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The objective of this paper is to assess the impact of mineral grain size and grain size distribution of aggregates on the deterioration of pavement surface microtexture. For the study, aggregates were collected from nine different sources to cover a wide variation in mineralogical type. The grain size parameters were obtained by detecting mineral grain boundaries using scanning electron microscope electron back scattered diffraction (SEM EBSD) analysis on thin sections prepared from the aggregates. Scanning electron microscope (SEM) analysis was also carried out on thin sections of all aggregate types to determine their mineralogical composition. Microtexture deterioration was measured by collecting the British pendulum number (BPN) of the aggregate after every hour of polishing for six hours using an accelerated polishing machine. From the mineral composition analysis, it was observed that the aggregates in the study belonged to three rock types: granite, amphibolite, and basalt (three sources of each type). The BPN values of the polished stones indicated that aggregates with finer grains offer more resistance to polishing. Statistical analysis of the test results also suggests that a wide variation in grain sizes in aggregates positively contributes to resistance against polishing. The study confirmed that, for a given rock type, coarse aggregates with finer grains and greater variation in grain size can better withstand microtexture deterioration caused by mechanical polishing from vehicular loads when used in the surface course of pavements. [ABSTRACT FROM AUTHOR]

The usage of iron tailings as construction aggregates is a potential route to save the cost of standard sands and protect the environment of mining area. This study mainly investigates the performance of cement mortars by partial replacement of the standard sands (SS) with sulfide-contained iron ore tailings (IOT). The physicomechanical properties, microstructure, and hydration products were measured by consistency test, porosity test, strength test, P-wave velocity test, scanning electron microscopy test (SEM), and X-ray diffraction test (XRD). It is proven that the graded IOT (GIOT), which has an identical particle size distribution with SS, is better than the ungraded IOT to serve as fine aggregate by replacing SS because a suitable GIOT content can better reduce the adverse effect of excess fine tailings (<0.15 mm) and sulfide on the cement mortar. The graded tailings cement mortar (GTCM) by using GIOT has denser pore structure, lower porosity, higher strength, and P-wave velocity than ungraded tailings cement mortar (UTCM) by using UIOT at the same curing condition and age. In addition, although a high sulfide content (approximately 4.44% to 5.55% by weight) by adding more than 40% GIOT is conducive to reduce the porosity and improve the strength of GTCM before 28 days, it is harmful for the long-term performance beyond 90 days. The expansive ettringite and gypsum produced by the reaction of excess sulfide will cause microcracks and thus reduce the strength beyond 40% GIOT. To ensure the long-term performance of GTCM, the sulfide content in the aggregate should be controlled below 3% by weight, and the optimal substitution ratio of GIOT corresponding to this sulfide content is approximately 20% to 30%. [ABSTRACT FROM AUTHOR]

This study aimed to compare the nanoleakage of retrograde fillings with premixed calcium silicate-based putty and mineral trioxide aggregate (MTA), using two different techniques (traditional and Lid). Sixty-four extracted human teeth were decoronated, then root canals and ends were instrumented for retrograde filling and divided into four groups according to the retrograde filling technique: the traditional and the Lid technique. Each group (n = 15) was filled with Ceraseal + Well-Root putty, Well-Root putty, Ceraseal + ProRoot MTA, and ProRoot MTA. The nanoleakage was evaluated using the Nanoflow device (IB Systems) on days 1, 3, 7, 15 and 30. Data were collected twice per second at the nanoscale (nL/s) and calculated after archiving the stabilization of fluid flow. The Kruskal–Wallis and Mann–Whitney U-tests were used for statistical analysis. All groups showed enhanced sealing ability over time. Regardless of filling materials, the Well-Root putty, Ceraseal+Well-Root putty, and Ceraseal+ProRoot MTA groups indicated less nanoleakage than the ProRoot MTA group in the first week of evaluation (p < 0.05). Although all groups did not show significant differences after 2 weeks, the Ceraseal+ProRoot MTA group leaked less than ProRoot MTA on Days 3 and 7 (p < 0.05). The scanning electron microscopic examined good adaptation to the cavity wall, which was similar to nanoleakage results. Premixed calcium silicate-based putty retrograde filling material alone and using the "lid technique" were shown to be faster and less prone to nanoleakage when compared to MTA. [ABSTRACT FROM AUTHOR]

The recycling bio-waste shells problem has grown more and more serious in recent years and many efforts have been made to solve this problem. One possible solution is to put these bio-shells into concrete and recycle them as building materials using the aggregate matrix concrete approach. To verify the engineering feasibility, the mechanical properties of bio-shells aggregated concrete were invested via gradient substitution rates at 10%, 30%, and 50% with a total of 78 groups of specimens in this paper. Our results show that the mechanical properties of the concrete were enhanced in maximum flexural strength and maximum compressive. Economic performance was also analyzed and found that the costs of frame-shear structure, frame structure, and tube-in-tube structure were reduced by 10.2%, 10%, and 10.3%. The carbon environmental assessment also shows superiority in the carbon reduction of a single specimen with various rates of the shell. In summary, compared with ordinary concrete materials, it is very possible to use waste bio-shells as a substitute for aggregates to develop the sustainable recycling development of concrete materials. [ABSTRACT FROM AUTHOR]

Background: To evaluate the three materials ability to prevent glucose leakage through root-end fillings: Ceramicrete, BioAggregate, and white ProRoot MTA (mineral trioxide aggregate). Materials and methods: Following root canal instrumentation, the apical 3 mm of maxillary incisors were resected and retro preparations, 3 mm in depth, were created with ultrasound. Rootend cavities were filled with the tested materials (15 roots per group). All roots were mounted in a double-chamber system to assess glucose penetration using 15 psi pressure application. After 1 h, glucose concentrations in the lower chamber were measured following an enzymatic reaction. Four roots were used as controls. One-way anova verified differences in glucose leakage between groups and Tukey test performed multiple comparisons. Significance was set at a = 5%. Results: There was a significant difference between the three materials (anova, P < 0.05). Ceramicrete had significantly lower glucose penetration than BioAggregate (Tukey, P < 0.05). There was no difference between the two bioceramic cements and white MTA (P > 0.05). Conclusions Both endodontic bioceramic repair cements displayed similar leakage results to white MTA when used as root-end fillings materials. Ceramicrete had significantly lower glucose penetration. [ABSTRACT FROM AUTHOR]

