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China adopted a “Zero-COVID” policy for nearly three years, making Chinese healthcare workers constantly involved in COVID-19-related work. However, little is known about how involvement in COVID-19-related work shaped Chinese nurses’ burnout. This study explores how nurses’ job demands and job resources are associated with their burnout by considering high and low frequent involvements in COVID-19-related work in China. This study employed a cross-sessional design. Guided by Job Demands-Resources (JDR) model, we developed hypotheses and tested them using regression analysis with a sample of 336 nurses working in four public hospitals in Guangdong, China. Overall sample results revealed: 1) frequency of involvement in COVID-19-related work was related to a higher level of workload; 2) nurses’ burnout was positively associated with workload, emotional demands, and work-family conflict, and negatively associated with a relationship with supervisor, remuneration, and independence of work; 3) emotional intelligence mitigated the positive relationship between workload and burnout. Comparison analysis showed significant differences due to the frequency of involvement in COVID-19 work. In the high-frequency group (N = 108), 1) emotional demands were related to a higher level of burnout, and emotional intelligence moderately accentuates the positive relationship between the two variables; 2) remuneration was related to a lower level of burnout; 3) nurses reported higher levels of workload and relationship with the supervisor. In the low-frequency group (N = 147), independence of work was related to a lower level of burnout; We found some evidence that nurses’ job demands and job resources and their associations with burnout differed due to their frequency of involvement in COVID-19-related work. Implications for policy-making and theoretical contribution are discussed.

This paper aims to explore the particularity of proprioception. Because of its internality, inseparable descriptiveness and ‘need no proof’ characteristics, it is different from perceptual knowledge, and because of its non-intentional, it is different from practical knowledge. Besides, as the intermediary of mind and body, it provides an important foundation for mind and external perception and intentional action.

ABSTRACT: Wellbore integrity to ensure efficient, economical, and environmentally friendly operations is a significant and fundamental challenge for CO2 sequestration wells. The carbonation reaction between Portland cement and CO2 can change the microstructure of the cement skeleton, change the cement mechanical properties, damage the annular seal, and finally induce CO2 leakage. This study utilizes an integrated approach including a CO2-cement degradation test, mechanical tests for strength and elastic properties, X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) for composition analysis, and finite element analysis for failure evaluation. The mechanical test results show that the carbonation reaction can improve the sealing effect of the cement during the early stage of degradation (~2 weeks). Mechanical and geochemistry test results show that the carbonation reaction would fundamentally change the composition and microstructure of the cement matrix after long-term CO2 degradation, thereby inducing significant decreases in strength, and enhanced porosity, and permeability. The numerical results indicate that during long-term CO2 injection, the sealing effect of the cement would decrease gradually, and the cement sheath is more likely to fail under external loads arising from wellbore pressure and temperature variations. The mechanical and geochemical test results also show that the temporal variations of cement strength and Ca2+ composition have a strong similarity, which should be further analyzed for possible correlation. In summary, this study provides an integrated approach to qualitatively and quantitatively evaluate the cement degradation and predict failure of CO2 sequestration wells. The allowable wellbore pressure and temperature ranges can be provided for different degrees of cement sheath degradation to assist the field operations and cement slurry design of CO2 sequestration wells. 1. INTRODUCTION The unwanted leakage from the CO2-injection wells impedes the stable and economic industrialization of the CO2 geological sequestration. Therefore, maintaining wellbore integrity becomes a priority task to ensure a successful CO2 sequestration project (Zhang et al. 2019, Xu et al. 2022). For CO2-injection wells, the carbonation reaction between Portland cement and CO2 is a complicated process controlled by CO2 concentration, presence of water, age of the cement, pressure, temperature, and the level of intactness of the cement matrix (Zhang et al. 2021, 2022a). Oilwell cement and CO2 reaction have been extensively investigated by various laboratory studies, including the influence of pressure and temperature (Barlet-Gouedard et al. 2006; Omosebi et al. 2017), reaction period (Barlet-Gouedard et al. 2006), and presence of various additives (Barlet-Gouedard et al. 2006). The major chemical reactions between CO2 and different compositions in the cement are presented in Figure 1 and Equation 1 to 5 (Kashef-Haghighi et al. 2015).

