Article
Engineering, Mechanical
Lena Leicht, Tomas Fila, Petr Maca, Manfred Curbach
Summary: This paper presents an innovative technique for measuring the bond stress-slip relationships during dynamic pull-out using a tensile split Hopkinson bar and a near-to-full-scale beam-end specimen. The complex wave propagation behavior during impact is characterized and two methods for separating the longitudinal stress waves are employed. The method is considered suitable for evaluating the dynamic bond stress-slip relationship.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Energy & Fuels
Geli Zhao, Xing Li, Ying Xu, Kaiwen Xia
Summary: This study developed a novel experimental system to determine the dynamic compressive response of deep rocks, and validated the system using green sandstone. The experimental results showed that the dynamic compressive strength of the rocks is influenced by loading rate, confining pressure, and pore pressure. The most common dynamic failure modes were single shear failure and X-type conjugate shear failure. The friction angle remained constant while the cohesion depended on the loading rate. Water had a bidirectional effect on dynamic strength, facilitating crack propagation but also impeding pore structure damage.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Construction & Building Technology
Baofeng Huang, Xiangfei Zhang, Xiaofeng Ma
Summary: The uniaxial compression behavior of building sandstone at high strain rates is investigated using dynamic and static compression tests. It is found that the static compression strength of flattened cylinders is 50% higher than that of standard cylinders. The study also explores the relationship between strain rate and fracture damage, and analyzes the correlations between dynamic strength, strain rate, and dynamic modulus based on experimental results.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Kyoung-Min Kim, Sangho Lee, Yongjae Yu, Jae-Yeol Cho
Summary: Dynamic increase factors (DIF) of concrete compressive strength have been proposed, but without considering the effect of coarse aggregate size. This study conducted experiments and numerical analysis to investigate the effect of maximum coarse aggregate size (Gmax) on DIF. The results showed that Gmax affected the dispersion of apparent DIF and values of pure rate DIF. Based on these findings, a guideline for fabricating specimens considering Gmax for concrete SHPB tests was suggested.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Kyoung-Min Kim, Sangho Lee, Jae-Yeol Cho
Summary: This study establishes a standardized lubrication technique for a concrete split Hopkinson pressure bar (SHPB) test through experimental and numerical research. The results show that the frictional effect can be eliminated in the concrete SHPB test when a lubricant with a dosage of equal to or greater than 12 mg/cm(2) is applied.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Construction & Building Technology
Wenping Du, Caiqian Yang, Hans De Backer, Chen Li, Kai Ming, Honglei Zhang, Yong Pan
Summary: The dynamic mechanical properties of recycled concrete (RC) and natural concrete (NC) were studied using impact tests and numerical simulation. The results showed that the quasi-static compressive strengths of the RC were slightly lower than that of the NC, but the increase in compressive strength under dynamic conditions was similar for both. An empirical equation was proposed to estimate the dynamic increase factor (DIF) of the RC.
Article
Mining & Mineral Processing
Xin Chen, Xiuzhi Shi, Jian Zhou, Enming Li, Peiyong Qiu, Yonggang Gou
Summary: The research utilized SHPB to test the high strain rate compressive behavior of cemented paste backfill (CPB). The results showed that increasing the cement content, tailings content, and curing age can improve the dynamic compressive strength and elastic modulus of CPB. Under dynamic loading, higher strain rates lead to larger increasing times of dynamic compressive strength, and there is an exponential correlation between dynamic compressive strength of CPB and strain rate.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Zhoujie Gu, Rongxi Shen, Zhentang Liu, Enlai Zhao, Hailiang Chen, Zichen Yuan, Xiaomeng Chu, Jiawei Tian
Summary: Dynamic failure experiments were conducted on coal samples under dynamic load in a triaxial Split-Hopkinson pressure bar test system to study the dynamic characteristics of coal in a multi-axial pre-stress state. The experiments showed that the 3D pre-stress state significantly affects the dynamic failure of coal. The dynamic initial stress of coal increases linearly with strain, then grows at a reduced rate until the peak strength, and the mechanical curve rebounds notably. The dynamic strength factors of coal vary significantly with the increase of confining pressure.