In this paper, the workability, mechanical, ion leaching, and drying shrinkage properties of alkali-activated concrete with recycled coarse and fine aggregates were studied, and the pore structure and micro-morphology of different alkali-activated recycled aggregate concretes (AARACs) were characterized by using the mercury intrusion method and scanning electron microscopy, respectively. The experimental results showed that with the increase in the replacement rate of the recycled fine aggregate (RFA), the flowability showed a decreasing trend. Adding a certain amount of RFA improves the mechanical properties of the AARAC. The compressive strength at a curing age of 28 days was 65.3 MPa with 70 wt% RFA replacement. When the replacement rate of the RFA was 100 wt%, the maximum splitting tensile strength (4.5 MPa) was obtained at a curing age of 7 days. However, the addition of the RFA had little effect on the flexural strength of the AARAC. As an extension of the curing age, the splitting tensile strength, flexural strength, tension-to-compression ratio, and flexure-to-compression ratio all showed an increasing trend at first and then a decreasing trend. At a curing age of 7 days, the tension-to-compression ratio and flexure-to-compression ratio were both high (except for those of R100), indicating that the ductility and toughness of the specimen were improved. The addition of the RFA increased the drying shrinkage of the AARAC. At a curing age of 120 days, compared to the specimen without the RFA, the drying shrinkage rate of the specimen with the addition of 70 wt% RFA increased by 34.15%. As the curing age increased, the microstructure of the reaction products became denser, but the proportion of large-diameter pores increased. This study evaluated the application of RFA in AARAC. The experimental results showed that the RFA-based AARAC had acceptable mechanical and durability properties. [ABSTRACT FROM AUTHOR]

Mineral trioxide aggregate (MTA) is a biomaterial used in endodontics due to its high bioactivity, antibacterial behaviors, and good biocompatibility. However, it has several disadvantages related to certain physical properties, including a long setting time and poor mechanical properties. Therefore, we hypothesized that coating MTA with gallic acid (GA) would regulate physical properties and lead to enhanced adhesion, proliferation, and secretion of angiogenic- and odontogenic-related proteins. This study examined whether MTA can be modified with GA to form GAMTA cement and evaluated its physicochemical and biological behaviors and immune suppression, angiogenesis, and odontogenesis capabilities. We soaked MTA in Tris buffer containing different concentrations of GA to coat the MTA powders. X-ray diffraction (XRD) and diametral tensile strength analyses were conducted to assess the physical characteristics of GAMTA. Then, we immersed GAMTA cement in simulated body fluid to evaluate its hydroxyapatite precipitation capabilities and silicon ion release profile. We used human dental pulp stem cells to assess the cell responses and the immunosuppressive, angiogenic, and odontogenic capabilities of GAMTA. The XRD results showed that GA was successfully coated onto MTA without the disruption or loss of MTA's advantageous original structural properties. GAMTA demonstrated excellent physicochemical and biological properties, improving hydroxyapatite formation and angiogenic, odontogenic, and anti-inflammatory properties compared with MTA alone. Our results indicate that the GAMTA cement is a useful dental material for future tissue engineering and clinical applications. [ABSTRACT FROM AUTHOR]

To study the composition and migration of agglomerate in reclaimed asphalt pavement (RAP), two different RAPs were selected, and the aging performance of RAPs was evaluated. Then, the RAPs were sieved into a single particle size from 13.2 to 0.075 mm, and hot-mix and extraction tests were carried out on the RAPs with single particle sizes. Through the comparative analysis of gradations of the hot mixing and extraction of RAPs with single particle sizes, the composition and its migration rule of agglomerates of RAPs were analyzed. The thickness of gradation (TG), thickness of gradation ratio (TGR), degree of separation (DS), and degree of separation ratio (DSR) were proposed to evaluate the fragmentation characteristics of RAP agglomerates with single particle sizes. According to the DS index, the grading standard of RAP agglomerates was determined. The results show that the agglomerate of RAP at each particle size is mainly composed of the mineral aggregate of the initial particle size of RAP, the aggregate with one gradation lower than the initial particle size, and other aggregates with smaller and finer content. During the hot mixing, the RAP with the single particle size larger than 2.36 mm mainly undergoes old agglomerate fragmentation, whereas RAP with the single particle size ≤2.36 mm will not only break into small particles, but also integrate new agglomerates. The RAP agglomerates can be divided into strongly bound agglomerates and weakly bound agglomerates according to whether they will be broken and separated during hot mixing. With the decrease of particle size of RAP, the proportion of strongly bound agglomerates gradually rises, whereas the proportion of weakly bound agglomerates declines. [ABSTRACT FROM AUTHOR]

This study investigated the suitability of recycled asphalt pavement and polyethylene wastes as coarse aggregate in asphaltic concrete by evaluating the impact of the use of polyethylene polymer wastes and recycled asphalt pavement composite as aggregates on the physical and mechanical properties of the asphaltic concrete. The physical characteristics of the aggregate and bitumen were determined using relevant parametric tests. Recycled asphalt pavement was used to make asphaltic concrete samples using LDPE at 5%, 10%, 15%, RAP at 5% and HDPE at 5%, 10%, 15%, and a mixture of LDPE + HDPE at 5+5%, 7.5+7.5% and 10+10% RAP at 5% as additives. Marshall Stability test was conducted to assess the mechanical strength of the asphaltic concrete, and the results included information on the aggregate's stability, flow, density, voids filled with bitumen, voids filled with air, and voids in mineral aggregate. In addition, the surface and crystal structure of the aggregates was studied by carrying out a microscopic examination with a Scanning Electron Microscope (SEM) and X-Ray diffraction (XRD). The results obtained from this study demonstrated that RAP, HDPE & LDPE are viable conventional aggregate substitute for asphalt concrete production. [ABSTRACT FROM AUTHOR]

Sensitivity analysis of influencing factors on frost resistance is carried out in this paper, and a two-stage neural network model based on grey theory and Back Propagation Neural Networks (BPNNs) is established for the sake of predicting the frost resistance of active-admixture recycled concrete quickly and accurately. Firstly, the influence degree of cement, water, sand, natural aggregate, recycled aggregate, mineral powder, fly ash, fiber and air-entraining agent on the frost resistance of active-admixture recycled-aggregate concrete was analyzed based on the grey system theory, and the primary and secondary relationships of various factors were effectively distinguished. Then, the input layer of the model was determined as cement, water, sand, recycled aggregate and air-entraining agent, and the output layer was the relative dynamic elastic modulus. A total of 120 datasets were collected from the experimental data of another author, and the relative dynamic elastic modulus was predicted using the two-stage BPNN prediction model proposed in this paper and compared with the BPNN prediction results. The results show that the proposed two-stage BPNN model, after removing less-sensitive parameters from the input layer, has better prediction accuracy and shorter run time than the BPNN model. [ABSTRACT FROM AUTHOR]

