Roller Compacted Concrete Pavement Research Articles

Deicer salt-scaling resistance of non-air-entrained roller-compacted concrete pavements

This paper investigates the effects of various pozzolans on the fresh and hardened performance of non-air-entraining, roller-compacted concrete pavement. Deicer salt-scaling resistance of the specimens was evaluated for freeze–thaw cycle conditions with either a long or a short freezing period. Water–cement ratios were 0.36 and 0.43. Natural pozzolan, fly ash and silica fume were used as partial replacements for the cement, by 8%, 20%, and 20%, respectively. The results showed that the pozzolans generally improved the consistency of the mixtures compared with reference samples. Introducing silica fume improved compressive strength and, particularly, salt-scaling resistance of the specimens. Salt scaling decreased as the duration of the freeze period in the freeze–thaw cycle decreased.

Assessing the effects of supplementary cementitious materials on the performance of low-cement roller compacted concrete pavement

Roller compacted concrete pavements (RCCP) are widely used for a variety of industrial and heavy-duty pavement applications that involve low speed traffic. The aim of this investigation is to evaluate the effects of using supplementary cementitious materials – silica fume and pumice – on the workability, compressive strength, and frost resistance of non-air-entrained low-cement content RCCP mixtures. Eight different RCCP mixtures were produced with four types of binder and two binder contents. A series of consistency, compressive strength, and long-term freeze–thaw tests were conducted. Test results indicate that the frost resistance of the low-cement RCCP mixtures improves with higher cementitious materials content. The addition of 10% silica fume increased both the compressive strength and frost resistance of the RCC mixtures; however, it significantly decreased the workability of fresh mixtures. The pumice made the specimens more workable, but had a negative impact on both the compressive strength and frost resistance.

Modelling of the Stresses and Strains Distribution in an RCC Pavement Using the Computer Code "Abaqus"

The Roller Compacted Concrete (RCC) pavements are built employing the Portland cement. The design of the rigid RCC pavements was developed gradually through methods of design. These methods were established by various organisms for the determination of the necessary thicknesses of roadways. In this study a numerical 3D modelling was used by introducing to the computer code "Abaqus" the behaviour law of the RCC. Several other methods of 2D modelling were applied for the determination of the stress and the strains in the RCC slab such as the Closed-form Formulas and the Portland Cement Association (PCA) method. Finally the results of 3D modelling are compared with those obtained by the various other methods. The comparison shows good correspondences although the 3D modelling gives results slightly lower than those given by the 2D methods in stresses.

Roller-Compacted Concrete Shoulder Construction on Interstate Highway in Georgia

In 2004, the Georgia Department of Transportation (GDOT) used roller-compacted concrete (RCC) for Interstate 285 shoulder reconstruction in Atlanta. This instance marks the first usage of RCC pavement in the Interstate highway system in the United States. The construction procedures are described, and the mix design data for the RCC material are presented. The results of a comprehensive field and laboratory investigation of the pertinent material properties are also presented. The 6- and 8-in. (150- and 200-mm) RCC shoulder was constructed with minimal disruption for the traveling public and has performed well to date. The RCC mix was designed for a 4,000-psi (27.6-MPa) compressive strength with 0.5-in. (12.5-mm) maximum size aggregate. More than 98% of the maximum wet density, as specified in the GDOT provision for average in-field density, was achieved in tests at random locations. The average compressive strength in the middle section showed close agreement with the design strength. Reasonably good density and strength values were achieved in the longitudinal joint area and right edge area. The strength from the field-manufactured cylinders did not adequately represent the core strength of RCC, but it was recommended to include the cylinder test in the specification to monitor mixture variability and strength development. A small increase in average density resulted in a larger increase in average compressive strength, but no strong linear relationship was established in individual data. The 8-in. RCC section demonstrated a higher average strength than the 6-in. section, but it also showed a greater propensity for shrinkage cracks.

Effects of Density and Mixture Proportions on Freeze-Thaw Durability of Roller-Compacted Concrete Pavement

Roller-compacted concrete (RCC) is widely used for industrial and heavy-duty pavements. An economical and durable material for paving and other applications, RCC has a high strength and a high density. Although the strength of RCC has been thoroughly investigated, the freeze-thaw durability of RCC remains a topic of contention. RCC has often performed well in harsh field environments, but it frequently fails laboratory freeze-thaw durability testing. In this study, 24 specimens were fabricated for freeze-thaw durability testing with a gyratory compactor. The study variables were the degree of compaction, the amount of water, and the water-to-cement (w/c) ratio (and, hence, the amount of cement). The specimens replicated the concrete found in typical RCC pavement and dam construction. The RCC specimens were subjected to up to 300 cycles of rapid freezing and thawing and were tested for fundamental transverse frequency and mass loss. Because of the low aspect ratios of the specimens, fundamental transverse frequency testing was not reliable. Several specimens completed the 300 cycles with a mass loss of less than 10%. The freeze-thaw durability of RCC was found to be dependent primarily on the amount of cement paste and the w/c ratio and to a lesser extent on the degree of compaction.

