Conventional Concrete Pavements Research Articles

Utilization of Aluminosilicate Industrial Wastes as Precursors in CO2-Cured Alkali-Activated Precast Concrete Pavement Blocks

This research focuses on the utilization of recently investigated aluminosilicate industrial wastes as precursors to produce non-structural precast alkali-activated concrete pavement blocks. For this purpose, conventional blocks (200 mm × 100 mm × 80 mm) were produced using electric arc furnace slag and municipal solid waste incineration bottom ashes as the sole binders. Portland cement and fly ash blocks were produced as references. The blocks underwent a curing regimen comprising thermal, dry, and carbonation curing stages. Control uncarbonated specimens were subjected to dry curing instead of CO2-based curing to evaluate the influence of carbonation on the blocks’ strength development. The specimens were subsequently examined following EN 1338, which is the European standard for assessing and ensuring the conformity of conventional concrete pavement blocks. The carbonated blocks revealed improved mechanical and physical properties in relation to the uncarbonated ones. All blocks met standard dimensions, showed minimal skid potential (most indicating extremely low potential for slip for reporting unpolished slip resistance values exceeding 75), and had enhanced abrasion resistance due to carbonation, showing 30% and 11% less volume loss due to abrasion for fly ash and bottom ash, respectively. Carbonated blocks performed better than non-carbonated ones, displaying lower water absorption (0.58% and 0.23% less water absorption for bottom ash and slag, respectively) and higher thermal conductivity (20%, 13%, and 8% increase in values for fly ash, slag, and bottom ash, respectively). These results confirm the effectiveness of the accelerated carbonation curing technique in improving the block’s performance. Despite the promising outcomes, further optimization of the alkaline solution and carbonation curing conditions is recommended for future research.

Ensemble and evolutionary prediction of layers temperature in conventional and lightweight cellular concrete subbase pavements

ABSTRACT Extreme and fluctuating weather has a significant impact on the material properties of flexible pavements. Lightweight cellular concrete (LCC) can effectively mitigate weather effects due to its favourable insulating properties. To date, there has been little research on predicting temperature for different layers of conventional and LCC subbase pavements. This study investigates the application of LCC as a subbase material and its impact on layer temperature. Temperature profiles of two test roads, Erbsville and Notre Dame Drive (NDD), in Canada, have been collected for evaluation. Extreme gradient boosting (XGBoost) and genetic programming (GP) models were employed to forecast layer temperatures of Erbsville control and LCC-subbase sections based on inputs including ambient temperature, day of the year and constant depth. Shapley adaptive explanations (SHAP) were utilised for XGBoost, and parametric analysis was conducted for GP. Results indicated the superior performance of XGBoost (R 2> 0.98, MAE < 1.5°C) over GP (R 2> 0.97, MAE < 1.87°C), with both models demonstrating better predictive accuracy for LCC-subbase compared to the control section. SHAP, parametric analysis and external validation using NDD sections further validated the models' effectiveness in predicting temperatures for both control and LCC sections at various densities up to a depth of 0.8 m.

Full-scale accelerated load testing of a new mechanised cement bound macadam (MCBM) pavement

The purpose of the research is to define and describe the performance behaviour during full-scale accelerated loading for a new heavy duty pavement type referred to as Mechanised Cement Bound Macadam (MCBM). MCBM is a cost-effective and reduced carbon footprint alternative to structural asphalt concrete and conventional concrete pavements. Four MCBM test sections were constructed with two key considerations in mind, the influence of layer thicknesses and maximum stone size within the gradation. In addition, defining the fundamental strength behaviour of the pavement, the failure mechanisms and their impact on perpetual pavement design were key objectives for the research. Dynamic and semi-static deflection measurements, strain measurements from strain gauges embedded in the pavement, crack mapping and transverse surface profile were collected at intervals throughout the accelerated loading. Performance testing showed that the stone interlocked structure is unique and undergoes multiple strength phases, enabling excellent shear and rut resistance by upholding vertical load bearing. The accelerated load testing also proved that significant structural strength remains post-bound phase. However, the MCBM design is based on a bound phase criterion and specifies a threshold fatigue stress value less than 30% of the flexural strength (breaking strength under four-point beam testing). Hence, the MCBM is perpetual by design and intended to function in the bound phase, requiring only intermittent resurfacing.