The global construction industry is increasingly utilizing concrete prepared from recycled aggregate as a substitute for natural aggregate. However, the subpar performance of recycled fine aggregate (RFA) has resulted in its underutilization, particularly in the structural concrete exposed to challenging environments, including those involving chlorine salts and freeze–thaw climates. This study aimed to enhance the performance of RFA as a substitute for river sand in concrete as well as fulfill the present demand for fine aggregates in the construction sector by utilizing accelerated carbonation treatment to create fully recycled aggregate concrete (FRAC) composed of 100% recycled coarse and fine aggregates. The impacts of incorporating carbonated recycled fine aggregate (C-RFA) at various replacement rates (0%, 25%, 50%, 75%, and 100%) on the mechanical and durability properties of FRAC were investigated. The results showed that the physical properties of C-RFA, including apparent density, water absorption, and crushing value, were enhanced compared to that of RFA. The compressive strength of C-RFC100 was 19.8% higher than that of C-RFC0, while the water absorption decreased by 14.6%. In a comparison of C-RFC0 and C-RFC100, the chloride permeability coefficients showed a 50% decrease, and the frost resistance increased by 27.6%. According to the findings, the mechanical and durability properties, the interfacial transition zones (ITZs), and micro-cracks of the C-RFC were considerably enhanced with an increased C-RFA content. [ABSTRACT FROM AUTHOR]

The article focuses on the treatment and recycling of aggregate. It also addresses the issue of treatments effects on mine tailings, fly ash and acid mine water on the measured parameters of concrete with load-bearing and backfilling paste with non-load-bearing function. Four different mixes were developed, and standard tests were performed on them. These mixtures were made with different types of mine tailing's fillers with varying degrees of treatment. Mineralogical and chemical tests were carried out on the treated aggregates, with sieve analysis and their subsequent adjustment for suitable aggregate gradation curve in concrete. Strength and volumetric weight tests were carried out on hardened samples at 28, 56 and 90 days. The results of the determined functional specimens showed that it is possible to develop an almost completely waste-free technology using recycled aggregate and fly ash from the ore mining and energy industries and its subsequent processing and use for backfilling of mine deposits with load bearing and non-load bearing function concrete. [ABSTRACT FROM AUTHOR]

This study explores the potential of using fine recycled aggregate (FRA) to replace natural sand in concrete production. The research was divided into two parts. In the first part, natural aggregate's complete fine fraction (0-4mm) was replaced with FRA in conventional concrete for two strength classes. In the second part, individual fine components of high-performance concrete (HPC) were substituted with a similar fraction of fine recycled HPC and concrete aggregate. The physical and mechanical properties of these mixtures with recycled aggregate were evaluated against reference mixtures that contained only natural aggregate, following European standards. Results showed that while most of the concrete and HPC mixtures with recycled aggregate showed slight decreases in properties compared to the reference mixes, the most significant reduction in mechanical properties was observed in the flexural tensile strength of the concrete mixture with FRA, which decreased by over 50 %. The absorption by immersion increased by up to 85 %. The deterioration in properties must be considered during the design stage and only used in applications where it will not affect the functionality of the structures. [ABSTRACT FROM AUTHOR]

Coarse recycled aggregates (CRAs) could be potentially used as aggregates for construction, providing an alternative option to expensive natural aggregates (NA). CRAs are of meager strength, with a weak interfacial transition zone, which has limited their widespread use as a substitute for NA. This study aims to investigate the effectiveness of different pretreatment techniques for CRAs and their potential to enhance the mechanical properties of alkali-activated concrete (AAC). Three distinct pretreatment techniques—mechanical, chemical, and hybrid processes—were employed to address the issue of adhered mortar in CRAs. The study maintained a fixed 0.1 M acidic solution to ensure treatment consistency. Data collection involved assessing residual mortar content (RMC), microstructural changes, durability, and fundamental properties. Among the three pretreatments, the hybrid process (HP) demonstrated the highest efficiency, effectively removing a significant portion of the RMC and resulting in CRAs with superior microstructural properties, including an 81% reduction in water absorption potential and a specific gravity of 98%, comparable to NA. Freeze–thaw and soundness tests revealed the enhanced durability of HP, with 50% less loss during freeze–thaw and 76% better soundness properties compared to unprocessed CRAs. The compressive strength of AAC incorporating 100% hybrid-processed coarse recycled aggregates (HPCRAs) reached 47.49 MPa. The findings suggest that HP is a promising method for enhancing the CRA's fundamental properties. It also shows that HPCRAs have the potential to improve the mechanical properties of AAC significantly. These outcomes pave the way for more sustainable construction practices, reducing reliance on NA and promoting the use of CRAs in AAC. [ABSTRACT FROM AUTHOR]

The present study illustrates the susceptibility of optimized-quality recycled concrete aggregate (RCA) to supplementary cementitious materials (SCMs), such as silica fume (SF), ground granulated blast slag (GGBS), and mechanically produced recycled fine (M-Fine or MF), in concrete. According to the present research, old interfacial transition zone (OITZ) characteristics may be controlled if RCA is developed in such a way as to reduce mortar adhesion optimally. It may facilitate the penetration of binder particles, strengthening the OITZ even further. A high-quality surface may improve RCA's self-cementing properties, which strengthen the new ITZ (NITZ). The combined effect may yield RCA characteristics equivalent to parent aggregate when interacting with a cement matrix based on SCMs. Substituting the cement with SF (11%), GGBS (14%), and MF (15%) contributes to the compressive strength of recycled aggregate concrete (RAC) up to 11.61% via strengthening the OITZ. SF and GGBS further enhance RAC tensile strength in a similar way to how they enhance natural aggregate concrete (NAC) tensile strength. The elastic modulus (MOE), fracture energy, and durability characteristics of RAC with SF and GGBS are significantly improved. RAC with MF (15%) shows compressive and tensile strength comparable to RAC with GGBS (14%) with marginal reductions in flexural strength. In comparison to RAC, RAC with MF has a 2.9% lower MOE. RAC-MF has 1.82% higher fracture energy than RAC. RAC-SF, RAC-GGBS, and RAC-MF have significantly reduced water absorption and water absorption rate (sorptivity) than RAC. There is a strong correlation between the compressive strength of RAC, RAC-SF, RAC-GGBS, and RAC-MF, and their UPV with R2=0.92. The sorptivity and electrical resistivity are also correlated with R2=0.86. SEM images show uniform and dense microstructure and EDS analyses shows Si-rich C-S-H gel formation, resulting in superior mechanical and durability properties in RAC with SCM compared to RAC. Practical Applications: About 20% to 30% of recycled fines (M-Fines) below 150 μm are generated during RCA processing from construction and demolition waste. In addition, M-Fines are also generated during the removal of the mortar attached to the RCA. Thus, M-Fines as by-products of mechanical processing of RCA could be used as cementitious materials. Despite M-Fine's low reactivity compared to SF, it may produce strength and durability characteristics comparable to other conventional supplementary cementitious materials like GGBS. In structural concrete, optimized-quality recycled concrete aggregates with supplementary cementitious materials, including M-Fines, can be used. In this way, it may be possible to promote construction and demolition waste recycling operations. Moreover, the effectiveness of SF and GGBS with RCA, as well as the performance of RAC-MF, may encourage the use of RAC as structural concretes and M-Fines as supplementary cementitious materials. [ABSTRACT FROM AUTHOR]

