Article
Construction & Building Technology
Yang Liu, Zhihua Liu, Hui Rong, Guowei Ma
Summary: This paper investigates the effect of stirring and foaming of culture medium solution and microbial solution under the same incubation conditions, as well as the factors affecting microbial foaming. It also explores the mechanical properties of foam concrete prepared by different preparation processes using a microbial foaming agent. The results show that the foaming nature of microbial foaming agents is the result of the synergistic effect of microorganisms, nutrients, and microbial metabolites. The foam concrete prepared by the prefabricated foam method exhibits better performance compared to the direct mixing method, meeting industry standards and having a uniform pore size distribution.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Li Hou, Jun Li, Zhongyuan Lu, Yunhui Niu
Summary: In the preparation of foam concrete, the interaction between foaming agent and cement plays a key role, while the property of the gas-liquid interface is the most important factor affecting the performance of foam concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Juan He, Guoyou Liu, Guochen Sang, Junhong He, Yonghua Wu
Summary: The multi-component composite foaming agent (CFA) with excellent properties was prepared by using sodium alpha-alkenyl sulfonate (AOS), sodium dodecyl sulfate (K12), coconut oil (CO), rosin liquid (RL), hydroxypropyl methylcellulose ether (HPMC), xanthan gum, and sucrose. The foam stability and its performance in an alkaline environment and slurry were studied.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Environmental Sciences
Reshmi Das, H. N. Chanakya, Lakshminarayana Rao
Summary: The study revealed that the significant source of pollution in Bellandur Lake was the entry of untreated sewage, containing surfactants. The anionic surfactant concentration in the Lake was 17 ± 3 ppm, and the surface tension remained around 50 mN/m. The presence of bacteria, with the most contributing family being Flavobacteriia, played a crucial role in stabilizing the foam.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Materials Science, Ceramics
I. C. Finhana, V. V. S. Machado, T. Santos Jr, O. H. Borges, V. R. Salvini, V. C. Pandolfelli
Summary: Liquid foams containing Al2O3 nanoparticles can be used to process macroporous refractory ceramics with higher porosity, a higher number of small pores, and lower linear shrinkage after firing at 1600 degrees C for 5 hours.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Ceramics
Jakob Konig, Rasmus R. Petersen, Niels Iversen, Yuanzheng Yue
Summary: This study investigates the use of foaming agents to foam cathode-ray-tube panel glass and explores the impact of carbon type, MnxOy, and furnace atmosphere on foaming effect and physical properties of foams. The results show that the best foaming effect is achieved with MnO2 in an oxidizing atmosphere, while oxidation of carbon is facilitated by Mn3O4 in an oxygen-free atmosphere, leading to the formation of CO and open porosity. The study demonstrates the potential for improving thermal insulation by decreasing density in closed-porous samples produced with carbon black and Mn3O4.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Food Science & Technology
Thao M. Ho, Andre Tanzil, Bhesh R. Bhandari, Nidhi Bansal
Summary: The presence of low molecular weight surfactants can interfere with milk proteins, leading to poor foam stability. This study investigated the effects of various surfactants on the foaming properties of reconstituted skim milk powders. Different surfactants with varying charges and molecular weights were tested, and their impact on foamability, foam stability, and structure was evaluated. The results showed that different surfactants had different effects on milk properties, leading to changes in foam behavior. Some surfactants decreased milk foamability, while others induced the production of large air bubbles in the foam, negatively impacting foam stability.
FOOD AND BIOPROCESS TECHNOLOGY
(2023)
Article
Chemistry, Physical
Andrew T. Tyowua, Adebukola M. Echendu, Stephen G. Yiase, Sylvester O. Adejo, Luter Leke, Emmanuel M. Mbawuaga, Bernard P. Binks
Summary: The effects of particle and molecular foaming agents in honey and water were compared. The results showed that the molecular foaming agent produced larger and more stable foam volume in honey, while the particle foaming agent exhibited better performance in water.
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
(2022)
Article
Food Science & Technology
Pascal Moll, Hanna Salminen, Elena Griesshaber, Christophe Schmitt, Jochen Weiss
Summary: High-pressure homogenization improved the foaming properties of insoluble pea proteins at pH 3 and 5. At pH 3, the homogenization disrupted large protein aggregates into smaller particles, resulting in the generation of foams. At pH 5, homogenization resulted in the formation of aggregates made of smaller protein entities, allowing insoluble pea proteins to foam.
JOURNAL OF FOOD SCIENCE
(2022)
Article
Polymer Science
Madalina Gabriela Oprica, Catalina Diana Usurelu, Adriana Nicoleta Frone, Augusta Raluca Gabor, Cristian-Andi Nicolae, Valentin Vasile, Denis Mihaela Panaitescu
Summary: This study employed an economically feasible method to produce PHBV-based foams. Thermally expandable microspheres were used as a blowing agent, while bacterial cellulose nanofibers served as a reinforcing agent and improved biocompatibility. The foams exhibited well-organized porous structures with increased water absorption capacity. The addition of thermally expandable microspheres and bacterial cellulose led to changes in thermal stability, melting temperature, and mechanical properties of the plasticized PHBV.
