In order to reduce energy dissipation of asphalt pavement hot air heating and achieve rapid yet accurate prediction of pavement temperature field, this study designed a thermal insulation device for the heating wall, and proposed a temperature fields prediction model based on a back propagation neural network optimized by the northern goshawk algorithm. Firstly, the asphalt pavement hot air heating model was established based on Ansys Fluent software, implementing sliding mesh movement and heating power switching through user-defined functions, with model reliability verified by field experiment. Then, a thermal insulation device was designed for the heating wall, with the optimal configuration of the thermal insulation materials determined. Ultimately, the training dataset was obtained through proper orthogonal decomposition of asphalt pavement hot air heating, and a northern goshawk-optimized back propagation neural network model was established for pavement temperature field prediction. The results demonstrate that the designed insulation device yields a 6.21 % temperature increase in the regeneration layer. The proposed neural network model outperforms comparative models by maintaining prediction errors below 4 % across all pavement depths and achieving a temperature field reconstruction error of only 0.54 % using the first 20 modes. The findings provide critical insights for optimizing heating wall design to reduce energy dissipation, while the proposed surrogate model offers a cost-effective alternative to field experiments by enabling rapid and accurate pavement temperature field prediction, as well as a valuable reference for future surrogate model development.

Concrete mixed with glazed hollow beads (GC) is a lightweight aggregate concrete that combines reduced density with thermal insulation; however, the compressive behavior and deformation capacity of reinforced GC columns remain insufficiently quantified. In this study, axial and large-eccentric compression tests were conducted on eight reinforced concrete columns, including six GC columns and two normal concrete (NC) control columns. The test variables were concrete type, slenderness ratio (4, 8, and 10), and eccentricity (0 and 200mm). The failure modes, load-deformation curves, lateral deformation, longitudinal reinforcement strain, and concrete strain were analyzed. The results show that GC columns cracked later and developed a wider damaged zone than NC columns, indicating improved deformation capacity. At a slenderness ratio of 8, the axial ultimate load of GC-8-0 was 4100 kN, which was close to that of NC-8-0 (4050 kN), whereas the large-eccentric ultimate load of GC-8-200 was 900 kN, 16.7% lower than that of NC-8-200 (1080 kN). As the slenderness ratio increased from 4 to 10, the ultimate load of GC columns decreased by 13.1% under axial compression and by 31.8% under large-eccentric compression, showing the stronger influence of second-order effects in slender GC columns. ANSYS finite element models provided acceptable agreement with the tests, with average simulated-to-test ultimate-load ratios of 0.90 for axial compression and 1.11 for large-eccentric compression. A design-oriented bearing-capacity calculation method was further proposed by introducing an equivalent stress coefficient for GC, and the experimental-to-predicted ratios were controlled within 1.25. The findings provide experimental and analytical evidence for using GC to improve the deformation capacity of reinforced concrete columns under compressive loading.

The rapid promotion and application of recycled concrete is an important way to achieve high-value utilization of construction solid waste. In underground structural engineering, the impermeability of recycled concrete under loading conditions is of critical importance, as it directly influences the durability, safety, and service life of the structure. This study focuses on the effects of different functional materials on the chloride ion penetration resistance of recycled aggregate concrete (RAC) under different uniaxial compressive loading, including glazed hollow beads, fly ash, and short discrete fibers. The results indicate that as the replacement rate of recycled coarse aggregates (RCA) in concrete increases, the adverse impact on the chloride ion penetration resistance of concrete becomes increasingly evident under loading. The reasonable addition of functional materials can reduce the adverse effects caused by RCA. The influence of functional materials on the chloride ion penetration resistance of RAC varies under different loading conditions, and the combined application of functional materials demonstrate the most significant enhancement. The impact of loading on chloride ion penetration resistance of RAC demonstrates a distinct threshold behavior. As the replacement rate of RCA increases, the critical threshold decreases progressively, promoting the formation and interconnection of transmission pathway of aggressive media in RAC. Conversely, the combined application of functional materials can significantly raise the critical threshold for chloride ion penetration resistance of RAC under loading, thereby offsetting the adverse effects caused by RCA. Specifically, the optimal composite mix (BA-BFPF) reduced the 28-day electric flux by 40.7% at a 50% RCA replacement rate and effectively elevated the damage threshold stress to 0.5 fc. This cross-scale synergy successfully offsets the adverse effects of RCA, providing a higher durability safety margin for underground structural engineering.

