Roller Compacted Concrete Pavement Research Articles

Sensitivity analysis of gyratory compactor variables to mimic roller compacted concrete pavement performance

ABSTRACT The compaction parameters suggested for Superpave gyratory compactor by ASTM C1800 are primarily derived from the asphalt mix (ASTM D6925). Since the rheological behaviour of Roller Compacted Concrete Pavement (RCCP) is significantly different from asphalt mixes, conventional Superpave compaction parameters cannot be directly adopted for RCCP. Hence, the current study focuses on formulating compaction parameters for the design of RCCP to resemble the field behaviour. For this task, response surface methodology was employed to investigate the effect of gyratory compactor parameters such as internal angle (0.82–3°), compaction pressure (600–1000 kPa), and gyration levels (60–120) on the performance of RCCP specimens. The accuracy of the response prediction model was verified with ANOVA analysis. Further, multiobjective optimization was performed and validated with experimental findings. For validation of laboratory findings, a field test section was constructed using a duplex roller (dual drum vibratory roller). The results showed that the ASTM C1800 suggested gyratory parameters resulted in lower fresh density and strength properties of 4% and 7–45%, respectively, than the field specimens. However, the specimens fabricated at 1.92° internal angle, 120 gyrations, 1000 kPa, and 1 aspect ratio in the gyratory compactor could provide comparable field properties.

Compaction Delay and Temperature Effects on Early-Age Properties of Roller-Compacted Concrete

The lower water content of roller-compacted concrete (RCC) coupled with climatic conditions (e.g., higher air temperature, increased wind speed, and lower relative humidity) and compaction delay factors (e.g., traffic delay, plant location, and paving speed) can significantly affect the in situ density and hardened properties of RCC pavements. In this study, a control RCC mix was batched and maintained at standard (21°C) and elevated (35°C) temperatures and then compacted at increasing delay times for up to 180 min. The elevated mix temperature and compaction delay times greater than 90 min prevented the RCC mix from achieving 98% of the initial wet density from the modified Proctor test. Two additional RCC mixes were batched to determine if they could maintain a longer compaction window, one containing a rheology-modifying and retarding admixture and the other incorporating saturated fine lightweight aggregates. The RCC with admixture was the most effective at maintaining moisture content, density, compressive strength, and fracture properties at all compaction delay times. For example, at 180 min of delay, the RCC mixture with admixture still maintained 98.2% of the initial wet density, 81% of the compressive strength, and approximately the same fracture toughness and energy. The addition of fine lightweight aggregates did not extend the compaction window relative to standard RCC mix. The gyratory compacted specimens were more sensitive to the effects of temperature and compaction delay on RCC mixes than the vibratory hammer prepared specimens.

Experimental investigation on mechanical properties of sustainable roller compacted concrete pavement (RCCP) containing waste rubbers as alternative aggregates

Different types of solid waste are generated every year due to global industrialization. With the rapid growth of the automobile industry, the disposal of billions of waste rubbers (WR), which pollute the environment and cannot be disposed of properly, is emerging as an urgent matter of concern. Recycling waste rubbers by using them on pavements will contribute to the elimination of ecological and economic problems. In this study, the effects of waste rubbers on the mechanical properties of roller-compacted concrete pavement (RCCP) were investigated by obtaining sustainable RCCP mixtures using different types of waste rubbers as coarse and fine aggregate substitutes. In this context, waste rubbers with three different sizes (powder, crumb and shredded) were substituted for aggregate by volume at seven levels (0%, 2.5%, 5%, 7.5%, 10%, 20% and 30%) with a maximum of 30% in RCC mixtures. Unit weight, mechanical properties, modulus of elasticity and ultrasonic pulse velocity (UPV) were evaluated and compared according to the waste rubber content in the RCC mixtures. In addition, microstructural analysis of the mixtures was performed through scanning electron microscopy (SEM). The experimental results revealed that the compressive, flexural and splitting tensile strength and modulus of elasticity decreased with increasing waste rubber content in RCC. The utilization of waste rubber increased the ductility of RCC and decreased the density to produce lighter concrete. RCC with a compressive strength of about 30 MPa could be obtained by substituting 10% of waste rubber for aggregate. Thus, the utilization of high waste rubber content in pavements was feasible. This study can contribute to a more sustainable RCCP production by replacing natural aggregates with waste rubbers.