Article
Construction & Building Technology
Khwairakpam Selija, Indu Siva Ranjani Gandhi
Summary: This study explores the use of natural surfactants extracted from sesame seed and hingot fruit in foamed concrete production, aiming to improve the environmental impact of foam concrete. The study also investigates the effect of water-solids ratio on the characteristics of foam concrete, which has limited literature available. The results show that the performance of foam concrete varies with different foaming agents, and there is an optimum water-solids ratio for maximum strength.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Jacek Golaszewski, Barbara Klemczak, Aneta Smolana, Malgorzata Golaszewska, Grzegorz Cygan, Christoph Mankel, Ignacio Peralta, Frank Roeser, Eduardus A. B. Koenders
Summary: This study focuses on the important properties of ultra-light foam concrete as a thermal insulation material, including compressive strength and thermal conductivity. The results indicate that the density of the foam concrete, the type of foaming agent, and the binder type all have significant effects on the mentioned properties. The best thermo-mechanical properties are achieved with a combination of protein-based foaming agent, OPC, and metakaolin.
Article
Construction & Building Technology
Manjun Li, Hongyuan Fang, Chao Zhang, Mingrui Du, Fuming Wang
Summary: Two-component polyurethane with different foaming ratios was obtained by adjusting the ratio of each component and foaming in water. The polyurethane with a foaming ratio of 16 was selected as the most suitable for foaming in water and its mechanical properties were deeply studied. The results showed that the strength of polyurethane increased with density and decreased with soaking time.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Kirubajiny Pasupathy, Sayanthan Ramakrishnan, Jay Sanjayan
Summary: This study investigates the method of enhancing the foaming behavior in geopolymer foam concrete using a superplasticizer. The results show that the dosage of superplasticizer significantly affects the expansion behavior of the concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Jung H. Lee, Raymond K. M. Chu, Ruosong Li, Kermit Kwan, Chul B. Park
Summary: This study utilized the one-step batch foaming technique with supercritical carbon dioxide as a physical blowing agent to develop microcellular foams from polysulfone and polyethersulfone. The results showed that different pressure and temperature conditions led to variations in cell densities and expansion ratios of the foams produced.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Energy & Fuels
Ana Ferreira, Manuel Duarte Pinheiro, Jorge de Brito, Ricardo Mateus
Summary: This study evaluates the energy and carbon emissions of a European retail building and compares the material flow with energy and carbon emissions. The results show that the embodied energy and carbon emissions of building materials account for 32% and 94% of the total lifecycle energy and carbon emissions, respectively. By choosing low-carbon building materials, the energy and carbon emissions of the building can be reduced.
Article
Green & Sustainable Science & Technology
Ana Ferreira, Manuel Duarte Pinheiro, Jorge de Brito, Ricardo Mateus, Rita Mendonca
Summary: This study examined the cost-optimal levels of envelope solutions in retail buildings in accordance with the Energy Performance of Building Directive and Portuguese regulation. The findings suggest that solutions with lower U-values, such as vacuum insulation panels and sandwich panels, can lead to 2-5% energy savings and are cost-effective over a 15-50 year period.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Civil
Ana Ferreira, Manuel Duarte Pinheiro, Jorge de Brito, Ricardo Mateus, Vitor Sousa
Summary: This study provides water intensity indicators for retail buildings and finds that variables such as number of workers, store size, location, and sales revenue have a statistical influence on water intensity indicators.
WATER RESOURCES MANAGEMENT
(2023)
Article
Chemistry, Physical
Antonio Galderisi, Miguel Bravo, Gianluca Iezzi, Giuseppe Cruciani, Eleonora Paris, Jorge de Brito
Summary: In this study, construction and demolition waste (CDW) from earthquake rubbles were utilized as recycled aggregates (RA) in cementitious binders. The amount of crystalline phases in each RA type was determined using X-ray Powder Diffraction (XRPD) analysis. It was found that recycled mortars rich in concrete, natural stones, and tiles exhibited better mechanical performance compared to those prepared with recycled bricks, perforated bricks, and roof tiles. Furthermore, the use of a mixture of recycled aggregates and quartz-rich virgin aggregates in mortars resulted in superior mechanical characteristics.
Article
Chemistry, Physical
Ghandy Lamaa, David Suescum-Morales, Antonio P. C. Duarte, Rui Vasco Silva, Jorge de Brito
Summary: Three industrial aluminosilicate wastes were studied as precursors for alkali-activated concrete. Different combinations of sodium hydroxide and sodium silicate solutions were tried to find the optimum solution for mechanical performance. The precursors showed reactivity when alkali-activated, and mixes with slag and glass exhibited compressive strengths of almost 40 MPa.
