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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Evolution of performance in quaternary slag powder-fly ash-based geopolymers and NSGA-III multi-objective optimization study</title>
      <link>https://trid.trb.org/View/2711935</link>
      <description><![CDATA[This study aims to realize the high-value utilization of solid waste resources and promote the sustainable development of low-carbon building materials by developing a quaternary geopolymer system using slag powder (SP), fly ash (FA), steel slag (SS) and silica fume (SF) as precursors. By systematically adjusting the dosages of SS, SF, and water glass as well as the curing age, the effects on workability and microstructural evolution were thoroughly investigated. A variety of characterization techniques including X-ray fluorescence (XRF), dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and thermogravimetry analysis (TG) were employed to comprehensively analyze the hydration process and the formation of reaction products. Furthermore, predictive models for slurry fluidity, mechanical properties, economic feasibility, and carbon emissions were established. Based on the criteria importance through intercriteria correlation (CRITIC), technique for order preference by similarity to ideal solution (TOPSIS), and NSGA-III multi-objective optimization algorithms, a synergistic optimization balancing performance, cost, and environmental benefits was achieved. The results provide a robust theoretical basis and technical support for the industrial application of solid waste-based building materials.]]></description>
      <pubDate>Sat, 08 Aug 2026 12:14:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2711935</guid>
    </item>
    <item>
      <title>Performance and Sustainability Assessment of Pavement Bases Incorporated with Hazardous Biomedical Waste Incinerated Ash in Geopolymer Binders</title>
      <link>https://trid.trb.org/View/2691641</link>
      <description><![CDATA[This research investigates the feasibility of employing biomedical waste incinerator ash (BMWIA) as a geopolymer binder for pavement base stabilization. An experimental program was undertaken to study the influence of BMWIA content, sodium hydroxide–sodium silicate ratio, curing regime, and curing period on the unconfined compressive strength (UCS) of conventional aggregate (CA)-BMWIA mixtures. The optimum mixture was achieved with 20% BMWIA and an activator ratio of 50:50 under ambient curing conditions, which yielded the highest strength and a dense microstructural matrix. The mechanical performance of this optimized geopolymer mixture was subsequently evaluated against conventional ordinary portland cement (OPC)-stabilized and BMWIA-OPC blend–stabilized bases in terms of UCS, indirect tensile strength, flexural strength, resilient modulus, fatigue behavior, and durability. The geopolymer-stabilized base exhibited superior resistance to weathering, retaining 98% of its UCS after 12 cycles of wetting and drying, fully satisfying IRC: SP:89-2018 requirements. Fatigue testing confirmed a significantly longer service life under repeated traffic loading compared with cement-based counterparts. Environmental assessments indicated that heavy metal leachability remained well below permissible limits, while CO₂ emissions were reduced by approximately 47.7% relative to OPC stabilization and 17% relative to BMWIA-OPC blends. Additionally, the approach demonstrated substantial economic benefits, with cost savings estimated at 3.14 million/km of roadway. Overall, BMWIA-based geopolymers represent a durable, sustainable, and economically advantageous alternative for pavement base construction.]]></description>
      <pubDate>Tue, 21 Jul 2026 09:50:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691641</guid>
    </item>
    <item>
      <title>Utilization of Geopolymerized Mine Overburden Soil for Sustainable Pavement Base Layer Applications</title>
      <link>https://trid.trb.org/View/2581008</link>
      <description><![CDATA[Open-cast mining produces large quantities of solid waste, mainly in the form of overburden (OB) soil, and its effective management is a key concern for the mining industry. Additionally, coal-fired electricity generation produces significant amounts of fly ash. The main objective of this study is to utilize mine OB soil along with fly ash-based geopolymer for pavement base layer applications. Two types of base layers from mine waste were investigated: the first is a base layer prepared with manufactured artificial aggregates made from a mixture of mine OB soil and fly ash-based geopolymer, and the second is base layer from mine waste treated directly with a fly ash-based geopolymer. The geopolymer-treated base used a mix of 50% mine OB and 50% fly ash with a liquid alkali activator, composed of sodium hydroxide (NaOH) and sodium silicate. pH-based Eades–Grim approach was employed to determine the optimal NaOH concentration. Unconfined compressive strength and repeated load triaxial tests were conducted on treated waste for curing time of 7, 14, and 28 days to assess the effects of curing time. The results indicated that the 7-day UCS met IRC 37-2012 requirements, with only a marginal increase in resilient modulus values beyond this time, making it optimal blend for faster construction. A comparison of resilient modulus characteristics between the artificial aggregate and geopolymer-treated mine waste, and natural aggregate showed that the geopolymer-treated specimens exhibited superior resilient modulus properties. Further investigations, such as durability and water absorption tests, are needed to assess the suitability of these base layers, with future research recommended.]]></description>
