Roller Compacted Concrete Research Articles

Evaluation of Concrete Structural Cracking Behavior Induced by Early Drying Shrinkage

In this paper, the early drying shrinkage coefficients of different hydraulic cement mortars are calibrated through laboratory experiments for moderate-heat Portland cement (MHPC) and low-heat Portland cement (LHPC). By developing an improved mesoscale modeling approach, a 3D highly detailed simulation of concrete was generated, which incorporates the phases of mortar, aggregates, and interfacial transition zone (ITZ). The simulation result is in good agreement with the concrete early drying shrinkage experiment, exhibiting an error of less than 4.99% after 28 days. Subsequently, the mesoscale model is employed to explain the influence of the ambient humidity, cement type, and aggregate volume ratio on the early drying shrinkage performance of concrete. The results show that the early drying shrinkage coefficient of the LHPC is approximately 82% of the MHPC. Additionally, the depth of ambient humidity influence is about 15 mm from the concrete surface after 28 days. The early drying shrinkage can be controlled by increasing ambient humidity via the LHPC or raising the aggregate volume ratio. The mass-loss rate of concrete decreases as the ambient humidity or aggregate volume ratio increases during the process of drying shrinkage. Furthermore, the results quantify the influence patterns of various factors on drying shrinkage, thereby facilitating their application in assessing the cracking time induced by early drying shrinkage in roller-compacted concrete (RCC) dams. This provides theoretical guidance for crack prevention in concrete structures and aids in developing strategies for the construction of crack-free dams.

COMPARISON OF ROLLER COMPACTED CONCRETE PAVEMENT RESPONSES TO STATIC AND DYNAMIC LOADS

The objective of the study was to compare Roller Compacted Concrete (RCC) pavements responses to static and dynamic loads. Two sets of non-destructive load testing were performed on RCC pavements. The first set used static loading and dynamic loading was utilized for the second. Static loading was provided by front wheels of a Letro-Porter (front loader) and a Heavy Weight Deflectometer (HWD) was used for dynamic loading. A back-calculation procedure for estimating concrete pavement parameters is also presented. The Roller Compacted Concrete pavements were located at Moran Terminal, Boston, Massachusetts. The pavement consisted of a RCC layer of 38 cm (15 in.), a 23-cm (9-in.) gravel subbase and a compacted subgrade. The RCC layer was constructed in three lifts from bottom to top of 14, 14, and 10 cm (5.5, 5.5 and 4 in.). Four slabs were selected for testing. Strains and deflections were measured for static loading tests. A Benkelman beam was used for measuring the static load induced deflections. Deflection basins were determined during HWD tests. Load transfer efficiency at cracks and construction joints was also measured for both tests. The back-calculation procedure has been demonstrated to be satisfactory in estimating in situ pavement material properties. Using estimated RCC elastic moduli and estimated moduli of subgrade reaction, the stresses in the slabs caused by the static loads were computed by the finite element computer program JSLAB and compared to field measured stresses. It was found that the computed stresses were always greater than the measured values. A factor of safety of about 4% can be expected when HWD deflection data are used in place of static vehicle test data in rigid pavement analysis and design.

Enhancement of Air-Entrained Grout-Enriched Vibrated Cemented Sand, Gravel and Rock (GECSGR) for Improving Frost and Thawing Resistance in CSGR Dams.

