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Full-Text Articles in Engineering

Soil-Water Characteristic Of Biochar-Clay Mixture In The Full Suction Range, Ming-Yu Li, Wen-Jing Sun, Qiang Huang, De-An Sun Nov 2022

Soil-Water Characteristic Of Biochar-Clay Mixture In The Full Suction Range, Ming-Yu Li, Wen-Jing Sun, Qiang Huang, De-An Sun

Rock and Soil Mechanics

Soil-water characteristic curve (SWCC) plays an important role in defining the hydro-mechanical behavior of unsaturated soils. Biochar has the properties of porous structure, high specific surface area and high adsorption. The hydraulic characteristics of biochar-amended soil may change due to the influence of natural environmental factors when applied as the cover layer of landfills. In order to study the effect of biochar content on the water retention behavior of biochar-clay mixture in full suction range, the suction of samples was controlled by vapor equilibrium technique (suction range 3–368 MPa), filter paper method (suction range 0–40 MPa) and pressure plate method …


Mechanical Properties Of Slag-Fly Ash Based Geopolymer Stabilized Sandy Soil, Jin-Jin Zhang, Bo Li, Chuang Yu, Mao-Yu Zhang Oct 2022

Mechanical Properties Of Slag-Fly Ash Based Geopolymer Stabilized Sandy Soil, Jin-Jin Zhang, Bo Li, Chuang Yu, Mao-Yu Zhang

Rock and Soil Mechanics

Silicate cement as a conventional soil curing agent has problems of high energy consumption and high emissions, and researchers have been seeking a more economical and environmentally friendly alternative to cement. In this study, geopolymers based on ground granulated blast-furnace slag (GGBS) and fly ash (FA) were used to reinforce sandy soils, and the effects of different factors on the mechanical properties of geopolymer stabilized sandy soils were investigated by adjusting the type and ratio of exciter, slag-fly ash ratio, water-cement ratio, and curing conditions. The specimens were studied in depth by unconfined compressive strength (UCS) test, electron computed tomography …


A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu Oct 2022

A Novel Iron Phosphate Cement Derived From Copper Smelting Slag And Its Early Age Hydration Mechanism, Yunlong Luo, Xintao Zhou, Zhongqiu Luo, Hongyan Ma, Yu Wei, Qin Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Copper slag (CS), a by-product of copper smelting, is normally stockpiled, leading to wastes of resource and space as well as environment pollution. It has not been massively reutilized as a supplementary cementitious material in Portland cement due to its low reactivity. In the present study, CS is for the first time utilized as the base component to prepare an iron phosphate cement (IPC) by reacting with ammonium dihydrogen phosphate (ADP) at room temperature. The influence of the raw materials mass ratio (CS/ADP) on the microstructure and performance of IPC pastes are investigated. It is found that the compressive strength …


Microstructure Variation And Empirical Fatigue Model Of Salt Rock Under Cyclic Loading, Qiang Zhang, Jun-Bao Wang, Zhan-Ping Song, Shi-Jin Feng, Yu-Wei Zhang, Tao Zeng Jun 2022

Microstructure Variation And Empirical Fatigue Model Of Salt Rock Under Cyclic Loading, Qiang Zhang, Jun-Bao Wang, Zhan-Ping Song, Shi-Jin Feng, Yu-Wei Zhang, Tao Zeng

Rock and Soil Mechanics

No abstract provided.


Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu May 2022

Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper studied the influence of pre-saturated lightweight sand (LWS) on the mechanical and microstructural properties of UHPC cast with steel fiber alignment. The changes in hydration kinetics, porosity, nano-mechanical, and mechanical properties were studied. The LWS was used at 0–50% replacement volumes of total sand. Predominant fiber alignment was favored through a flow-induced casting method during casting of flexural prisms. Experiment results showed that the 28-d autogenous shrinkage was decreased from 450 to 275 μm/m with the LWS content increasing from 0 to 50%. The addition of 20% LWS led to maximum increases of 15%, 15%, and 20% in …


Mechanical Properties Of Saline Soil Solidified With Lime, Fly Ash And Modified Polyvinyl Alcohol Under Freeze-Thaw Cycles, Min Li, He-Miao Yu, Hong-Pu Du, Bao-Yu Cao, Shou-Xi Chai Apr 2022