Aim: To assess the association between demographic and clinical variables and the outcome of root-end surgery using digital periapical radiographs (PA) and cone-beam computed tomography (CBCT). Methodology: One hundred and fifty teeth that received endodontic microsurgery were clinically and radiographically examined (PA and CBCT scans) after 1 and 2 years. Two calibrated endodontists evaluated the radiographic healing based on a six-point outcome classification. The outcome was classified using both strict (healed) and loose (healing) criteria. The success rates were calculated, and several outcome prognostic factors were assessed. Results: One hundred and fifty teeth were assessed with both radiographic systems. When "loose" success criteria were applied using PA, 90% (n = 135) of teeth were assessed as having had a favourable outcome (90%; 95% CI: 85.2–94.8%), whereas 90.7% (n = 136) of teeth showed a successful outcome when assessed with CBCT (90.7%; 95% CI: 86.0–95.3%). When "strict" success criteria were applied, there was a statistically significant difference (p = 0.018) between the success rates of mineral trioxide aggregate (MTA) (63.7%) and Biodentine (95.5%). Conclusions: Within the limitations of this study, endodontic microsurgery showed a high success rate. Among all the demographic and clinical variables assessed, in the multiregression analysis, only the use of Biodentine was associated with a higher proportion of "complete" healings compared to MTA or Intermediate Restorative Material (IRM) when assessed using CBCT. MTA and Biodentine performed similarly when "incomplete" healings were regarded as successful outcomes. [ABSTRACT FROM AUTHOR]

In countries that are big producers of olive oil such as Spain, Italy, or Greece, large amounts of olive husk remain as waste from processing olives and pose a serious environmental issue. One of the solutions could be to use this waste to partially replace sand in cement mortar to preserve the environment, decrease the consumption of cement, and improve economic benefits. This work presents our initial results which show the viability of using olive waste as an aggregate in cementitious mortars, indicating that the organic materials studied can be promising for this purpose. [ABSTRACT FROM AUTHOR]

Context: Asphalt, a polymer mixture composed of various hydrocarbons, is extensively utilized due to its excellent performance. To evaluate the sensitivity of asphalt concrete to chloride salt damage at the nanoscale, considering the anisotropy of aggregate mineral crystal orientation, molecular dynamic simulations were employed to model the interface interactions between asphalt and aggregate mineral components (silica and calcite) under chloride salt exposure. The wetting processes of water droplets and chloride salt droplets on different crystal surfaces of silica and calcite were analyzed. Furthermore, the adhesive energy, decohesion energy, degradation ratio, and energy ratio of the interaction model between asphalt and aggregate mineral interfaces were analyzed to reveal the variations in the interfaces between the two components. The results demonstrated that the anisotropy of the minerals significantly affects the adhesion energy of asphalt and aggregate. Moreover, the surface hydrophilicity of calcite was larger than that of silica. The interfacial adhesion energy of asphalt-calcite was larger than that of asphalt-silica under dry condition and chloride salt attack, and the interfacial adhesion energy of both asphalt and mineral decreased with the increase of chloride salt concentration. The degradation ratio and energy ratio values of asphalt and calcite were larger than those of asphalt and silica, and the anisotropy of the mineral surface affected the degradation ratio and energy ratio values. This study provides a new method and theoretical basis for further research on the damage mechanism and strengthening measures of asphalt-aggregate under chloride salt attack. Methods: To investigate the interaction between asphalt and mineral aggregates under chloride salt erosion, models of asphalt, aggregate, and asphalt/aggregate composite systems were constructed using the Amorphous Cell module in Materials Studio 2020 software. Molecular dynamic simulations of the asphalt/aggregate composite system were then conducted using the Forcite module, employing the COMPASS II force field to describe atomic and molecular interactions. Initially, considering the crystal orientation and surface configuration of the aggregate minerals, the impact of mineral anisotropy on the asphalt-aggregate interface model was analyzed. Subsequently, by simulating the contact states of nano water droplets and chloride salt droplets with different mineral surfaces, the wetting characteristics of nano water droplets on silica and calcite surfaces were determined. Lastly, considering the corrosion effect of chloride solution at different concentrations, the adhesion energy, debonding energy, degradation ratio, and energy ratio of the asphalt-aggregate interface interaction model were analyzed. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study was to evaluate the effect of the pre-application of a dentin-bonding agent and the application of different lasers on the prevention of tooth discoloration caused by mineral trioxide aggregate (MTA) in the presence of blood. Sixty extracted human anterior teeth were selected, with root lengths standardized to 10 mm and root canals shaped using Gates-Glidden drills #3 to #5. The samples were divided into six groups (n = 10): Group 1 with no surface treatment and Groups 2 to 6 with Optibond universal adhesive and Neodymium yttrium aluminum garnet (Nd:YAG), Erbium yttrium aluminum garnet (Er:YAG), Erbium-chromium-yttrium-scandium-gallium-garnet (Er:Cr:YSGG), and diode laser applications, respectively. Root canals were filled with fresh human blood, and ProRoot MTA and a collagen barrier were then placed. Color changes were measured with a spectrophotometer at 0, 7, 30, 90, and 180 days post MTA placement. Color differences (∆E) were analyzed using a two-factor mixed-design ANOVA with the Sidak method (p = 0.05). All treatment groups exhibited discoloration above the acceptability threshold. Although all treatment approaches exhibited less color change compared to the control group (p < 0.05), there was no significant difference among them in terms of preventing color change (p > 0.05). It was determined that none of the methods could guarantee 100% prevention of discoloration caused by MTA–blood contact. [ABSTRACT FROM AUTHOR]

Construction with recycled aggregate concrete – Influence on design and construction of reinforced concrete structures Apart from the need to reduce huge quantities of CO2 emitted in cement production in particular, an efficient use of diminishing natural resources such as sand and gravel is indispensable for a more eco efficient concrete production. In this context, the use of recycled aggregates seems to be a promising alternative to natural aggregates in conventional concrete to save natural resources. Since 1998, the use of recycled aggregate in structural concrete is allowed in Germany following the guideline issued by the German Committee for Structural Concrete (DAfStb). With the new edition of Eurocode 2 (FprEC2), regulations for the use of recycled aggregate concrete (RAC) are also included for the first time. Starting with the properties of RAC compared to natural aggregate concrete (NAC), the current regulations for design of RAC are compared and an outlook on future research focussing not only resource efficiency but also CO2 emission reduction in concrete production is given. [ABSTRACT FROM AUTHOR]

Recycled concrete aggregate (RCA) can be used in landfill and slope cover systems, where its unsaturated hydraulic properties play an important role. The hydraulic behavior of RCAs can be potentially controlled through mixing coarse and fine aggregates by a pre-determined proportion, which lacks experimental validation. In this study, water retention curve (WRC) and permeability function (PF) of RCAs with different fine aggregate contents (fc) were investigated. Experiments on 9 RCAs with different gradations reveal that when fc is between 20% and 30%, a second air entry value appears, and the shape of both WRC and PF becomes bimodal, which is probably resulted from an uneven dual-peak pore size distribution. With an increasing fc, the first air entry value and the residual water content increases. The unsaturated coefficient of permeability decreases with the increasing fc for a low suction level (<0.1 kPa), but increases with the raise of fc for high suction (>10 kPa). Overall, adopting a properly mixed RCA with fc value of less than 10% or over 40%, instead of a narrowly graded RCA, is recommended for coarse- and fine-grained layers in a capillary barrier, respectively. [ABSTRACT FROM AUTHOR]

