Carlos Javier Rojas

Mr. Carlos Javier Rojas

Universidad Autónoma de Chile, Temuco, Araucanía, Chile
+3
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2019 in Sustainable Materials and Technologies
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Journal Article
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Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
MCMara Cea
Mara Cea
AIAlfredo Iriarte
Alfredo Iriarte
GVGonzalo Valdés
Gonzalo Valdés
RNRodrigo Navia
Rodrigo Navia
Juan Pablo Cárdenas-RamírezJuan Pablo Cárdenas-Ramírez
Juan Pablo Cárdenas-Ramírez

22 May 2023 in Sustainability
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GRGuisel Del Carmen Romero
Guisel Del Carmen Romero
Matías SotoMatías Soto
Matías Soto
Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
KNKarin Rosario Rodriguez Neira
Karin Rosario Rodriguez Neira
Juan Pablo Cárdenas-RamírezJuan Pablo Cárdenas-Ramírez
Juan Pablo Cárdenas-Ramírez
The construction industry faces a significant challenge in addressing both the housing crisis and climate change. To mitigate this challenge, there has been a push toward the incorporation of industrialization in the construction process to improve product quality, reduce execution times, and lower production costs. However, it is also crucial to implement materials with sustainable characteristics to decrease the environmental impact of housing. In light of this, the present study analyzes the environmental and economic impacts through the development(design) of a modular construction system using materials with low environmental impact. Specifically, the structural components of the system are constructed using plywood boards, thermal insulation is provided by wheat straw, and the interior finish is made of clay plaster. The Skylark 250 model served as the chassis for the structure, with the wheat straw being applied through a blowing process and the clay plaster applied manually. Thermal transmittance, energy demand, environmental impact, and economic analysis were all evaluated for this solution. The study results yielded a modular housing solution with an energy demand of 55 (kWh/m2/year), which, when paired with photovoltaic panels, meets the Net Zero challenge. In terms of construction time, the proposed system requires 44% less time than traditional construction methods and is 29% less expensive economically, making it an attractive option for the housing market.

21 December 2022 in Sustainability
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Matías SotoMatías Soto
Matías Soto
Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
Juan Pablo Cárdenas-RamírezJuan Pablo Cárdenas-Ramírez
Juan Pablo Cárdenas-Ramírez
The thermal envelope is a key component of a building’s energy efficiency. Therefore, considerable efforts have been made to develop thermal insulating materials with a better performance than the existing products. However, in the current climate change scenario, these materials must be sustainable, principally during their production stage. In this context, the use of recycled raw materials and agro-industrial waste can be the basis of a material with a low environmental impact and a good thermal performance. In this study, cellulose and wheat straw were characterized. Then, they were mixed in different proportions and densities and the best thermal behavior was selected. The materials were chemically analyzed by TAPPI 2007, thermogravimetric and infrared spectroscopy, together with the measurement of their thermal conductivity with a thermal property analyzer based on the transient line heat source method. The results show that both raw materials are chemically similar to each other. When mixed, they have a thermal conductivity ranging from 0.031 to 0.036 (W/mK), being comparable with several conventional thermal insulators. On the other hand, to achieve the commercial use of this material, an installation through a blowing process has been proposed and proves to be highly promising, achieving a proper density and efficiency in its application.
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8 June 2024 in Buildings
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KNKarin Rosario Rodriguez Neira
Karin Rosario Rodriguez Neira
Juan Pablo Cárdenas-RamírezJuan Pablo Cárdenas-Ramírez
Juan Pablo Cárdenas-Ramírez
Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
Laia HaurieLaia Haurie
Laia Haurie
ALAna Maria Maria Lacasta Lacasta
Ana Maria Maria Lacasta Lacasta
AGAna Gutiérrez
Ana Gutiérrez
Developing environmentally friendly building materials with low environmental impacts is receiving more attention nowadays to face the global challenges of climate change; building insulation materials made from agricultural waste can be used for their low environmental impact and to generate responsible supplies that utilize natural resources adequately. The study aims to assess a panel made from rice husk using the pulping method. An experimental design established the proportion of rice husk, the percentage of additive (NaOH concentration), boiling time and blending time. Taguchi’s method was applied to investigate the effect on density and thermal conductivity; the final panel with optimum conditions was morphologically analyzed using scanning electron microscopy (SEM); the thermal behavior was studied by thermogravimetric analysis (TGA); fire reaction and smoldering behavior were analyzed; and characterization in water absorption and acoustic absorption performances were established. The results show thermal conductivity values between 0.037 and 0.042 W/mK, a smoldering velocity of 3.40 mm/min, and a good acoustic absorption coefficient in octave frequency bands between 125 Hz and 4 kHz greater than 0.7. These characteristics are competitive with other insulating bio-based materials available on the market. This study employed chemicals utilized by other biomaterials for the pulping process and in flame retardants. However, it is important to investigate natural treatments or those with a diminished environmental impact.

21 February 2025 in Applied Sciences
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Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
Aner Martinez-SotoAner Martinez-Soto
Aner Martinez-Soto
CAConstanza Avendaño-Vera
Constanza Avendaño-Vera
RCRodrigo Cancino
Rodrigo Cancino
NRNatalia Andrea Reyes
Natalia Andrea Reyes
In the scientific literature, it is highlighted that industrialized construction has significant comparative advantages over traditional construction, primarily in four indicators: (i) cost reduction, (ii) time reduction, (iii) increased energy performance, and (iv) reduced environmental impacts. However, there is no certainty about the range of variation of these indicators for these comparative advantages, creating uncertainty about the real impact of industrialized construction. In this work, through a systematic literature review based on PRISMA, 90 articles that met the selection criteria related to the four mentioned indicators were selected and analyzed. The results show that industrialized construction has comparative advantages over traditional construction but with a wide spectrum of variation in each of the indicators. In the cost indicator, reductions between 7% and 50% and increases between 26% and 72% are observed; in time, reductions between 9% and 50% and increases up to 32% are recorded, and reductions in energy demand between 20% and 90% are also reported. For the environmental indicators, data were only provided for projects in the design stage or for construction solutions on a scale, demonstrating the need to obtain indicators in the operational stage. It is concluded that although industrialized construction offers significant advantages, it is essential that new construction solutions consider contextual variations, initial investment, logistical challenges, and specialized labor to maximize their benefits.

5 April 2024 in Journal of Building Engineering
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Journal Article
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Carlos Javier RojasCarlos Javier Rojas
Carlos Javier Rojas
Aner Martinez-SotoAner Martinez-Soto
Aner Martinez-Soto
CAConstanza Avendaño-Vera
Constanza Avendaño-Vera
JCJuan Pablo Cárdenas-R
Juan Pablo Cárdenas-R