Table of Content

Volume 43 Issue 11
15 November 2024

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Cement and Concrete

Research Progress on Pore Structure of Shotcrete and Its Influence on Durability

GAO Mingshuang, PAN Huimin, ZHAO Qingxin

2024, 43(11):  3895-3910. 

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Shotcrete is a widely used material in the fields of construction and civil engineering, and its pore structure has a significant impact on the macroscopic performance and durability of shotcrete. This article summarizes the pore structure models, and elaborates on and compares the testing methods for pore structure. A systematic analysis is conducted on the factors affecting the pore structure of shotcrete, including curing temperature, admixtures, water binder ratio, mineral admixtures, pumping pressure, and time. In depth exploration is conducted on the influence of pore structure on the frost resistance, impermeability, carbonation resistance, and chemical erosion resistance of shotcrete, and prospects are proposed for future research on pore structure of shotcrete.

Research Progress on Characteristics of Manufactured Sand and Its Influence on Concrete Performance

ZHU Hongzhou, DU Junchi, CHEN Xiang, YANG Song, TAN Qiqi

2024, 43(11):  3911-3922. 

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With the restriction on natural sand mining, the use of manufactured sand has become an inevitable trend. Due to the significant differences in the formation processes of manufactured sand and natural sand, there are notable differences in their properties, which also affect the performance of manufactured sand concrete. In order to promote the application of manufactured sand and ensure that the workability and mechanical properties of manufactured sand concrete meet the required standards, this paper analyzes the influences of preparation method and particle characteristics of manufactured sand and proportion of concrete on the performance of concrete. The influences of manufactured sand parent rock lithology, stone powder content, particle morphology, gradation, and proportion of concrete on manufactured sand concrete are systematically summarized. Additionally, the limitations of existing research and the problems that need to be addressed are discussed to provide a reference for future research.

Research Status and Development Trend of Frost Resistance of Phase Change Concrete

ZHANG Yichao, LIANG Jiatong, YU Kaikai, YU Jian, LI Xuan, LIU Zhicheng, LI Tong, FANG Yanfeng

2024, 43(11):  3923-3934. 

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The frost resistance of concrete in cold regions is a key indicator for evaluating the durability of concrete. The ice swelling stress and static water stress caused by the positive and negative temperature cycles in the external environment and changes in concrete saturation will cause internal and external cracks in the concrete structure, reduce the strength and stiffness of the concrete, damage the overall integrity, stability and durability of the structure, and even induce penetrating cracks until failure. The use of phase change materials to release latent heat compensation during the phase change process to alleviate the freezing of internal pore water in concrete, thereby improving the frost resistance of concrete in cold regions, will be of great significance for extending the service life of concrete structures. This article summarizes and analyzes the research progress on using phase change materials to improve the frost resistance of concrete at home and abroad, and proposes the urgent problems in current research and the future research directions of phase change concrete.

Research Progress on Chloride-Sulfate Coupling Erosion Mechanism, Model and Numerical Simulation of Concrete

LI Guoman, LI Haoran, QIU Guobin, LI Junling, ZHANG Rui

2024, 43(11):  3935-3946. 

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In coastal and inland saline soil environments, reinforced concrete structures are susceptible to coupling erosion of chloride-sulfate, and face more prominent structural durability problems. While experimental and numerical model research is abundant on the erosion process of reinforced concrete caused by either chloride or sulfate alone. Studies on the coupling erosion by chloride-sulfate are relatively limited. Hence, this paper summarizes the research achievements from recent years both domestically and internationally, explores the differences in the mechanism of single salt erosion and chloride-sulfate erosion, and discusses the influence of sulfate ion on the diffusion rate and binding capacity of chloride ion. The existing coupling models for reinforced concrete subjected to chloride-sulfate composite environment are compared, and the construction process of erosion models are elaborated from three aspects: the ionic transport process, chemical reaction, and pore expansion. The currently applied numerical simulation methods are summarized. Finally, the current research on chloride-sulfate coupling erosion of reinforced concrete is reviewed, and an outlook for subsequent research is given.

Effect of Compounding of Viscosity Reducing Admixtures on Hydration Performance of Cement

WANG Lin, DU Genkun, PAN Yuefan, XU Yubo, TIAN Xiying, GUO Hong

2024, 43(11):  3947-3957. 

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This study aimed to address the problem of high viscosity and poor workability of high-strength and ultra-high-strength concrete mixtures caused by high usage of binding materials and low water-binder ratios, which in turn affects construction quality, by developing a new type of reducing agent admixture. The reducing agent admixture was formulated using polycarboxylic acid water-reducing agent mother liquor, defoaming agents, air-entraining agents, rheological agents, retarders, and early-strength agents as functional additives. Single-factor experiments and orthogonal experiments were performed to investigate the effects of different components on the viscosity, flowability, and strength of cement paste and mortar, in order to determine the optimal ratio of the reducing agent admixture. The influence of the reducing agent admixture on hydration heat and hydration products of cement was investigated by conducting micro-tests on hydration heat and XRD. The experimental results show that the mass ratio of optimal preparation process for the reducing agent admixture is water reducer mother liquor∶polyether defoaming agent∶AE-II∶triterpenoid saponin∶rheological agent∶sodium tripolyphosphate∶sodium hexametaphosphate∶sodium gluconate∶citric acid∶sodium thiosulfate∶sodium sulfate=1 000∶3.5∶0.5∶1.5∶4∶10∶5∶15∶5∶15∶10. When a viscosity reducing admixture is added to the cement slurry, the heat release rate of cement hydration is delayed and the amount of hydration products is inhibited.

Amino Trimethylene Phosphonic Acid and Potassium Dihydrogen Phosphate Modified Foamed Magnesium Oxysulfate Cement

ZHANG Yuting, HOU Zhanli, QIAO Zixuan, FU Xinyu, YANG Hongjian, LIU Xiaoli

2024, 43(11):  3958-3967. 

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Foamed magnesium oxysulfate cement (FMOSC) was prepared by using organophosphonic acid-amino trimethylene phosphonic acid (ATMP) as a modifier, and the effects on dry density, compressive strength, and water resistance of FMOSC were investigated when ATMP was modified alone and when ATMP was modified in combination with potassium dihydrogen phosphate (KDP), respectively. The physical phase composition and microscopic morphology of FMOSC before and after modification were analyzed by a variety of microscopic tests, analyses and characterizations, such as pore structure distribution, XRD, FT-IR, TG-DSC and FESEM. The results show that the compound modification is most effective at m(ATMP)∶m(KDP)=1∶1 with a total dosage of 1.00% (mass fraction, same as below) compared to ATMP single modification, and it has a significant enhancement on the water resistance and pore structure of FMOSC. The addition of the modifier changes the physical phase composition of FMOSC and generates a new strength phase 5Mg(OH)₂·MgSO₄·7H₂O (5·1·7 phase).