Article
Chemistry, Physical
Lucas Sequeira, Javier Forero, Miguel Bravo, Luis Evangelista, Jorge de Brito
Summary: The durability performance of sustainable concrete with the incorporation of reactive magnesium oxide (MgO) and fly ash (FA) was evaluated. The partial replacement of cement with these two materials resulted in significant reduction of shrinkage and offers sustainability benefits. Both individual incorporation of MgO and FA, and their simultaneous incorporation were evaluated. Performance losses between 3% and 95% were obtained in all tests, however, the difference in performance relative to reference concrete tends to decrease over time.
Review
Chemistry, Physical
Ghandy Lamaa, Antonio P. C. Duarte, Rui Vasco Silva, Jorge de Brito
Summary: This paper presents a literature review on the effects of accelerated carbonation on alkali-activated materials. It provides a better understanding of the influence of CO2 curing on the chemical and physical properties of alkali-activated binders. The changes in chemistry, mineralogy, and physical properties caused by induced carbonation are discussed, along with the influence of this curing method on the strength development of alkali-activated materials.
Article
Chemistry, Physical
Lucas Sequeira, Blas Cantero, Miguel Bravo, Jorge de Brito, Cesar Medina
Summary: In the construction industry, cement is the most widely used material. To improve sustainability, it is important to find more sustainable alternatives for cement. This study analyzes the mechanical properties of mortars containing recycled cement, fly ash, and magnesium oxide. The results show that ternary mortars with these materials have improved mechanical capacity compared to binary mortars.
Article
Construction & Building Technology
Filipe Miguel, Jorge de Brito, Rui Vasco Silva
Summary: The increasing demand for sustainability in construction has led to interest in using recycled materials in concrete production. This study aims to evaluate the performance of alkali activated concrete with different contents of fly ash (FA) and municipal solid waste incinerator bottom ash (MIBA). Tests were conducted on various mixes including natural aggregates and recycled aggregates from construction and demolition waste. The results showed that substituting FA with MIBA negatively affected durability-related performance, while the incorporation of recycled aggregates significantly decreased compressive strength and overall durability performance. However, the use of recycled aggregates resulted in less dimensional variation in terms of shrinkage.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Qifan Ren, Joao Pacheco, Jorge de Brito
Summary: This paper proposes refined formulae to consider the wall effects in the geometric mesostructure modelling of concrete. The calibration of the wall effect in geometric modelling has been rarely researched. The proposed formulae are calibrated and validated using measurements on real specimens, and a demonstrative application shows good agreement with experimental data.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
M. I. Romero-Gomez, R. V. Silva, I. Flores-Colen, J. de Brito
Summary: This study characterizes the residual physico-mechanical performance of gypsums with polypropylene and nylon plastic waste after exposure to high temperatures. Measurements of bulk density, ultrasonic pulse velocity, young's modulus, mechanical strength, fire reaction performance, and toxicity assessment were conducted. The results show that the residual properties are influenced more by reactions in the gypsum matrix than by the plastic waste content, and the plastic-containing composites can be classified as A2 non-combustible material.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Geological
Sohrab Sharifi, Renato Macciotta, Michael Hendry, Drew Rotheram-Clarke, David Huntley
Summary: Interferometric synthetic aperture radar (InSAR) has gained considerable attention as a landslide monitoring strategy due to its high accuracy, wide coverage, and relatively low costs. This study investigated four renowned topography-based methods in evaluating the magnitude and geometry of total velocity vectors. The results showed that the Aspect Parallel Flow Model (APFM) provided the lowest magnitude error compared to other methods, while the Surface Parallel Flow Model (SPFM) and Steepest Terrain Following Model (STFM) were sensitive to LOS variance.
Article
Materials Science, Multidisciplinary
Tian Li, Rita Nogueira, Jorge de Brito, Jiaping Liu
Summary: This study investigates the influence of fine aggregate's grading on mortar's rheology. The non-uniformity coefficient (Cu) and the coefficient of curvature (Cc) were used to quantitatively evaluate the fine aggregate's grading. The results show that Cu provides a good quantitative description of the fine aggregate's grading and presents a good correlation with its packing density. The study suggests that for a packing density higher than a critical value (0.7391), improving the rheology of mortar may be more effective by acting on aspects other than the fine aggregate's grading.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Review
Construction & Building Technology
Joana Barrelas, Ana Silva, Jorge de Brito, Antonio Tadeu
Summary: Climate change could significantly impact buildings if not recognized properly. Consideration of climate action at the planning stage is crucial to promote durability of constructions. Portugal, as part of the Mediterranean region, is vulnerable to climate change impacts, such as higher temperatures and decreased precipitation. The research focuses on assessing the risks of climate-induced degradation on exterior cement renders.
Article
Environmental Sciences
Ana Ferreira, Vitor Sousa, Manuel Pinheiro, Ines Meireles, Cristina Matos Silva, Jorge Brito, Ricardo Mateus
Summary: This study explores the technical and economic feasibility of rainwater harvesting systems as an alternative water source for a retail store in southern Portugal. The simulation shows that the system can save 32-36% of water consumption, resulting in a financial gain of 330-372 euros per month.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(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)