      <pubDate>Tue, 21 Jul 2026 09:49:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2581008</guid>
    </item>
    <item>
      <title>Sustainable solution for soil cement stabilisation reinforced with fibres – monotonic and cyclic behaviour</title>
      <link>https://trid.trb.org/View/2686833</link>
      <description><![CDATA[The sustainability-performance paradox in soil improvement is addressed in this study by comparing geopolymer and Portland cement binders reinforced with polypropylene (PP) and sisal fibres. A multi-scale experimental programme was conducted, integrating monotonic and cyclic Unconfined Compressive Strength (UCS) tests, ultrasonic pulse velocity (UPV) measurements, and SEM/EDS microstructural analyses. It was found that geopolymer stabilisation yields a significantly denser matrix, dominated by sodium aluminosilicate hydrate (N-A-S-H) gels, resulting in a stiffness increase of up to 270% compared to cement. Superior chemical compatibility was exhibited by sisal fibres within the alkaline geopolymer matrix, with a 55.2% increase in strength being achieved. However, a critical performance gap was identified under cyclic loading: despite the high monotonic strength, brittle failure and rapid plastic strain accumulation were observed in geopolymer-stabilized soils within the first 2,500 loading cycles. Conversely, superior resilience to cyclic degradation was demonstrated by cement-stabilized samples through a strain-hardening mechanism, sustaining 5,000 loading cycles at deviatoric stress levels up to 75%. Optimal PP fibre contents were identified as 0.55% for cement (19.8% strength gain) and 1.10–1.65% for geopolymer composites (48.6% and 20,5% strength gain, respectively) to mitigate brittleness. These findings provide a strategic framework for the selection of binders and reinforcements based on the prevailing loading regime, monotonic vs. cyclic, and recommended geopolymers for high-load monotonic applications, such as foundations, and Portland cement for cyclic loading conditions like transportation subgrades.]]></description>
      <pubDate>Thu, 09 Jul 2026 13:29:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2686833</guid>
    </item>
    <item>
      <title>Geopolymer Stabilization of Industrial Wastes for Sustainable Pavement Base and Subbase Layers: Strength, Durability, and Environmental Assessment</title>
      <link>https://trid.trb.org/View/2685695</link>
      <description><![CDATA[This study investigates the geopolymer stabilization of industrial wastes—coalmine overburden (OB), basic oxygen furnace slag (BOFS), and granulated blast furnace slag (GBFS)—as a sustainable substitute for pavement base/subbase layers. The effect of the molar concentration ratio (MCR) of NaOH to Na2SiO3 (1, 2, and 4) on strength and durability was analyzed. A blend of 40% OB, 40% BOFS, and 20% GBFS at MCR=1 achieved the highest 28-day unconfined compressive strength (UCS) of 6.5 MPa, meeting Indian Road Congress standard. Durability assessments confirmed maximum mass loss of 6.38% and UCS retention of 4.71 MPa after 12 wet–dry cycles for MCR=4, along with low water absorption (6.97%) and capillary rise (<25% in 24 h). X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) analyses identified calcium-aluminosilicate hydrate (C-A-S-H) gel as the primary strength contributor. Toxicity tests confirmed heavy metal leaching below regulatory limits. A comparative cost and carbon footprint estimate demonstrated a 9.7% reduction in construction costs and a 28.4% decrease in CO2 emissions for constructing a 1-km highway. These findings highlight geopolymer-treated OB-BOFS-GBFS as a feasible, environment-friendly alternative to cement-based roadway materials.]]></description>
      <pubDate>Thu, 09 Jul 2026 13:29:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2685695</guid>
    </item>
    <item>
      <title>Assessment of Geopolymer Synthesis Parameters for Strength of Stabilized Fat Clay Using Statistical and Machine Learning Techniques</title>
      <link>https://trid.trb.org/View/2704073</link>