Limestone calcined clay cement (LC3), consisting of ordinary Portland cement (OPC) clinker, calcined clay, limestone powder, and gypsum, has been considered a promising solution to current challenges in the cement and concrete industry, such as high carbon emissions, high energy consumption, and resource shortages. This study carries out a series of experimental investigations of LC3-based paste, mortar, and concrete, including microstructural analyses (e.g. hydration product characterization and pore structure analysis) and macro-scale testing (e.g. workability and mechanical properties), using raw materials from south China. The results show that, in LC3 paste, the replacement of clinker by calcined clay and limestone leads to an increased volume of small pores but decreased total volume of pores. The workability of LC3 mortar and concrete can be readily tailored using conventional superplasticizers. When designed for comparable 28-d compressive strength, the LC3 mortar and concrete tend to have lower early-age compressive strength, but comparable compressive strength and higher flexural strength than those of the OPC counterparts at late ages. This study also examines the bond-slip behavior between LC3 concrete and steel bars and finds that the bond strength is comparable to that of OPC concrete with the same 28-d compressive strength, but that the LC3 concrete-rebar interface exhibits higher bond-slip stiffness. These findings on LC3 concrete provide fundamental information and guidance for furthering the application of LC3 binder in structural concrete in the near future.

In this study, a home-built Rayleigh scattering based optical frequency domain reflectometry (OFDR) technique is used for the measurement of strain distribution in a loaded cement paste. The system offers a spatially-continuous strain measurement on an optical fiber with a spatial resolution of 1 cm, dynamic range of 1 km, measurement accuracy of ±2 microstrain, and an update rate of 10 Hz. The feasibility and performance of this technique for detection of uneven strain distribution are studied and evaluated. The distributed optical fiber sensors are embedded in a cement paste cantilever. A controlled deflection is applied at the free end of it, and the strain is measured. The results are compared with the values obtained from theoretical analysis using Euler-Bernoulli beam theory and a finite element simulation. The comparison shows a reasonable consistence in overall deformation, demonstrating that the proposed technique can be used for real time strain monitoring in cement based materials; while this technique can reflect the uneven distribution of local strains due to the material heterogeneity with a controllable, high spatial resolution.

A strong nanocellular composite with stiff magnesium phosphate cement (MPC) particles and soft polyurea aerogel (PUA) has been synthesized and characterized. Utilizing the nano-confinement effect, the effective Young’s modulus and the compressive strength of the ligaments are 8–10 times higher than those of PUA. Taking advantage of the hierarchical cellular structure of PUA, the low density (0.285 g·cm−3) and high porosity (86.4%) features are preserved. This bioinspired nano-composite design has shown superior composite action, offering both high strength and deformability. The verified analytical model reveals the bioinspired designing rules for MPC/PUA material system.

In this study, a new type of locally resonant unit is designed, analyzed and tested. Its effectiveness to be used as a sound-proof building envelop material is evaluated. Each unit consists of a hard circular plate adhered on the soft membrane that fixed in a rigid frame. This new type of locally resonant unit can easily be installed into building envelope materials, such as extruded hollow concrete, hollow wooden board and other types of light weight partition panels, to enhance their sound proof property. An analytical model is developed to describe the ability of this composite material in low-frequency sound blocking. The model provides a direct explanation for the nature of the system and an accurate method to calculate the effective mass per unit area. It is shown that the effective mass per unit area can turn to negative at certain frequency ranges, which could lead to a complete sound attenuation. In order to measure the sound transmission gap position and verify the theoretical model, experimental works are carried out. The experimental results show good agreement with the theoretical predictions.

An image-based multi-level modeling method is proposed to estimate the effective bulk thermal conductivity of lightweight aggregate (LWA) impregnated with phase change material (PCM). The pore structure heterogeneity of the LWA and the uneven distribution of the PCM are considered by the model. The microstructure of the LWA is represented at two length scales (micro-level and macro-level), which are analyzed individually using imaging techniques. The reconstruction process is conducted on two-dimensional images to obtain three-dimensional digital representative volume element of the LWA, upon which multi-level numerical modeling of heat conduction is performed to estimate the effective bulk thermal conductivity of the PCM-LWA. The computed thermal conductivity of 0.34 W/(m∙K) is closed to experimental result and compared with estimates based on five traditional analytical methods for the sake of superiority analysis. Finally, the simulated thermal conductivity is used in a concrete level simulation to show its feasibility for modeling the thermal behaviors of PCM-LWA-incorporated concrete mixtures, in which PCM are employed to mitigate the hydration heat and prevent thermal cracking in mass concrete. The scale-up simulation manifests that the PCM-LWA not only reduced the peak temperature in the concrete by 3.18 °C but also changed the temperature distribution and gradient pattern inside the concrete.

