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Researchers in Changsha, China, have explored the potential of recycling single-use surgical face mask waste for reinforcing cement-treated and untreated dredged marine sediments in road construction. The study found that incorporating mask fiber into the sediments significantly improved compression and tensile strength, while also enhancing ductility and residual strength. The research suggests that this innovative approach could offer an environmentally friendly and cost-effective solution for road construction materials. The study was funded by the National Natural Science Foundation of China and the Natural Science Foundation of Hunan Province and has been peer-reviewed. [Extracted from the article]

A recent study conducted by researchers at Chongqing Jiaotong University in China explores the bonding behavior between ultra-high performance concrete (UHPC) and normal concrete (NC) in building and construction. The study examines various experimental methods, including direct characterization techniques such as tensile, shear, and compressive tests, as well as indirect techniques like X-ray computed tomography (XCT), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). The results indicate that tensile tests are effective in assessing interface roughness and moisture variation, while techniques like XCT offer visual insights into the internal characteristics of the bonding interface. The study provides valuable recommendations for experimental characterization methods to improve the repair of concrete structures. [Extracted from the article]

A study conducted by researchers at Wuhan University of Technology in China explored the effects of a fume suppressant called DOPO on the chemical composition and performance of asphalt. The researchers found that DOPO reacted with unsaturated groups in the asphalt, resulting in changes to its properties such as softening point, viscosity, and aging resistance. The modified asphalt with DOPO exhibited improved high-temperature performance and aging resistance, while also reducing the emission of noxious fumes. The study provides valuable insights into the potential use of DOPO in asphalt production. [Extracted from the article]

Researchers at Anhui Jianzhu University in Hefei, China have conducted a study on the composition design of alkali-activated cements (AAC) for building and construction. The study aimed to address the issues of rapid solidification and significant shrinkage in alkali-activated slag cement. By adjusting the proportion of slag and calcined coal gangue powder, regulating the content of activator components, and using calcium carbonate whiskers, the researchers were able to create AAC with slow coagulation and shrinkage reduction. The study establishes a relationship between composition and performance, which is significant for the practical engineering application of AAC and the resource utilization of coal gangue. [Extracted from the article]

A recent study conducted by researchers at Shihezi University in Xinjiang, China, investigated the effects of different components and curing regimes on the performance of fly ash-based geopolymer mortar (FA-GPM) used in building and construction. The study found that adding silica fume (SF) and ordinary Portland cement (OPC) to the FA-GPM significantly increased its compressive strength. The researchers also discovered that steam curing at 60 degrees Celsius resulted in the highest compressive strength, while carbonation curing for 12 hours improved strength development. The study highlights the potential benefits of using SF and OPC in FA-GPM and identifies environmentally friendly curing regimes for large-scale applications. [Extracted from the article]

Researchers at Beijing University of Technology have conducted an experimental study on the pore characteristics and rock damage mechanism of thermal-cooling treated sandstone. The study aimed to provide a theoretical basis for underground coal gasification and geothermal resource exploitation. The researchers used nuclear magnetic resonance equipment to test thermal-cooling sandstones with three different cooling methods (natural cooling, liquid nitrogen cooling, and water cooling) and observed the generation and development of pores and fissures. The results showed that the porosity of sandstone increased with the increase of thermal treatment temperature, and the main contribution to pore development was from micropores. The study also analyzed the thermal damage mechanism of thermal-cooling sandstone, which involved physical and chemical changes in the mineral particles and the development of intergranular and transgranular cracks. The research concluded that the superposition effect of high temperature and cooling created thermal stresses inside the rock, leading to further development of pores and cracks. [Extracted from the article]

A study conducted by researchers at Guangxi University in Nanning, China, explored the water saturation degree of cement paste using hydrogen nuclear magnetic resonance (1H NMR) signals. The study found that the saturation degree of the cement paste increased with the duration of saturation until it reached equilibrium. Increasing the saturation pressure and using vacuum saturation with high pressure were found to increase the saturation degree and reduce saturation time. The researchers recommended a saturation duration of at least 4 hours with a vacuum pressure of 8 MPa for cement paste with water-to-cement ratios (w/c) of 0.2 and 0.35, and a saturation duration of at least 0.5 hours with a vacuum pressure of 8 MPa for cement paste with a w/c ratio of 0.5. [Extracted from the article]