Tunnel muck is increasingly processed into manufactured aggregates for concrete, but the effect of aggregate lithology on long-term deformation remains insufficiently understood. This study investigated drying shrinkage and compressive creep of concretes incorporating tunnel muck aggregates with four representative lithologies: sandstone, limestone, granite, and gneiss. Drying shrinkage was monitored for 56 days, and compressive creep under a 40% stress level was measured for 180 days. The results show that both shrinkage and creep were strongly lithology-dependent. The 56-day shrinkage strain followed the order sandstone > granite > gneiss > limestone, while the 180-day creep coefficient followed the order granite > sandstone > gneiss > limestone. These trends indicate that shrinkage was mainly governed by moisture transport, whereas creep was more closely related to load transfer, aggregate restraint, and ITZ integrity. The ACI 209.2R-08 and CEB-FIP 2010 models were recalibrated using lithology-dependent amplitude and time-scale correction factors, achieving R² > 0.95 for all lithologies. A performance-based risk zoning framework was proposed to support the rational and sustainable use of tunnel muck aggregates in mountain transportation infrastructure.

Perlite is a common natural silica-aluminium non-metallic minerals, its rapid heating in the environment at 800 °C to 1200 °C, the volume of the rapid expansion of the formation of expanded perlite. Based on its calcination process, which includes an expansion stage (700°C-800 °C) and a surface vitrification stage (1200 °C), and differences in pore structure, it is classified into open-cell expanded perlite and closed-cell vitrified microspheres. Expanded perlite is widely used in construction, chemical industry, agriculture, forestry, horticulture and other fields due to its unique porous structure and high adsorption and compressibility. In the field of civil engineering, the combination of expanded perlite with traditional concrete reduces the material's apparent density by approximately 15% and lowers its thermal conductivity to 0.19–0.27 W/(m·K). This results in excellent thermal insulation, fire resistance, water resistance, and other durable properties. It is frequently used as a substitute for natural aggregates or as a cement additive. This paper first summarizes and categorizes the material properties of expanded perlite itself and related modification techniques. Furthermore, based on the advantageous properties of expanded perlite concrete identified in existing research and considering the characteristics of its service environment, this paper provides a comprehensive review. Key aspects covered include: manufacturing processes and preparation methods, mechanical properties, thermal insulation performance, shrinkage and creep behavior, fire resistance and high-temperature tolerance, water resistance and freeze-thaw resistance, as well as self-healing capabilities. This review aims to provide recommendations and a theoretical foundation for the practical application of functional concrete based on expanded perlite and for future research directions.

The lightweighting of ultra-high-performance concrete (UHPC) is critical for expanding its application scope. However, conventional lightweight UHPC (LUHPC) relies on lightweight aggregates that are either costly or reduce matrix strength. To address these challenges, a cost-effective LUHPC was developed using glazed hollow beads (GHBs) combined with hybrid steel–polypropylene (PP) fiber reinforcement. Within a lightweight matrix containing a 40% volume replacement ratio of GHBs, the effects of steel fiber content (1%–3%) and PP fiber content (0%–0.3%) on apparent density and mechanical performance were systematically investigated. At a steel fiber content of 2.5% and a PP fiber content of 0.2%, LUHPC exhibited optimal overall performance. The apparent density was 2149 kg/m3, corresponding to a reduction of 10.5%–14.0% compared with conventional UHPC. The compressive strength reached 127.1 MPa, representing an increase of 3.3%–15.0% relative to reported LUHPC, while the tensile strength was 78.8% higher than that of the control group. Acoustic emission (AE) analysis showed that fiber synergy produced more uniform energy release, increased the proportion of shear cracking, and shifted failure from brittle to progressive ductile behavior with enhanced energy dissipation. Cost analysis indicated that the unit cost and strength-normalized cost of the S2.5P0.2 mixture decreased by 3.8%–36.1% and 4.3%–39.2%, respectively, compared with existing LUHPC. This study provides a basis for the design of high-performance, cost-effective LUHPC for engineering applications.