Experimental investigation of mechanical properties of roller compacted concrete pavement (RCCP) reinforced with date palm fibres

The mechanical properties of roller compacted concrete pavement (RCCP), reinforced with date palm fibres, were investigated for the first time in this study. Date palm fibres extracted from the trunk of date palm trees located southeast of Iran (Yazd), cut into 20 mm and chemically treated were used. After curing for 28 days, cylindrical specimens were conducted to tests such as compressive strength and splitting tensile strength, while flexural strength and toughness index tests were carried out on prismatic specimens using the four-point flexure method. The results of the conducted tests indicated that the maximum flexural strength and splitting tensile strength were increased by 11.68% and 16.83%, respectively in the specimens containing 500 g/m3 of date palm fibres. Moreover, adding 750 g/m3 of date palm fibres resulted in a maximum toughness index of 1.188 among the specimens, which was a remarkable increase over the control specimen.

Enhancing bonding performance in two-layer roller-compacted concrete pavements: Bridging laboratory insights with field performance

Roller Compacted Concrete (RCC) pavements, especially in industrial areas, harbors, warehouses, or heavily trafficked roads, often require a two-layer construction due to their greater thickness requirements. Adequate bond strength is typically achieved within one hour of casting the second layer, but after a period of time, interlayer treatments are often required to achieve acceptable bond strength between the two consecutive layers. Traditional cement mortar is the standard interlayer treatment, but alternatives such as latex, bitumen emulsions, epoxy resin, and adhesive mortars are gaining popularity. This study evaluates the bond performance of RCC layers with different treatment methods. Six groups of two-layer RCC slant shear test specimens were prepared and tested under compressive loading. The groups included an untreated group, another group roughened between layers with a metal rake, and those treated with latex emulsion, cationic bituminous emulsion, epoxy resin, and polymer-modified cement-based adhesive mortar enhanced with silica fume. Some of the laboratory test results were later implemented in a two-layer RCC paving project and were verified using cored samples from that project. The results indicate that in laboratory and field test results, two-layer RCC specimens with the adhesive mortar exhibit strength values of 94% and 98% when compared to monolithic/single-layer RCC specimens, respectively. Although the epoxy-treated two-layer RCC specimens experienced separation between layers in the laboratory, they achieved around 85% of the strength observed in the monolithic RCC specimens, ranking second in performance based on the slant shear tests. Cationic bituminous emulsion, common in flexible pavements, acts as a bond breaker and is unsuitable for bonding the two layers of an RCC pavement. In the field, the two-layer RCC pavement without interfacial treatment showed significant performance degradation, achieving only about 50% of the flexural strength of the monolithic RCC road section. This implies that in the presence of cold joints, pavement flexural strength is limited to 50% of the ultimate strength without any treatment. Field testing is essential for accurate interpretations, emphasizing the importance beyond laboratory assessments.

Influence of Slurry Impregnation Technique of Recycled Concrete Aggregates on the Roller Compacted Concrete Pavement

Influence of Slurry Impregnation Technique of Recycled Concrete Aggregates on the Roller Compacted Concrete Pavement

Effects of Relative Humidity and Temperature on the Drying Shrinkage of Roller-Compacted Concrete Pavements

Roller-compacted concrete (RCC) pavements have been the subject of studies focused on their increasing deterioration over time due to the influence of vehicular loading and ambient factors in humidity and temperature conditions ranging from medium to low (40% relative humidity and 25 °C temperature). Therefore, it is necessary to understand how they behave under various relative humidity and temperature conditions since these parameters vary in each geographic region. In this context, this research focused on analyzing the effect of drying shrinkage on RCC pavements under the influence of vehicular loading using a computational model calibrated with data obtained under typical ambient conditions. For this purpose, laboratory experiments were performed, numerical modeling was used, and the results for RCC pavements were validated using statistical analysis. The results revealed validated models providing moisture content and drying shrinkage curves. These results also underline the importance of considering ambient effects when calculating pavement stresses as a response variable in structural designs. In particular, these effects are highlighted as they can generate changes in pavement stresses of up to 10%, emphasizing the relevance of the models proposed in this study as they consider this phenomenon when predicting the performance and durability of RCC pavements.

Prediction of the Physical-Mechanical Properties of Roller-Compacted Concrete Pavements under Different Service and Mix Conditions Based on Cement and Water Content.