Cemented Sand, Gravel, and Rock (CSGR) dams have traditionally used either Conventional Vibrated Concrete (CVC) or Grout-Enriched Roller Compacted Concrete (GERCC) for protective and seepage control layers in low- to medium-height dams. However, these methods are complex, prone to interference, and uneconomical due to significant differences in the expansion coefficient, elastic modulus, and hydration heat parameters among CSGR, CVC, and GERCC. This complexity complicates quality control during construction, leading to the development of Grout-Enriched Vibrated Cemented Sand, Gravel, and Rock (GECSGR) as an alternative. Despite its potential, GECSGR has limited use due to concerns about freeze-thaw resistance. This project addresses these concerns by developing an air-entrained GECSGR grout formulation and construction technique. The study follows a five-phase approach: mix proportioning of C1806 CSGR; optimization of the grout formulation; determination of grout addition rate; evaluation of small-scale lab samples of GECSGR; and field application. The results indicate that combining 8-12% of 223 kg/m3 cement grout with 2-2.23 kg/m3 of admixtures, mud content of 15%, a marsh time of 26-31 s. and a water/cement ratio of 0.5-0.6 with the C1806 parent CSGR mixture achieved a post-vibration in situ air content of 4-6%, excellent freeze-thaw resistance (F300: mass loss <5% or initial dynamic modulus ≥60%), and permeability resistance (W12: permeability coefficient of 0.13 × 10-10 m/s). The development of a 2-in-1 slurry addition and vibration equipment eliminated performance risks and enhanced efficiency in field applications, such as the conversion of the C1804 CSGR mixture into air-entrained GECSGR grade C9015W6F50 for the 2.76 km Qianwei protection dam. Economic analysis revealed that the unit cost of GECSGR production is 18.3% and 6.33% less than CVC and GERCC, respectively, marking a significant advancement in sustainable cement-based composite materials in the dam industry.

A Reliability-Based Risk Analysis of a Roller Compacted Concrete Dam – A Case Study

A Reliability-Based Risk Analysis of a Roller Compacted Concrete Dam – A Case Study

Utilizing genetic programming to evaluate and predict roller-compacted concrete pavements reinforced with coal powder and basalt fiber

ABSTRACT Roller-compacted concrete (RCC) pavement technology has drawn significant attention in recent years, thanks to its many advantages over conventional paving materials. The main benefits of RCC include decreased shrinkage, reduced life-cycle expenses, early access to traffic and a decrease in the urban heat island effect. This study proposed a cost-effective method to address the disposal of coal powder (CP), which is an important contributor of environmental problems, by integrating it into the manufacturing of RCC. Cement was replaced with CP at weight ratios of 5%, 10%, 15%, and 20%. CP was substituted for cement, with weight ratios of 5%, 10%, 15% and 20%. The albedo and mechanical properties of the obtained RCC mixtures were measured. The albedo of the RCC mixture with 20% CP decreased approximately 2.3 times in comparison to that of the reference mixture. After 28 days, RCC mixes had compressive strengths of 26–38 MPa and flexural strengths of 4.3–6.1 MPa. Flexural and splitting tensile strengths increased substantially with BF. RCC mixtures with 5% CP and 0.5% BF improved freeze-thaw resilience after 100 cycles. The genetic algorithm approach may improve RCC design optimisation. Thus, RCC made with CP may be environmentally friendly and Sustainable.

Tire wastes and durability: the influence of crumb rubber and recycled steel fibre on properties of roller compacted concrete

ABSTRACT The roller compacted concrete pavement construction requires essential factors, including durability, strength, sustainability, and economy. Cement substituted 5% silica fume and 27.5% slag by weight to mitigate the detrimental effects of liquids. These optimized substitutions were based on Taguchi design findings. In addition, waste tire byproducts have been studied. Volumetrically, crumb rubber replaced sand at 0, 2, 5, and 10%. RSF was added as a volume of RCCP at 0.2, 0.4, and 0.6%. Increasing CR lowers fresh density by 4%, and increasing RSF increases it by 2.7% compared to reference. Volume voids decreased by 18.2% and absorption by 45.1% as CR and RSF increased, indicating durability. Ion chloride penetration improved as CR and RSF ascent by 41.3% and 57% for 10% CR and 10% CR+ 0.6% RSF mixes, respectively. All mixes were within the durable range (low - very low). RSF makes RCCP more ductile and energy-absorbing. Compared to reference specimens, toughness increased by 909%. Mathematical models describe how CR and RSF affect RCCP's fresh density, permeability void volume, absorption, ion chloride penetration, and toughness. The results of ANOVA indicated a significant correlation between variables. The results suggest that RCC mixtures are more durable against harmful liquids and more ductile.