Effect of Co-Addition of Graphene and Hydroxyl Graphene on Properties of Cement Mortar

ZHANG Yizhou, SU Junru, ZHENG Cheng, WANG Yinghao, PU Yundong, ZHANG Huiyi, YUAN Xiaoya

2024, 43(11):  3968-3975. 

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In this study, in order to solve problem that graphene (G) is easy to agglomerate in cement paste, the co-addition of hydroxyl graphene (HO-G) with better dispersion and graphene was adopted to improve the agglomeration phenomenon of graphene. The effect of co-addition of graphene and HO-G in different mass ratios on mechanical properties and durability of cement mortar was studied. The microscopic tests MIP, SEM and XRD were carried out on mortar specimens after 28 d of curing. The results show that the co-addition of graphene and HO-G in different mass ratios exhibits a more significant strengthening and toughening effect and improves the durability of cement mortar at the same time, but has little impact on the workability of cement mortar. When the mass ratio of co-addition of graphene and HO-G is 3∶7, the mechanical properties of cement mortar are the best. Compared with reference group, the 28 d flexural strength and compressive strength improve by 11.1% and 26.2%, respectively. The co-addition of graphene and HO-G in cement mortar refines the internal pores of mortar, and regulates the growth of cement hydration products, resulting in a more regular and dense internal structure of cement stone, which enhance the durability of cement mortar specimens.

Mechanical Damage Characteristics and Fracture Morphology Fractal Characteristics of Cemented Filling Body at Different Ages and Cement/Sand Ratios

ZHANG He, LIU Yanzhang, HUANG Shibing, HU Puda, XIA Yongxi, CAO Wenyao, SU Xu

2024, 43(11):  3976-3985. 

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In order to investigate the influences of age and cement/sand ratio on the mechanical damage characteristics and fractal characteristics of damage fracture morphology of filling body, as well as the relationship between mechanical damage characteristics of filling body and fractal characteristics of fracture morphology, five types of cement/sand ratio cemented filling body samples were prepared using a certain metal ore tailings. Porosity, acoustic wave velocity tests, uniaxial compression and damage fracture morphology scanning tests were carried out on samples at four curing ages. Based on the principle of strain equivalence, the damage evolution equation of filling body was constructed to characterize the damage characteristics of filling body. The “small island method” was used to calculate the fractal dimension of fracture morphology and quantitatively characterize its fractal characteristics. The results show that the uniaxial compressive strength and elastic modulus of filling body increase exponentially with age, increase with the increase of cement/sand ratio, and show an exponential decreasing relationship with the fractal dimension of fracture morphology. The damage evolution process of filling body can be divided into three stages: initial damage, accelerated damage growth, and damage failure. The fractal dimension of fracture morphology of filling body decreases exponentially with age, and decreases with the increase of cement/sand ratio. The effect of age on fractal dimension of filling body with a larger cement/sand ratio is more significant. There is a linear negative correlation between damage value at peak stress of filling body and fractal dimension of damage fracture morphology.

Acoustic Emission Characteristics and Failure Modes of Casing Material under Pulse Gas Splitting

ZHANG Yanbo, ZHANG Lei, HOU Ning, HUANG Feng

2024, 43(11):  3986-3995. 

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In order to address the issues of high grouting pressure and poor slurry diffusion uniformity caused by the lack of cracks in the casing material during sleeve valve pipe grouting, a method of pre-splitting the casing material using pulsed gas is proposed. The acoustic emission characteristics and crack evolution mechanism of the casing material under the action of pulsed gas were studied. Based on a self-constructed pulsed gas loading device combined with acoustic emission nondestructive testing technology, experimental research on the pulsed gas splitting of the casing material was conducted. The acoustic emission characteristics during the damage process of the casing material were analyzed through acoustic emission parameter analysis, and the effect of pulsed gas splitting was evaluated. The development and identification of crack types in the casing material were carried out using the comprehensive RA-AF analysis method and the Gaussian mixture model (GMM). The research results show that the entire acoustic emission evolution process can be divided into the crack generation and propagation (Ⅰ) stage and the post-peak damage (Ⅱ) stage. In terms of acoustic emission characteristics, the splitting effect of the pulsed gas on the casing material aged for 3 and 5 d is better than that at 7 d. Considering the compressive strength requirements, the splitting effect of the A2 group casing material is optimal when aged for 5 d. As the loading progresses, the RA-AF data points move towards high RA values and low AF values, with the proportion of tensile cracks decreasing and the proportion of shear cracks increasing. The failure mode is a mixed tensile-shear failure dominated by shear failure.

Influence Mechanism of Curing Regime on Strength of Barite Radiation Shielding Concrete

SI Pengchao, XUE Kaixi, ZHOU Ziqin, WANG Shengfu, HU Yanxiang, OUYANG Zhihui

2024, 43(11):  3996-4003. 

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In order to further improve the strength of radiation shielding concrete, this paper investigates the strength of barite radiation shielding concrete under different curing regimes by setting up four curing regimes: standard curing, steam curing, combined curing 1 (3 d steam curing +25 d standard curing) and combined curing 2 (7 d steam curing +21 d standard curing). The effects of different curing regimes on the radiation shielding concrete hydration products, interfacial transition zone (ITZ), fiber and steel shot bonding property were investigated by scanning electron microscope (SEM). The test results show that both steam curing and combined curing enhance the strength of radiation shielding concrete compared to standard curing, in which the 28 d compressive strength and splitting tensile strength of steam curing improve the most compared with standard curing, which increase 12.7% and 9.5%, respectively, and both high temperature and high humidity curing environments stimulate the volcanic ash activity of silica fume and promote Ca(OH)₂ to participate in the secondary hydration to generate honeycomb-like C-S-H gel, and the formation of needle-like or columnar calcium alumina (AFt), making the microstructure more dense; at the same time, it will enhance the stability of the internal ITZ of radiation shielding concrete and reduce the gaps; and the fibers and steel shot with the substrate bonding property is better, and better tensile and pull-out resistance, of which steam curing is more obvious. This paper provides a new reference for the research of radiation shielding concrete.

Mechanical Properties and Frost Resistance of Multi-Scale Carbon Fiber Modified Concrete

FANG Ying, WEN Zhu

2024, 43(11):  4004-4011. 