Natural zeolite (NZ), synthetic zeolite (SZ) and sasobit (S) additives have been utilized by many for warm-mix asphalt (WMA) mixtures production. However, the engineering properties of WMA mixtures under long-term aging (LTA) process still need to be determined. This paper examines the effect of laboratory aging process in accordance to AASHTO R30 on WMA (NZ, SZ, and S) mixtures by characterizing Marshall stability, Marshall quotient, indirect tensile strength, tensile strength ratio, flexural strength, and creep compliance. The results from this study indicated that at the α = 0.05 level: (1) the difference in the Marshall stability, unconditioned tensile strength, conditioned tensile strength, flexural modulus, and stiffness modulus as a function of the LTA effects between NZWMA and SZWMA mixtures was found to be statistically insignificant, whilst, the difference in the creep compliance was found statistically significant; (2) the difference in the Marshall stability, unconditioned tensile strength, conditioned tensile strength, and creep compliance as a function of the LTA effects between SZWMA and SWMA mixtures was found to be statistically significant, whilst, the difference in the flexural and stiffness modulus was found statistically insignificant; (3) the performance of WMA mixtures after LTA ranked in an increased order as follows: NZWMA ˃SZWMA˃SWMA; and (4) all mixtures (i.e., NZWMA, SZWMA, and SWMA) satisfy the minimum requirements of 8kN stability, 2–4 mm flow, and 14% voids in mineral aggregate, except for SWMA mixture which not satisfies voids in mineral aggregate requirements after LTA. [ABSTRACT FROM AUTHOR]

Dental biomaterials are commonly used in vital pulp therapy to protect dentin against degradation. However, the protection role of the ions diffusing in affected dentin in indirect pulp capping remains not fully understood due to the limitations of experimental techniques to validate it at the atomic scale. In this study, molecular dynamics (MD) is used for studying two bioactive materials, during mineral apatite formation and remineralization. LAMMPS code with DREIDING Force Field and Universal Force-Fields (UFF) simulated the behaviour of calcium hydroxide and mineral trioxide aggregate in the tooth structure in the oral environment. The comparison of the physical parameters provided by the simulation is discussed in detail to explore the possibilities of crystallization depending on potential energy, lattice constant, XRD pattern, atomic volume and radius of gyration. MD results show that the crystallization process occurs in both materials after about 10 ns, at 310 K and 1 bar. [ABSTRACT FROM AUTHOR]

The conventional design approaches for reclaimed asphalt pavement (RAP) mix follow blending rules to select the grade of the virgin binder for hot recycled bituminous mixtures. The interactions of RAP binder with the virgin binder are highly complex in the presence of the rejuvenator. Identifying the optimal proportion of RAP binder, virgin binder, and rejuvenator is often a trial-and-error procedure, involving considerable experimental data collection. The current research study proposes the statistical-based design of experiments (DoE) framework to design ternary RAP binder blend, develop response surface prediction models, and optimize the proportions to meet targeted binder properties of viscosity grade (VG30) binder. A desirability-based multiple response optimization is carried out, and the optimal blend proportions with target binder properties are arrived at with different desirability levels. A total of 13 RAP binder blends are formulated using the I-Optimal algorithm in the current study. Experimental data such as softening point, high-temperature performance grade (PG), and linear viscoelastic parameters in the temperature range of 46°C to 70°C and frequency range of 0.1 to 50 Hz are collected. The binder blends are evaluated using master curve parameters and relaxation spectrum. The response surface models are developed for two measured parameters (high-temperature PG and softening point), three computed master curve parameters, and four relaxation spectrum parameters. These models capture the possible individual component effects and combined component effects on the final RAP binder blend through linear and nonlinear terms. A desirability-based simplex optimization is adopted to identify combinations of constituents at various levels of desirability that comprises only direct measurements, direct measurements and master curve parameters, and direct measurements, master curve parameters, and relaxation spectrum. Using this proposed approach, a wide range of solution zones are identified with various levels of desirability. Reclaimed asphalt pavement (RAP) consisting of aged bitumen coated on mineral aggregates is used for recycling in pavement construction. Many challenges exist related to the optimal use of such material. The aged binder may need to have the required properties suitable for recycling. Generally, rejuvenators are added to the RAP to enhance the properties of aged binder. However, how much rejuvenator should be added is unclear. Aged bitumen from different sources of RAP can have different degrees of aging. In addition, it may not be easy to estimate the extent of blending of the RAP with the virgin materials (aggregates and bitumen), as it is linked to the characteristics of aged binder and the choice of fresh bitumen and rejuvenator. Also, the aged bitumen, when mixed with a rejuvenator and virgin bitumen, may not necessarily result in a final mix with bitumen that meets the requirements. As can be seen, the choices are entirely diverse and varied. This research attempts to solve such issues using a statistics-based tool called design of experiments (DoE). Using such a tool, this study demonstrates how to optimally choose the proportions of virgin bitumen, RAP bitumen, and rejuvenator. This work presents a methodology that can be implemented efficiently using commercial software by any asphalt mix designer. [ABSTRACT FROM AUTHOR]

Direct pulp capping (DPC) is a conservative approach for preserving tooth vitality without requiring more invasive procedures by enhancing pulp healing and mineralized tissue barrier formation. We investigated the effectiveness of Platelet Rich Plasma (PRP) vs. Mineral Trioxide Aggregate (MTA) as a DPC agent. Forty-two teeth from three mongrel dogs were divided into two equal groups. After three months, the animals were sacrificed to evaluate teeth radiographically using cone-beam computerized tomography, histopathologically, and real-time PCR for dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE), and nestin (NES) mRNA expression. Radiographically, hard tissue formation was evident in both groups without significant differences (p = 0.440). Histopathologic findings confirmed the dentin bridge formation in both groups; however, such mineralized tissues were homogenous without cellular inclusions in the PRP group, while was osteodentin type in the MTA group. There was no significant difference in dentin bridge thickness between the PRP-capped and MTA-capped teeth (p = 0.732). The PRP group had significantly higher DSPP, MEPE, and NES mRNA gene expression than the MTA group (p < 0.05). In conclusion, PRP enables mineralized tissue formation following DPC similar to MTA, and could generate better cellular dentinogenic responses and restore dentin with homogenous architecture than MTA, making PRP a promising alternative DPC agent. [ABSTRACT FROM AUTHOR]