Combined effect of jute fiber and corn cob ash on sustainability assessment and mechanical properties of roller compacted concrete using RSM modelling

The increasing demand for cement has substantially affected the environment, and its manufacturing requires substantial energy usage. However, most countries in the world recently encountered a significant energy problem. So, researchers are exploring the use of agricultural and industrial waste resources with cementitious characteristics to minimize cement manufacturing, cut energy consumption, and contribute to environmental protection. Therefore, this research is performed on roller compacted concrete (RCC) reinforced with 5%, 10%, 15%, and 20% of corn cob ash (CCA) as substitution material with different percentage of cement and 0.25%, 0.50%, 0.75%, and 1% of jute fibre (JF) together for determining the mechanical properties and embodied carbon (EC) by applying response surface methodology (RSM) modelling. The cubical samples were prepared to achieve the targeted strength about 30 MPa at 28 days and then obtained mix proportions were employed for all combinations at various water-cement ratios to maintain roller-compacted concrete’s zero slump. Results showed that at 0.50% JF and 10% CCA, the flexural strength, splitting tensile strength and compressive strengths, and modulus of elasticity of RCC obtained were 5.3 MPa, 3.8 MPa, 32.88 MPa, and 33.11 GPa at 28 days, respectively. Besides, the embodied carbon of RCC is recoded reducing with combined addition of different levels of JF and CCA as compared to control mixture. In addition, the generation of response prediction algorithms was performed using analysis of variance (ANOVA) at a threshold of significance of 95%. The coefficient of determination (R2) readings for the statistical models ranged from 96 to 99%. It is observed that the use of 0.50% of JF along with 10% of CCA as cementitious constituent in RCC provides best outcomes. Therefore, this method is a superior choice for the construction industry.

Assessment and modelling of the mechanical strength of roller-compacted concrete incorporating recycled asphalt pavement

Integrating recycled asphalt pavement (RAP) into roller-compacted concrete (RCC) as a replacement for natural aggregates has recently emerged as a sustainable practice with significant environmental benefits. This study investigates the mechanical properties of RCC incorporating RAP aggregates, with a focus on developing a predictive model for its flexural and split tensile strengths. RCC mixtures with varying RAP content were developed and tested for compressive, split tensile, and flexural strengths. The results revealed a decline in composite performance with an increased RAP level. Nevertheless, mechanical strength met standard requirements for replacement rates of up to 60%. A new model was then developed, considering RAP rate alongside compressive strength, to predict the flexural and split tensile strengths of RCC. Existing models for conventional concrete were also evaluated for their applicability to RCC mixtures containing RAP. The proposed model demonstrated close alignment with experimental data from this study and other studies. It exhibited the lowest root mean square error, which confirms its accuracy in predicting the mechanical properties of RCC with RAP. This model provides a valuable tool for practitioners to estimate key parameters for designing pavement made with this composite.

An experimental and numerical analysis study of roller-compacted concrete based on recycled asphalt pavement

The contribution of this study is to examine the potential of using reclaimed asphalt pavement (RAP) as a replacement for natural aggregates (NA) in the production of roller-compacted concrete (RCC). In several countries, recycling old asphalt pavements has gained interest due to its economic and environmental advantages. However, in Algeria, large quantities of RAP are generated annually, yet they are rarely quantified or reused. This research investigates the use of RAP as coarse aggregates, testing five different replacement levels (0%, 25%, 50%, 75%, and 100%). The properties of fresh concrete, such as density, were measured, along with the impact of curing temperatures (20°C, 40°C, and 60°C) on the hardened properties, including compressive strength and modulus of elasticity. The results reveal that it is possible to produce RCC with up to 50% RAP, providing significant environmental benefits by reducing waste and preserving natural resources. These studies confirm that using up to 50% RAP in RCC is both feasible and environmentally beneficial, while maintaining good concrete performance. As part of the study, an accurate numerical model simulating the mechanical behavior of RCC, including time-dependent deformations and the non-linear stress-strain relationship, was created using finite element analysis in ANSYS-FEM. The purpose of this model is to highlight how RCC with RAP can be used in pavement applications.