Researchers at the University of Tokyo have published a report on the mechanical behavior of self-compacting recycled concrete reinforced with recycled disposable medical mask fiber. The study aimed to find a solution for the large number of waste disposable medical face masks (DMFMs) that are polluting the environment due to the COVID-19 epidemic. The researchers found that incorporating DMFM fiber into the concrete improved its mechanical properties, such as compressive strength and flexural strength. The study provides valuable insights for the application of waste DMFM fibers in self-compacting recycled concrete. [Extracted from the article]

A report from Shaoxing University in China discusses the use of 1H low-field nuclear magnetic resonance (NMR) as a non-destructive test method to study the hydration characteristics of cement pastes. The researchers found that hydroxyethyl methyl cellulose (HEMC) with different viscosities affects the hydration process of cement by acting on the water in different states. Incorporating HEMC can effectively control bleeding water and delay the enrichment of gel pores water and interlayer water. The viscosity of HEMC also influences the hydration process, with higher viscosity significantly delaying it compared to lower viscosity. This research provides insights into the early hydration characteristics of Portland cement. [Extracted from the article]

Researchers from the University of Leuven (KU Leuven) in Belgium have conducted a review on the potential of microwave technology for the electrification of clinker and calcination treatments in the cement industry. The study explores the conversion of electricity into electromagnetic radiation that can be absorbed by the product, and discusses different pathways for scaling up the technology. The research was supported by financial assistance from VLAIO (Flanders Innovation & Entrepreneurship). The findings have been peer-reviewed and published in the journal Construction and Building Materials. [Extracted from the article]

A study conducted by Chang'an University in Xi'an, China, explores the impact of high temperatures on the pore structure and moisture transfer mechanisms of concrete. Concrete samples exposed to temperatures ranging from 200 to 800 degrees Celsius were analyzed using scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) techniques. The results indicate that high temperatures significantly affect the capillary water absorption process in concrete, leading to changes in pore sizes and the type of pore filling. This research provides valuable insights into the behavior of concrete under extreme heat conditions. [Extracted from the article]

A recent report from Qingdao University of Technology in China discusses the use of waste rubber particles in concrete as an environmentally friendly alternative to traditional aggregates. However, previous studies have shown that rubber aggregates can negatively impact the mechanical properties of concrete. The researchers in this study incorporated silane coupling agent-modified rubber into ultra-high-performance concrete (UHPC) and found that it effectively bridged the rubber and UHPC. The addition of the modified rubber increased the shear strength and flexural strength of the UHPC. The researchers suggest further mix ratio design to incorporate rubber powder into the UHPC system. [Extracted from the article]

A recent study conducted by researchers at Taiyuan University of Technology in Shanxi, China, has proposed new methods for non-destructive characterization of the hydration degree of geopolymer concrete. The study utilized low-field nuclear magnetic resonance and cyclic voltammetry techniques to evaluate the setting and hardening characteristics of the concrete. The results showed that the hydration process of geopolymer concrete is divided into different stages, forming two gel phases. The research concluded that these findings will facilitate non-destructive monitoring of geopolymer concrete during construction projects to ensure safety. [Extracted from the article]

A study conducted by researchers at Islamic Azad University in Ahvaz, Iran, explores the use of Ground Granulated Blast-furnace Slag (GGBS), lime, and fly ash to improve the geotechnical properties of gypsum soil. The researchers found that the combination of these materials led to increased strength in the soil, with the most significant improvements observed after 28 days of curing. The study also revealed the formation of cementitious compounds and crystal growth within the soil samples. The research sheds light on the mechanisms that enhance the geotechnical properties of gypsum soil and highlights the complex interplay between additives and curing durations. [Extracted from the article]

Researchers at Chongqing Jiaotong University in China have conducted a study on the fume emissions of rubber modified asphalt used in building and construction. They found that the addition of kaolin and sepiolite as composite modifiers in the asphalt reduced the concentration of volatile organic compounds (VOCs) by 42.26% and hydrogen sulfide (H2S) by 65.28%. The study also revealed that the composite modifiers improved the road performance of the asphalt by increasing its rutting factor and fatigue factor. The researchers concluded that kaolin and sepiolite had a synergistic effect on the fume suppression of rubber modified asphalt. This research has been peer-reviewed. [Extracted from the article]