Inspection of Thermo-Mechanical Behavior on Sintered Fly Ash Aggregate in Pavement Quality Concrete

Conventional concrete pavement is more efficient towards mechanical load but combing with environmental loads compromises serviceability. This paper mainly focuses on utilizing sintered fly ash (SFA) aggregate to partially replace coarse aggregate in pavement quality concrete. Incorporating SFA aggregate in concrete pavement enhances the thermal behavior of rigid pavement due to higher voids and lower thermal conductivity. Coarse aggregate was partially replaced with SFA aggregate at an interval of 10 % till 40% by volumetric replacement. Pavement quality concrete (PQC) was designed as per Indian standards with a fixed water-cement ratio of 0.36 to achieve a minimum of 40 N/mm2 compressive strength. Compressive, split tensile and flexural strengths were inspected as mechanical behavior and thermal conductivity was examine as thermal behavior of different SFA mixed PQC. It has been observed that there is a slight decrement in mechanical strength by incorporating SFA in PQC but the thermal property of PQC was improved. Overall, it can be concluded that incorporating SFA at a certain level enhances the combined thermo-mechanical properties of PQC.

Comparative Analysis of Jointed Plain Concrete Pavement and Roller-Compacted Concrete Pavement

Jointed plain concrete pavement (JPCP) is the widely preferred conventional concrete pavement for highways; however, the higher initial construction cost and extended time for traffic opening limit its applicability. Recent advancements like roller-compacted concrete pavement (RCCP) could address the above concerns of JPCP. Yet, there is a lack of knowledge and comparative studies on the performance assessment, sustainability, and economic analysis of RCCP and JPCP. Therefore, this study aims to evaluate the engineering properties (density, compressive and flexural strength, and fluid flow properties), cost analysis (materials and initial construction cost), and sustainability (carbon dioxide emissions and energy consumption) of both pavements. The fresh density and mechanical properties of RCCP were 8%–9% and 13%–35% higher than JPCP; thus, 44%–89% and 24%–57% reductions in water absorption and porosity were observed in the considered RCCP mixes against JPCP. The higher strength properties of RCCP significantly reduced the pavement thickness by 10%–25%, thereby lowering the materials and initial construction costs by 52%–78%. Further, sustainability assessment through the cradle-to-gate (from raw material extraction to transportation phase) and gate-to-gate (only concrete production in a ready-mix plant) approaches revealed that employment of RCCP could significantly reduce carbon dioxide emissions (9%–30%) and energy consumption (10%–32%) compared with JPCP mixes. The findings show that RCCP can be considered sustainable, economical, and higher-performance pavement than JPCP.

Investigating the Properties of Drainage Concrete Pavement through the Pore Creation Method: A Study

Background: Over the past decade, the pervious concrete pavement has become a popular innovation due to its highly porous spaces that allow for easy air and water flow from the surface to the underlying layers. However, the increased void content could potentially make the concrete weaker and less durable, which creates a need for alternative methods to maintain its strength while improving its drainage capabilities. Objective: This study aims to analyze the characteristics of drainage concrete pavement using a novel method for creating pore structures. Methods: To address the challenges of conventional concrete pavement, various pore patterns and diameters were examined, including a 2x2, 3x3, and 4x4 row arrangement with pore diameters of 2, 3, and 4 mm. The concrete mixture was formulated to comply with the standards established by the Department of Highways in Thailand. The study analyzed both the fresh concrete properties, such as slump test and setting time, and the hardened properties, such as compressive strength, flexural strength, and water absorption. The draining capability was evaluated through water permeability performance and the clogging effect was measured by very fine sand particles. Results: The test results showed that the slump value of concrete complied with the design specifications, and the initial setting time was recorded to be 230 minutes. The compressive strength and flexural strength tended to decrease while water absorption tended to increase as the pore pattern arrangement and pore diameter increased. However, the compressive strength of all mixtures exceeded 85% when compared to the control. Additionally, the water permeability coefficient ranged between 2.69-18.52 mm/s, and the permeability coefficient tended to decrease when the clogging effect occurred in the range of 18.18-37.27%. Conclusion: The findings of this study contributed to our understanding of the properties and behavior of concrete with pore creation. By refining our knowledge of the intricate correlation between porosity and compressive strength, it has become evident that reducing porosity is necessary to enhance the mechanical properties of concrete and ensure its long-term durability. Furthermore, sustainable infrastructure applications can improve the relationship between permeability and effective porosity through construction techniques.