Roller-compacted concrete (RCC) for pavements has experienced problems with its physical-mechanical performance over extended periods due to ambient and in situ curing conditions. Accordingly, this study aimed to present multiple regression equations for calculating the physical-mechanical properties of RCC for pavements under different service and mix conditions. For this purpose, the research included two cement and two water contents, one reduced with admixture, and four combinations of temperature and relative humidity. For model calibration and definition of the equations, cubic and beam samples were fabricated to carry out physical-mechanical tests, such as moisture content, shrinkage, and modulus of rupture. Laboratory-obtained data were studied with the Response Surface Methodology (RSM) to determine the best regression equations. The main findings determined that the behavior of a mixture of RCC at a prolonged ambient exposure time is possible because the surface models and the RSM were consistent with the different service and mix conditions. The models showed an accuracy of 98.99% in detecting shrinkage changes from 12 to 16% cement with 5.65% water in dry to wet ambient conditions. Similarly, moisture content and modulus of rupture had a 98.27 to 98.88% fit. Finally, the drying shrinkage, with mixes of 12% cement and water content variations with water-reducing admixture and superplasticizer effects, had an adjustment of 94.87%.

EVALUATION OF BASALT FIBER REINFORCED ROLLER COMPACTED CONCRETE CONTAINING COAL POWDER FOR PAVEMENT

Introduction: The utilization of colored roller compacted concrete (RCC) for pavements in order to mitigate the urban heat island effect is a popular approach: increasing solar reflectance can reduce the effect. The paper explores the possibility of applying the reverse mechanism for regions with cold climates. The purpose of the study was to evaluate the mechanical, durability and solar reflectance properties of roller compacted concrete with coal powder (CP) and basalt fiber (BF) additives for pavement. Methods: an UV-Vis-NIR spectrophotometer was utilized for the albedo measurements. Consistency of the specimens was determined with Vebe consistometer. Compressive, flexural, and splitting tensile strengths were recorded at 7, 28 and 90 days. Frost resistance of the specimens was also investigated. Result: The combined utilization of 5% CP and 0.5% BF showed great performance for the roller compacted concrete pavements. Furthermore, the obtained albedo values also have the potential to increase the ambient temperature in cold climates.

Optimizing the mix design of roller-compacted concrete pavement (RCCP) to improve the compressive and flexural strengths

Optimizing the mix design of roller-compacted concrete pavement (RCCP) to improve the compressive and flexural strengths

Comparative Study between Recycled Fine and Coarse Aggregate Used in Roller Compacted Concrete Pavement

To decrease the impact on the environment of building waste, the recycled aggregate may be used in various sustainable engineering applications, such as roller compacted concrete pavement (RCCP). This research examined how using recycled aggregate as a partial replacement for natural aggregate as coarse or fine affected the mechanical properties of roller-compacted concrete pavement. The recycled aggregate was crushed and sieved to coarse and fine aggregate before being used in the roller-compacted concrete pavement. Compressive strength, splitting tensile strength, and flexural strength were all evaluated after the samples were prepared at 28 and 90 days of curing. According to the study's findings, the partial replacement of coarse or fine aggregate with recycled aggregate by (10, 15 and 20%) by volume resulted in decreasing the mechanical properties and increasing the absorption and porosity of RCCP due to the contaminated cement paste on the surface of RCA when compared to the reference mix made with natural aggregate. Because the recycled aggregate contains un-hydrated cement particles, the results have improved after 90 days.

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.

Tailoring of Compaction Parameters of the Vibratory Table and Vibratory Hammer for Roller Compacted Concrete Pavements to Resemble Field Properties

Previous studies have indicated that roller compacted concrete pavement may demonstrate significant variations in field behavior compared to laboratory specimens. This discrepancy can be attributed to the dissimilarities in compaction efforts between laboratory and field conditions, wherein the laboratory efforts fail to emulate the field compaction. Thus, in the present study, efforts have been made to optimize the compaction parameters, especially the number of layers of widely employed compaction methods, viz, the vibratory hammer (VH) and vibratory table (VT). A field slab was constructed using a duplex roller to provide a target value for the optimization process. Parameters such as packing density, fresh density, mechanical properties, viz, compressive, split tensile, and flexural strength, and porosity were considered for the tailoring process. Fresh density results showed that VT and VH-compacted specimens with ASTM parameters were loosely (−1.1%) and densely compacted (+5%), respectively, compared with field specimens (FSs). Therefore, to determine the optimal compaction parameters, the number of layers increased to five in the VT method and decreased to one in the VH method. Among different compaction layers, only the specimen fabricated with four layers and one layer in the VT and VH methods, respectively, could closely resemble the fresh, mechanical, and porosity of FSs. In addition, a new compaction procedure for fabricating prismatic specimens is developed for the VH and VT methods based on the compaction energy and packing density approaches.

