Article
Construction & Building Technology
Tara L. Cavalline, Jorge Gallegos, Reid W. Castrodale, Charles Freeman, Jerry Liner, Jody Wall
Summary: Lightweight aggregates show advantageous thermal properties in building materials like lightweight concrete, grout, mortar, and concrete masonry units. Limited data exists on the thermal properties of materials with lightweight aggregates, but this study found that lightweight aggregate building materials have the potential for significant energy savings in building energy simulations.
Article
Construction & Building Technology
Payam Shafigh, Zakaria Che Muda, Salmia Beddu, As'ad Zakaria, Zaher Almkahal
Summary: The construction industry needs to consider both the mechanical and thermal performances of structural materials for energy-efficient buildings. There are conflicting properties between normal weight concrete (NWC) and lightweight aggregate concrete (LWAC). LWAC has high thermal efficiency but low mechanical strengths, while NWC has high mechanical strength but poor thermal efficiency. The inclusion of fibres in LWAC can improve its mechanical properties, but the thermal performance is not fully understood.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Osman Gencel, Oguzhan Yavuz Bayraktar, Gokhan Kaplan, Oguz Arslan, Mehrab Nodehi, Ahmet Benli, Aliakbar Gholampour, Togay Ozbakkaloglu
Summary: This study investigates the physico-mechanical, durability, and insulation properties of foam concrete using waste glass sand as an aggregate. The results show that the addition of glass sand improves the physical and mechanical properties of foam concrete. The addition of expanded perlite increases the insulation properties. Therefore, the study suggests that sustainable insulating foam concrete can be produced using waste glass sand.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Marzena Kurpinska, Leszek Kulak, Tadeusz Miruszewski, Marcin Byczuk
Summary: The study focused on the thermal and mechanical properties of lightweight concrete, optimizing its insulation performance by varying the type and quantity of lightweight filler and other parameters.
APPLIED SCIENCES-BASEL
(2021)
Article
Construction & Building Technology
Xiao Sun, Wenyu Liao, Aditya Kumar, Kamal H. Khayat, Zhenghong Tian, Hongyan Ma
Summary: An image-based multi-level modeling method is proposed to estimate the effective bulk thermal conductivity of lightweight aggregate impregnated with phase change material. The study successfully models the microstructure of the lightweight aggregate and simulates the change in thermal behavior of PCM-LWA in concrete.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Green & Sustainable Science & Technology
Maria da Gloria Gomes, Jose Alexandre Bogas, Sofia Real, Antonio Moret Rodrigues, Rita Machete
Summary: This paper evaluates the thermal behavior of structural lightweight aggregate concrete through experimental research, finding that it has lower thermal conductivity and higher specific heat capacity compared to normal-weight concrete. The study also confirms the suitability of the transient pulse method and heat transfer method for assessing thermal conductivity and specific heat capacity.
Article
Construction & Building Technology
S. Farshad Ahmadi, Mohammad Reisi, S. Mohammad Sajadi
Summary: This experimental study compared the characteristics of Lightweight Aggregate Concrete (LAC) made with Lightweight Expanded Clay Aggregate (LECA) and foamed concrete (FC) at different densities. The results showed that the compressive strength of FC was higher than LAC at higher densities, but the opposite was seen at lower densities. Additionally, FC had higher flexural strength and water absorption, while the thermal conductivity of FC and LECA concretes were similar.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Construction & Building Technology
Yohannes L. Yaphary, Jian-Xin Lu, Bin Zhao, Hiu Wun Cheng, Peiliang Shen, Dongxing Xuan, Chi Sun Poon
Summary: The study demonstrates that cold bonded aggregate lightweight concrete units (CBA-LWCMU) have excellent properties, meeting standard requirements, and offering cost advantages and thermal conductivity benefits compared to products made with other aggregates.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Energy & Fuels
Lin Zhu, Faning Dang, Yi Xue, Weihua Ding, Kai Jiao
Summary: The addition of MPCM to lightweight aggregate concrete significantly affects its properties, with increasing MPCM content leading to higher porosity, lower density, and decreased compressive strength. The compressive strength of MPCM-LWAC increases with longer curing times, but the growth rate decreases with higher MPCM content.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Thermodynamics
Ayman Karaki, Malek Mohammad, Eyad Masad, Marwan Khraisheh
Summary: This study investigates the thermal properties of lightweight concrete (LWC) and evaluates the performance of different analytical models in predicting the effective thermal conductivity. Experimental results show that the use of expanded perlite can significantly reduce the thermal conductivity of concrete, with the Woodside & Messmer model performing well.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Construction & Building Technology
Payam Shafigh, Mohamed Ahmed Hafez, Zakaria Che Muda, Salmia Beddu, As'ad Zakaria, Zaher Almkahal
Summary: This study investigates the influence of different climatic ambient temperatures on the thermal properties of fiber-reinforced lightweight aggregate concrete (LWAC). The results show a linear dependence of thermal conductivity, specific heat, thermal diffusivity, and thermal effusivity of fiber-reinforced LWACs on the different ambient temperatures.