      <description><![CDATA[Calcium-based chemical stabilizers are traditionally used for the stabilization of weak subgrade soils. However, these traditional stabilizers incur significant environmental costs which make them less desirable. As a result, alternative materials based on recycled waste and industrial byproducts are becoming popular. Geopolymers (GP) are a new addition to this list that are gaining traction because of their environmental benefits. GPs improve the soil by precipitation of a polymer gel as a result of mixing an alkaline activator (activator) with an aluminosilicate source (precursor). The effectiveness of GP and the improvement in engineering performance of GP-stabilized soils is contingent on sound GP synthesis parameters. This study investigates the effectiveness of GP-based treatments in improving weak soil and evaluates the significance of various parameters in contributing to the efficacy of GP treatment. As a result, a group of eight GP mixes was designed with a range of values for controlling parameters namely water/solid, activator/precursor, Si/Al and cation/Al ratios. A fat clay was treated by the application of these GP mixes at a dosage of 10% by dry weight. Improvements in mechanical strength were evaluated through unconfined compression strength testing. This was followed by statistical inference on laboratory strength data using analysis of variance (ANOVA) and post hoc tests. Ultimately, parameter importance was quantified by the random forest (RF) regression model. The results indicated that GP-based treatments enhanced the strength of untreated soil. Additionally, GP with higher aluminosilicate content and sufficient activator performed better. Overall, this study provides insight into the relative contribution of various GP synthesis parameters to the performance of GP-stabilized subgrade soils.]]></description>
      <pubDate>Thu, 21 May 2026 09:09:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2704073</guid>
    </item>
    <item>
      <title>Mechanical and microstructural properties of high-calcium fly ash geopolymer mortar with warm-weather conditions for pavement overlays</title>
      <link>https://trid.trb.org/View/2672403</link>
      <description><![CDATA[High-calcium fly ash (HCFA)-based geopolymer composites face challenges when used as a general-purpose concrete material due to their rapid setting properties and limitations for cast-in-place. This article examined the use of HCFA-based geopolymer mortar as an overlay material for concrete pavement in tropical regions. The research objective is to explore how practical factors affect the mix design of HCFA-based geopolymer mortar, with a focus on its key engineering properties for pavement overlays, using a full-factorial design approach. The alkali-activated solution to fly ash ratio (AA/FA) and its interaction on the sodium hydroxide (SH) molarity and the sodium silicate to sodium hydroxide ratio (SS/SH) were observed as the significant factors affecting the key engineering properties. The regression models for the HCFA-based geopolymer mortar were proposed to predict the initial setting time and 7-day compressive strength. The multiple-response optimization was conducted to suggest a recommended practical approach for determining the optimal mix design of HCFA-based geopolymer mortar at any desired target strength and setting time. The HCFA-based geopolymer mortar with AA/FA, SH molarity, and SS/SH of 0.63, 8.05 M, and 1.13 was concluded as the optimized key factors to achieve a 7-day compressive strength of 28 MPa that meets the minimum requirement of ASTM C928/C928M with an initial setting time of 18.2 min. Finally, the Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) tests revealed the microstructural changes and the formation of new bonding products, such as Si-O, O-H, and C-S-H, due to geopolymerization.]]></description>
      <pubDate>Thu, 14 May 2026 14:00:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2672403</guid>
    </item>
    <item>
      <title>Legitimate and Pioneering Technologies for Construction &amp; Maintenance of Roads</title>
      <link>https://trid.trb.org/View/2691789</link>
      <description><![CDATA[Need for such highway innovations stems from necessity for highway to become more genuine, adaptive, efficient, authentic and responsive to changing demands to move quickly/easily. Integration of New Technologies are vital for incorporating "smart" technologies to make it a flexible, customer-centric and sustainable. Legitimate technologies refer to established rules, laws, or IRC/IS/International standards, and pioneering technologies refers to breaking new ground, innovating, and operating in uncharted/unfamiliar/unexplored territory. Various such innovative technologies viz use of waste plastic, cold/warm mix technologies, jute/coir geo textile, geogrid coated with PMB (Polymer Modified Bitumen), fully mechanised pavers for recycling of asphalt pavement, ultra-high performance concrete, glass fibre reinforced polymer bars and sheets as per IRC:137-2022/IS:18256- 2023 and IS 14856:2000 respectively in case or marine environment to make transportation very easy due to light in weight, use of Construction and Demolition (C&D) waste, very advanced material i.e. geopolymer, recycling of asphalt pavement, high performance bituminous pavements IRC:SP:139-2023 SUPERPAVE, determination of interlay shear strength of tack/prime coat, performance tests on asphalt mixes, determination of surface area of aggregates