Effects of Density and Mixture Proportions on Freeze–Thaw Durability of Roller-Compacted Concrete Pavement

Roller-compacted concrete (RCC) is widely used for industrial and heavy-duty pavements. An economical and durable material for paving and other applications, RCC has a high strength and a high density. Although the strength of RCC has been thoroughly investigated, the freeze–thaw durability of RCC remains a topic of contention. RCC has often performed well in harsh field environments, but it frequently fails laboratory freeze–thaw durability testing. In this study, 24 specimens were fabricated for freeze–thaw durability testing with a gyratory compactor. The study variables were the degree of compaction, the amount of water, and the water-to-cement (w/c) ratio (and, hence, the amount of cement). The specimens replicated the concrete found in typical RCC pavement and dam construction. The RCC specimens were subjected to up to 300 cycles of rapid freezing and thawing and were tested for fundamental transverse frequency and mass loss. Because of the low aspect ratios of the specimens, fundamental transverse frequency testing was not reliable. Several specimens completed the 300 cycles with a mass loss of less than 10%. The freeze–thaw durability of RCC was found to be dependent primarily on the amount of cement paste and the w/c ratio and to a lesser extent on the degree of compaction.

Proportioning RCCP mixes under hot weather conditions for a specified tensile strength

The work presented in this paper introduces the use of roller-compacted concrete pavements (RCCPs) as a substitute to the traditional asphalt concrete pavements that suffer from severe rutting and cracking due to heavy loading and hot weather which prevail in most of the Middle East countries. A soil compaction method (Kneading compaction) was used in this research to simulate compaction in the field. The variables affecting the mix proportioning of RCCP in hot weather have been evaluated and discussed. The variables included in this research were cement content, aggregate-to-cement ratio, water-to-cement (W/C) ratio, and degree of compaction. The effects of these variables on the density, tensile, and compressive strengths have been studied. Various plots and tables showing the interrelations between the studied variables were included in the paper. Results showed that under hot weather conditions, slight alterations in material proportions should be made to arrive at the required properties of RCCP mixes. A W/C ratio of 0.45 has been found to produce the optimum density and tensile strength for concrete in hot weather under the conditions of the experiments. One of the major findings was that the main factor that controlled most of the fresh and hardened properties is the cement content. Another important factor is that, unlike normal concrete, lowering the W/C ratio below an optimum value may not result in increase in the strength. Based on the results, simple relationships and equations have been obtained to predict the tensile strength of RCCP using the proportions of the mix. In addition, it has been found that a simple relationship, similar to the one presented in the ACI 325.10 state-of-the-art report, exists between the compressive and the tensile strength of concrete. The equation is presented in the simple form: f ct = 2 3 f cu Based on the extensive study, the paper proposed a method of mix design that is suitable for RCCP in the Middle East. However, the method can be extended for other situations.

Simplified Design of Roller-Compacted Concrete Composite Pavement

Roller-compacted concrete (RCC) is a durable, economical paving material for heavy-duty traffic. In the past, most RCC pavements have been built for low-speed traffic because of the difficulty of producing a smooth surface. A composite pavement system consisting of an RCC pavement structure and a hot-mix asphalt (HMA) riding surface is proposed. Simplified design tables, based on mechanistic analysis, are presented. Only fatigue cracking was considered, because performance studies of RCC have shown very little tendency for joint or crack faulting. Use of the design procedure is illustrated through an example. Results are compared with several other design procedures. Guidance for materials selection for the HMA surface layer and the subbase layer is provided, and construction considerations are reviewed. Cost data show that the initial cost of RCC pavements may be as low as 62% of the cost of conventional paving alternatives (not counting the HMA surface course). Suggested areas for further research into RCC composite pavements are discussed. The advances in RCC technology over the past two decades have made RCC a durable, economical alternative for industrial and multimodal pavements. Further use of RCC as part of a composite pavement system for highways offers considerable potential. One obstacle to use of RCC for highways has been the absence of a suitable design procedure. That need has been addressed in this research.

Roller-Compacted Concrete Mix Design Procedure with Gyratory Compactor

Roller-compacted concrete (RCC) pavements are durable and can be built rapidly and economically. In previous research, the gyratory compactor has proved to be a reliable instrument and overcome the drawbacks of other methods used to mold laboratory and field samples. Work is under way by different organizations in Canada, Japan, and the United States to improve mix design procedures for RCC. One procedure widely used for RCC pavements was developed by the U.S. Army Corps of Engineers. This research investigated improving mixture proportioning of RCC by using a gyratory compactor. Previous research suggested that the gyratory compactor could be used effectively to produce RCC test samples for both compressive and splitting tensile strength. An RCC mix design procedure using the gyratory compactor can benefit many transportation agencies because it provides a reliable way to evaluate the strength and density of RCC mix designs. Results for several RCC mixtures compacted to different densities are presented, along with comparisons with modified Proctor test results. Using the gyratory compactor to design better RCC mixtures might lower the costs and improve the reliability of RCC pavements.