Article
Energy & Fuels
Domagoj Tkalcic, Bojan Milovanovic, Mergim Gasi, Marija Jelcic Rukavina, Ivana Banjad Pecur
Summary: To reduce heat transfer losses in low energy buildings, the study focuses on thermal bridges in LSF cavity insulated walls. By optimizing the design of thermal bridges and choosing suitable insulation materials, overall heat losses can be significantly reduced.
Article
Materials Science, Multidisciplinary
Peng Liu, Ao Luo, Lei Liu, Yongling Li, Sanling Zhang, Weiting Zhi, Dong Pan, Ying Chen, Zhiwu Yu
Summary: An orthogonal test was conducted to optimize the component design of aerated concrete, aiming to improve its strength, cracking resistance, and water absorption. The effects of cement content, water-binder ratio, foaming agent content, and polypropylene fiber content on the performance of aerated concrete were investigated, and the optimal composition was determined. The results showed that the dosage of foaming agent greatly influenced the dry density, compressive strength, thermal conductivity, and water absorption of aerated concrete.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Multidisciplinary
Juan Enrique Martinez-Martinez, Felipe Pedro Alvarez Rabanal, Mariano Lazaro, Mar Alonso-Martinez, Daniel Alvear, Juan Jose del Coz-Diaz
Summary: This study investigates the thermal properties of different types of structural lightweight concrete at varying temperatures and highlights the significant impact of moisture content, temperature, and porosity on these properties. The findings suggest a need to update Eurocodes 2 and 4 to better reflect the thermal properties of LWC.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Ceramics
Hayam Ahmed Mahmoud, Taher A. Tawfik, Mahmoud M. Abd El-razik, A. Serag Faried
Summary: This paper investigates the feasibility, physical and mechanical properties, thermal conductivity, and acoustic absorption of modified geopolymer concrete (GPC) with different types of lightweight aggregates (LWA). The results show that GPC exhibits high compressive strength and good sound absorption and thermal insulation properties. Among the LWAs tested, LECA is the most suitable aggregate, providing higher mechanical strength and improved acoustic absorption.
CERAMICS INTERNATIONAL
(2023)
Article
Environmental Sciences
Vitor Sousa, Jose Alexandre Bogas, Sofia Real, Ines Meireles
Summary: This study estimates the energy consumption and carbon emissions associated with a novel process for producing cement by recycling used concrete and mortars. Comparisons with traditional Portland cement production show higher energy consumption but lower carbon dioxide emissions. Optimizing the production process could potentially lead to greater benefits.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Construction & Building Technology
J. L. Parracha, A. Rita Santos, R. Lazera, I. Flores-Colen, M. Gloria Gomes, A. Moret Rodrigues
Summary: In recent years, the trend and market of thermal mortars have increased in both new and thermal retrofitting of building facades due to their enhanced thermal performance. These mortars are formulated using different lightweight aggregates to reduce density and thermal conductivity without compromising durability or mechanical performance. This study evaluates the thermophysical and mechanical performance of commercially available and experimentally designed lightweight thermal insulating mortars with different aggregates, with the aim of developing innovative and sustainable materials.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Energy & Fuels
G. R. Araujo, Henriqueta Teixeira, M. Gloria Gomes, A. Moret Rodrigues
Summary: This research focuses on the impact of different switching temperature ranges and thermochromic coating transmittance values on energy use in office rooms in different climates. The optimization results indicate that low transition temperatures of thermochromic glazings can lead to a 200% increase in electric lighting energy use, while the optimum solutions show a 15% improvement in total energy use compared to off-the-market thermochromic glazings.