Considering the anticipated decline in ground granulated blast furnace slag production, this study explored the use of natural minerals, limestone or magnesite, as partial replacement for slag to form a ternary system. The results revealed that with a 10 % limestone addition, the chloride binding capacity of the ternary system was comparable to that of binary slag cement. As for the magnesite-containing system, the binding capacity decreased with the increasing substitution ratio. A 10 % limestone addition had little effect on the chloride diffusion coefficient; however, at a 25 % replacement level, the coefficient rose by 53.6 %. The magnesitecontaining blends exhibited weaker resistance to chloride ingress, with 10 % and 25 % replacement enhancing the diffusion coefficient by 28.5 % and 84.2 % respectively. Except for the critical pore diameter, the incorporation of limestone/magnesite generally led to a coarsening of pore structure, including total porosity, capillary porosity, critical pore diameter, and overall pore size parameters. Magnesite reduced the tortuosity of pore, while limestone showed an opposite trend. The authors believed that the results in this paper provided insightful findings regarding the long-term durability of cement-slag-limestone/magnesite ternary blends, which was beneficial for developing next-generation low-carbon cements with improved performance on durability.

The size effects of nanomaterials play a critical role in their reinforcement efficiency for polymer and metal nanocomposites, yet it has not been thoroughly demonstrated in cementitious matrices. This study systematically investigates the size effects of graphene oxide (GO) on cement hydration, microstructure, strength, and creep resistance. Compared to small-sized GO, large-sized GO (LGO) significantly enhances C-S-H packing density, hydration degree, and mechanical performance while reducing creep. These improvements stem from LGO's stronger templating effect and larger lateral size, which promote C-S-H nucleation and interparticle bonding, thus limiting C-S-H redistribution under load. Importantly, we reveal that GO enhances creep resistance not only by densifying C-S-H but also by modulating interfacial bonding in a size-dependent manner-a mechanism previously overlooked. These findings underscore the critical role of nanomaterial size effects in regulating stress transfer and microstructural evolution in cementitious systems, offering a new pathway for designing highperformance cement-based materials.

As a potential substitute for natural aggregates in concrete, steel slag exhibits poor stability, leading to uncontrollable cracking and diminished mechanical properties during service, which significantly compromises its durability and service life. This paper focuses on the reinforcement and stabilisation of steel slag aggregates. By measuring indicators for concrete using steel slag as natural aggregate substitute-including physical and mechanical properties, stability, and self-healing capacity-and combining with microstructural phase changes and elemental statistical distribution, the study evaluates the impact of microbial mineralisation strategies on the performance of both aggregates and concrete. Research findings indicate that microbial modification significantly enhances both the aggregate and concrete's physical and mechanical properties. Aggregate crushing value reduction reached a maximum of 75.5 %, while compressive strength improvement attained 45.5 %. Furthermore, stability was markedly improved, with concrete cracking during saturated boiling significantly suppressed. Compressive strength reduction decreased from 15 %-26.5 % to 1.4 %-17.7 %. Moreover, the inherent microbial carrier function of steel slag aggregate enables a macro-level closure rate of approximately 80 % for micro-cracks with a maximum width of less than 0.4 mm. At the microscopic level, macro-fractures on the surface of steel slag aggregates are bridged and filled by cubic block-like and acicular crystals during modification. Energy dispersive spectroscopy signals indicate a significant decrease in calcium content and a marked increase in oxygen-tocarbon element ratio. The consumption of free calcium through mineralisation/hydration enhances the overall stability of aggregates and concrete, offering novel perspectives and theoretical underpinnings for the utilization and resource recovery of steel slag aggregates.

Microbial mineralization promotes the self-healing of concrete cracks, extending structural service life. However, harsh conditions within concrete hinder the long-term viability and self-healing potential of microorganisms. While Bacillus strains are commonly used to deposit calcium carbonate on crack surfaces, their aerobic nature presents challenges in complex environments. This study assesses the long-term survival and mineralization performance of four composite microbial systems designed according to mineralization-pathway complementarity, alkaline tolerance, oxygen-gradient adaptability, and long-term viability in cementitious environments. At pH 9 after 180 days, survival rates of composite systems increased by 2.75% to 33.15% compared with single bacteria, with mineral precipitation rising by 2.44% to 3.24%. The Bacillus subtilis and Pseudomonas aeruginosa combination exhibited superior crack self-healing, achieving a maximum healing width of 1.07 mm at 270 days, with over 80% healing for cracks up to 0.7 mm. These results underscore the potential of composite microbial systems for engineering applications.