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Carbon nanofibers (CNFs) and carbon fibers (CFs) are nanoscale and micrometer carbon-based fibers, respectively. By mixing them into concrete, one kind of carbon nanofibers modified concrete (CNFsMC, the volume content of CNFs is 0.3%) and four kinds of multi-scale carbon fibers modified concrete (MCFsMC, the volume content of CNFs is fixed at 0.3%, and the volume content of CFs is 0.05%, 0.10%, 0.15%, 0.20%, respectively). The effect of multi-scale carbon-based fibers on mechanical properties and frost resistance of concrete were studied, and the modification mechanism of multi-scale carbon-based fibers on concrete was analyzed. The results show that the mechanical properties and frost resistance of concrete can be further improved by adding appropriate content of CFs on the basis of 0.3% CNFs. When the content of CFs is 0.1%, the mechanical properties and frost resistance of MCFsMC are the best, and the total porosity and average pore size before and after freeze-thaw cycle are the minimum. And the compressive strength, flexural strength, flexural-compressive strength ratio and splitting tensile strength of MCFsMC increase by 13.93%, 25.08%, 9.83% and 20.15%, respectively, compared with CNFsMC. After 200 freeze-thaw cycles, the mass loss rate of MCFsMC is only 0.95%, the relative dynamic elastic modulus is 89.2%, and the strength loss rate is less than 14%. CNFs and CFs have positive hybrid effect, and they can complement each other, construct multi-scale crack resistance network and effectively play an effect on cracks with different sizes, and double enhance the mechanical properties and frost resistance of concrete.

Mechanical Properties and Pressure Sensitivity of High Strength Cement Concrete Modified by Nano-Carbon Black

YI Biliang, LI Gengying, WANG Linbin, GAO Han

2024, 43(11):  4012-4018. 

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The high strength cement concrete (HSCC) has excellent mechanical properties and durability, and it is one of the most commonly used construction materials in the key major civil engineering projects. Realizing the pressure sensitivity of HSCC can automatically monitor and test the service capacity of structures, and improve the safety and reliability of buildings. In this paper, HSCC with a 28 d compressive strength of more than 80 MPa was constructed by using micro steel fibers and nano-carbon black (NCB). The effect of NCB content on the mechanical properties and pressure sensitivity of HSCC was studied. The results show that the mechanical properties of HSCC are affected by NCB. The compressive and flexural strength of HSCC with an optimal NCB content of 0.05% of cement mass fraction are about 21.0%~33.0% and 9.6%~33.8% higher than that of the control one, respectively. NCB significantly improves the pressure sensitity of HSCC. The higher the content is, the more significant the pressure sensitivity is, the smaller the noise is, and the better the stability is. The force-electric signal relation follows exponential function relationship and the fitting degree is 0.923. The effect of NCB on the pressure sensitivity of HSCC conforms to the seepage principle, and its seepage threshold is about 0.1%, and the average sensitivity coefficient is increased by 5.0 times.

Effect of Curing Process on Properties of Sand-Free Macroporous Recycled Concrete

XU Chenyang, ZHANG Zhizhu, ZHANG Pengfei, LI Qiuyi, KONG Zhe, GUO Yuanxin, CHEN Mingxu

2024, 43(11):  4019-4026. 

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To address the waste of natural aggregates and limited application of recycled aggregates, this study prepared sand-free macroporous recycled concrete using natural and recycled aggregates. Macro and micro properties of dry, water spraying, and coating sand-free macroporous recycled concrete were investigated via mechanical properties, microhardness, scanning electron microscopy, and X-ray diffraction analysis. The results show that different curing processes affect the hydration reaction of ordinary Portland cement, and sand-free macroporous recycled concrete “honeycomb” structure and recycled aggregate characteristics complicate the hydration process. The best curing method is coating, followed by dry, while water spraying is least effective. Microhardness and scanning electron microscopy tests reveal that the free water absorption in matrix increases during water spraying, resulting in concrete expansion, deteriorating adhesion of aggregate-cement interface and decreasing hardness. X-ray diffraction analysis results confirm the effects of curing methods on sand-free macroporous recycled concrete via composition of hydration products like portlandite.

Influences of Preconditioning and Carbonization Time on Carbonization Effect of Foam Concrete and Analysis

LIU Yuhang, LUO Ping, JIANG Shanping, LIU Ji, JING Daiyan, LIU Rongjin

2024, 43(11):  4027-4035. 

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Carbon mineralization technology is considered one of the most direct and effective approaches for CO₂ sequestration and addressing the issue of greenhouse effect. Stainless steel slag, primarily composed of γ-dicalcium silicate (γ-C₂S), possesses significant potential for carbonation due to its composition. In this study, 80% (mass fraction) stainless steel slag and granulated blast furnace slag powder were used as main raw materials to prepare A12 dry density grade foam concrete. The effects of preconditioning time and carbonation time on the compressive strength and carbon fixation ratio of foam concrete were investigated in a carbonation environment of 0.4 MPa and 60 ℃. The results show that the best preconditioning time is 2 d. The compressive strength of foamed concrete with preconditioning 1 and 2 d reaches the peak after carbonization for 3 d. The compressive strength of foamed concrete with preconditioning 2 d is 51.19% higher than that of preconditioning 1 d. When carbonization for 3 d, the carbon fixation ratio of foamed concrete with preconditioning for 1 and 2 d is 9.94% and 12.10%, respectively. In this study, it is of great significance to realize the carbon mineralization process by using industrial solid waste in a simple carbonization environment, which not only consumes a large amount of solid waste, but also stores carbon dioxide.

Dynamic Compressive Properties of Rock-Filled Concrete with Initial Pores

YU Lei, QIAO Haoyang, WANG Guoji, LIU Yunke, REN Tao, YANG Tao

2024, 43(11):  4036-4046. 

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Initial defects are identified as one of the root causes affecting the mechanical properties of concrete. In this paper, expanded polystyrene (EPS) particles were utilized to prefabricate initial defects of rock-filled concrete (RFC), and the defect content was quantified by porosity. Uniaxial compression tests of four porosities of RFC at four strain rates were systematically conducted, and the effects of strain rate and porosity on RFC failure modes, compressive strength, elastic modulus, and critical strain were studied. The results show that the RFC failure modes under different operating conditions are similar to the “hourglass” type. The compressive strength, elastic modulus and critical strain of RFC all have strain rate strengthening effect. As the porosity increases, the sensitivity of RFC compressive strength, elastic modulus, and critical strain to strain rate decreases. Compared with strain rate, the effect of porosity on compressive strength, elastic modulus, and critical strain of RFC is more significant. Additionally, based on the Sargin model, a dynamic constitutive model of RFC with initial pores is constructed. It is used to illustrate the mechanical behavior of RFC with initial pores at low strain rates.