Article
Construction & Building Technology
M. Pedroso, I. Flores-Colen, J. D. Silvestre, M. Gloria-Gomes, A. Hawreen, R. J. Ball
Summary: There is an increasing demand for highly efficient thermal insulating materials in buildings. This study presents a novel solution incorporating nanomaterials, such as silica aerogel, which can achieve low thermal conductivity values (below 0.030 W m-1 K-1) in renders. A key challenge of using aerogels is their low mechanical strength and high capillary water absorption. Here we describe a novel approach employing fibres which mitigates against some key properties which are decreased as a consequence of using aerogel.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Energy & Fuels
Goncalo Roque Araujo, Ricardo Gomes, Maria Gloria Gomes, Manuel Correia Guedes, Paulo Ferrao
Summary: This study integrates a baseline multi-objective optimization process with a widely used building energy simulation tool to minimize energy use and cost in a residential building complex. A surrogate model is created using machine learning and optimization techniques to accurately predict simulation results. Different metaheuristics with tuned hyperparameters are compared, and the results show significant improvements in optimization results with a decrease of up to 22% in total cost while having similar performance results and execution times up to 100 times faster.
Article
Energy & Fuels
Marco Pedroso, Maria da Gloria Gomes, Jose Dinis Silvestre, Ahmed Hawreen, Ines Flores-Colen
Summary: This study compared the hygrothermal behavior of an aerogel-based render with different fiber additions and found that the incorporation of fibers improved the hygrothermal properties, reducing capillary absorption and increasing water vapor permeability. These renderings showed a high potential for improving energy efficiency in building envelopes by up to 20% compared to conventional solutions.
Article
Polymer Science
Bruno Esteves, Pedro Aires, Umut Sen, Maria da Gloria Gomes, Raquel P. F. Guine, Idalina Domingos, Jose Ferreira, Helder Viana, Luisa P. Cruz-Lopes
Summary: The properties of particleboards made with young Paulownia trees from Portuguese plantations were studied. Single layer particleboards were produced with different processing parameters and board compositions to determine the best properties for use in dry environments. Particleboards meeting the requirements for dry environment could be produced with young Paulownia wood with a density of around 0.65 g/cm(3) and a thermal conductivity of 0.115 W/mK.
Article
Construction & Building Technology
M. Gloria Gomes, A. Tome
Summary: This paper presents a digital integrated methodology combining Terrestrial Laser Scanning (TLS), Aerial Digital Photogrammetry (ADP), and Infrared Thermography (IRT), which has shown great potential in data collection and preservation monitoring of historic structures.
DEVELOPMENTS IN THE BUILT ENVIRONMENT
(2023)
Article
Construction & Building Technology
J. H. Sousa, M. Gloria Gomes, F. Marques da Silva, A. Tome
Summary: This paper investigates various spatial functional layouts and their impact on pedestrian comfort under shell structures. Wind tunnel tests were conducted on a triangular thin shell scale model with different user area layouts, leading to conclusions that can guide future projects and contribute to a multidisciplinary understanding of these innovative structures.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Marco Pedroso, Jose Dinis Silvestre, Ines Flores-Colen, M. Gloria Gomes
Summary: This research evaluates the environmental impacts of aerogel-based fibre-enhanced thermal insulating renders and the respective multi-layered coating system for buildings' envelopes. The results show that the most critical environmental contribution is related to the raw materials incorporated in the thermal render. Even a small powder substitution by natural and synthetic fibres can have significant impacts on the environmental performance of the aerogel-based thermal render. The research concludes that these thermal renders show promising application potential from an environmental perspective and further optimization can lead to even lower impacts.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Polymer Science
Marco Pedroso, Jose Dinis Silvestre, Maria da Gloria Gomes, Ahmed Hawreen, Jessica D. Bersch, Ines Flores-Colen
Summary: This study evaluates aerogel-based fibre-enhanced thermal renders using an integrated approach, considering environmental, energy and economic factors. Optimum insulation thicknesses, cost optimization, and environmental impacts are quantified. Aerogel-based fibre-enhanced thermal renders provide significant benefits in terms of energy savings and environmental impact reduction.