Sustainable consumption of construction materials is an important segment of sustainable development goals towards reducing climate change. Since the consumption of natural aggregates raises environmental concerns, there is an increasing demand for use of recycled aggregates (RAs), as it enhances social and environmental benefits and creates a market opportunity. This paper presents the practice of using recycled construction and demolition waste (CDW) in the Belgrade city area (Serbia) as a resource. Two groups of CDW from Vinča landfill site near Belgrade are analyzed: raw material before, and RAs after, construction of a recycling facility on site. Comprehensive characterization is performed (including particle size distribution, density, water and organic pollutants content, various mechanical resistances, flakiness index, etc.) and compilation of samples analyzed and compared to show a holistic overview. The test outputs in both groups show acceptable values and meet required standards, indicating that recycled CDW generated in the Belgrade area can be used as a substitute to natural aggregates. In addition to that, the environmental and economic benefits from this use as a substitute are analyzed and discussed, proving the substantial income from sold Ras and the landscaping benefits, as well as ecological and economic benefits from energy savings. [ABSTRACT FROM AUTHOR]

The aim of this two-center randomized controlled trial was to assess the outcomes and relative factors associated with pulpotomies performed using a premixed injectable calcium silicate cement, as compared to mineral trioxide aggregate in mature permanent premolar and molar teeth with reversible pulpitis. Included teeth were randomly divided into two groups according to pulpotomy material (ProRoot MTA [PMTA] group, Endocem MTA Premixed [EPM] group). After pulp exposure, the superficial pulp was either removed to a depth of 2 mm (partial pulpotomy) or completely amputated to the level of the root canal orifice (full pulpotomy). A 3-mm layer of either material was randomly placed over the pulp wound, followed by the application of a thin layer of a light-cured glass ionomer composite liner. The restoration procedure was then carried out during the same visit. After one year of treatment, the pulpotomy success rate was 94.4% (67/71), with no significant difference between the PMTA and EPM groups. The success rate was 93.9% in the PMTA group and 97.1% in the EPM group. There were no significant factors related to the procedures. EPM is a viable alternative to PMTA for single-visit pulpotomies of permanent premolars and molars. [ABSTRACT FROM AUTHOR]

The aim of this two-center randomized controlled trial was to assess the outcomes and relative factors associated with pulpotomies performed using a premixed injectable calcium silicate cement, as compared to mineral trioxide aggregate in mature permanent premolar and molar teeth with reversible pulpitis. Included teeth were randomly divided into two groups according to pulpotomy material (ProRoot MTA [PMTA] group, Endocem MTA Premixed [EPM] group). After pulp exposure, the superficial pulp was either removed to a depth of 2 mm (partial pulpotomy) or completely amputated to the level of the root canal orifice (full pulpotomy). A 3-mm layer of either material was randomly placed over the pulp wound, followed by the application of a thin layer of a light-cured glass ionomer composite liner. The restoration procedure was then carried out during the same visit. After one year of treatment, the pulpotomy success rate was 94.4% (67/71), with no significant difference between the PMTA and EPM groups. The success rate was 93.9% in the PMTA group and 97.1% in the EPM group. There were no significant factors related to the procedures. EPM is a viable alternative to PMTA for single-visit pulpotomies of permanent premolars and molars. [ABSTRACT FROM AUTHOR]

Aim: The aim and objective of this in vitro study was to evaluate the antibacterial efficacy of mineral trioxide aggregate, bioactive glass sealer, and epoxy-resin–based sealer. Materials and Methods: In the present study, 22 Mueller Hinton agar (MH agar) plates were employed and equally divided into two groups. Three holes were made by removal of agar at equidistant points and filled with root canal sealers. The strains of the bacteria used in this study were S. aureus (ATCC 6538) and C. albicans (ATCC 10231) and were divided into two groups and root canal sealers were divided into three subgroups: mineral trioxide aggregate (MTA) fillapex Sealer, Nishika Bioactive Glass sealer, and Syntex Epoxy Resin base sealer. For Staphylococcus aureus, peptone water was placed in a 2 mL test tube and bacteria were extracted from blood agar plates using a nichrome wire loop and poured into the peptone water–containing test tube and incubated for 2 hours and for C. albicans, fungi were grown at 37°C for 24 hours in MH Broth and seeded into MH agar to produce turbidity of 0.5 on the McFarland scale, which corresponds to a concentration of 108 CFU/mL. This MH broth was used as a second layer. The seeded agar was then added over the plates immediately after the insertion of sealer cement. After incubation, the diameters of zones of inhibition around the plates were measured. Results: The results of this study showed that the highest inhibition was recorded in Syntex sealer against Staphylococcus aureus followed by MTA fillapex sealer and Nishika sealer, whereas MTA fillapex showed the highest inhibition against C. albicans followed by Syntex sealer and Nishika sealer. Conclusion: Syntex sealer exhibits better antibacterial efficacy against Staphylococcus aureus and MTA fillapex exhibit better antibacterial efficacy against C. albicans. [ABSTRACT FROM AUTHOR]

The paper aims to develop a method to rapidly detect the content of tylosin tartrate. In Clark-Lubs buffer solution with pH 6.6, malachite green can induce strong resonance light scattering due to the construction of supermolecule aggregates, and tylosin tartrate can react with malachite green cations, resulting in the decomposition of supermolecule aggregates constructed by malachite green, which significantly weakens the resonance light scattering intensity of the system. The maximum detection wavelengths are at 285 nm and 332 nm. Due to the additive nature of the resonance light intensity ( I), the two wavelengths are superimposed for measurement. The linear range of tylosin tartrate is 0.2-0.6 mg/L, the linear regression equation is IRLS= 5 299 C-766.4, the correlation coefficient ( R) is 0.999 8, and the detection limit is 0.004 1 mg/L. The result indicates that the method is simple and sensitive, and can be successfully applied for the determination of tylosin tartrate. [ABSTRACT FROM AUTHOR]

Recycled fine aggregates (RFAs) encompass inorganic particles derived from the crushing of building and demolition waste, constituting an environmentally sustainable source for the concrete industry. This study explores the integration of construction and demolition (C&D) waste-based RFAs in concrete, aiming to reduce carbon emissions and promote eco-friendly construction practices. The RFAs, obtained from aging concrete structures, contribute fines to the concrete mixture, and their viability is assessed in this research. The investigation encompasses strength and microstructural analyses of RFA-based concrete blends with varying replacement percentages (20%, 40%, 60%, 80%, and 100%). The comprehensive evaluation spans 7 and 28 days of water curing, with particularly promising outcomes observed up to a 40% replacement threshold. The optimal performance is identified at the 40% RFA replacement, justifying the applicability of RFAs as an alternative fine aggregate. Microstructural studies conducted through a secondary electron microscope (SEM) specifically for the 40% RFA replacement substantiate the particle packing effect and corroborate the experimental findings. The findings underscore the sustainable potential of incorporating RFAs in concrete formulations, offering a pathway toward environmentally conscious and resilient concrete structures. [ABSTRACT FROM AUTHOR]