NATURAL RESOURCES RESEARCH
(2023)
Article
Construction & Building Technology
Thong M. Pham, John Davis, Ngoc San Ha, Emad Pournasiri, Feng Shi, Hong Hao
Summary: The study developed ultra-high-performance rubberized concrete incorporating different rubber contents and steel fibres, finding that the compressive strength decreased with increasing rubber content but remained higher compared to other rubberized concretes. The dynamic compressive strength and energy absorption of the UHPRuC were sensitive to strain rate and increased with rubber content.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Physical
Albin Wessling, Jorgen Kajberg
Summary: This paper presents a detailed study on the dynamic mechanical characterization of two rock materials (Kuru grey granite and Kuru black diorite) using a Split-Hopkinson Pressure Bar and high-speed imaging. The study provides information about the fracture initiation and propagation, as well as the indirect tensile strain and strain rates on the surface of the materials. The results show that a proper selection of the sensing region and high temporal resolution can reliably estimate crack formation and subsequent propagation.
Article
Construction & Building Technology
Yixin Mo, Jianchun Xing, Songlin Yue, Yamei Zhang, Qizhen Zhou, Xiao Liu
Summary: This study evaluates the dynamic properties of 3D printed cement mortar, finding that the anisotropy of dynamic compressive strength decreases with increasing strain rate. Acoustic indices can be used to evaluate the anisotropy of dynamic compressive strength, and the energy dissipation density varies in different printing directions.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Construction & Building Technology
Xing Chen, Changzhong Wang, Suwen Chen, Siyi Yi, Yong Lu
Summary: Low-iron ultra-clear float glass (LIFG) has become popular in landmark and large-scale buildings for its aesthetic characteristics. This paper investigates the dynamic mechanical properties of LIFG for blast resistance design by conducting quasi-static and dynamic tests. The results show that the dynamic compressive and tensile strengths of LIFG are strain-rate dependent, with the tensile strength being more sensitive to strain rate. The strain rate effect does not significantly affect the Young's modulus of LIFG.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Mechanics
Zelin Yan, Feng Dai, Yi Liu, Ang Li, Hongbo Du
Summary: This study numerically investigates the rate-dependent progressive cracking behaviors of single-flawed rock specimens under different strain rates. The results show that the progressive cracking behaviors of rock specimens exhibit evident changes with increasing strain rates.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Instruments & Instrumentation
Eranga Gayanath Jayawickrama, Takuma Sekiguchi, Jun Muto, Sando Sawa, Hiroyuki Nagahama, Yoshio Kono, Kyung-Oh Bae, Hyung-Seop Shin
Summary: Researching rock pulverization in large-scale strike-slip faults is crucial. We developed an experimental setup capable of generating high strain rates and accurately reproducing dynamic pulverization. Cracks were observed to propagate along grain boundaries at high speeds, and energy dissipation was found to increase with stronger impacts. Our apparatus can produce particle size distributions similar to naturally pulverized rocks.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Materials Science, Composites
Kada Zemani, Abdelghani May, Lionel Gilson, Djalel Eddine Tria
Summary: This study focuses on the mechanical behavior of metal-ceramic functionally graded materials (FGMs) at high strain rates using a Split Hopkinson Pressure Bar (SHPB) technique. Numerical simulations were performed to investigate the dynamic response of specific FGMs at different strain rates. The results showed that the compositional gradient exponent and striker velocity have significant effects on the dynamic behavior of the FGMs, while the increasing/decreasing stiffness has a minor effect. The study highlights the importance of considering high strain rates in the design and optimization of FGMs behavior under dynamic loading.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Computer Science, Interdisciplinary Applications
Sheng-Qi Yang, Ye Li, Guo-Wei Ma, Bo-Wen Sun, Jing Yang, Jie Xu, Yong-Hao Dai
Summary: The dynamic compression experiments were conducted on granite specimens after high-temperature treatments, and the fragmentation characteristics were evaluated using fractal dimension and average fragment size. The results showed that the physical properties of the granite were closely related to the temperature, and microcracking occurred at 900 degrees Celsius. The fractal dimension and average fragmentation size were found to be inversely linearly related, and the crack propagation during dynamic compression followed a pattern of initial appearance on the surface and gradual propagation to the interior.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Geological
Meiyu Li, Guowei Ma, Tuo Li, Yun Chen, Huidong Wang
