Article
Construction & Building Technology
Hongwei Tian, Dietmar Stephan, Christian Lehmann
Summary: Solar thermal energy is a technology that utilizes radiant energy from the sun to generate heat or electricity. Thermal energy storage is crucial to compensate for the fluctuations in solar thermal energy output over time, and hot water tanks are commonly used for this purpose. Ultrahigh-performance concrete (UHPC) is employed in constructing such tanks for applications at high temperatures. This study examines the mechanical strength and microstructure of UHPC after long-term temperature-pressure load (autoclaving). The compressive strength of UHPC remains strong due to accelerated hydration, while flexural strength is affected by the transformation of amorphous calcium silicate hydrate (C-S-H) to more ordered phases. Autoclaved samples exhibit poorly crystallized C-S-H, hydroxylellestadite, and hydrogarnet. Porosity does not have a significant impact on mechanical strength compared to the influence of hydrate assemblage after long-term autoclaving. Partial replacement of cement with limestone powder enhances the mechanical strength by densifying the microstructure and increasing poorly crystallized C-S-H. However, excessive poorly crystallized C-S-H can lead to reduced strength due to thermal mismatch between the matrix and quartz aggregates after cooling. Thus, an appropriate addition of limestone powder is essential to ensure durable UHPC structures under autoclaving conditions.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Yuanbo Du, Wencui Yang, Yong Ge, Sha Wang, Penghuan Liu
Summary: The study found that adding metakaolin increased thermal conductivity in cement paste, while adding waste glass powder and limestone filler decreased thermal conductivity. Cement paste containing metakaolin exhibited lower porosity and higher compressive and flexural strength.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Construction & Building Technology
Binbin Zhang, Tao Ji, Yu Ma, Qilin Zhang
Summary: The effect of metakaolin (MK) and magnesium oxide (MgO) on the flexural strength of ultra-high performance concrete (UHPC) was studied. Results showed that an appropriate replacement of MK and MgO can enhance the flexural strength of UHPC, while excessive replacement has a negative effect.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Construction & Building Technology
Soner Guler, Zehra Funda Akbulut
Summary: This study compares the changes in mass loss, relative dynamic modulus of elasticity (RDME), residual compressive strength (RCS), residual flexural strength (RFS), and residual flexural toughness (RFT) of 3D, 4D and 5D steel fiber-reinforced concrete (SFRC) specimens after freeze-thaw (F-T) cycles. The results show that steel fibers do not affect mass loss of concrete after F-T cycles, but SFRC samples have higher RDME, RCS, RFS, and RFT values than control concrete. Furthermore, 5D steel fibers are more effective in improving the residual strength and toughness capacity of concrete after F-T cycles due to their stronger fiber/matrix interface.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Maryam Hojati, Ali M. Memari, Mehrzad Zahabi, Zhengyu Wu, Zhanzhao Li, Keunhyoung Park, Shadi Nazarian, Jose P. Duarte
Summary: This study proposes the use of barbed wires as a reinforcing component in 3D-printed concrete to improve its mechanical performance, especially moment capacity and bond strengths. The twisting of wires and the unique geometry of the 4-point barbs contribute to the enhancement of mechanical properties in 3D-printed concrete reinforcement.
AUTOMATION IN CONSTRUCTION
(2022)
Article
Construction & Building Technology
Maryam Hojati, Ali M. Memari, Mehrzad Zahabi, Zhengyu Wu, Zhanzhao Li, Keunhyoung Park, Shadi Nazarian, Jose P. Duarte
Summary: This study proposes a new reinforcement method for 3D-printed concrete, using barbed wires with sharp thorn-like projections, which successfully improves the mechanical performance. This method allows for in-process reinforcement during 3D printing and has the potential for further automation.
AUTOMATION IN CONSTRUCTION
(2022)
Article
Construction & Building Technology
Khaldoun N. Rahal, Walid Hassan
Summary: The study found that concrete made with recycled aggregates had lower shear and compressive strengths compared to natural aggregates concrete with similar water to cementitious materials ratios. However, the relationship between push-off shear strength and cube compressive strength was similar for both types of aggregates. Lower water to cementitious materials ratios resulted in smoother failure surfaces, while the use of recycled aggregates slightly affected the failure surfaces. Additionally, a relationship between tensile cracking strength and push-off shear strength for concrete specimens was established.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Polymer Science
Baek-Il Bae, Hyun-Ki Choi
Summary: This paper investigates the structural performance of lap-spliced beams and the effect of steel fiber inclusion in ultra-high-performance fiber-reinforced concrete (UHPFRC). The results show that steel fiber significantly increases the strength of lap-spliced beams and using a hybrid-type UHPFRC with lower steel fiber volume fraction can improve bond strength. The study also validates lap splice length design methods, finding that most design equations underestimate the bond stress of UHPFRC.
Article
Chemistry, Physical
Moses Karakouzian, Visar Farhangi, Marzieh Ramezani Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh
Summary: This research investigated the combined effect of nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on the compressive and flexural strengths of cement paste. The study found that the combined utilization of silica and carbon nanomaterials did not necessarily result in the maximum strengths, and using higher percentages of pristine NS without MWCNT could further enhance the strength properties of the cement paste.
Article
Green & Sustainable Science & Technology
Pang Chen, Zhaoyue Shi, Shaojun Cao, Ping Liu, Xian Rong, Lida Wang
Summary: This study investigated the mechanical properties of alkali-activated slag lightweight aggregate concrete (AAS-LWAC) and analyzed the effects of lightweight aggregate and fiber materials on its performance.
JOURNAL OF CLEANER PRODUCTION
(2022)
Review
Construction & Building Technology
Jie Li, Jun Xia, Luigi Di Sarno, Guobin Gong
Summary: This review focuses on the manufacturing methods and performance optimization of fiber-reinforced pervious concrete (FPC), including mix design, mixing procedures, compaction techniques, and curing methods. By analyzing the available research data, recommendations for optimizing fiber usage in PC are provided, and the effects of different fiber types on PC performance are summarized.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Yi Zhang, Hui Li, Ahmed Abdelhady, Jie Yang, Hanbing Wang
Summary: The study investigated the influence of size and shape on the permeability and mechanical properties of porous concrete. The results showed that factors such as porosity, aggregate size, aggregate type, and cement grade could affect the strength of porous concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Vikas Mehta
Summary: The utilization of industrial waste and byproducts as alternatives to removal has become attractive due to landfill scarcity and high disposal costs. This research aims to develop systematic multiscale models to predict the compressive, tensile, and flexural strengths of concrete containing waste foundry sand (WFS) without theoretical constraints. Artificial neural networks (ANN) are found to be the most efficient model for predicting the strengths of concrete with WFS.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Yunshi Pan, Yaowen Zhang, Shuangxin Li
Summary: The study explores the combined application of microwaving curing and RPC, finding that isothermal microwave curing can effectively improve the mechanical properties of concrete and is more energy efficient and easier to control compared to nonisothermal curing.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
P. K. Akarsh, Shriram Marathe, Arun Kumar Bhat
Summary: This study investigates the use of graphene oxide in high strength concrete containing silica fume. The results show that a concrete mix with 7% SF and 0.15% GO can achieve high compressive strength and flexural strength, indicating the effectiveness of GO-based concretes in pavement quality concrete applications.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
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)