[Display omitted] • Case study was proposed: Resource utilization strategy of hematite tailings. • The SiO 2 grade and yield in concentrate respectively reached 95.26% and 42.45%. • High purity SiO 2 grade reached 99.961% after mixed acid leaching. • The mechanisms of S-HGMS and mixed acid leaching were elaborated. Hematite tailings (HTs) are rich in silica and are used as replacements for fine aggregates in the preparation of construction materials. However, there is scope for a more effective utilization of the valuable elements present in HTs. In this paper, a process for preparing high-purity SiO 2 using HTs procured from Ansteel (China) is proposed. HTs were treated using the superconducting high-gradient magnetic separation (S-HGMS) technology, where the silica as part of the nonmagnetic fraction was obtained in the form of a high-silica concentrate, which was then subjected to mixed-acid leaching to dissolve impurities to achieve refined purification. The optimum process conditions for S-HGMS were determined, and the response surface methodology was applied to optimize the process parameters of the mixed-acid leaching process. The process indicators of the mixed-acid leaching step included the leaching time, leaching temperature, and molar ratio of the mixed acids. The optimum process conditions for S-HGMS were as follows: the magnetic strength-to-velocity ratio in the weak magnetic separation stage was set to 0.034 T·s/m whereas it was maintained at 0.076 T·s/m in the strong magnetic separation stage; the pulp concentration was 40 g/L, the pulp velocity was 500 mL/min, and the dispersant concentration was 1 mg/g. Under these conditions, the high-silica pulp was processed. The corresponding SiO 2 grade increased from 71.788 % to 95.260 %, and its recovery and yield reached 56.330 % and 42.450 %, respectively. The SiO 2 content in the sample increased from 95.260 % to 99.961 %. Further, the mechanisms of the S-HGMS and mixed-acid leaching were revealed. The proposed process is environmentally friendly and operationally inexpensive. It can reduce the amount of HTs by 42.450 %, and the obtained high-purity silica product has high economic value and good industrialization prospects. [ABSTRACT FROM AUTHOR]

The preservation of natural resources has been gaining considerable space in recent decades, encouraging the use of industrial and civil construction waste. In this work, the recycled asphalt pavement (RAP) from the milling of the pavements was used to replace virgin aggregates for the construction of road base layers. Due to the large amounts of materials involved in road construction, it is necessary to develop alternative binders. Particularly when it comes to alkali-activated materials, the use of residues in the production of sodium silicate has not yet been investigated for RAP stabilization. Therefore, in this study, rice husk ash (RHA) was activated in an alkaline environment, playing the role of an alternative source of silica, for the formation of an alkali-activated binder (AAB). The exposure of these mixtures to seasonal variations in humidity and temperature was evaluated through durability tests from wet–dry cycles and the unconfined compressive strength (UCS) retained in the samples after the cycles. AAB permanence was also verified through long-term mechanical performance and its environmental impact through leaching tests. The results indicated that mixtures with a RAP to AAB ratio = 40:40, 50:30, and 50:40 reached the minimum design strength (2.1 MPa) even after wet–dry cycles; however the mixture with RAP:AAB = 40:40 is potentially superior for better performance in field conditions, possibly without premature failure. In addition, this mixture has no environmental impact because the results of environmental tests did not show any significant risk or hazardous characteristics. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the dislodgement resistance and structural changes of different mineral trioxide aggregate cements (MTA) like Pro-Root MTA, Ortho MTA, and Retro MTA after exposure to sodium hypochlorite (NaOCl), NaOCl-Ethylenediaminetetraacetic acid (EDTA), 1-hydroxyethylidene-1, 1-bisphosphonate (Dual Rinse HEDP), and NaOCl-Maleic acid (MA). The root canal spaces of 150 dentine slices were obturated using tricalcium silicate cements and divided into 3 groups (n = 50): Group1: ProRoot MTA, Group2: Retro MTA, and Group3: Ortho MTA. The samples in each group were further subdivided into four experimental (n = 10) and one control groups (n = 10): 2.5% NaOCl-17% EDTA, Dual Rinse HEDP, 2.5% NaOCl-7% Maleic acid, 2.5% NaOCl, distilled water (control). The dislodgement resistance and structural changes of cements were measured. Use of DR HEDP resulted in higher dislodgement resistance compared to17% EDTA and 7% MA in the samples obturated with Ortho MTA and Pro-Root MTA (p<0.001). In Retro MTA group, samples treated with DR HEDP and 17% EDTA had higher dislodgment resistance compared to 7% MA (p<0.001). On microstructural and elemental analysis of all the three MTA cements, samples treated with 17% EDTA and 7% MA were more amorphous and granular when compared to DR HEDP, which was pettle shaped. Calcium level was decreased more in samples treated with 17% EDTA and 7% MA when compared to DR HEDP. [ABSTRACT FROM AUTHOR]

The paper presents the results of the valorization of sand and gravel aggregate deposits in Poland. The study aims to identify the most valuable deposits of potentially strategic importance that require protection. Undeveloped gravel deposits (gravel content above 70%) with resources exceeding 10 million tons and sand and gravel deposits (gravel content 25–70%) with resources above 20 million tons were selected for analysis. The valorization of deposits was carried out using two multi-criteria methodologies. The first of them was proposed by Nieć and Radwanek-Bąk (2013, 2014), while the second one was developed as part of the MINATURA 2020 project (Galos et al. 2016). They include criteria regarding a degree of geological knowledge, raw material quality and quantity, mining attractiveness, and the accessibility of deposits for future exploitation resulting from environmental and land-use conditions. Out of 4,110 undeveloped deposits that constitute the national resource base for producing sand and gravel aggregates, only 8 gravel deposits and 64 sand and gravel deposits exceeded the threshold set for the volume of resources. As a result of the valorization, it was determined that most of the analyzed deposits, which can be considered as deposits of potentially strategic importance at the regional level, have limited availability due to environmental and land-use conditions. Only one gravel deposit and 7 sand and gravel deposits have simultaneously high resource quantity and quality and favorable geological and mining, environmental, and land-use conditions. The article also presents some recommendations regarding the need to adapt the valorization criteria to the specificity of deposits recognized for sand and gravel aggregate production. [ABSTRACT FROM AUTHOR]

As a result of the rapid increase in the demand for transportation vehicles recently, the accumulation of waste tires causes environmental problems. One of the methods that can contribute to the reduction of this environmental problem is the recycling of waste tires as a construction material in aggregate form. This research investigated the impacts of waste tire crumb rubber with/out steel fiber (SF) on the two-way punching-shear behavior alkali-activated concrete (AAC) flat slabs and performed center point load tests. In the study, one-type of SF and two kinds of scrap tire waste i.e., crumb rubber (CR) and tire particles, were used on the producing of rubberized AAC slabs obtained by 100% as binder made of ground-granulated blast furnace slag (GGBFS). Also, while both fine crumb rubber (FCR) and coarse crumb rubber (CCR) were used together in the AAC slabs, tire crumb rubber (TCR) was used alone at the same proportion. Additionally, the fine aggregate was substituted with 10% and 15% FCR and CCR, and coarse aggregate was substituted with TCR in the same proportions. Additionally, AAC slabs with recycled tire rubber (RTR) were produced as fibrous and non-fibrous using 1% by volume hook-end SF. In total, nine AAC slabs with sizes of 50 x 50 x 6 cm3 were manufactured for the study. Experimental data showed that the inclusion of RTR only slightly reduced the punching shear strength of AAC slabs and the punching shear strength of the slabs increased when SF was added to the mixtures containing RTR. [ABSTRACT FROM AUTHOR]