Laboratory and Full-Scale Testbed Study in the Feasibility of Styrene-Butadiene-Styrene Asphalt Pavement Having Epoxy Resin and Crumb Rubber Powder

Conventional asphalt concrete pavements have deteriorated rapidly due to the current increased traffic and extreme climate impacts. In addition to the upgrading in the construction quality, there is an urgent need to expand the utilization of modified asphalt binders to improve road capacity and traffic safety. The proposed research aims to combine epoxy resin (ER) and crumb rubber powder (CRP) contents into conventional Styrene-butadiene-styrene (SBS)-modified asphalt binder to not only reduce the consumption of normal asphalt binder but also promote the usage of recycled waste material in practice. To cope with this research objective, the ER and CRP were designed at 3% and 5% by weight of asphalt binder, respectively. Various laboratory tests were performed to evaluate the performance of modified mixtures (ERCRP), including the Frequency Sweep Test, Multiple Stressed Creep and Recovery, Dynamic Modulus, Semi-Circular Bending (SCB), and Cantabro Durability Tests. Additionally, an assessment of the modified asphalt concrete pavement via field testbed was conducted through Falling Weight Deflectometer and Ground Penetrating Radar. Overall, by adding the ER and CRP, the strain value of the control reference mix can be reduced up to 31.8% and 28.3% at MSCR 0.1 and 3.1 kPa, respectively. Additionally, the dynamic modulus of the ERCRP-modified samples was approximately 32,267 and 189 MPa, while the value of the reference mixture was 28,730 and 105 MPa at the highest and lowest frequency, respectively, indicating an enhancement under repeated loads. Regarding the SCB test results at 0 °C, the peak stress of the ERCRP-modified mixture was 4.75 MPa, while the value of the reference specimens was only 4.2 MPa, noticing the improved stress-bearing capacity. Based on a full-scale testbed, the FLWD elastic modulus of reinforced pavement shows a novel improvement (6.75%) compared with the control pavement, suggesting a potential application of ERCRP-modified asphalt binder for sustainable development purposes.

Enhancing the Performance of Roller-Compacted Concrete Pavement by Synergetic Improvement of Packing Density, Lubrication, and Moisture State of Recycled Concrete Aggregate

Roller-compacted concrete pavement (RCCP) is considered superior to other pavement types with reference to cost, ease of construction, and performance. However, the aggregate demand is significantly higher in RCCP than in the conventional concrete pavement. It is predicted that natural minable limestone sources would be exhausted in India in the next 30 to 40 years. One way to reduce the natural aggregates (NA) requirements in RCCP is through the integration of recycled concrete aggregates (RCA). However, the physical property of RCA is significantly inferior to that of NA owing to the presence of adhered mortar (AM), which increases the water demand by 2.3 to 4.6 times and affects the compactness and hardened-state behavior of RCCP. This study has tried to enhance the compactness and improve the performance of RCCP containing RCA (coarse, fine, and total RCAs) through different synergetic approaches. This, in turn, enhances the interlocking capacity using the particle packing approach, followed by mitigating the negative effects of AM by altering the moisture states, then improving the compactability and lubricating the matrix with superplasticizers. The results depict that altering the moisture states alone could adversely affect the RCCP performance because of the moisture transfer mechanism from the hydraulic gradient. Moreover, the inclusion of superplasticizers in different moisture states could manifest better aggregate rearrangement and compactability. Further, it could improve the tensile behavior of the RCCP compared with the concrete containing NA. These findings favor the complete replacement of NA by RCA for low-volume rural road construction.