Durability and Stomatal Structure of Cellulose Fiber Air Entrained Concrete

MA Chao, ZHU Jian

2024, 43(11):  4047-4054. 

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In order to compensate for the strength loss caused by air entraining agent, and further improve the durability of concrete, the effects of cellulose fiber content (0.08%~0.12%, volume fraction) and air content (2%~4%) on the mechanical properties of concrete were studied by adding cellulose fiber and air entraining agent to concrete, and the air content of air entrained concrete was determined. The effect of cellulose fiber on the durability of air entrained concrete was studied by plastic shrinkage test, impermeability test, sulphate-wet and dry cycle test and freeze-thaw test. Combined with the bubble spacing test, the stomatal structure of cellulose fiber air entrained concrete was analyzed. The results show that the addition of air entraining agent can reduce the mechanical properties of concrete, the cellulose fiber can improve the mechanical properties of concrete, and the air content of concrete should not be more than 3%. Cellulose fiber can improve the shrinkage resistance, impermeability, sulfate erosion resistance and freezing resistance of air entrained concrete. When the cellulose fiber content is 0.10%, the mechanical properties and durability of cellulose fiber air entrained concrete are the best. The air entraining agent can obviously improve the characteristics of bubble system of concrete. When the air content is more than or equal to 3%, the bubble spacing coefficient of cellulose fiber air entrained concrete is less than 250 μm.

Basic Mechanical Properties of Grouting Material for Offshore Wind Power Foundation under Different Seawater Pressures

JIANG Guangqiu, LI Zhi, ZHOU Xingzheng, ZHANG Kuoji, WU Zhaoqi

2024, 43(11):  4055-4060. 

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The connection between offshore wind power foundation structures and steel pipe piles is usually carried out by grouting. With the development of offshore wind power to deep sea, the grouting connection between wind power foundation and steel pipe piles is deeper and deeper in underwater position. To determine the influence of seawater pressure on the basic mechanical properties of grouting material, the grouting material specimens were placed in a pressure vessel for curing, and then their basic mechanical properties such as compressive strength, flexural strength, and elastic modulus were tested. In addition, the phase composition and microstructure were analyzed by X-ray diffractometer and scanning electron microscope. The results show that the compressive strength of grouting material is improved after curing under a pressure environment. Seawater pressure does not produce a “wedging” effect, but further improves the compactness of grouting material. When the seawater pressure increases from 0 MPa to 0.75 MPa, the compressive strength, flexural strength, and elastic modulus of grouting material increase by 10.7%, 2.9%, and 16.7%, respectively. Seawater pressure does not change the phase composition of grouting material, but reduces its internal porosity and increases its compactness, thus improving its mechanical properties.

Uniaxial Tensile Damage Constitutive Model of Polypropylene Fiber Reinforced Engineered Cementitious Composites

JIA Yi, ZHAO Qiang, WEI Chaokuan, SONG Haobo, LI Tangwei, SHEN Xiantao

2024, 43(11):  4061-4071. 

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Polypropylene fiber reinforced engineered cementitious composite (PP-ECC) is a ductile material with good properties, low cost and wide application prospect. In this study, the impact of varying fiber content on the tensile mechanical behavior of PP-ECC was explored, encompassing parameters such as initial cracking stress and strain, peak stress and strain, stress-strain relationship, and elastic modulus. Drawing from uniaxial tensile tests, damage factors were defined and a constitutive model tailored to the tensile characteristics of PP-ECC was formulated, leveraging existing engineered cementitious composite (ECC) damage constitutive models and theories. Refinements were made to the fitting function of damage factor, employing a univariate 6th-degree function and utilizing Origin and Matlab for parameter calculation and identification within the damage factor function. The optimized constitutive model demonstrates enhance alignment with experimental results, marking a significant improvement in model accuracy.

Solid Waste and Eco-Materials

Advances in Low Carbon High Belite Sulfoaluminate Cement Based on Industrial Solid Waste

HE Shiqin, LI Fawen, SUN Xiaoyan, WANG Hailong

2024, 43(11):  4072-4082. 

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The development of high belite sulfoaluminate cement based on industrial solid waste is an important means to realize low carbon sustainable development of the construction industry. As a cementitious material with high early strength and good later strength development, high belite sulfoaluminate cement has broad application prospects.This paper summarizes the existing research on the preparation process and cement properties of high belite sulfoaluminate cement, analyzes the influence of the sintering methods on the target mineral composition of cement clinker and the criteria for judging the optimal sintering methods, compares the energy consumption of different calcination systems, and elaborates on the development law of compressive strength of ternary and quaternary systems and the hydration properties of cement, which will help to improve the utilization of industrial solid wastes and the development of low carbon sustainable construction industry. It provides a reference for the utilization of industrial solid waste and the in-depth research and wide application of high belite sulfoaluminate cement.

Research Progress of Geopolymers in Sewage Treatment

LIU Boyan, PENG Xinpan, GUO Zhaocheng, LIU Qi, FAN Lihua, SONG Xuefeng

2024, 43(11):  4083-4098. 

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Geopolymer is a novel type of inorganic cementitious material prepared from aluminosilicate industrial solid waste and burnt clay as raw materials through a process of “depolymerization-condensation-reconstruction” under the action of chemical excitation. Compared to traditional Portland cement, geopolymer is known as the most promising green cementitious material in the 21st century due to its low-carbon environmental protection, controllable structure, and adjustable performance during the preparation process. At the same time, geopolymer has the material and structural genetic characteristics of zeolite minerals due to the formation process similar to synthetic zeolite. Based on the ion exchange and adsorption properties of zeolite, the application of geopolymers as an adsorption material for sewage treatment is rapidly becoming a research hotspot. This paper summarizes the synthesis mechanisms and structural characteristics of geopolymers, outlines the current research status of geopolymers in the field of sewage treatment, and discusses the problems and development prospects of geopolymers in the field of sewage treatment.

Analysis of Influencing Factors and Forming Mechanism of Artificial Aggregate Based on Coal Gangue

ZHAO Younan, YAN Renwei, ZHANG Taiqing, ZHAI Xinming, WANG Haoyu, DENG Wei, XIONG Rui

2024, 43(11):  4099-4106. 