Mechanical Properties Of Saline Soil Solidified With Lime, Fly Ash And Modified Polyvinyl Alcohol Under Freeze-Thaw Cycles, Min Li, He-Miao Yu, Hong-Pu Du, Bao-Yu Cao, Shou-Xi Chai

Rock and Soil Mechanics

The repeated freeze-thaw cycles with seasonal alternations have an obvious effect on soil structure. To reduce the temperature sensitivity of saline soil and then use it in engineering, a combined treatment method is proposed, where lime, fly ash and modified polyvinyl alcohol (MPA) are used as solidified materials. Unconfined compressive strength (UCS) tests and microstructure characterization are firstly used to evaluate the solidified effect and obtain the parameters range of solidified materials. Then, the shear strength tests for determining cohesion and internal friction angle are conducted. Experiments are conducted by considering separate and combined treatments of materials mentioned above. The …


Development And Characterization Of Magnesium Phosphate Cement Based Ultra-High Performance Concrete, Jihui Qin, Fumin Dai, Hongyan Ma, Xiaobing Dai, Zhen Li, Xingwen Jia, Jueshi Qian Apr 2022

Development And Characterization Of Magnesium Phosphate Cement Based Ultra-High Performance Concrete, Jihui Qin, Fumin Dai, Hongyan Ma, Xiaobing Dai, Zhen Li, Xingwen Jia, Jueshi Qian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims at the development of magnesium phosphate cement-based ultra-high performance concrete (MPC-UHPC). To this end, MPC paste phase was designed by using high magnesia-to-phosphate (M/P, 3.5) and low water-to-cement (W/C, 0.10–0.16) mass ratios, and certain amounts of ultra-fine fly ash (UFA, 5%–15%). Fresh and hardened properties, and microstructure of the developed MPC-UHPC were evaluated, and compared with those of conventional UHPC as well. Test results showed that lower W/C resulted in higher mechanical strengths and lower drying shrinkage, but the sharp decrease of workability and increase of autogenous shrinkage. At a constant W/C, the addition of UFA effectively …


Design, Dynamic Performance And Ecological Efficiency Of Fiber-Reinforced Mortars With Different Binder Systems: Ordinary Portland Cement, Limestone Calcined Clay Cement And Alkali-Activated Slag, Wu Jian Long, Zhuorui Wu, Kamal Khayat, Jingjie Wei, Biqin Dong, Feng Xing, Jinrui Zhang Feb 2022

Design, Dynamic Performance And Ecological Efficiency Of Fiber-Reinforced Mortars With Different Binder Systems: Ordinary Portland Cement, Limestone Calcined Clay Cement And Alkali-Activated Slag, Wu Jian Long, Zhuorui Wu, Kamal Khayat, Jingjie Wei, Biqin Dong, Feng Xing, Jinrui Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The dynamic mechanical properties and ecological efficiency of cement-based composites are of vital importance to the development of green building materials and dynamic loadings resistance. In this study, the dynamic mechanical properties, ecological and economic efficiency of fiber-reinforced mortars (FRMs) made with different binder systems, including ordinary Portland cement (OPC), limestone calcined clay cement (LC3), and alkali-activated slag (AAS), were compared. In addition, different rheological parameters were designed to evaluate the dynamic mechanical properties of FRMs. The fiber pull-out testing, Barrett-Joyner-Halenda (BJH) testing, and scanning electron microscope (SEM) were used to reveal the difference in the dynamic mechanical properties of …


Dynamical Properties Of Environmental High-Performance Composites With Calcined Clay, Jingjie Wei, Wu Jian Long, Kamal Khayat, Biqin Dong, Liu Mei, Feng Xing Feb 2022

Dynamical Properties Of Environmental High-Performance Composites With Calcined Clay, Jingjie Wei, Wu Jian Long, Kamal Khayat, Biqin Dong, Liu Mei, Feng Xing

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete structures may be exposed to dynamic loadings within short periods such as earthquakes and vehicles load, resulting in substantial damage to human life and property because of the collapse of concrete structures. The research achievements on dynamic properties of high-performance composites with LC3 (HPC-LC3) are limited, although dynamic loadings are commonly encountered in infrastructure. The study aims to develop a new-green concrete product (HPC-LC3) with high dynamical properties and promote its mass use in a vibration service environment by investigating dynamical properties of HPC-LC3. Dynamical properties of structure can be promoted at material level by means of enhancing the …