curaua (Ananas erectifolius) as reinforcement in the cementitious composite panels’ production process. For the production of these panels were determined extractives content and bulk density of the fibers. The panels were produced with curaua fibers, varying the contents (5%, 10% and 20%). Also, as a methodology, vegetable fibers were treated through immersion in cold water for 24 hours, immersion in hot water for 6 hours, and finally immersed in NaOH solution for 2 hours at a concentration of 1%. The panels were manufactured in the dimensions of 500x500x15 mm, a nominal bulk density of 1.60 g/cm³ and kept under pressure (4 MPa) for 24 hours. After pressing the panels were conditioned for 28 days for cement cure. As a result, it was observed that the incorporation of 10% curaua fibers is possible as reinforcement in the cementitious matrix, in the manufacture of wood-concrete panels. It was also found that the chemical treatment of the fibers provided the improvement in the physical properties of the composites.

Abstract

Concrete is the most used building material worldwide, involving thousands of field, academic and laboratory professionals in its production, transportation and its application, which creates a great margin of possible error that may yield in a poor quality concrete. Each professional takes care of the concrete quality according to his/her experience or academic knowledge/expertise. In order to analyze the factors that concrete workers in Barranquilla (Colombia) perceive as the most important for achieving a high-quality concrete, a survey was made to both academic and field experts with different years of experience and analytic hierarchy process (AHP) was applied to weigh the perception of each factor in the concrete quality. Results have shown that for the survey respondents one of the most important factors is the environment; this may be associated with geographic location of the city, which is in a coastal region.

Abstract

Green building construction has experienced significant growth in the recent decades and Peru is not the exception because actually several of the prime office buildings have or are pursuing any green building certification. However, the higher initial costs affect its continuity and growth speed. Researchers have studied the tools and techniques for cost containment and their application had effective use in the construction process. The aim of this study was to suggest a specific tool or technique for traditional constructions that can benefit and enhance the cost containment of green buildings. The findings from this study show the impact and applicability of collaborative working in design and construction as a management tool, through a survey among construction professionals in regards cost containment for green buildings. These results could encourage the green buildings construction growth in this country, through the appliance of this tool.

 

Abstract

Water hammer in pipe networks is a subject little discussed in the technical literature. This may be due to the belief that the network shape helps to reduce its impact, since the pressure waves would tend to subdivide as they propagate through the system pipes. In this article the water hammer is analysed in a pipe network due to the closure of a valve modelled how if it were of type butterfly, gate circular, gate square, ball, needle and globe. It is concluded that the extreme pressure values depend on the type of valve which it is being closed, and that the network shape is not a relevant factor that it helps to attenuate the transient pressures.

Abstract

Context: The use of solar energy, rather than an alternative, is the viable solution to the energy demands of our planet for sustainable development. Given the population increase and the quality of life at a global scale, it is very reasonable to forecast an increase in global energy demand. In this context, solar cooling systems are a viable and timely strategy to follow.
Methods: This work offers a state of the art on the different methods of obtaining solar cold. The review is generated by using the tools offered by the Scopus directory and using the VOSviewer bibliometric analysis software.
Results: Solar thermal cooling in buildings is shown as a trend within these energy practices, followed by photovoltaic solar cooling. Today, the United States of America, Italy, and China are the nations that lead this field. The most fertile research areas in this subject matter are engineering, energy and materials science.
Conclusions: The next few years will be decisive for the development of solar cooling technologies since they depend on the incentives and promotion plans offered by those responsible for formulating environmental and energy efficiency policies for buildings.

Abstract

Currently, construction companies have shown a need to adopt process improvement systems in order to function competitively in the market. However, civil construction, compared to the manufacturing, still has deficiencies relating to the incorporation of new improvement systems. Thus, the use of Kaizen Events (KE) is one of the main mechanisms used to perfect processes during the production (execution) phase of a product, ensuring enhanced performance and added value to the client. The present research sought to evaluate a method for adopting KE in the construction sector. The data-gathering tools used were a questionnaire and a focus group where academics and/or experts who fit a specific profile participated. A methodological strategy for the development of the work was adopted under the approach of Design Science Research (DSR) and the theoretical referential was developed from a Systematic Literature Review (SLR). Improvements were made to the method to improve its applicability and functionality in real life scenarios using the results obtained. Accordingly, the results show horizons for future research on KE in civil construction.