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After calcination treatment, coal gangue exhibits good mechanical properties and has the potential to be fired into aggregates. This study investigated the effects of different ratios of coal gangue to feldspar, forming pressure and calcination temperature on the physical properties of aggregates, and analyzed the significance of each influencing factor using the grey correlation method. The microstructure and phase composition of the aggregates were explored using SEM and XRD. The results indicate that both the raw material ratio and calcination temperature significantly affect the physical properties of the aggregates. A high proportion of coal gangue reduces the liquid phase content and viscosity in the system, and the inability of gases produced during calcination to escape leads to the formation of more pores and microcracks inside the aggregates, degrading their mechanical properties. Increasing the proportion of feldspar powder and the calcination temperature promotes crystal nucleation. As potassium-sodium feldspar melts, the K⁺ and Na⁺ content increases and combines with [AlSiO₄] to form potash feldspar and plagioclase, promoting a dense internal structure of the aggregates. This study provides valuable insights for the precise utilization of coal gangue.

Macroscopic Mechanical Properties and Mesoscopic Behaviors of Cement-Fly Ash Fluid Solidified Soil for Road Engineering

GUO Jukun, CAO Xinxin, MA Yongming, HUI Yingxin, HUANG Yajuan, SHEN Bingyao

2024, 43(11):  4107-4118. 

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In order to explore the macroscopic mechanical properties and microscopic behavior evolution of cement-fly ash fluid solidified soil, X-ray diffraction (XRD) and scanning electron microscope (SEM) testing methods were used, combined with mechanical experiments and particle flow code (PFC) discrete element numerical simulation experiments, to study the strength characteristics of fluid solidified soil with different mix ratios under freeze-thaw action, and to analyz its mesoscopic morphology and crack evolution characteristics. The research results indicate that the flowability of fluid solidified soil is positively correlated with the dosage of cement and fly ash, and the addition of fly ash effectively reduces the wet density of fluid solidified soil. The gel material generated by the pozzolanic reaction of fly ash significantly improves the late strength and frost resistance of fluid stabilized soil. The cracks in the fluid solidified soil specimen first appear when the axial strain is about 1%, and then the number of cracks increases linearly. It tends to stabilize when the axial strain is within the range of 4% to 5%, and parallel through cracks appear on the surface of specimen.

Preparation of CaO·6Al₂O₃-Al₂O₃ Composite Ceramics by Ferrotitanium Slag Phase Reconstruction

HU Kaiwen, WANG Ying, LI Chengzhuo, DENG Tengfei

2024, 43(11):  4119-4129. 

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The present study focus on the preparation of Al₂O₃-CA₆ composite ceramics by co-firing ferrotitanium slag with Al₂O₃. CA₆ was formed through the reconstruction of ferrotitanium slag phase, with a long plate-like morphology and good compatibility with Al₂O₃. CA₆ was used as a toughening phase for ceramics. This study reveals the influence of CA₆ content and sintering temperature on the properties and microstructure of Al₂O₃-CA₆ composite ceramics by regulating the formula composition and sintering temperature. With the increase of CA₆ content, the bulk density, bending strength, and fracture toughness of ceramic samples all show a decreasing trend. As the temperature increases, the bulk density and bending strength of ceramic samples increase first and then decrease. The bulk density, apparent porosity, bending strength, and fracture toughness of two sets of samples containing 90% (mass fraction) Al₂O₃ and 85% (mass fraction) Al₂O₃, respectively, are obtained by sintering at 1 320 ℃. The values are 3.79 g/cm³, 0.22%, (385.01±21.67) MPa, and (5.33±0.21) MPa·m^1/2, respectively; 3.69 g/cm³, 0.12%, (371.22±9.65) MPa, (4.94±0.08) MPa·m^1/2, the utilization rate of titanium iron slag is higher than 75%, which is of great significance for the resource utilization of titanium iron slag.

Effects of PVA Latex Powder and PP Fiber on Bonding Property of Alkali-Activated Slag Self-Leveling Repair Mortar

HE Juan, WU Jiahan, ZHU Mingming, REN Haitao, SANG Guochen

2024, 43(11):  4130-4139. 

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The bonding interface is the weak link of old concrete structure after repair, and it is an important factor affecting the bonding properties of the interface between repair mortar and concrete matrix. In this paper, AAS cement was used as cementitious material to prepare repair mortar. The effects of polyvinyl alcohol (PVA) latex powder and polypropylene (PP) fiber on the interfacial bonding properties and microstructure of alkali-activated slag self-leveling repair mortar (ASLRM) were studied by fluidity test, interfacial flexural tensile strength test, interfacial tensile strength test and microscopic test. The results show that both PVA latex powder and PP fiber can effectively improve the interfacial bonding properties of ASLRM. When the two are mixed, the interfacial flexural tensile strength of 28 d increases by 43.1%, and the interfacial tensile strength of 14 d increases by 69.9%.

Preparation of Foamed Ceramics from Pearlite Tailings

WU Xiaojian, FAN Junmin, ZHOU Mingkai, ZHANG Zhaoyang, MEI Wenzheng

2024, 43(11):  4140-4149. 

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Foamed ceramics were prepared using perlite tailings as main raw material and SiC micro powder as foaming agent. The effects of temperature, heating rate, holding time, foaming agent content, raw material granularity, and SiC particle size on density, apparent porosity, compressive strength, and pore structure of foamed ceramics were studied. The results show that with the appropriately increase of temperature, holding time, SiC content, and the decrease of raw material granularity and SiC particle size, the sample density and compressive strength decrease, and the apparent porosity increases. When SiC reaction is excessive, black centers appears in sample. At 1 250 ℃, with a heating rate of 8 ℃/min, a holding time of 1 h, an external addition of 0.6%(mass fraction) SiC, and a raw material particle size D₃₂ of 7.51 μm, the prepared foamed ceramics has the best comprehensive performance, with density of 462.77 kg/m³, apparent porosity of 1.26%, compressive strength of 8.1 MPa, and average pore diameter of 0.33 mm.

Effect of Granite Waste Powder on Strength and Durability of Mortar

SHENTU Cun, ZHENG Guangyuan, TAN Xingmiao, ZHOU Mingsu, HU Saiqun, LIANG Chaofeng

2024, 43(11):  4150-4158. 