Centrifuge modelling of ultra-thin high strength steel fibre reinforced concrete pavements

Ultra-thin continuously reinforced concrete pavement (UTCRCP) is an innovative pavement type that consists of a 50 mm high strength steel fibre reinforced concrete (HS-SFRC) layer overlain on a pavement substructure. The thickness results in a flexural stiffness significantly smaller than for conventional concrete pavements. In this paper, the conceptual understanding of the response of UTCRCP to traffic loading was investigated using centrifuge modelling. Simplified pavement models were subjected to a bidirectional moving axle load. The results indicated that axle loading, and not single wheel loading, should be used to investigate the response of UTCRCP as there is significant interaction in substructure deformation caused by the wheels on the ends of an axle. Due to the flexural toughness of the highly reinforced concrete layer, a gap forms between the ultra-thin HS-SFRC overlay and its substructure. Brittle, cemented bases between the HS-SFRC overlay and subgrade should be used with caution, as the flexible nature of the layers above and below the stabilised layer may result in rapid degeneration of the brittle layer.

Setting time in Roller-Compacted Concrete (RCC)

The principal differences of RCC from conventional concrete pavements are workability, rheology, paste content, and compactive effort. RCC pavements obtain significant strength during compaction and, therefore, can be opened to traffic in less time than conventional concrete pavements. For both types of concrete, there are methods to evaluate workability in the fresh state, e.g., slump and Vebe test. However, no standard method is available for either concrete pavement type for evaluating setting time in-situ. Construction activities such as tining/texturing, curing membrane, and sawing of contraction joints are related to the concrete setting time. A recently developed technique for setting time of conventional mortar and concrete with fully contactless ultrasound has shown promising results with higher paste content mixtures. This recently proposed method monitors the initiation time of leaky Rayleigh waves (LR-wave) signals in time and space over the conventional concrete surface. The objective of this study is to determine the setting time in RCC pavements which has significantly lower paste volume and higher aggregate content. Preliminary results have shown that the setting time of an RCC mixture with overfilled paste can be successfully determined. Additional tests on a wider range of RCC mixture constituents and proportions, e.g., lower aggregate void and paste contents, are being conducted to evaluate the limitations of this contactless sensing method and necessary adjustments. Reliable set time determination in RCC pavements can improve QC/QA practices and indicate repeatable triggers for other construction activities like sawing contraction joints.

Development of a Fatigue Damage Model for Roller Compacted Concrete Pavement Based on In Situ Saw-Cut Beams and Accelerated Pavement Performance

As a durable, economical, and low-maintenance concrete material, roller compacted concrete (RCC) is steadily becoming the preferred choice for many pavement applications. However, the fatigue models in current pavement thickness design procedures have generally been found to over-predict the RCC pavement fatigue damage under in situ heavy truck loading. In this study, a comprehensive beam fatigue test experiment was performed using field saw-cut RCC slab samples from two full-scale accelerated pavement testing (APT) sections to investigate the fatigue behavior of in situ RCC pavements. This is the first research study to investigate the fatigue behavior of field RCC beam samples prepared and constructed with a high-density asphalt-type paver and a vibratory roller. The results indicate that a well-compacted RCC pavement can achieve higher flexural strength and exhibit better fatigue life than conventional concrete pavement. Based on the beam fatigue test results and in situ fatigue performance of APT test sections, an RCC fatigue-life model was developed, providing a more accurate solution for estimating the allowable number of load repetitions of RCC pavements subjected to vehicular fatigue loading. This model could be used in RCC thickness design procedures to determine the optimum RCC design thickness and long-term fatigue performance of RCC pavements for roadway application.

Strength properties of roller compacted concrete pavement (RCCP) under different curing methods

The curing of roller compacted concrete (RCC) pavements requires much more attention and importance than conventional concrete pavements due to its very dry consistency. This research was conducted to determine the effects of different curing types and their application times on mechanical properties of RCC. In addition, the effects on physical properties of RCC were determined in the study, as well. In the experimental study, 4 different curing types as the curing compound, burlap, membrane and water that have been widely used in the market, were applied for 15, 30, and 60 min and immediately after casting. Compressive strength, flexural strength, weight loss, ultrasonic pulse velocity and rebound hammer tests were applied to determine the physical and mechanical properties of RCC specimens. According to the results, the best curing method for compressive and flexural strengths of RCC was determined as water curing, providing approximately 29% and 34% increase in strength compared to uncured mixtures, respectively. In terms of weight loss, the best result was obtained with water curing, increasing the amount of moisture, unlike other curing methods.