A study conducted by Zhejiang Agriculture & Forestry University in Hangzhou, China, explores the use of bamboo in construction, furniture, and decoration. The researchers aimed to address the issues of dimensional instability and susceptibility to mildew that affect the economic value of bamboo. They developed a wax-based composite system composed of paraffin, microcrystalline wax, and stearic acid to improve the hydrophobicity, dimensional stability, and mold resistance of bamboo. The modified bamboo showed significant improvements in these properties, suggesting potential applications for the protection of bamboo products. The study was supported by the National Natural Science Foundation of China and has been peer-reviewed. [Extracted from the article]

Researchers from Xi'an University of Technology in China have conducted a study on stabilizing aeolian sand, which is difficult to use as construction material due to its poor gradation and loose structure. The researchers mixed fiber, silt, and cement to stabilize the sand and found that the addition of fibers and silt significantly improved the strength and ductility of the cement-stabilized aeolian sand. Under optimal mixing conditions, the strength of the sample increased by 274.2% compared to ordinary cement-stabilized aeolian sand. The study suggests that using local silt to stabilize aeolian sand can improve mechanical properties, reduce project costs, and have environmental benefits. The findings have important implications for engineering and design in aeolian sand areas. [Extracted from the article]

Researchers from China University of Geosciences Beijing have developed a nondestructive method to measure the capillary absorption coefficient of porous building materials. The method uses a single-sided nuclear magnetic resonance (NMR) technique, which is accurate, rapid, and does not damage the sample. The researchers also analyzed the water transport behaviors in these materials and established a water transport model. The study found that difficulty in removing air leads to a reduced rate of water absorption in the second stage. This research provides valuable insights for understanding the durability of buildings and improving measurement methods. [Extracted from the article]

A study conducted by researchers at Beijing University of Technology in China explores the influence of compatibilizer components on the properties of modified asphalt used in disposable medical masks. The researchers investigated the effects of different compatibilizers on the performance of the modified asphalt through various tests and experiments. The results indicate that the higher the aromatic content in the compatibilizer, the better the low-temperature performance and high-temperature stability of the modified asphalt. The study provides valuable insights for addressing the environmental concerns associated with the production of disposable medical masks. [Extracted from the article]

A recent report from Pukyong National University in Busan, South Korea, explores the internal curing mechanism of cement composites with cellulose microfibers (CMFs) derived from kenaf stalk bast. The study found that the CMF content in the composites influenced the amount of water absorbed by the CMFs, which facilitated internal curing. The research used nuclear magnetic resonance (NMR) analysis to study the proton signals and observed a correlation with thermal decomposition and hydration. The findings highlight the significant role of CMFs in enhancing internal curing effects in cement composites. [Extracted from the article]

A recent study conducted by investigators at Zhejiang Agriculture & Forestry University in Hangzhou, China, explores the use of perillaldehyde (PAE) as a natural antimicrobial agent to improve the durability of bamboo. Bamboo is a potential substitute for wood, but its susceptibility to mold has hindered its practical use. The researchers successfully immobilized PAE in bamboo using diethylenetriamine, resulting in enhanced surface hydrophobicity and resistance to mold. While the modification process improved the dimensional stability of bamboo, it slightly reduced its elasticity and hardness. This study offers a novel approach to preserving bamboo and enhancing its resistance to mold. [Extracted from the article]

A study conducted by researchers at the University of Lille in France explores the development of a geopolymer mortar that can be cured under ambient conditions using flash-calcined dredged sediment and flash-calcined excavated clay as substitutes for Meta kaolin. The study investigates the effect of binder composition on the mechanical and durability performance of the geopolymer mortar samples. The results show that using these substitutes and a small percentage of granulated blast furnace slag can result in similar or better properties in terms of strength and durability. The study also examines the network classification of the geopolymer mixes using nuclear magnetic resonance testing. [Extracted from the article]

A study conducted by investigators at Hohai University in Nanjing, China, examined the mechanical properties and microstructure of porous organic polymer (SPOP) reinforced low-grade sand under wetting-drying cycles. The researchers found that the addition of SPOP significantly increased the mechanical strength, elastic modulus, and cohesion of the sand. However, specimens with high SPOP content were more susceptible to moisture, and the mechanical properties of the SPOP-sand mixtures decreased with increasing wetting-drying cycles. The study concluded that cyclic wetting and drying caused the soil aggregates to loosen and the polymer membrane to soften and break, resulting in an unstable structure under external pressure. [Extracted from the article]