Fly ash is a waste produced during combustion of coal that is a significant fossil fuel source for electricity production. Main beneficial use of fly ash has been defined in cement and concrete industry. However, low-grade fly ashes (LGFA), due to their high carbon content and low glass content, can hardly be used in making cement or concrete. Magnesia-phosphate cement (MPC) is a promising but costly binder material for utilizations in repair works of degraded infrastructure and some functional applications. Low-grade fly ash is possible to be consumed in making LGFA-MPC binder, which will undoubtedly reduce the cost and bring additional environmental benefit. In this paper, an MPC paste with the magnesia-to-phosphate molar (M/P) ratio of 8 and a water-to-solid (W/S) ratio of 0.2 is selected as the reference, and a LGFA is used to replace 20%, 40% and 60% of the solid phase by volume, respectively, to examine this possibility. The compressive strengths of the four pastes are measured following the increasing ages, and the water resistance indices of them are also evaluated. The results show that the higher the fly ash replacement, the lower the compressive strength at all ages, but the better the long-term water-resistance. Based on a three-limit theory, the effect of fly ash replacement on compressive strength is explained, and it is proved that the fly ash is more than an inert filler. The influence of fly ash on water resistance is also explained through a microstructural analysis.

In this study, the effects of phase change material (PCM) on the thermo-mechanical behaviors of concrete pavement slabs are investigated so as to test the feasibility of utilizing PCM for mitigation of thermal curling of pavement. The PCM is elaborately stabilized in porous lightweight aggregate then loaded into concrete, without compromising strength associated with PCM incorporation. Thermal analysis indicates that the PCM introduces a latent heat capacity of about 21 J/g to the pavement slab. Two emerging fiber-optic monitoring techniques, i.e., truly distributed strain/temperature sensors and a high-resolution inclinometer, are employed to continuously monitor distributions of the temperature, strain, and tilting angle of the slabs subjected to heating and cooling, respectively. Validated by the obtained experimental results, a finite element simulation framework is established to further investigate the temperature gradient distributions, slab deformations/curvatures, and thermal strain and stress inside the slabs. The results suggest that the PCM-incorporated slab has a higher top surface temperature, a larger top-vs-bottom surface temperature difference, and thereof a larger curvature. However, the temeprature gradient reveals that heat accumulates at the upper layer before PCM melts completely, thus accounting for most of the temerpature difference. Moreover, regardless of the larger top-vs-bottom strain difference and stress nonlinearity, the linear strain of the PCM slab is smaller due to its lower coefficient of thermal expansion, and the later stage stress at the middle of the PCM slab center is smaller. Based on the findings, strategies of using PCM to control thermal curling of pavement slabs are proposed.

Phase change materials (PCMs) have great potential for applications in energy efficient buildings. In this study, an innovative method of macro-encapsulation of PCM using hollow steel balls (HSB) was developed and the thermal and mechanical performance of PCM-HSB concrete was examined. The macro-encapsulation system (PCM-HSB) was attached with a metal clamp (c) for better mechanical interlocking with the mortar matrix. The latent heat of PCM-HSB-c that can be acquired is approximately 153.1 J/g, which can be considered to rank highly among PCM composites. According to the self-designed thermal performance evaluation, the PCM–HSB-c concrete panel is capable of reducing and deferring the peak indoor temperature. The indoor temperature of the room model using PCM-HSB-c panels was significantly lower than the ones with normal concrete panels by a range of 3–6%. Furthermore, the test room using a higher PCM-HSB-c content demonstrated a greater ability to maintain a lower indoor room temperature for a longer period of time during heating cycles. In consideration of the mechanical properties, thermal performance and other aspects of cost factors, 50% and 75% PCM-HSB-c replacement levels are recommended in producing concrete.