Influence of Compaction Methods on the Optimum Moisture Content and Performance of Roller Compacted Concrete Pavements

Despite numerous advantages, there are a few challenges associated with the designing and fabrication of roller compacted concrete pavement (RCCP) specimens—compaction mechanisms employed in the RCCP mix proportioning, specimen fabrication, and actual pavement construction are different in principle, leading to significant disparity between the field and laboratory performance. To reconcile this discrepancy, an effort has been made to study the effect of compaction on the performance of RCCP. Initially, the effect of different compaction types, namely vibrating table, vibrating hammer, modified Proctor, and gyratory compactor (GY) on the optimum moisture content of RCCP was investigated, then the roles of moisture content and compaction type on dry density, mechanical aspects (compressive strength, indirect tensile strength, and flexural strength), rideability, and transport properties (porosity and absorption) of RCCP were elucidated. Also, alternative methods for quantifying the workability and compactability of GY compacted specimens are proposed. The findings from this study suggest employing a particular compaction mechanism both for the mix proportioning as well as specimen fabrication to avoid the under- or overestimation of RCCP performance.

Optimization of Silica Fume and Slag in Roller Compacted Concrete by Taguchi Method

Roller Compacted Concrete Pavement (RCCP) is one type of concrete poured and compacted with the same machines utilized to construct heavy-duty pavements, log sorting, and parking. In this work, a combination of three factors was optimized to produce a sustainable RCCP. These factors were densified silica fume, ground granulated blast-furnace Slag, and mixing water contents. By weight, sulfate-resistant Portland cement was substituted with cementitious materials such as silica fume and slag in the amounts of (5, 7.5, and 10%) and (25, 27.5, and 30%), respectively. In addition, various percentages (5, 6, and 7%) of water content were utilized. Using the Taguchi approach, the impact of these factors was investigated based on the results of compressive strength and bulk density. The cubic specimens of compressive strength and bulk density, with 100 mm length, were tested at 7, 14, and 28 days. According to the results, the optimum percentages of silica fume, slag, and water contents were (5, 27.5, and 6%), respectively. Comparing the optimal mixture to the reference, the compressive strength enhancement was about 13.9%. According to Taguchi's study, water content has a most significant influence on the characteristics of RCCP than silica fume content. The slag content has the least impact on RCCP.

Investigation of In Situ Thermal Properties and Early-Age Pavement Behavior in the Design and Performance Evaluation of Roller Compacted Concrete Pavement in Louisiana, U.S

The proven durability and high load-carrying capacity of roller compacted concrete pavement (RCCP), combined with its simple and cost-effective construction method and high placement speed, has created a great deal of interest from many states and local transportation agencies in the U.S. Roller compacted concrete (RCC) mixture uses less cement content and less water compared with conventional concrete mixtures, which reduces the total shrinkage strain and RCC set temperature during the hardening stage, resulting in a reduction of early-age deformation and stress developments in the RCCP. Currently, research on the early-age behavior and other thermal properties of RCCP has not been well documented. Therefore, investigations of early-age behavior and thermal properties such as coefficient of thermal expansion, ultimate shrinkage, and built-in curling are needed to understand the true behaviors of RCCP under real climatic conditions. On the other hand, the currently available RCC thickness design procedures, for example, Street-Pave and Pavement Designer, are in general short of flexibility in consideration of the combined effect of wheel and environmental loading on RCCP performance. The primary objective of this work is to investigate the early-age behavior of RCCP and to evaluate the effect of thermal properties on the design and performance of RCCP constructed in Louisiana.