MIX DESIGN AND LABORATORY COMPACTION METHODS OF RCCP – A REVIEW

This article analyzes the difficulties in reproducing the actual circumstances of concrete compaction with rollers in the laboratory and mix design аfeatures of RCCP (Roller Compacted Concrete Pavement). While quick and straightforward, the Proctor compaction test may not adequately reflect the field compaction achieved with rollers. Gyratory compactors simulate the movement of the rollers, providing a more realistic situation with greater accuracy. However, they are expensive and require specialized knowledge. Due to the Vibratory hammer limited application and unrealistic vibration pattern compared to rollers, it is mostly used in laboratories for sample preparation rather than compaction. A vibrating table is effective for less rigid RCC mixture combinations and provides good compaction, although it does not perfectly simulate the action of a roller. The paper also underlines the need to create a link between density and moisture content to achieve maximum RCC performance.

Gyratory compactor and mixture volumetric evaluation of roller-compacted concrete for pavement constructability

Standard roller-compacted concrete (RCC) test methods such as the modified proctor, Vebe, and vibratory hammer are used to determine final mixture proportions, evaluate consistency, and prepare cylindrical specimens for strength. However, these methods do not replicate the method and levels of compaction observed in the field and require multiple iterations to find a constructable and sustainable RCC mixture for pavements. Better linking RCC compaction properties with mixture volumetrics can enable more efficient RCC constituent selection and proportions. For this research, a typical RCC pavement mixture was selected from which the aggregate voids filled by paste (VFP) varied six levels to achieve mixtures ranging from underfilled (VFP=63.4 %) to overfilled (VFP=126.9 %). A gyratory compactor with a vertical and torque load cell was employed to continuously measure the compaction energy evolution in each specimen and for all mixtures. The volumetric compaction energy required to reach 90 % of the absolute density (Einitial0−90) and incremental energy to compact 90–95 % absolute density (Efinal90−95) was determined and used to evaluate RCC paveability and compactability, respectively, and relate it to mixture volumetrics. All RCC mixtures were able to achieve the initial density but at least equifilling was required to achieve final density under reasonable energy levels (≤ 2.70 MJ/m3), with compaction energy decreasing exponentially as the VFP increased. The gyratory compactor more efficiently compacted the reference mixture (VFP=117.9 %) to the same density as the modified proctor test (1.88 vs 2.70 MJ/m3) or cylinders with the vibratory hammer (3.10 vs 10.0 MJ/m3). The gyratory compactor with a perforated mold also enabled quantification of paste mobility within the aggregate skeleton. The time needed for initial and final seepage through the mold perforations was better and more sensitive than the Vebe and vibratory hammer compaction times, with seepage times ranging from 5 to 166 seconds for RCC mixtures from overfilled to underfilled. The perforated mold and a wet sieve analysis also allowed for experimental determination of intergranular voids (IGV) and total paste volume (TPV) of the RCC mixtures, respectively, which had an average relative error of 3.4 % and 4.0 %, respectively.

Onsite Seismic Monitoring Behavior of Undamaged Dams During the 2023 Kahramanmaraş Earthquakes (M7.7 and M7.6).