Microbially induced carbonate precipitation (MICP) provides a sustainable approach for the autonomous repair of microcracks in concrete. However, its practical application is limited by the poor long-term survival of microorganisms in the highly alkaline environment of cement matrices. This study used expanded perlite as an immobilization carrier to systematically investigate the effects of pH, temperature, and aging on microbial spore survival. Under non-immobilized conditions, acclimatized spores showed optimal long-term activity at pH = 10 and 0°C. After 180 days, the spore survival rate reached 12.31%, and urease activity achieved 0.74 mmol/(L·min)-approximately twice and nine times higher, respectively, than those recorded at 30°C over the same period. Although environmental factors reduced microbial mineralization capacity under immobilized conditions, mineral precipitation stabilized at around 5.60 g, representing a 28-fold increase compared to non-immobilized results over the same duration. These findings confirm that the carrier effectively alleviates the adverse effects of high alkalinity and temperature variations. The expanded perlite-based immobilization strategy significantly extended microbial service life, improved remediation efficiency, enhanced engineering feasibility, and reduced long-term maintenance costs. This research offers critical technical support for the development of durable and high-efficiency self-healing concrete systems.IMPORTANCEMicrobially induced carbonate precipitation (MICP) has gained significant attention as a promising technology in architecture and civil engineering. However, the understanding of microbial long-term activity and mineralization capacity within cement-based materials remains limited. This study investigated the influence of environmental factors on microbial spore survival in such materials by monitoring key indicators, including microbial concentration, urease activity, and mineral precipitation. Furthermore, it identified specific environmental conditions that support prolonged microbial viability. The use of expanded perlite as a carrier material aimed to mitigate external environmental stresses on microorganisms, thereby extending their mineralization capability over extended periods. These findings provide a scientific basis for the rational design of microbially mediated self-healing concrete systems.

This study addresses the underutilization of steel slag (SS), which results in land resource wastage, ecological degradation, and a shortage of supplementary cementitious materials (SCMs) in ultra-high performance concrete (UHPC). By co-grinding SS with granulated blast furnace slag (GBFS), we produced a blended material termed steel slag-granulated blast furnace slag powder (SGP) as an SCM to partially replace cement in the preparation sustainable UHPC (SUHPC). This approach aimed to achieve efficient utilization of SS and the synergistic use multi-source metallurgical solid wastes. Specifically, we obtained a dense UHPC matrix using the modified Andreasen & Andersen model, and substituted cement with SGP, while using separately ground SS and GBFS control group for cement replacement. The study evaluated a range of properties of SUHPC, including ability, compressive strength, durability, and microstructure. Results indicated that the ball-bearing effect, filling effect, and reactivity of SGP were superior to those of the combined use of SS and GBFS. The substitution cement with SGP improved the flowability of SUHPC, increasing maximum flowability by 45 mm compared the reference (Ref.) group; 7-day compressive strength increased by 1.9%, and 28-day compressive strength 2.3%; the depth of chloride ion penetration and charge passed were reduced by 25.8% and 21.6%, respectively. Microstructural testing revealed that the synergistic optimization of SGP's pore-filling, nucleation, hydration activity, and pozzolanic activity resulted in additional hydration products, reduced porosity, and enhanced microstructure of SUHPC. This research provides a viable pathway for the engineering application of SUHPC offers insights into the synergistic application of multi-source metallurgical solid wastes in civil engineering systems.

Heavy metal contamination, particularly lead (Pb), poses severe threats to ecosystems due to its persistence and bioaccumulation. This study investigates the remediation of Pb-contaminated soil using bio-augmented microbial induced carbonate precipitation (MICP). The effects of Pb concentration and soil depth on bacterial activity (viable cell counts and urease activity) were evaluated. Furthermore, the impact of different calcium sources and Pb concentrations on immobilization efficiency was assessed via unconfined compressive strength (UCS) tests. The results indicate that the bacterial tolerance threshold for Pb is 50 mmol/L, beyond which the MICP process is significantly inhibited. However, within this threshold, bio-augmented MICP effectively enhances soil strength, achieving a UCS of 0.94 MPa in soil with 50 mmol/L Pb. Microstructural and physicochemical analyses reveal that the remediation mechanism involves the precipitation of carbonate, co-precipitation, and the transformation of macropores into capillary pores. Notably, this study elucidates the distinct advantages of bio-augmentation, particularly its robust tolerance to Pb toxicity and sustained mineralization capability, in reducing the bioavailability of Pb in contaminated soil matrices.