Summary: In this study, an equivalent discontinuum analysis (EDA) method is proposed to deal with complexly fractured rock masses, which effectively maintains stress variability and displacement discontinuity while improving computational efficiency.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Construction & Building Technology
Dimuthu Wanasinghe, Farhad Aslani, Guowei Ma
Summary: In order to achieve electromagnetic interference (EMI) shielding in cementitious composites, electrically conductive and electromagnetic absorbing additives are commonly used. This study investigated the impact of adding electric arc furnace slag (EAFS) or heavyweight aggregates (HWA), alone and in combination with carbon fibre (CF), on the EMI shielding properties of cementitious composites. The optimal shielding performance was achieved with aggregate contents of 1.5 wt%, with values of 5.18 dB for EAFS mixes and 3.25 dB for HWA mixes, within the frequency range of 30 MHz to 1.5 GHz. Hybrid mixes with CF showed the best shielding performance with EAFS and HWA contents of 1 wt%, resulting in shielding levels of 34.21 dB and 36.78 dB, respectively, within the frequency range of 30 MHz to 1.5 GHz. An increase in aggregate content led to a gradual reduction in EMI shielding effectiveness.
MAGAZINE OF CONCRETE RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Miao Liu, Li Wang, Guowei Ma, Weiwei Li, Yuanyuan Zhou
Summary: In this study, a novel reinforcing approach for 3D concrete printing (3DCP) using U-type steel wire mesh (USWM) is proposed. The introduction of USWM significantly improves the flexural performance of 3D printed structures.
Article
Computer Science, Artificial Intelligence
Xuefei Wang, Xuping Dong, Jiale Li, Zhishuai Zhang, Jianmin Zhang, Guowei Ma
Summary: The current methodology of assessing the compaction characteristic of subgrade fillers is time-consuming and biased. This study proposes an advanced approach based on ANN algorithms to determine compaction parameters of subgrade fillers. A large number of compaction tests are performed to assess the compaction quality and the particle gradation is specifically considered. The developed PSO-BP-NN model can automatically predict the compaction parameters of different filling materials.
ADVANCED ENGINEERING INFORMATICS
(2023)
Article
Construction & Building Technology
Guowei Ma, Tingyu Hu, Fang Wang, Xiongfei Liu, Zhijian Li
Summary: This paper develops a systematic approach to evaluate and optimize the printability and printing quality of powder-based 3D magnesium phosphate cement (MPC) printing. The results show that mapping the proportions of ingredients and using specific modulators can improve printing accuracy and surface quality. The addition of 1,2-propylene glycol and Surfynol 465 to the binder, and quartz sand to the powder bed, significantly enhances the viscosity, reduces surface tension, and improves spreadability and surface flatness. The use of appropriate content of polyvinyl alcohol (PVA) controls the penetration and diffusion of the binder, leading to improved printing accuracy and reduced porosity.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Yushi Liu, Weichen Tian, Guowei Ma
Summary: In this study, electric activation (EA) curing was used to rapidly manufacture on-site reinforced concrete (RC) beams in severely-cold environment. The results showed that EA cured beams maintained a stable increasing trend in electrical resistance during the entire curing process, and the temperature field inside the structure remained uniform at around 45 degrees Celsius. Mechanical property tests demonstrated that EA curing could rapidly enhance the strength of RC beams under severely-cold conditions, reaching a compressive strength of 28.4 MPa, equivalent to C30 concrete grade. Furthermore, the structural performance of EA manufactured RC beams was found to be superior to beams manufactured through standard curing methods. This research provides a comprehensive investigation into the performance development of RC beams subjected to EA curing in extremely-harsh environments, facilitating the rapid fabrication of high-quality concrete structures in cold regions.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Qiaoyan Li, Guowei Ma, Yulin Lu
Summary: This study investigates the friction performance and compression properties of geotextile bags under different degrees of consolidation using the slope sliding test, direct shear test, and unconfined compression test. The geotextile bags consist of geotextile and tailings sands from a prototype tailings dam in Yunnan Province. The friction coefficients between the bags are obtained through the slope sliding test, while the direct shear test examines the ability of the bags to withstand vertical load. The unconfined compression test reveals that the ultimate bearing capacity of the geotextile bags remains the same under slow loading conditions despite different moisture contents before the test. Additionally, a stability analysis method based on the limit equilibrium theory is developed to assess the improved stability of the tailings dam using geotextile bags (TDGB) compared to a general tailings dam.