On 6 February 2023, two major earthquakes struck Türkiye, with their epicenters in the Pazarcık (M7.7; focal depth: 8.6 km) and Elbistan (M7.6; focal depth: 7 km) districts of Kahramanmaraş city. Most of the dams in the earthquake region remained structurally safe and stable. However, 17 dams in Türkiye and 1 dam in Syria were damaged during the 2023 Kahramanmaraş earthquakes. The main objective of this study was to better understand the real seismic behaviors of the dams during the two mainshocks and significant aftershocks. An earthfill dam, a concrete-faced rockfill dam (CFRD), and a roller-compacted concrete (RCC) dam constructed in the disaster area were selected to identify the real seismic behaviors of different types of dams during strong earthquakes. Acceleration records measured at the crest, right and left abutments, and foundations of the selected dams during the 2023 Kahramanmaraş earthquakes were taken into account to determine the real seismic behavior of the dams before, during, and after the earthquakes. The results of this investigation provide valuable insights into the real seismic behaviors of different types of dams in the vicinity of fault lines during strong earthquakes.

Improved probabilistic design method to quantify the fracture properties of roller compacted concrete

In this paper, the material parameters pertaining to fracture properties of Roller Compacted Concrete (RCC) were evaluated using the boundary element method (BEM). The fictitious crack growth length Δafic is determined by the relative size (T-a0)/di, while the individualized values of material parameters (KIC&ft) of RCC for different water-to-cement ratios were obtained. In this study, the three-parameter Weibull fracture statistical model was proposed for the first time to analyze the discreteness of these individualized values of material parameters (KIC&ft) of RCC. The statistical analysis minimum value of material parameters (KIC&ft) of each group is obtained. The failure curves of each group of RCC were predicted from the three-parameter Weibull fracture statistical model, and the simple calculation model for material parameters (KIC&ft) was validated. Further, a two-point design method was proposed for RCC material parameters (KIC&ft) with varying strengths and water-to-cement ratios.

Two-lift concrete pavement with advanced fibre reinforced concrete as the top lift and roller compacted concrete as the bottom lift

Roller Compacted Concrete (RCC), developed for pavements and dams due to its low cement content, is constrained by limited fatigue resistance, making it suitable only for low-traffic pavements. This study aims to develop a high-fatigue-resistant Two-lift Concrete Pavement (TLCP) incorporating RCC, with three primary objectives: (i) constructing TLCP with a two-thirds RCC bottom layer and a one-third ultra-high-performance fiber-reinforced concrete (UHPFRC) or engineered cementitious composites (ECC) top layer, (ii) conducting fatigue testing on 225 specimens, and (iii) analyzing fatigue data using statistical methods to determine the best approach. Results showed that TLCP specimens had higher compressive and flexural strengths than RCC, though lower than UHPFRC or ECC. A graphical method was found most accurate for predicting fatigue life. TLCP with UHPFRC achieved 3.85–7.5 times greater fatigue life, while TLCP with ECC showed 2.63–5.96 times higher fatigue life than RCC, with ECC offering significant cost savings.

Two-Phase Flow Modelling Based on Roughness Surface Effect of Roller Compacted Concrete

One of the most important considerations that are interest to researchers on the stepped spillway in hydraulic structure is the location of the point at which the flow begins to transform into two phase-flow and the development of boundary layers. In this study, an unconventional rough surface was used (RCC materials), which has completely different properties from what is used in previous laboratory studies, which uses smooth surfaces in reality to represent the actual roughness of the surface. Benchmark mixes are evaluated as a reference standard concrete to determine the optimal combination proportions for RCC according to The U.S. Army Corps of Engineers Standard. A laboratory study of different models enhanced by a mathematical model CFD with VOF technics to described the two- phase interaction to investigate the location of the inception point and compare the results with the proposed equations assumed by different researchers in this topic. The results obtained from the study showed a clear effect of surface roughness on the location of the inception point and the formation of the boundary layer for laboratory models. It’s clearly found that the two-phase flow starts with closer locations than it is for conventional models and the ratios vary (10 % - 20 %) according to the discharge values (where the effect of surface roughness is evident in the low discharges compared to the high discharges in which the boundary Lear effect begins to fade.