Load spreading in ultra-thin high-strength steel-fibre-reinforced concrete pavements

Ultra-Thin Continuously Reinforced Concrete Pavement (UTCRCP) consists of a 50 mm thin High-Strength Steel-Fibre-Reinforced Concrete (HS-SFRC) overlay placed on existing pavements as rehabilitation or used as part of new pavements. Difficulties have been experienced with the construction of UTCRCP. Additionally, the thin HS-SFRC has superior fatigue properties, but poor load-spreading ability compared to conventional concrete pavements due to its reduced thickness. This results in high deflections when the pavement is loaded. The substructure of UTCRCP plays an important role in its performance. Cement-stabilised granular materials can be used to ensure gradual load spreading with depth, but its behaviour under flexible concrete layers is not yet well understood. In this study the effect of increasing the HS-SFRC layer thickness and the effect of incorporating cement-stabilised base layers were investigated using linear elastic finite element modelling. From stress levels calculated, it was found that C1 and C2 materials perform well underneath a 50 mm HS-SFRC layer subjected to standard axle loads of 80 kN, while C3 and C4 would deteriorate faster. Stabilised layers placed below a thin, flexible concrete layer may however crack, resulting in increased damage to supporting layers. It is recommended that the response of UTCRCP should be investigated using advanced material models for the cement-stabilised base and other substructure layers.

A 3D Slab-Based Methodology to predict end of life for concrete pavements

ABSTRACT Observation of fatigue cracking in concrete pavement slabs can be an indication that the life of the pavement is coming to an end. Alternatively, cracked slabs can be due to uneven foundation support and just an isolated occurrence. The resulting action and cost for these two conditions are vastly different. What if there was a way to predict when a pavement’s life could be extended using concrete pavement restoration compared to when it was necessary to reconstruct? This paper provides a novel way, using a 3D Slab Based Methodology to characterise cracking in jointed plain concrete slabs and combines this with Remaining Service Life and hazard rate based on Weibull reliability theory to provide that answer for conventional concrete pavements. Using examples of several different pavements a comparison of this method to the traditional percent cracking is made. The results show that the new method, incorporating the impending failure concept, enables researchers and transportation agencies to identify the end of a concrete pavement’s life better than percent cracking by taking full advantage of 3D pavement surface data.

Structural and hydrological design of permeable concrete pavements

Permeable pavements are used to mitigate urban flooding. However, conventional concrete permeable pavements have low compressive strength and are prone to clogging, which degrades performance and reduces service life. A new type of permeable pavement, high-strength clogging resistant permeable pavement (CRP), has recently been developed that overcomes many limitations of conventional permeable pavements. This paper presents a new design methodology for CRP that takes into account both structural and hydrological considerations. This is used in 12 case studies which compare CRP with conventional permeable pavements. The results highlight several advantages of CRP and demonstrate that CRP with low porosity (∼5%) can cope with severe rainfall run-off volumes. The suitability of using CRP in both light and heavy load bearing applications is demonstrated. The research also shows that the use of CRP allows considerable reductions in pavement depth compared to conventional permeable pavements with reduced material costs.

Developing Porous Concrete Interlocking Pavement Blocks Utilizing Recycled Concrete Aggregate for Rainfall Harvesting Use

Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. The use of porous pavement is one of the most effective solutions to handle this matter. Thus, this study aims to develop Porous Interlocking Concrete Pavement (PICP) using recycled aggregate from concrete waste. This porous pavement, then later, can be utilized in low traffic areas and parking lots to harvest water by infiltration and reduce surface runoff. First, the physical properties of the porous concrete blocks, such as density (unit weight), absorption, coefficient of permeability, and porosity, were studied. Also, the mechanical properties of concrete mixtures like compressive strength and flexural strength were tested. This study used two types of PICP, the first one with ordinary coarse aggregate (P1) and the second with recycled crushed concrete coarse aggregate (P2), and then compared their performance to the conventional concrete pavement blocks used the two types of coarse aggregate (R1 and R2). The results show that the unit weight (density) of porous types was reduced by 25% and 26%, and the total porosity increases by around 2.4 times and 18 times respectively, as compared to conventional concrete pavement types. However, the compressive strength and flexural strength of porous concrete types decreased by (55% and 71%), respectively, compared to conventional types. Overall, the infiltration test results showed that the infiltrated water through porous concrete increased by about 83% in comparison to conventional concrete. From the results, utilizing porous concrete pavement can be considered a promising material in terms of water harvesting and decreasing rainwater flooding. Additionally, using recycled concrete can bring economical and environmental benefits.