and thereby thickness of bituminous layer over aggregates (specified value is 6-8 micron as per IRC:SP:135-2022), use vacuum technology in automatic oven directly giving binder/moisture content, use of bamboo piling and vacuum technology in Prefabricated Vertical Drains (PVD) to accelerate consolidation for ground improvement using vacuum technology, short panel concrete pavement IRC:SP:140-2024 particularly in new pavement, gradients and hilly areas where temperature stresses are higher, white topping over damaged asphalt pavement, bonded rigid pavement on gradients, and advanced digital/robotic mainly in tunnel, quality control with the help of drone system, use of RFID in the manhole covers etc to avoid theft and bio technologies are gaining momentum these days and being applied in the field in road construction as well. Further, new age binders in road construction primarily refer to sustainable and performance-enhanced alternatives to traditional petroleum-based bitumen. The viscosity grade bituminous binders may beknow modified with graphene/ultra fine/nano size mineral admixtures or alternatively pyro based using waste rubber or biobased bituminous materials may be also adopted to improve performance and sustainability with less reliance on fossil fuels/environmental impact. The paper thus describes innovative technologies saving time, space, energy, improving environment, minimising pollution. There will be literally saving of conventional materials viz cement, soil, natural aggregates and steel/aluminium.]]></description>
      <pubDate>Tue, 05 May 2026 13:15:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691789</guid>
    </item>
    <item>
      <title>Sustainable Reuse of Excavated Soils Stabilized With Fly Ash and Slag-Based Geopolymers for Backfill Applications</title>
      <link>https://trid.trb.org/View/2692347</link>
      <description><![CDATA[A clayey soil excavated from the Paris region was investigated for reuse as a backfill material. It was stabilized with alkali-activated fly ash and ground-granulated blast-furnace slag with lime as a reference material. Geopolymer activation was performed using a 14 M sodium hydroxide solution combined with sodium silicate. Cylindrical specimens (33 mm diameter × 71 mm height) were tested for unconfined compressive strength. Untreated soil showed low compressive strength of 0.15 MPa and was unsuitable for direct backfill applications. Lime-treated soil reached compressive strengths of 0.52 and 0.75 MPa at 7 and 28 days, respectively. Alkali-activated fly ash achieved the strength of 0.65 and 0.89 MPa at 7 days and 28 days, satisfying the strength requirements for controlled low-strength backfill. Activated slag achieved strengths of 0.46 and 0.69 MPa at 7 days and 28 days, respectively. The modulus of elasticity reached 87 MPa, 84 MPa, and 85 MPa for lime-treated, activated fly ash, and activated slag at 28 days. Mineralogical analyses confirmed geopolymerization through reduced quartz intensity and the formation of calcium silicate hydrate and calcium aluminosilicate hydrate. These findings showed that geopolymer binders effectively improved the mechanical properties of excavated soil for its reuse as backfill material.]]></description>
      <pubDate>Tue, 21 Apr 2026 09:30:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2692347</guid>
    </item>
    <item>
      <title>Optimized Gradient Boosting Model for Estimating Unconfined Compressive Strength of Pozzolanic Geopolymer-stabilized Granular Materials Using Pufferfish Algorithm</title>
      <link>https://trid.trb.org/View/2694386</link>
      <description><![CDATA[Numerous studies on predictive modeling methodologies have been conducted in order to evaluate the quality of treated granular materials as a consequence of the increased need for efficient soil stabilization solutions. The purpose of this study is to examine whether or not machine learning (ML) can be used to predict the unconfined compressive strength (qᵤ) of low-quality sand that has been saturated with natural pozzolanic geopolymer. Through the use of the Gradient Boosting Regression (GBR) approach, the link between these factors and qᵤ has been successfully identified. Both the Red Fox optimization (RFO) and the Pufferfish optimization (PuO) are examples of complex metaheuristic optimization procedures that are used for hyperparameter tweaking in order to increase the anticipated accuracy and stability of the GBR model. The findings demonstrate the effectiveness of machine learning-driven approaches in determining the stability of granular materials and provide a valuable analysis for the improvement of geotechnical engineering techniques via the use of data-driven modeling application tools. According on the supplied data, it is likely that both GBR (Pu) and GBR (RF) will precisely compute qᵤ. The effectiveness of the GBR (Pu) model exceeds that of the GBR (RF) technique about the ultimate objective it aims to achieve.]]></description>
      <pubDate>Tue, 21 Apr 2026 09:30:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2694386</guid>
    </item>
    <item>