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In view of the problems of large output and serious environmental pollution of granite waste powder (GWP), the activity of GWP at different ball milling times (0, 10, 20 and 30 min) and the effect of equal mass substitution (0%, 10%, 20% and 30%) on the macro and micro properties of GWP mortar were investigated. The experimental results show that the GWP activity after ball milling for 30 min is high, reaching 72.98%. As the GWP replacement rate increases from 10% to 30%, the flexural strength, compressive strength and dynamic elastic modulus of the mortar decrease by 6.31%~23.94%, 3.02%~26.11% and 5.35%~24.29%, respectively. The carbonization depth and chloride ion permeability coefficient of the mortar increase by 20.43%~81.40% and 2.31%~20.61%, respectively. The addition of GWP makes the mortar microstructure deteriorate, cracks and holes increase, and harmful holes increase. Based on the established relationship between the GWP replacement rate and the strength, durability of the mortar, the optimal replacement rate of GWP is from 12.37% to 21.74%, in which the performance of GWP mortar is still close to that of the benchmark group although there is a certain degree of decrease. Comparing the energy consumption and economic cost of GWP mortar with different substitution rates, each additional 10% of GWP used to prepare unit volume of mortar can reduce energy consumption by 107.08 MJ and economic cost by 46.01 yuan.

Experiments and Applications on Preparation of Natural Hydraulic Lime by Calcination of Industrial Solid Waste

MAO Zhitian, DUAN Xiang, HAO Zehui, DENG Hongyang, TANG Wei, HE Yuan

2024, 43(11):  4159-4166. 

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Natural hydraulic lime (NHL) has both pneumatic and hydraulic components, so NHL can be widely used in the restoration of historic building masonry walls. Industrial solid waste contains certain elements of Ca and Si, meeting the mineral element requirements for the preparation of NHL. In this study, limestone, slag, fly ash and silica fume were used as raw materials to prepare NHL by calcination with different calcium-silicon ratio parameters. The composition, product composition, microstructure, mechanical properties, and setting time of NHL were tested using XRD, TG, compressive and flexural tests, SEM-EDS, and Vicat apparatus. Meanwhile carry out engineering applications. The study shows that it is feasible to prepare NHL by industrial solid waste calcination. The prepared NHL is mainly composed of calcium hydroxide and dicalcium silicate. The 28 d hydration carbonization products include hydrated calcium silicate, CaCO₃, and Ca(OH)₂. NHL can be prepared by calcium-silicon ratio at 4.6 that meets European standards. The repair results of the weathered surface of masonry meet the requirements of reversibility and compatibility. The article responds to the call of national policies for the protection of historical architectural relics and ecological environment, which is conducive to protecting historical culture and creating better economic benefit and environmental benefit.

Strength Characteristics and Microscopic Mechanism of Expansive Soil Improved by Lime-Zeolite Powder

ZHANG Yuguo, ZHAO Chunhao, ZHANG Zhaobin, ZHANG Zilai

2024, 43(11):  4167-4176. 

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Aiming at the engineering disease problems caused by expansion and contraction of expansive soil and the pollution problems caused by lime improved expansive soil, this paper taked the expansive soil in Nanyang area of Henan province as the object of study, and prepared the specimens of vegetal expansive soil and improved soil with different dosages of lime and zeolite powder. The unconfined compressive test, free expansion rate test, triaxial test, X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) test were carried out to study the strength characteristics and microscopic reinforcement mechanism of the lime-zeolite powder composite improved expansive soil. The results indicate that lime improvement and lime-zeolite powder composite improvement can effectively improve the strength of soil and reduce the free expansion rate, and the composite improvement effect is better. The optimum content of lime and zeolite powder is 6% (mass fraction) and 12% (mass fraction), respectively. The stress-strain curves of lime improved soil and composite improved soil are transformed into the strain-softening type. The addition of lime significantly improves the cohesion of the expansive soil. With the increase of zeolite powder content, the triaxial shear strength of composite improved soil increases continuously, and the internal friction angle increases first and then decreases. Zeolite powder reacts with lime to form a large amount of cementitious material, which fills the pores with soil and makes the microstructure more dense, increases the frictional resistance between soil particles, and increases the strength of the soil at the macro-level.

Optimization of Mix Ratio of Alkali-Activated Slag-Fly Ash Mortar Based on Response Surface Methodology

TIAN Ying, WU Shichao, LI Jingjun, SUN Keke

2024, 43(11):  4177-4184. 

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A quadratic regression model was constructed based on the response surface methodology using water/binder ratio, sodium silicate modulus, alkali equivalent (Na₂O content) as independent variables and 28 d compressive strength, 28 d flexural strength, setting time and fluidity as response target values. The model was analyzed for variance and significance, and the optimal mix ratio was determined. The results show that the most significant effect of water/binder ratio on compressive strength, flexural strength, setting time and fluidity, followed by sodium silicate modulus and alkali equivalent, there is a more significant interaction between the factors, in which the interaction between water/binder ratio and sodium silicate modulus is the most significant. The optimal mix ratio is 0.39 water/binder ratio, 1.38 sodium silicate modulus and 4.7% (mass fraction) alkali equivalent, and the error between the model prediction and the experimental results is less than 10%. The high accuracy of this regression fitting model further confirms the effectiveness of the response surface methodology in determining the optimal mix ratio parameters of alkali-activated materials.

Microwave-Induced Self-Healing Performance of Asphalt Mixtures with Coal Gasification Slag

DING Donghai, WU Xingxing, XIAO Guoqing, GUAN Bowen, JIN Endong

2024, 43(11):  4185-4194. 

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Asphalt mixtures have certain microwave-induced self-healing performance, but the self-healing process is relatively slow. Wave-absorbing fillers can be added to enhance the microwave absorption capacity of asphalt mixtures, thereby accelerating the self-healing process. In this paper, coal gasification slag was used as a wave-absorbing filler to prepare asphalt mixtures. The microwave-induced self-healing performance and mechanism of asphalt mixtures with coal gasification slag were investigated. The results show that the microwave heating rate of asphalt mixtures with 50% and 100% (mass fraction) replacement of coal gasification slag increases by 23.1% and 53.8%, respectively, compared with that of ordinary asphalt mixture. Coal gasification slag can significantly improve the dielectric properties of asphalt mixtures. Under microwave radiation, coal gasification slag can convert more electromagnetic energy into thermal energy, which in turn induces the occurrence of self-healing process in asphalt mixtures. The self-healing performance of asphalt mixtures with coal gasification slag is significantly better than that of ordinary asphalt mixtures. After 90 s of microwave heating, the self-healing efficiency of asphalt mixtures with 50% and 100% replacement of coal gasification slag is 2.59 times and 3.36 times higher than that of ordinary asphalt mixtures, respectively. The addition of coal gasification slag also significantly improves the damage level of asphalt mixtures after healing, resulting in superior self-healing performance.