Cationic asphalt emulsion as an additive of RCC Pavement: Exploring for Mode-I fracture behavior and dynamic modulus properties

So far, several studies with the aim of investigating the feasibility of applying emulsified asphalt as an additive in the different types of cement concrete have been conducted, of which the results show a promising performance. Nonetheless, a relevant study on the dynamic and cracking behavior of Roller Compacted Concrete (RCC) containing Cationic Emulsified Asphalt (CEA) have been seldom accomplished. Therefore, it paved a way for studying this issue by conducting experiments on cylindrical and semi-circular bending (SCB) specimens made with CEA contents of 0, 2, 4, 6, 8 and 10% by weight of cement. The SCB specimens were subjected to three-point bending test (mode-I fracture) to evaluate the effect of CEA on the fracture properties. The cylindrical specimens were subjected to dynamic modulus testing with sinusoidal loading/unloading with different frequencies (5, 2, 1, and 0.5 Hz) as per AASHTO T342 to assess the effect of CEA on the dynamic modulus. Non-destructive ultrasonic pulse velocity (UPV) test was also performed on the cylindrical specimens 200 × 100 mm, which were prepared by cutting 50 mm disc from two ends of the specimens. Applying multiple linear regression on experimental results, a set of models were thus developed for estimating mechanical properties based on UPV measurements at a 95% confidence level. Using ANOVA at a 5% significance level, the results revealed a significant decline in stress intensity factor and thereby cracking resistance following the addition of 4% or more CEA to the mixture. Adding 6% or more CEA significantly reduced the mixtures’ dynamic modulus but also significantly increased their fracture energy. Given that adding CEA and changing the loading frequency, respectively, had no significant impact on the mixtures’ phase angle and mechanical properties, it was concluded that the behavior of the RCC made with CEA additive remained within the linear elastic range.

Recycled Concrete Aggregated for the use in Roller Compacted Concrete: A Literature Review

The using of recycled aggregates from construction and demolition waste (CDW) can preserve natural aggregate resources, reduce the demand for landfill, and contribute to a sustainable built environment. Concrete demolition waste has been proven to be an excellent source of aggregates for new concrete production. At a technical, economic, and environmental level, roller compacted concrete (RCC) applications benefit various civil construction projects. Roller Compacted Concrete (RCC) is a homogenous mixture that is best described as a zero-slump concrete placed with compacting equipment, uses in storage areas, dams, and most often as a basis for rigid pavements. The mix must be sufficiently dry to support the weight of vibratory machinery while still being sufficiently moist to enough paste binder dispersion throughout the mass for efficient compaction. Limited studies into the use of RCC with fine recycled aggregate not from pavements are figured. This study aims to see how well-recycled concrete aggregates (RCA) perform in RCC mixtures. Also how well waste concrete could be used as a fine and coarse aggregate substitute in roller-compacted concrete pavement mixes, to create a good concrete mix in both wet and firm phases. The test results of mechanical properties showed 10% RCA is similar to those in the reference mix in the compressive strength, a 100% RCA ratio reduces compressive strength by almost 30%. Comparing Reference mix and Recycled concrete by 30% replacement, the compressive strength drops by just 6% when the RCA ratio is 30%.

Comparative investigation of laboratory and field compaction techniques for designing roller compacted concrete pavements (RCCP)

ABSTRACT The disparity in the compaction mechanism associated with optimum moisture content determination & specimen fabrication process in the laboratory and actual pavement construction leads to either underestimation or overestimation of Roller Compacted Concrete Pavements (RCCP) performance. Hence, in this investigation, different techniques to design RCCP, such as modified Proctor (MP), vibratory hammer (VH), vibratory table (VT), and gyratory compactor (GC), are studied and compared with the field specimens (FS); the considered fresh, mechanical, and functional properties are dry density, compressive strength, flexural and indirect-tensile strength, elastic modulus, water absorption, porosity, and abrasion & skid resistance. The laboratory results indicated that the compaction mechanism greatly affects the fresh and mechanical characteristics of RCCP. Further, it was observed that the strength properties are sensitive to the cohesion between the particles, which in turn, depends on the compaction type used to compact the RCCP. Compared with the field slab, only MP could produce comparable properties; other techniques manifested either higher or lower fresh and mechanical properties, except flexural strength. Although GC could simulate the field compaction mechanisms, it cannot mimic field properties, which necessitates further optimisation of gyratory compaction parameters (angle, pressure, and gyrations) to represent the actual pavement properties. Moreover, to achieve the field properties, the considered compaction methods shall impart a degree of compaction near to theoretical maximum constituent density.

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.