      <title>Performance evaluation of geopolymer concrete pavement after five years of service</title>
      <link>https://trid.trb.org/View/2670426</link>
      <description><![CDATA[This study presents a five-year performance evaluation of a geopolymer concrete (GPC) pavement installed in 2019 in Alexandria, City of Sydney, as part of an Australian Government initiative supporting low-carbon infrastructure. The condition of the in-service GPC slab was compared with that of a companion blended cement concrete (BCC) slab, both subjected to identical traffic loads and environmental exposure. Visual inspection and testing reveal that while both slabs developed flexural and shrinkage cracks, the GPC exhibited only one flexural crack over five years, compared to three in the BCC slab. Surface abrasion was more pronounced in the GPC, resulting in greater surface loss. Cores showed that the GPC met the required design compressive strength but was 18 % lower than the BCC. However, the performance difference in terms of abrasion is primarily attributed to aggregate grading and hardness – the GPC mix incorporated a gap-graded 14 mm olivine basalt. In comparison, BCC used a well-graded 8 mm granite aggregate. Image analysis confirms a higher aggregate fraction on a typical GPC surface than on a BCC surface. Petrographic analysis, along with on-site abrasion testing, indicates that aggregate hardness and grading significantly influence abrasion resistance. Both pavements have maintained their structural integrity under service conditions. The findings highlight the importance of selecting high-quality aggregates, their relative volume, and grading for pavement applications, and identify areas for improvement, including subgrade preparation and curing methods. With these enhancements, GPC has strong potential as a sustainable alternative for pavement applications and in infrastructure projects.]]></description>
      <pubDate>Mon, 23 Feb 2026 11:24:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2670426</guid>
    </item>
    <item>
      <title>Investigating the impact of various parameters on the properties of fly ash geopolymer concrete using a hybrid optimisation approach</title>
      <link>https://trid.trb.org/View/2643495</link>
      <description><![CDATA[This paper proposes an efficient hybrid method for analyzing the effect of alkaline solutions on the properties of fly ash-based geopolymer concrete. The proposed technique, BOA-MPNN, combines the Butterfly Optimization Algorithm (BOA) and Multilayer Perceptron Neural Network (MPNN). The objective is to evaluate how different curing methods (ambient and oven curing) influence the physical, mechanical, and microstructural properties of geopolymer concrete while reducing its setting time. BOA optimizes the parameters of geopolymer concrete, while MPNN predicts its strength. The proposed model is implemented in MATLAB and compared with existing techniques. The results indicate that the BOA-MPNN technique outperforms the Salp Swarm Algorithm (SSA), Color Harmony Algorithm (CHA), and Gannet Optimization Algorithm (GOA). The proposed approach achieves a setting time of 26 min, significantly lower than SSA (30 min), CHA (35 min), and GOA (40 min). Moreover, the mixture attains a compressive strength of 35 MPa, exceeding FA-GGBFS-GPC (30 MPa), AAH-GPC (25 MPa), and CH-GPC (22 MPa). These findings confirm that the proposed technique delivers superior performance compared to existing methods, making it a promising approach for enhancing geopolymer concrete properties.]]></description>
      <pubDate>Sun, 22 Feb 2026 17:36:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643495</guid>
    </item>
    <item>
      <title>Effect of desert sand content on road performance of geopolymer stabilized desert sand pavement base</title>
      <link>https://trid.trb.org/View/2642489</link>
      <description><![CDATA[Traditional Portland cement-stabilized bases are extensively applied in pavement structures; however, cement production and the extraction of natural river sand are associated with significant environmental impacts and resource depletion. This study employed desert sand as fine aggregate and alkali-activated slag-fly ash waste as the binder to systematically investigate the mechanical performance and freeze-thaw durability of geopolymer stabilized desert sand (GDS) bases at high desert sand contents. Experimental results indicate that ultrafine particles in desert sand participate in geopolymerization under alkaline activation, enhancing the interfacial bonding between the geopolymer matrix and desert sand, thereby surpassing the adhesion achieved in Portland cement-desert sand systems. With increasing desert sand content, the geopolymer binder content decreases, reducing its coating and cementation effect on sand particles, while porosity increases, resulting in declines in unconfined compressive strength, compressive resilient modulus, splitting tensile strength, and flexural strength. Even at a desert sand content of 90 %, the corresponding values of these properties remained 12.03 MPa, 1034.00 MPa, 0.93 MPa, and 4.50 MPa, respectively, satisfying base layer requirements. After 60 freeze-thaw cycles, the relative dynamic modulus of elasticity remained approximately 60 %, indicating substantial freeze-thaw durability. Compared with cement stabilized desert sand (PDS) bases, GDS bases exhibited a 30–73 % reduction in carbon emissions, demonstrating pronounced environmental benefits. This study provides a theoretical foundation for the high-value utilization of industrial solid wastes and desert sand in sustainable pavement base materials.]]></description>