Experimental appraisal for characterizing laboratorial and field performance parameters of pervious concrete pavement

Abstract Loratorial tests with pervious concrete comprised porosity and hydraulic conductivity as well as mechanical parameters as compressive, indirect tensile and bending strengths besides assessing its static and dynamic elasticity moduli. Later, a pervious sidewalk area of 1.0 x 8.65 square meters was built in order to determine the variation of the infiltration rate along time; over such experimental sidewalk, impact deflection tests performed allowed to assess back calculated moduli of the pervious concrete layer, resulting 33% to 13% lower than conventional concretes. A mechanistic analysis allowed to estimate the required thickness of concrete for heavy- and light-traffic areas. Tests disclosed no significant difference among the different concrete mixes, with 25% porosity and 0,1 cm/s permeability. Initial sidewalk infiltration rate of 0.5 cm/s dropped 50% four months after construction. It was verified that pervious concrete thicknesses for trucks and buses use are far higher than conventional concrete pavements.

Potential benefit of photovoltaic pavement for mitigation of urban heat island effect

Pavements in roadway and parking lots occupy large urban areas and contribute to the development of urban heat island (UHI). Photovoltaic (PV) pavement can use PV panels on conventional asphalt concrete (AC) pavement to harvest solar energy at light traffic conditions. This study aimed to evaluate the potential benefit of PV pavement to mitigate UHI effect. First, the heat transfer models for AC and PV pavements were developed. The pavement surface temperature and heat output from pavement surface to near-surface environment were then calculated that were used as the indicator of pavement contribution to UHI effect. A parametric study was conducted to analyze the influences of front glass and wind speed on thermal performance of PV pavement. Varying the thickness and transmittance of front glass have shown noticeable influences on pavement temperature, while the change of heat output is limited. Although the increase of average wind speed results in lower pavement temperatures, the heat output experiences slightly increase. The comparison of PV pavement and conventional AC pavement shows that PV pavement can decrease surface temperature by 3–5 °C in summer and generate 11–12% less heat output at various climate conditions.

The water footprint of permeable sidewalk pavement in China

As China continues to urbanize, the area of impervious surface in city is increasing, leading to serious problems of water logging, water resources shortage, and water quality deterioration. Thus, the comprehensive management of urban water resource is facing severe challenges. Based on the concept of “sponge city”, this study employed the life cycle assessment (LCA) modeling approach to calculate the water resource footprint of permeable sidewalk pavement in Beijing, China, and compared the result with conventional concrete brick pavement. The results show that the water consumption of 1-m2 permeable pavement is 253kg, 19% higher than that of concrete brick pavement (212kg). Given that the average annual precipitation of Beijing is 597mm, 1-m2 permeable pavement can collect 5972kg of water resources throughout its 10-year life cycle, enabling a net water-saving benefit of 5.7 tons.

Developing a novel solar-driven cool pavement to improve the urban microclimate

The thermal properties of pavement play a significant role in raising urban temperatures and creating urban heat islands (UHI). This phenomenon leads to increased energy consumption in buildings and reduces the thermal comfort of outdoor urban spaces. A standard modest application of thermoelectricity has been limited to indoor use to cool or heat buildings and outdoor use to harvest energy from asphalt. While the application of thermoelectric technology to cool the outdoor environment is rare, a novel solar-driven pavement thermoelectric system (SDPTES) has been developed to use solar energy in combination with rainwater and/or graywater to decrease the outdoor ambient air temperature and improve the urban microclimate. An SDPTES prototype was fabricated to verify the cooling capacity based on outdoor tests in the hot climate of Cairo. The study found that the application of SDPTES led to a reduction in pavement surface temperature of 14.1° C compared to conventional concrete mosaic pavement. These results represent a starting point for the development and application of thermoelectric paving technology for outdoor cooling purposes.