Article
Chemistry, Multidisciplinary
Rogerio Duarte, Maria da Gloria Gomes, Antonio Moret Rodrigues, Fernando Pimentel
Summary: Earth-air heat exchangers (EAHX) utilize soil thermal capacity to reduce the amplitude of outdoor air temperature fluctuations. This study provides a detailed quantitative analysis of the performance of a large-diameter EAHX in standalone cooling of an office building. The results demonstrate its effectiveness in reducing CO2 emissions and energy consumption.
APPLIED SCIENCES-BASEL
(2023)
Article
Construction & Building Technology
Qi Jiang, Wei Liu, Shaopeng Wu, Xuanwen Gou
Summary: This study analyzes the erosion mechanisms of NaCl solution on asphalt concrete and finds that NaCl solution softens asphalt and promotes the intrusion of crystalline salt into it. Salt crystallization alters the surface roughness of aggregates, resulting in a decrease in skid resistance but an improvement in compressive strength. Additionally, the concentration of NaCl solution initially has no significant impact on the mechanical performance of asphalt concrete, but its domination gradually increases with the intensification of cyclic effects.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Lili Kan, Lan-qing Dai, Ning Kong, Bin Peng, Fei Wang
Summary: This paper investigates the effect of freezing and thawing cycles on the tensile behavior of cracked ultra-high performance concrete (UHPC). The results show that long-term freezing and thawing action deteriorates the cracking strength, tensile strength, tensile strain, and strain energy of cracked UHPC. On the other hand, the action of water generally favors the development of tensile properties of UHPC. The crack distribution tends to be unsaturated under freezing and thawing environment, and the re-hydration reaction is hindered. The pore structure near the crack varies under different environments.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Xin Xiao, Jingwei Li, Qingke Meng, Xiangshan Hou, Yanhui Liu, Xujiang Wang, Wenlong Wang, Shengtao Lu, Yuzhong Li, Yanpeng Mao, Tong Li
Summary: Preparing gypsum-based self-leveling mortar (GSLM) using beta-hemihydrate gypsum and solid wastes-derived sulfoaluminate cement (WSAC) can improve the mechanical performance of the mortar, but phosphorus impurities can weaken the hydration speed and degree.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Sihang Bao, Junzhen Di, Yanrong Dong, Ziqing Gao, Qing Gu, Yuanfang Zhao, Hongyu Zhai
Summary: Tailings dam break and leakage accidents pose a threat to the safety of people in mining areas and cause severe environmental pollution. This study focuses on solidifying tailing sand using microbial induced calcite precipitation (MICP) to improve strength and fix heavy metals. The curing time of MICP bio-cemented tailings is found to significantly impact the strength of tailings, while its effect on heavy metal fixation is minimal. The optimized MICP curing time is 10 days, resulting in improved strength and cementation of tailings particles.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Ferhat Benmahiddine, Fares Bennai, Achraf Charaka, Ameur El Amine Hamami, Abdelkader Tahakourt, Rafik Belarbi
Summary: This paper studied the effects of hysteresis on the hygrothermal behavior at the building scale. Through laboratory validation and numerical simulations, it was found that hysteresis has a significant impact on the relative humidity and total heat fluxes in buildings, while it does not have a noticeable effect on temperature variations.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
You Gao, Wei He, Xiayang Zhang, De'an Sun, Pei Li
Summary: This study determined the boundary line between the swelling and compression deformation zone in lateritic clay through wetting tests, and proposed a simple bimodal SWRC model. It also found that the existing strength model underestimated the tested values in the medium to high suction range, therefore a segmented strength equation was introduced for enhanced predictions of the strength properties of lateritic clay.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Prabhath Ranjan Kumar Soda, Asheer Mogal, Kalyan Chakravarthy, Nikhil Thota, Nimish Bandaru, Sanjay Kumar Shukla, K. M. Mini