The selective reduction of NO by C3H8 and the sensitivity to H2O and SO2 have been studied over monolithic cordierite-based Fe/Al2O3 catalysts, which were prepared by the sol–gel and impregnation method. The catalysts were investigated by N2 adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) techniques. Results showed that NO reduction was more than 90% in the absence of oxygen at 500 °C and in the presence of oxygen at 600 °C respectively. In a continues test of 12 h at 600 °C, 0.02% of SO2 caused an irrecoverable decrease of NO conversion from 94% to 85% and 2.5% of H2O caused a drop of NO conversion from 86% to 56%, while NO conversion totally recovered when H2O was removed. The catalysts lost 15% of the initial activity after a hydrothermal treatment due to the agglomeration of iron oxide nanorods. Sulphidation treatment caused about a loss of 30% of the initial activity because of the deposited SO42− species. In situ study by DRIFTS indicated that coexisting H2O influenced the formation NO2 adspecies and unidentate nitrate, while SO2 slightly inhibited the formation of NO2/NO3− species, but promoted the formation of acetate/formate species during NO reduction by C3H8. Based on the results, a preliminary mechanism was proposed and discussed. The results may help understand the fundamental performance of monolithic cordierite-based Fe/Al2O3 catalysts and provide some reference for SCR-HC catalyst design.

When evaluating the carbonation resistance of paint coated concrete, the effects of both the strength grade and the curing conditions (standard curing and accelerated curing) of concrete substrate on carbonation resistance of paint coated concrete were investigated. The concept of the carbonation suppression ratio of paint was presented for evaluation of the anti-carbonation performance of the two types of paints (exterior and interior paints) when applied to a reference concrete substrate. The test results showed a good linear relationship between the carbonation depths of the paint coated concrete and the square root of exposure times. Concrete with higher strength grade exhibited greater carbonation resistance. The carbonation depth of the C35 standard cured concrete was reduced by 56% in comparison with that of the C25 standard cured concrete. It was found that concrete substrate prepared by accelerated curing method displayed lower carbonation resistance than standard cured concrete. Compared with the standard cured specimen, the carbonation depth of the accelerated cured specimen increased by 61% for the control C25 concrete and by 56% for the control C35 concrete. This phenomenon was attributed to the formation of a higher volume of capillary pores in concrete prepared by accelerated curing. Additionally, the exterior paint had a higher carbonation suppression ratio than the interior paint. The suppression ratios of the exterior and interior paint coatings applied on C25 standard cured concrete were 71% and 56%, respectively. The exterior paint coated concrete had a better carbonation resistance with longer effective blockage time and smaller carbonation rate.

This study aims to evaluate the potential of sugarcane bagasse ash (SCBA) as a supplementary cementitious material (SCM) in terms of composition. Using coal-combustion fly ash (CFA) as the benchmark, SCBA is characterized thoroughly using multiple tools to determine and compare particle size, particle morphology, chemical composition, glass content, element distribution and chemical status. It is found that SCBA has fine particle size (d50 = 6.76 μm, compared to 2.2 μm of CFA), high glass content (78.5 wt%, compared to 81 wt% of CFA), and relatively stable chemical composition, making it a potential effective SCM. The glass content of SCBA is dominated by amorphous silica (77.2%, compared to 53.6% of CFA), which can lead to formation of secondary calcium silicate hydrates in pozzolanic reactions. However, SCBA contains no spherical glass grains but many porous grains, which may compromise the workability of fresh-state cement-based materials. Another two detriments of SCBA are high carbon and potassium contents, which could potentially interfere the performance of cement-based materials. However, due to their existence forms (i.e., either light or dissolvable, as revealed by X-ray photoelectron spectroscopy), these detrimental effects can be mitigated through washing. A literature-survey based analysis shows that the ash samples adopted in this study are representative, so the conclusions drawn from this study are generally meaningful.

An intellectual system is developed to monitor concrete pavement slab subjected to external temperature fluctuations. Truly distributed fiber-optic temperature and strain sensors and an innovative Fabry-Perot interferometer-based optical fiber inclinometer are installed in the concrete pavement slab so as to monitor and evaluate its thermal curling process. The system is demonstrated to be effective in detecting the thermal curling of slab. The results substantiate that the top surface of the slab has a fast reaction rate to the heating/cooling process. The bottom surface temperature has a time-lag comparing to the top surface, which results in a sharp increase then a slow reduction in the top-vs-bottom temperature difference. In the light of the inclinometer, it is proven that the tilt angle of the curvature of the slab has a high degree of synchronization with the top-vs-bottom temperature difference. The temperature/strain distribution maps are also presented and uneven distributions of temperature and strain are captured. Moreover, taking the advantage of the multiplexing capacity of the distributed fiber-optic sensors, the coefficient of thermal expansion (CTE) of the slab can be easily obtained and used to feed a finite element model. Finally, a three-dimensional finite element model is established to completely understand the curling process measured from the monitoring system. The model and the experimental data agree well with each other. While the sensors output realistic temperature and deformations at certain locations, the validated model is able to reveal more details of the nonlinearity inside the slab.