Ceramics

Preparation and Thermal Expansion Properties of (ZrMg)_xY_2-2xW₃O₁₂ Ceramics

WANG Xianli, WANG Haili, XU Kun, DUAN Xiangyang, CHEN Dongxia

2024, 43(11):  4195-4200. 

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(ZrMg)_xY_2-2xW₃O₁₂ (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0) ceramics were developed with a simple solid state method, and the structure, hygroscopicity and thermal expansion property of ceramics were characterized by X-ray diffraction, Raman spectroscopy, thermal analyzer and thermal dilatometer. The results show that with the increase of Zr⁴⁺/Mg²⁺ content, the hygrosopicity of (ZrMg)_xY_2-2xW₃O₁₂ ceramics decreases obviously, and the coefficient of thermal expansion increases gradually from negative thermal expansion to positive thermal expansion. A near-zero thermal expansion is realized for (ZrMg)_0.6Y_0.8W₃O₁₂ (455~1 050 K,-0.54×10^-6 K^-1) as x=0.6, and the coefficient of thermal expansion of a, b and c axes are measured to be α_a=-1.13×10^-6 K^-1, α_b=1.77×10^-6 K^-1 and α_c=-1.80×10^-6 K^-1, respectively. The intrinsic volumetric coefficient of thermal expansion α_v is -1.21×10^-6 K^-1.

Properties of BiFeO₃-(Ba_0.85Ca_0.15)(Zr_0.10Ti_0.90)O₃ Ceramics Prepared by Two-Step Sintering Method

CUI Yuhan, WANG Weiyi, WANG Ting, ZHANG Jingxiang, LIU Xuchong, HUANG Chen, LU Junming

2024, 43(11):  4201-4207. 

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The ferroelectric property of ceramics can be significantly improved by adding (Ba_0.85Ca_0.15)(Zr_0.10Ti_0.90)O₃ into BiFeO₃. However, the sintering temperature of ceramics prepared by traditional solid-state method is high, resulting in increasing internal defects of ceramic materials. In this study, 0.7BiFeO₃-0.3(Ba_0.85Ca_0.15)(Zr_0.10Ti_0.90)O₃-0.15% (mass fraction) MnCO₃ (abbreviated as 0.7BF-0.3BCZT) ceramics were sintered using the two-step sintering method based on the short-term sintering at high temperature (T₁) and long-term holding at low temperature (T₂). The effect of T₁ temperature on the phase composition, microstructure, ferroelectric and dielectric properties of as-prepared ceramics was investigated. The results reveal that the phase structures of as-prepared ceramics are coexistence of rhombohedral and pseudo-cubic phases with no evidence of secondary phase. With the increase of T₁ sintering temperature, the bulk density, dielectric constant and remanent polarization of ceramics increase first and then decrease. Consequently, the ceramics prepared at T₁=1 040 ℃ demonstrate excellent dielectric and ferroelectric properties. The maximum dielectric constant and remanent polarization are 6 706.10 and 8.53 μC/cm², respectively.

Glass

Preparation and Gas Selectivity of ZIF Crystal-Glass Composite Film

GUO Siyu, GU Shaoxuan, QIAO Ang, TAO Haizheng

2024, 43(11):  4208-4214. 

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Metal organic framework (MOF) crystal films have attracted much attention in the field of gas separation due to their pore structure regulation at molecular level. However, the preparation of high quality MOF gas separation film has always been a challenge due to many grain boundary defects and the difficulty of film formation. Therefore, a solution to prepare MOF crystal-glass composite film was proposed in this paper, taking advantages of MOF glass without grain boundary and easy forming. Firstly, ZIF-8/ZIF-62 crystal film with mixed crystal composite and double layer composite was prepared by in-situ solvothermal method, and then the crystal-glass composite film was prepared by melting and cooling. The results show that the fused ZIF-62 liquid phase can effectively bridge the grain boundary defects and make film dense. Compared with mixed crystal films, the crystal-glass composite films prepared by ZIF-8/ZIF-62 multilayer composite films have higher gas selectivity and separation efficiency for H₂/N₂, H₂/CH₄, CO₂/N₂, and CO₂/CH₄ mixed gases. Especially for H₂/CH₄ and CO₂/CH₄, the selectivity can reach 27.7 and 26.5, respectively.

Controllable Oxidation of Kovar Alloy and Wetting Performance with Borosilicate Glass

GUO Hongwei, NIE Dong, WANG Yi, LIU Mi, ZHU Nantian, GUO Shouyi, GAO Yibo, ZHAO Zhilong

2024, 43(11):  4215-4223. 

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In this paper, the high temperature oxidation treatment of Kovar alloy was carried out under different oxidation atmosphere conditions, and the optimum oxidation process of Kovar alloy was optimized. The wetting test and sealing test were carried out with borosilicate glass. At the same time, the oxidation composition and sealing interface were analyzed by XRD, XPS, SEM, EDS and other analytical methods. The results show that Fe, Co and Ni elements all participate in oxidation reaction at high temperature, and the oxidation dynamics of Kovar alloy follow the parabolic rule. The optimal oxidation process of Kovar alloy is: oxidation temperature 850 ℃, oxidation time 11.7 min, N₂ flow 1 L/min, and dew point 30 ℃.After oxidation treatment in different atmospheres, the hermeticity of Kovar alloy and glass sealing changes little. The tensile strength of glass and Kovar alloy with surface oxide of Fe₃O₄ is the highest after sealing.

Refractory Materials

Effects of Lightweight Alumina Aggregates on Erosion Mechanisms of Alumina Magnesia Carbon Refractories Used for Impact Zone of Steel Ladle Bottoms

GAO Jie, CHEN Qilong, LIU Cheng, LI Tianqing, FENG Runtang, ZUO Qixiu

2024, 43(11):  4224-4231. 

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The lightweight of refractories used for steel ladles is of great significance for energy saving and reduction of the specific refractory consumption per ton of steel. In this paper, the erosion mechanisms of alumina magnesia carbon refractories containing lightweight alumina aggregates in the impact zone of 170 t steel ladle bottom were investigated, and the comparison with traditional dense alumina magnesia carbon refractories was analyzed. The results show that the alumina magnesia carbon refractories using lightweight alumina aggregates exhibit a better application effect. The wear rate decreases from the original 1.79 mm/heat to 1.35 mm/heat, and the service life increases by nearly 24.6%. It is found that the introduction of lightweight alumina aggregates with high surface roughness and abundant micro-sized pores can not only strengthen the bonding interface between aggregates and matrix, but also absorb the thermal stress through pores, which contributes to the improved erosion resistance and thermal shock resistance of alumina magnesia carbon refractories. It also promotes the formation of a thick dense calcium hexaluminate and MgAl₂O₄ spinel composite isolation layer at the hot face, which impedes the slag corrosion and penetration as well as oxidation of carbon. In addition, slag can be absorbed by the lightweight alumina aggregates and a special core-shell structure formed, and thus better slag corrosion resistance is obtained.