Key Clinical Message: This case report focuses on the diagnosis and treatment of a maxillary lateral incisor affected by a talon cusp, a rare developmental dental anomaly. The case presented with irreversible pulpitis and an immature apex. The article discusses the prevalence, etiology, classification, and treatment options for talon cusps, highlighting their clinical significance and potential complications. Clinical and radiographic findings obtained from a periapical radiograph and a cone‐beam computed tomography (CBCT) scan are outlined. The treatment approach involved the removal of the talon cusp, endodontic therapy including apexification with mineral trioxide aggregate, and aesthetic restoration of the tooth. The report underscores the value of precise diagnosis, careful treatment planning, and the utility of CBCT scans in effectively managing talon cusps. [ABSTRACT FROM AUTHOR]

Recently, a paste-type premixed calcium silicate-based mineral trioxide aggregate (MTA) product that quickly solidifies through a pozzolanic reaction was introduced to replace existing MTA, which has the disadvantage of a long setting time. In this study, we evaluated the effect of moisture content in the root canal on the setting time of premixed calcium silicate-based MTA in a simulated root canal environment using Endoseal MTA and Well-Root ST, among commercially available products. The setting time was measured according to ISO 6876/2012. A mold made using grades 2, 3, and 4 dental gypsum according to the classification of ISO 6873/2013 was used to reproduce the difference in moisture environment. Differences in moisture content were measured using micro-computed X-ray tomography (micro-CT). The micro-CT results showed that the moisture content was the highest and lowest in the grade 2 and 4 gypsum molds, respectively. Moreover, the setting time indicated by the manufacturer was the shortest for the grade 2 gypsum mold. Hence, the differences in moisture content significantly affect the setting time of MTA. This result can help set future experimental conditions and develop premixed calcium silicate-based MTA products. [ABSTRACT FROM AUTHOR]

With the rapid evolution of the pavement industry and growing traffic on roadways, construction materials have also evolved, with non-traditional materials increasingly being employed. The key motivation for using non-conventional components was the scarcity of natural resources and their high costs, which drove the trend toward using waste materials in asphalt pavement construction to achieve environmental sustainability. This paper aims to provide an overview of the effect of adding waste vegetable oil (WVO) to asphalt binders and asphalt concrete mixtures. The information was obtained from several Scopus database studies conducted over the period of 2005 to 2022 and was used to evaluate the performance of asphalt under different dosages of WVO. It was concluded that almost all the researchers reached an agreement that adding WVO to the asphalt reduces the softening point, viscosity, complex modulus, creep stiffness, the resistance to deformation, and elastic recovery quality of asphalt. On the other hand, it increases its penetration, ductility, phase angle, m value, stress relaxation characteristic, and thermal cracking resistance. For asphalt mixtures, it was found that adding WVO increases the flow value and Voids in Mineral Aggregate (VMA). In contrast, it reduces stability and the air voids in the mixture. [ABSTRACT FROM AUTHOR]

Difficulties in meeting the minimum voids in mineral aggregates (VMA) requirement of Superpave have been a common adversity for researchers in the mix design phase. The rationale behind having minimum VMA criteria was to guarantee durability of asphalt mixtures. However, multiple studies have demonstrated weak relationship between VMA and durability. In this study, the validity of the VMA criteria of the Superpave mix design was investigated using the film thickness perspective. Seven gradations with a nominal maximum aggregate size NMAS of 12.5 mm of different types (coarse, dense, gap, and fine) were considered. A poor relationship was found between the VMA and the film thickness FT (durability indicator) enforced with a coefficient of determination R 2 = 0.0098 for the regression between FT and VMA. Moreover, a poor relationship was found between the effective binder content (Pbe) and VMA supported with a coefficient of determination R 2 =0.01 for the regression between the effective binder content (Pbe) and VMA. Both regression results indicate that the current VMA criteria is not strongly referring to the mixture durability. The weakness of these relationships was also verified on seven 19 mm gradations. An approach to calculate the minimum VMA based on the mixture components is suggested. Based on the proposed approach and volumetric results, it is shown that the minimum VMA requirement of Superpave is disqualifying acceptable mixtures, especially coarse graded, that have VMA values higher than the minimum required to ensure the durability. [ABSTRACT FROM AUTHOR]

Anisotropic and heterogeneous solids, comprising a minimum of two or more elements with different properties, appear pervasively in rock materials including the pore structure and mineral composition of quartz and granite and usually have extensive applications in construction aggregates, dimension stone, geotechnical engineering, and petrology/geology. The elastic stress fields of inhomogeneous materials or composites inevitably change due to the presence of heterogeneous microstructure under applied external conditions, and hence the total mechanical and physical properties are affected by the temperature and pore pressure fluctuations beneath the surface. In this paper, the thermoporoelastic (TPE) approach on the basis of eigenstrain concept is introduced to predict the stress fields in fluid-saturated porous geologic materials like hydrocarbon reservoirs or aquifers by accounting for the coupling between thermal, poroelastic, and mechanical effects. It is an extension of the micromechanical theory that also incorporates thermal effects like pore pressure changes and temperature alternations. In addition, the TPE approach provides an important multiphysical modeling tool for understanding subsurface fluid-rock interactions and stress states in applications like unconventional oil/gas and geothermal energy. [ABSTRACT FROM AUTHOR]

This paper presents a probabilistic model for predicting the dynamic modulus |E*| of asphalt concrete (AC). A Bayesian Neural Network (BNN) trained on a substantial dataset collected from various states was employed. This approach accounts for the inherent stochasticity in the data generation process (i.e. aleatoric uncertainty) and addresses epistemic or model uncertainty as well. The model successfully predicted dynamic moduli for unseen testing datasets. In practice, predicted moduli could be as accurate and effective as measured values, considering the model uncertainty and |E*| test variability. However, an elevated epistemic uncertainty at extremely low and high |E*| ranges would be expected due to relatively low data points. To enhance interpretability, Shapley Additive Explanations (SHAP) analysis was utilised, demonstrating adherence to physical laws. The primary factors influencing predicted moduli, as identified by the analysis, are temperature, frequency, voids in mineral aggregates, reclaimed asphalt pavement content, and binder low-performance grade. The BNN model was deployed in a web application, making it accessible for application. [ABSTRACT FROM AUTHOR]