Carbonation-induced steel depassivation in concrete is a time-dependent problem involving uncertainties of materials and environment. Most existing studies on concrete carbonation remain limited to deterministic prediction, which cannot be adopted for reliability-based durability design. This study proposed a physics-guided probabilistic machine learning framework that linked carbonation depth prediction, uncertainty quantification, and full-probabilistic durability design together. A dual-branch neural architecture was developed to predict the effective initial carbonation depth d0 and carbonation rate k, and carbonation depth was determined through an empirical evolution law. Three probabilistic models, including heteroscedastic Gaussian neural network, mixture density network, and artificial neural network with Monte Carlo dropout, were evaluated over 50 repeated random train-test splits. The physics-guided mixture density network achieved the best overall performance, exhibiting high prediction accuracy, reliable interval estimation, and physically reasonable long-term extrapolation. Following, this model was refined through feature ablation and validated using an independent external dataset. Finally, the predictive distribution was coupled with Monte Carlo simulation to propagate input and model uncertainties based on the carbonation-induced limit state function. Overall, the proposed framework provides a practical tool for performance-based durability design of concrete structures exposed to CO2-rich environments by translating probabilistic carbonation prediction into quantitative failure probability assessment, reliability index evaluation, and minimum cover depth determination.

Crack self-healing based on microbially induced carbonate precipitation (MICP) endows structures with self-sensing and self-repair capabilities. However, most research on repair via MICP has focused on single-microorganism systems and the self-healing of cracks in static water environments. This approach struggles to achieve effective crack repair for structures operating under complex service conditions and long-term dynamic water flow. This study investigates three self-healing systems comprising urease-producing bacteria, aerobic bacteria, and a mixed consortium of urease-producing, aerobic, and denitrifying bacteria, all immobilized on expanded perlite, for their effects on the crack self-healing performance of cement mortar specimens. The crack repair efficacy of these self-healing specimens under different aquatic conditions was also examined. Results indicate that after 28 days of curing, the crack repair widths in static water reached 0.41 mm, 0.31 mm, and 0.44 mm for the three systems, respectively. Under dynamic water flow at 20 ml/h, the crack repair widths were 0.0137 mm, 0.0188 mm, and 0.0325 mm. The permeability recovery rates of the three systems reached 100%, 90.56%, and 100%, respectively, all exceeding the 32.41% achieved by the system without microorganisms. Under the optimal mineralization repair system, the compressive strength recovery rate was 70.23%. Microscopic analysis revealed that the mineralization products from the mixed microbial consortium exhibited a dense structure with a high calcium carbonate content. This study provides a theoretical basis for the optimized design of MICP-based self-healing cementitious materials in complex aquatic environments.

The mechanical strength and impermeability of concrete are critical to its structural reliability and long-term durability. However, conventional concrete lacks autonomous crack-healing capacity, which can lead to progressive degradation under sustained mechanical and environmental stresses. This study presents a novel selfhealing concrete system incorporating polyvinyl alcohol (PVA) fibers and microbially induced calcium carbonate precipitation (MICP), designed to synergistically improve both material performance and crack-sealing efficiency. Experimental results indicate that the inclusion of PVA fibers significantly enhances mechanical and durability properties. Compared to plain concrete, the 28-day compressive and flexural strengths increased by 32.47 % and 22.54 %, respectively, while water penetration depth was reduced by 23.25 %. Moreover, the relative permeability coefficient and volume of harmful capillary pores decreased by 50.81 % and 19.27 %, respectively. After 28 days of autonomous healing, the specimens exhibited a compressive strength recovery rate of 66.59 % and an ultrasonic pulse velocity recovery of 58.82 %. Microstructural analysis confirmed the precipitation of dense calcite crystals within cracks, contributing to pore refinement and intrinsic property enhancement. This work not only advances the autonomous healing capability of concrete but also substantially improves its mechanical and impermeable performance, offering a promising strategy for developing highly durable construction materials.