Properties of Cement-Bonded Aggregate and Matrix Synergistic Low-Conductivity Mullite Castable

LI Yawei, SONG Shaohui, LIAO Ning, KE Wenli, LIU Wenjing, TIE Shengnian, LIU Xin

2024, 43(11):  4232-4239. 

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Given the imperative of energy conservation, safety, and durability in high-temperature industrial furnaces, current research focuses on reducing the thermal conductivity of refractories used in furnace linings while ensuring optimal performance. The research subject of this study was cement-bonded mullite castable. Firstly, the hydration behavior of calcium aluminate cement was regulated by incorporating magnesium silicate hydrate (M-S-H) with a high specific surface area to enhance bonding strength. Additionally, thermal conductivity was cooperatively reduced by lightweight mullite aggregate and introducing air-entraining agent in the matrix. The results indicate that M-S-H with a high specific surface area provides more nucleation sites for hydration products, thereby facilitating the formation of pin CAH₁₀ during cement hydration and improving castable bonding strength. Furthermore, through the incorporation of M-S-H and 0.01% (mass fraction) air-entraining agent in castables with lightweight mullite aggregate, the pore within 1~100 μm significantly increases after heat treatment at 1 250 ℃. Moreover, at 1 000 ℃, the thermal conductivity is only 0.599 W·(m·K)^-1, which is 18.9% lower than that observed in traditional castables.

Road Materials

Experimental Study on Uncertainty Evaluation of Typical Mechanical Parameters of Pavement Materials

TANG Limin, GONG Guien, PENG Shoubo

2024, 43(11):  4240-4253. 

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To test and reflect the influences of objects, instruments, methods, and conditions on results and to obtain more reliable and accurate representative values of the mechanical parameters of pavement materials, this study was based on the theory of measurement uncertainty. It used cement stabilised aggregates and AC-16C asphalt mixtures as study objects and proposed using synthetic standard uncertainty instead of standard deviation in calculating the representative value to determine the standard deviation of measurement results. The synthetic formula was employed to determine the standard variance of measurement results. The results were evaluated with class A and class B uncertainties and verified by the Monte Carlo method (MCM). The results indicate that using synthetic standard uncertainty instead of standard deviation to calculate the representative value for structural design is more conservative and accurately reflects the actual project situation. The representative value of pavement mechanical parameters obtained based on measurement uncertainty theory effectively reflects the uncertainty of the mechanical parameters of the pavement material. This, in turn, affects the uncertainty of the pavement structural mechanical calculation and the pavement performance in the later stages of the project. The “Guide to the Expression of Uncertainty in Measuremen” (GUM) is applicable to the measurement uncertainty of pavements. While the GUM has a wide range of applicability, it presents significant errors for nonlinear measurement models and mathematical models with strong correlation components. Compared with the MCM, the evaluation process of GUM is relatively complex and prone to errors. The findings of this study are expected to provide a reference for accurately evaluating the representative values of typical mechanical parameters of pavement materials, thereby promoting the widespread application of measurement uncertainty evaluation theory in design, construction, and quality control.

Crack Resistance Performance of Cement-Stabilized Macadam Mixed with Modified Rubber Powder

HAN Hongyu, LI Shaoqiu, WEI Wuwei, JI Jie, WANG Junwu, LI Zengbao, ZHENG Wenhua

2024, 43(11):  4254-4260. 

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To study the effects of rubber powder, recycled construction waste aggregate and gradation on the crack resistance performance of cement-stabilized macadam, a semi-circular bending test was conducted to evaluate the crack resistance performance of cement-stabilized macadam mixed with modified rubber powder, using indicators such as stiffness, fracture energy, and fracture toughness. The results demonstrate that unmodified rubber powder enhances the fracture energy and fracture toughness of mixture, with modified rubber powder exhibiting a more significant improvement in crack resistance performance. The crack resistance gradation can improve the stiffness, fracture energy, and fracture toughness of mixture, thereby enhancing its crack resistance performance. The crack resistance performance of cement-stabilized macadam mixed with modified rubber powder decreases with the increase of recycled aggregate. When 30% of the natural aggregate is replaced with recycled aggregate on an equal volume basis, the crack resistance performance and strength of cement-stabilized macadam mixed with modified rubber powder are superior to those of ordinary cement-stabilized macadam.

Experimental Study on Mechanical Properties and Road Properties of Solidified Construction Waste Soil

GUO Shaohua, ZHAN Shizuo, KANG Tianbei, DING Xiangqun, WANG Fengchi

2024, 43(11):  4261-4269. 

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In order to solve the problems of difficult treatment of construction residue and low degree of resource utilization, this paper proposes to use a curing agent to solidify construction residue. In this paper, the effects of cement content, curing agent content, and curing age on the unconfined compressive strength, splitting tensile strength, water stability, freeze-thaw resistance, and dry shrinkage resistance of solidified soil were analyzed, and the curing mechanism of co-curing agent and cement was revealed by SEM and XRD tests. The results show that, when the cement content is 7%, and the content of curing agent is 3%, the unconfined compressive strength of solidified soil residue is 6.91 MPa, the splitting tensile strength is 0.98 MPa, and the hydraulic stability coefficient is 91.52% for 28 d, compared with cement curing, which increases by 15.7%, 31.2% and 12.2%, respectively. The incorporation of the curing agent has the effect of improving the dry shrinkage resistance of solidified soil. After 10 freeze-thaw cycles, the mass loss rate of solidified soil decreases by 44.6% and the residual strength increases by 34.9% compared with that of cement cured specimens. The C-S-H and C-A-H cementitious substances generated by the cement hydration reaction of the curing agent make the soil particles agglomerate into a granular structure and form a network skeleton to provide strength. The SiO₂ and Al₂O₃ in the curing agent reduce the content of free water and adsorbed water between the soil particles, and the strength and road performance of the solidified soil is enhanced and improved after the addition of the curing agent. The results of the study provide a theoretical basis for the application of cured construction residue soil in roadbeds.