Determining the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) of Roller-Compacted Concrete: A Basis of Its Optimum Design Mix

Determining the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) of Roller-Compacted Concrete: A Basis of Its Optimum Design Mix

Analyzing Lab and Field Compaction Methods for designing Roller Compacted Concrete Pavements (RCCP) with Different Curing Processes

Analyzing Lab and Field Compaction Methods for designing Roller Compacted Concrete Pavements (RCCP) with Different Curing Processes

Design of Two-Layer Roller Compacted Concrete with Joints by KENSLAB

Roller compacted concrete (RCC) is a type of rigid pavement that is designed in a similar way to conventional concrete pavements reflecting its mode of failure. The thickness design of RCC pavements is based on keeping the flexural stresses and fatigue damage in the pavement caused by wheel loads within allowable limits. As in all jointed concrete pavements, there is a greater effect from loads placed along edges and less at interior locations in the pavement. Joints in RCC pavement are clearly critical areas and form weak points. RCC is typically constructed with saw-cut joints to prevent random cracking, improve the appearance of the pavement surface, and maintain the highest possible load transfer across the joints. This paper presents an approach to designing the thickness of a two-layer RCC with induced cracks (i.e., joints) based on load transfer stiffness and fatigue damage, using the KENSLAB program to obtain pavement life, predict joint deterioration, and pavement damage.

Experimental investigation on the frost resistance of RCC layers with various interface treatments

This research investigates the influence of various interface treatment methods on the frost resistance performance of Roller Compacted Concrete (RCC) layers. Freeze-thaw cycle tests were conducted on RCC with interfaces treated using cement mortar, expansion agent mortar, and nano-SiO2 mortar. The study evaluated shear failure modes, shear strength, crack expansion, pore structure, and liquid uptake of the RCC interface after freeze-thaw cycles under different treatment methods. Results reveal that expansion agent mortar and nano-SiO2 mortar improve the shear strength of RCC after freeze-thaw cycles more effectively than cement mortar. The freeze-thaw cycles increase the width and expansion rate of cracks at the RCC interface during the shear process, while mortar treatments help delay crack development. Additionally, the pore volume at the RCC interface gradually increases, and the uniformity of pore distribution decreases under freeze-thaw cycles. During liquid uptake, mortar treatments slow down the upward migration of liquids by improving the pore structure at the interface. The liquid uptake of RCC exhibits a distinct linear relationship with its shear strength and pore structure. As liquid uptake time increases, water first fills larger pores before gradually entering smaller ones. Freeze-thaw cycles cause an increase in pore volume and enlargement, which leads to greater liquid uptake. Based on the damage mechanism of the RCC interface under freeze-thaw conditions, a model of shear strength degradation due to freeze-thaw cycles was established, aligning well with experimental results. Mechanism analysis indicates that nano-SiO2 and expansion agents enhance frost resistance by filling interface pores and cracks through reactions with certain compounds, thereby improving the microstructure.

Istraživanje upotrebe betona i uvaljanog betona umjesto vruće bitumenske mješavine pri izgradnji kolnika autoceste u regijama s visokim temperaturama

This study examines the impact of temperature on the Cizre-Silopi highway’s bituminous hot mix asphalt (HMA) pavement, focusing on rutting issues exacerbated by high temperatures, which can reach up to 50 °C in the region. Despite rapid deterioration, especially under heavy truck traffic, the HMA pavement exhibited significant stability and flow resistance loss (approximately 52 %) between 20 and 50 °C. Concrete (C25) and roller-compacted concrete (RCC) pavements displayed minimal strength reductions under the same temperature conditions. These findings suggest that given the prevalent high temperatures and heavy axle loads in the region, concrete (C25) or RCC should be prioritised over HMA for pavement construction to enhance resistance against wheel rutting and temperature-induced damage. The observed rutting issues, even in the initial summer post-construction, underscore the urgency of adopting more temperature-resistant materials for road infrastructure under specified climatic conditions.