Article
Engineering, Manufacturing
Qian Wan, Wenwei Yang, Li Wang, Guowei Ma
Summary: 3D concrete printing is a promising construction technology for freeform civil structures. This study proposes an adaptive path-planning method based on medial-axis decomposition and transfinite mapping for multi-branched regions. The proposed method can eliminate discontinuity, minimize sharp turns, and avoid defects in solid filling, and support various types of grid generation with desired global continuity.
ADDITIVE MANUFACTURING
(2023)
Article
Construction & Building Technology
Guowei Ma, Kuo Jia, Panpan Xie, A. Ruhan, Li Wang, Xiaoyong Ding, Diandong Ju
Summary: This paper investigated the effects of different aerogel contents in concrete and exposure to elevated temperatures on its physical, mineralogical, thermal, mechanical, and microstructural performances. The study revealed the mechanisms of heat-induced degradation and how aerogel mitigates the degradation. Incorporating aerogel into concrete alleviated the strength loss after exposure to high temperatures, with the most significant effect observed after exposure at 200-600 degrees C. The sintering properties of aerogel played a crucial role in mitigating the heat-induced degradation of concrete.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Yaoyao Wu, Xiongfei Liu, Zhuang Wang, Guowei Ma, Yifei Hao
Summary: The integrated design of multicomponent microwave absorbents in foamed cementitious materials improves the electromagnetic wave absorption performance. The multilayer structure enhances the impedance-matching characteristics, allowing more electromagnetic waves to be absorbed. By combining interlayer reflection scattering, interface polarization, and resonance effects, the electromagnetic dissipation of cementitious materials is significantly improved. The flexibility of the multilayer structure in adjusting the absorbent type and content in each layer leads to a greatly improved electromagnetic wave absorption performance.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Civil
Daobo Zhang, Peng Feng, Peizhao Zhou, Weiguo Xu, Guowei Ma
Summary: This paper presents an innovative continuous reinforcement method using fiber reinforced polymer textile and Engineered Cementitious Composite in 3D printed concrete structures. The proposed method effectively addresses the lack of tensile reinforcement and corrosion of steel bars. The mechanical tests show that the reinforced 3D printed walls have better material utilization efficiency and mechanical properties.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Civil
Wenwei Yang, Li Wang, Guowei Ma, Peng Feng
Summary: This paper presents an integrated design method for 3D concrete printing by incorporating extrusion-based manufacturing characteristics into the topology optimization algorithm. The method considers manufacturing constraints such as nozzle size and path continuity, as well as material and design constraints to achieve desired mechanical performance and lightweight designs. It also incorporates controls for closed regions and overhang angle to ensure global path continuity and stable stacking of printed structures.
ENGINEERING STRUCTURES
(2023)
Article
Construction & Building Technology
Youyu Wang, Guowei Ma, Li Wang, Wengang Zhang, Hanlong Liu
Summary: This study uses 3D printing to create similar models of underground caverns in different sizes, and explores the size effect on strength, failure mechanisms, energy storage, and deformation through experimental tests and numerical simulations. The results show that larger test models have lower overall strength, more violent damages, and a linear relationship between allowable deformation and model size. Material heterogeneity is identified as the main factor causing the size effect, while large fractures in larger models also play a substantial role.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Article
Construction & Building Technology
Jingqi Jia, Yun Chen, Hao Luo, Guowei Ma
Summary: This study develops a numerical method for studying non-Darcy seepage in fractured rocks around deep-buried tunnels. The proposed method is validated by comparing it with field data and analytical solutions. The results show that fractures with higher conductivity dominate the non-Darcy effect, and this effect is most significant during periods of heavy rain. Additionally, the seepage stability of the tunnel lining under different conditions is found to vary.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