The formation mechanism on the convection zone (“skin effect”) of chloride ingress are explored systematically by contrasting concretes in marine atmospheric, splash, tidal, and submerged zones. The depth of convection zone, Δx, and the maximum chloride concentration, Cmax, are two important indicators for estimating the degree of action of the skin effect. Influences of various factors on the skin effect are analyzed, including environmental conditions, mixture proportion, exposure time, and construction method. Statistics of the Δx and Cmax were extracted from field test data in the literatures. Influence of skin effect on the apparent surface chloride concentration (Cs) and diffusion coefficient (Da) was analyzed. Results show that the skin effects of concrete in atmospheric, tidal, splash and submerged zones are different, and it is highlighted that the convection zone exists even in submerged zone. The skin effect of concrete significantly impacts the fitting values of Cs and Da. Effective processing approaches can account for the skin effects of the concrete during durability design.

This paper develops and employs an ensemble machine learning (ML) model for prediction of surface chloride concentration (Cs) of concrete, which is an essential parameter for durability design and service life prediction of concrete structures in marine environment. For this purpose, a database containing 642 data-records of field exposure data of Cs (along with the associated mixture proportion parameters, environmental conditions and exposure time) is established based on extensive literature surveying, which covers splash, tidal, and submerged zones in various areas in the world. The database is used to train five standalone ML models, that is, linear regression (LR), Gaussian process regression (GPR), support vector machine (SVM), multilayer perceptron artificial neural network (MLP-ANN) and random forests (RF) models, as well as an ensemble weighted voting-based ML model, and subsequently used to compare their prediction performances. It is shown that, by meta-heuristically combining predictions of RF, MLP-ANN, and SVM, the ensemble ML model produces higher accuracy of prediction compared to all standalone ML models tested in this study. The prediction performances of eight conventional quantitative models for Cs prediction are also analyzed based on the testing dataset selected for ML. The results show that adoption of more diverse datasets and consideration of more factors in conventional models can improve their prediction performance. The ensemble ML model established on a large database, can easily consider the twelve influencing factors (which is difficult for conventional models) in the database, and has superior prediction performance, yet better time-efficiency, compared to conventional models.

To achieve high heat exchange efficiency of a microencapsulated phase change material (MPCM) and energy storage for buildings, a graphite-modified MPCM (GM-MPCM) was prepared and incorporated into the cement mortar to develop a type of cement mortar with both high heat storage efficiency and considerable mechanical strength. The thermophysical properties of the GM-MPCM and the thermal and mechanical properties of the GM-MPCM mortar were investigated. The results indicated that more than 50% of the paraffin (PCM used in this study) could be effectively encapsulated in the GM-MPCM. A thermal cycle test showed that thermal energy storage capacity of the GM-MPCM had not been reduced undergoing 10 thermal cycles. In addition, the diameters of the most GM-MPCM with approximately 7.74 μm polyurea shell ranges from 150 to 350 μm. Thermal performance tests using room models revealed that the small room models prepared with GM-MPCM-CM panels can reduce both the temperature fluctuations and maximum indoor centre temperature effectively. The cement mortars with GM-MPCM can be used for thermal energy storage in buildings. Moreover, adding GM-MPCM into cement would also lower and delay the hydration heat, which is helpful to reduce the thermal cracking of cement-based materials. Although adding GM-MPCM can weaken the mechanical strength of cement mortar, the compressive and flexural strengths of cement mortar with 20% GM-MPCM by weight of cement were still as high as 32.9 MPa and 7.6 MPa, respectively. Therefore, the cement mortars with different GM-MPCM are suitable structural and functional building materials.