Ensuring the long-term performance of infrastructure in cold regions necessitates evaluating the frost durability of subgrade materials. This study comprehensively investigates the mechanical behavior of cement-stabilized silty clay, a common material for subgrade improvement, under freeze–thaw (F–T) cycles. A series of unconfined compressive strength (UCS) and resilient modulus (MR) tests were conducted to quantify the effects of cement content (3%, 6%, 9%), initial moisture content (OMC − 2% to OMC + 6%), and the number of F–T cycles (0 to 9). The results demonstrate that increasing the cement content significantly enhances the MR, with the most effective improvement observed up to 6%. Specifically, increasing cement from 3% to 6% boosted MR by 11.62% to 26.69%, while a further increase to 9% yielded a smaller gain of 4.59% to 12.60%, indicating an optimal content. Both UCS and MR peak at the optimum moisture content (OMC) and degrade markedly with F–T cycles, with the first cycle causing over 50% of the total MR loss in most cases. Properties tend to stabilize after approximately six cycles. The stabilized soil exhibits superior performance, with its MR being 2.29–2.43 times that of the original soil at OMC after nine F–T cycles. Furthermore, a logarithmic model (R2 = 0.87–0.94) effectively captures the attenuation of MR with F–T cycles, while a strong linear relationship (R2 = 0.90–0.96) exists between the initial moisture content and the degradation coefficient. An empirical predictive model for UCS, integrating cement content, moisture content, and F–T cycles, is proposed and shows excellent correlation with experimental data (R2 > 0.92). Microstructural analysis reveals that the enhancement mechanism is attributed to hydration, cation exchange, and flocculation, which collectively form a stable cementitious network. The findings and proposed models provide critical quantitative insights for optimizing the design of frost-resistant cement-stabilized subgrades, thereby contributing to the enhanced durability and performance of overlying structures in seasonal freeze–thaw environments.

Concrete-filled pultruded glass fibre-reinforced polymer (GFRP) box beams are innovative structural members with superior corrosion resistance and flexural capacity. However, GFRP profiles are vulnerable to thermal degradation at elevated temperatures, potentially compromising structural integrity. This study experimentally investigates the flexural behaviour of concrete-filled pultruded GFRP box beams after exposure to elevated temperatures to evaluate the fire resistance effects of the infilled concrete. Residual material properties of GFRP profiles were first studied by 88 groups of coupons subjected to temperatures from 50 to 350 degrees C (25 degrees C increments) for 15-60 min (15 min increments). A logistic-function-based theoretical model was then proposed to predict residual tensile and compressive strength. Subsequently, four-point bending tests were performed on hollow and concrete-filled GFRP box beams after exposure to temperatures of 250, 300 and 350 degrees C for various durations. The experimental results revealed that the flexural behaviour of the hollow GFRP box beams deteriorated significantly after being exposed to temperatures exceeding Tg, with the flexural capacity decreasing by 65% at 350 degrees C after 60 min exposure. In contrast, the infilled concrete remarkably enhances the fire resistance of the GFRP box beams due to the isolation effect from direct air exposure, resulting in only minor reductions in flexural capacity and stiffness after heating. Finally, a residual flexural capacity prediction model of the beams was proposed and showed good agreement with experimental results.

Currently, the primary method for utilizing coal gangue is in the preparation of building materials. However, high-sulfur coal gangue, which constitutes approximately 80% of the total stockpile, is difficult to incorporate into such materials due to the risk of sulfur oxidation. Even when used, the potential for sulfur release remains inadequately controlled. To address this issue, this study proposes a method of co-embedding high-sulfur coal gangue aggregates and composite microbial sulfur stabilizers into concrete. The stabilizers consist of Acidithiobacillus ferrooxidans (At.f) and Sporosarcina pasteurii (Sp.p) immobilized on expanded perlite (EP) and zeolite powder (ZP). An orthogonal experimental design was employed to optimize the carrier type, microbial ratio, and KNO3 concentration. The resulting concrete exhibited a 28-day compressive strength ranging from 32.55 MPa to 38.4 MPa. Sulfur leaching tests demonstrated a maximum sulfur stabilization efficiency of 78.74%. The stabilization mechanism involves the formation of a passive biofilm (mainly jarosite) by microorganisms on the coal gangue surface within the pore solution, combined with a significant improvement in the concrete pore structure induced by the passivation products. This approach eliminates the need for additional desulfurization pretreatment, providing an effective solution to the sulfur risk associated with HSCG in concrete and overcoming a major barrier to its large-scale utilization.