      <pubDate>Thu, 19 Feb 2026 09:44:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2642489</guid>
    </item>
    <item>
      <title>Geopolymer Concrete for Sustainable Design and Construction: Age-Dependent Behavior, Microstructure, and Predictive Models for Strength and Elastic Modulus</title>
      <link>https://trid.trb.org/View/2646157</link>
      <description><![CDATA[This study investigated the age-dependent compressive strength (fc), static modulus of elasticity (Es), and microstructure of geopolymer concrete (GPC) incorporating varying proportions of fly ash (FA) and ground granulated blast furnace slag (GGBFS). GGBFS was introduced as a partial replacement for FA at levels of 0%, 20%, 40%, 60%, and 80%. Testing was conducted at six ages: 7, 28, 60, 90, 150, and 180 days. Additionally, an ordinary portland cement concrete (OPCC) mix with the same binder content was also studied for comparison. Experimental results showed that all GPC mixes exhibited consistent gains in fc and Es with age. The inclusion of GGBFS significantly enhanced early-age and long-term fc and Es. Optimal performance was observed in mixes with 40% and 60% GGBFS, which surpassed OPCC strength after 90 days. Microstructural analysis using scanning electron microscopy and energy dispersive spectroscopy revealed that increasing GGBFS content improved the matrix compactness by enhancing the formation of calcium-alumino-silicate-hydrate (C─ A─ S─ H) gel in synergy with sodium-alumino-silicate-hydrate (N─ A─ S─ H) gel, which resulted in superior mechanical properties. Additionally, new predictive models for fc and Es were developed, incorporating the effects of age and GGBFS content, and validated against experimental data and published literature. Further, the sustainability aspect of GPC in terms of CO2 reduction revealed that all GPC mixes demonstrated significantly better sustainability performance compared to OPCC. Overall, this study provides a comprehensive understanding of the mechanical and microstructural behavior of GPC with FA and GGBFS, offering valuable insights for its application in sustainable construction and guiding the design of optimized GPC mixes.]]></description>
      <pubDate>Thu, 29 Jan 2026 17:02:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2646157</guid>
    </item>
    <item>
      <title>Fatigue life prediction of Pavement Quality Geopolymer Concrete (PQGC) with recycled geopolymer concrete aggregates using probabilistic approach</title>
      <link>https://trid.trb.org/View/2632492</link>
      <description><![CDATA[Geopolymer Concrete (GPC) is increasingly recognized as an alternative sustainable material to cement based concrete due to its potential for low carbon footprint. For the first time, the flexural fatigue performance of Recycled GPC as Coarse Aggregates (RGCCA) in Pavement Quality Geopolymer Concrete (PQGC) based on fly-ash/ground granulated blast furnace slag was studied, which is an essential parameter for pavement design. Experiments were conducted to determine the feasible replacement of RGCCA in PQGC mixes based on the required strength criteria as per IRC:58–2015, and it was found that 50 % RGCCA was a feasible replacement. PQGC specimens with 100 × 100 × 500 mm3 was prepared, and tested for repeated action of loading under four-point bending with various stress ratios ranging from 0.7-to-0.9 at 5 Hz frequency, for fatigue performance studies based on 90-days flexural strength. From the experimental fatigue life, the Stress ratio (applied flexural stress to the flexural strength of concrete) vs No. of cycles to failure curves (S-N curves), fatigue life distributions and fatigue strength were evaluated. The fatigue life distribution measured for RGCCA based PQGC mixes based on 2-Parameter Weibull Distribution (2-PWD) agreed well with experimental results, and the goodness-of-fit test showed that the model is valid at 5 % significance level. Furthermore, the coefficient of fatigue equation using power’s law-relationship was determined for the fatigue strength of RGCCA based PQGC at various survival probabilities. With the use of RGCCA in PQGC, the flexural fatigue strength of PQGC decreased. Also, the fatigue strength of 50 % RGCCA-PQGC at the 2-million cycles with a 90 % survival probability (for National Highways) were 0.581 of the static flexural capacity, which is 13.3 % less than that of PQGC mix (0.6021).]]></description>
      <pubDate>Tue, 27 Jan 2026 09:19:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2632492</guid>
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