Summary: This study investigates the use of encapsulated bacteria to improve the self-healing ability of concrete. Through various tests, it is found that using 20% cement-coated alginate beads (CCAB) and 5% nanosilica (NS) can achieve optimal strength and healing. This research is significant for enhancing the durability of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Shizhe Wang, Haiping Wu, Wen Yang, Wei Wang, Zhibo Zhu, Kun Nie, Luoxin Wang, Hua Wang, Jing Wu
Summary: In this study, photothermal-heat storage concrete (PHSC) was developed with excellent photothermal conversion performance and heat storage capacity. By absorbing and storing solar energy during the day and releasing it at night, PHSC can effectively reduce energy consumption in buildings.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Robin Deb, Jialuo He, Geetika Mishra, Yaghoob (Amir) Farnam
Summary: Incorporation techniques of phase change materials in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates. The results showed that ramp rates affect the nucleation and crystallization growth process during the phase transition, and the pore structure of the aggregates affects the supercooling phenomenon and confinement pressure of the PCM.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Eduardo Ferreira, Payam Sotoudeh, Dagmar Svecova
Summary: This study investigates the fatigue behavior of concrete under different stress reversal conditions. The results indicate that stress reversal generally causes more severe damage and reduces the cycles to failure compared to tensile fatigue. Additionally, adding some level of compression contributes to the energy required for failure under stress reversal fatigue. Specimens with higher concentration of fractured aggregates achieve longer fatigue lives.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Mag Raj Gehlot, Sandeep Shrivastava
Summary: This study evaluates the compatibility relationship between plaster bonds and the substrate under an accelerated aging environment, and finds that incorporating an appropriate amount of granite cutting waste can improve the strength parameters and adhesion of the cement mortar.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Min Zhang, Qirui Luo, Mingke Deng, Shixing Zhao
Summary: This study investigated the bond behavior between carbon FRCM composites with added short fibers and concrete substrates. The effects of different factors were considered and 36 specimens were tested and discussed. The experimental results were analyzed in terms of failure mode, load-slip curve, and characteristic parameters, and the contribution of weft yarns was taken into account in the developed bondslip model.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Dengkai Liu, Hongniao Chen, Ray Kai Leung Su
Summary: The susceptibility of building stones to fire and high temperature was investigated in this study by examining their physical and mechanical properties. The results show that both compressive and tensile properties of stones are affected by temperature changes. The tensile strength is particularly sensitive to temperature changes, requiring special attention to the components subjected to tensile stress in stone buildings. Principal component analysis was used to predict the mechanical properties of stones, providing a new method for calculating the residual mechanical properties after high temperature or fire.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Joso Maria Raposo, Eduardo Cavaco, Luis Costa Neves, Eduardo Julio
Summary: This paper investigates the correlation between the friction coefficient and the surface roughness of concrete-to-concrete interfaces. Experimental tests were performed on specimens with different surface treatments, and the surface roughness parameters were analyzed and correlated with the shear strength and friction coefficient. The results showed that certain roughness parameters had a strong positive correlation with the friction coefficient, while others had little or no correlation. A novel combined roughness parameter with optimized correlation was proposed.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Chiara Riccardi, Massimo Losa
Summary: The interest in using bio materials in asphalt pavements is growing due to economic reasons and environmental benefits. This study aimed to review the use of bio extenders as additives in binders, with a focus on replacements greater than 20% of fossil binder. The properties of bio-extended binders were found to vary substantially depending on the biomass source and production process.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