Monolithic cordierite-based Fe/Al2O3 catalysts were prepared using a sol-gel and impregnation method and characterized by N2 adsorption, XRD, SEM, XPS, H2-TPR, and an activity test for the reduction of NO with C2H6. The results indicated that the textural properties, surface morphology, nanorod size, crystallinity, reducibility, and NO reduction activity of the catalysts were correlated with the iron loading. The order of the C2H6-SCR activity was as follows: 5.5Fe/Al2O3/CM > 3.5Fe/Al2O3/CM > 8Fe/Al2O3/CM > 2Fe/Al2O3/CM. High activity (97% NO conversion) was observed with 5.5 wt.% iron at 600 °C in the presence of oxygen. The results indicate that the iron oxide nanorods distributed on the surface of the Al2O3 layer may act as the SCR active site. Based on in situ DRIFTS spectral analysis, O2 can act as a promoter for the formation of the NO2/NO3− species. However, the formation of -NCO species does not appear to be accelerated by O2.

In this research, we focused on the development of composite phase-change materials (CPCMs) by incorporation of a paraffin through vacuum impregnation in widely used building materials (Kaolin and ground granulated blast-furnace slag (GGBS)). The composite PCMs were characterized using environmental scanning electron microscopy (ESEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Moreover, thermal performance of cement paste composite PCM panels was evaluated using a self-designed heating system. Test results showed that the maximum percentage of paraffin retained by Kaolin and GGBS was found to be 18% and 9%, respectively. FT-IR results show that CPCMs are chemically compatible. The phase-change temperatures of CPCMs were in the human comfort zone, and they possessed considerable latent-heat storage capacity. TGA results showed that CPCMs are thermally stable, and they did not show any sign of degradation below 150 °C. From thermal cycling tests, it was revealed that the CPCMs are thermally reliable. Thermal performance tests showed that in comparison to the control room model, the room models prepared with CPCMs reduced both the temperature fluctuations and maximum indoor center temperature. Therefore, the prepared CPCMs have some potential in reducing peak loads in buildings when applied to building facade.

The mechanism of Fe+NO was calculated by the Density Functional Theory (DFT) with the B3LYP methods combined with the 6-311+G (d, p) basis set. The geometry of reactants, transition states, intermediates and products of two reaction systems were completely optimized, and all the transition states were verified by the vibration analysis and intrinsic reaction coordinate (IRC) calculations. The “Two State Reactivity (TSR)” was used to analyze the reaction mechanisms; Results showed that the reaction system preferentially involves low-spin state entrance channel and the high-spin state exit channel. In the reaction channel, the crossing point appears, which would effectively reduce the activation energy and increase the release of reaction heat, play a significant and beneficial role in the kinetic and thermodynamic aspects of this catalytic reaction.

The utilisation of recycled concrete aggregate (RCA) in Self-Compacting Concrete (SCC) has the potential to reduce both the environmental impact and financial cost associated with this increasingly popular concrete type. However, to date limited research exists exploring the use of coarse RCA in SCC. The work presented in this paper seeks to build on the existing knowledge in this area by examining the workability, strength, and fracture properties of SCCs containing 0%, 25%, 50%, 75%, and 100% coarse RCA. The experimental programme indicated that at RCA utilisation levels of 25% to 50% little or no negative impact was observed for strength, workability, or fracture properties, with the exception of a slight reduction in Young’s modulus.

In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM) manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs) incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement) were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35–36 °C, 55–56 °C and 72–74 °C) decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55–56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content.

One of the most efficient and environmentally friendly methods for preventing a landslide on a slope is to vegetate it. Vegetation-pervious concretes have a promising potential for soil protection. In this study, the vegetation-pervious concrete with low alkalinity was developed and studied. Combined with a grid beam structure system, the stability and strength between the vegetation-pervious concrete and base soil are believed to be enhanced effectively. For improving plant adaptability, the alkalinity of concrete can be decreased innovatively by adding a self-designed admixture into the cement paste. The effects of the admixture content on alkalinity and compressive strength of the hardened pervious concrete were investigated using X-ray diffraction (XRD) and compression test, respectively. Meanwhile, the permeability of the vegetation-pervious concrete was studied as well. Through comparing with ordinary pervious concrete, the effect of low alkaline pervious concrete on vegetation growth was investigated in a small-scale field for ten weeks. The test results indicated that the alkalinity of the cement samples decreased with the increase of admixture content, and the vegetation grew successfully on previous concrete. By increasing the admixture content to approximately 3.6%, the compressive strength of pervious concrete was more than 25 MPa.