Strength and Durability of Roller-Compacted HVFA Concrete Pavements

The aim of this investigation was to collect state-of-the-art information on the strength and durability of roller-compacted concrete (RCC) for pavement construction made with and without supplementary cementitious materials, and to describe the construction experience gained in 2 pavement projects recently completed in Wisconsin. Past studies have shown that mechanical behavior of RCC pavement is similar to that of conventional paving concrete. However, nonair-entrained RCC is susceptible to freezing and thawing (F&T) damage if critically saturated when subjected to freezing actions. Lab testing of specimens derived from the test pavements showed excellent results for conventional high-volume fly ash pavement, and satisfactory performance of the RCC pavement except for F&T resistance. Other results are also provided and discussed.

Roller-Compacted Fiber Concrete Pavement Foundation with Recycled Aggregate and Waste Plastics

A laboratory investigation was conducted to evaluate the performance of a moderate-strength roller-compacted concrete (RCC) made from reclaimed crushed concrete used as aggregate, Class C fly ash, and wasteplastic fibrous reinforcement. The motivation for evaluating this primarily waste composite is to develop a high-quality foundation layer for a conventional flexible or rigid pavement while attempting to address such crucial issues as the ever-increasing solid waste disposal problem, rapidly depleting landfill spaces, and conservation of natural resources. A summary is given of the findings of materials characterization studies with the following objectives: ( a) to evaluate the effectiveness of recycled high-density polyethylene strips in stabilizing the tensile crack propagation through the brittle cementitious matrix; ( b) to determine the strength and toughness characteristics of the composite; and ( c) to suggest performance-based mixture design proportions for recycled aggregate, fly ash, cement, and recycled plastic fibers. Because an RCC pavement slab will be subjected to repeated tensile stresses under traffic loads, the study focused on instrumented split tensile and flexural tests to evaluate the performance of the foundation material. Results indicate that a mix containing only 8 percent cement and 92 percent recycled materials can achieve 28-day compressive strengths of up to 14 MPa and split tension strength of 1.5 MPa. It is found that the plastic fibers can improve the toughness characteristics significantly in split tension and moderately in flexure. Therefore, the new cement-bound composite made primarily from recycled products offers promise as an alternative material for construction and rehabilitation of highway pavements.

Development of a Roller-Compacted Concrete Pavement Crack and Joint Spacing Model

The development of a mechanistically based model (CRACK) that predicts the spacing of cracks in roller-compacted concrete (RCC) pavements due to restraint of drying shrinkage and thermal contraction is presented. The model considers the RCC pavement thickness, paving lane length, base friction characteristics, climatic time-temperature regimes, as well as the RCC drying shrinkage, coefficient of thermal contraction, strength gain, and modulus of elasticity. The model also determines the tensile stresses and displacements of the RCC slab along its length, from which the crack width is predicted. The CRACK program was used to predict the crack spacing and width at four RCC pavement field sites, and the predicted results were compared with field measurements. The model tends to overpredict the observed crack spacings, in part because of the simplifying assumptions used in the model development and the fact that the model does not consider fatigue stresses from warping, curling, or traffic-related loads, which cause additional cracking. However, the predicted crack spacing provides a basis for selecting joint spacings, and the predicted crack widths may help in the design of joint sealant reservoirs.

Deicer Salt Scaling Resistance of Roller-Compacted Concrete Pavements

In the fourth year of a research project of roller-compacted concrete pavements, a test section was cast during the summer of 1990, using four different mixtures. Two types of binder and two binder contents were used to prepare these mixtures. In order to verify if a proper air-bubble network could be obtained, and if it is necessary to have bubbles in RCC to be frost resistant, three of the four mixtures were prepared with an air entraining agent. Based on previous good results, the four mixtures were cured with two different white membrane curing compounds. Samples representative of all mixtures were taken from the pavement after 28 days. The air-void characteristics of all concretes were determined in accordance with American Society for Testing and Materials (ASTM) C 457 and the salt scaling resistance of all mixtures was evaluated using ASTM C 672 on rolled surfaces. Despite the large dosages of air entraining agent used, microscopical examinations clearly indicated that it was not possible to entrain spherical air bubbles in all RCC mixtures. The mass of scaled-off particles after 50 cycles of freezing and thawing in presence of a salt solution is higher than the 1 kg/sq m2 limit for most of the samples tested. Test results also indicate that the construction of a deicer resistant roller-compacted concrete pavement is possible, but only under certain conditions, some of which are not clearly defined. Good construction practices are clearly required. The use of supplementary cementitious materials also appears to be a requirement.

Load Transfer Characteristics of Roller-Compacted Concrete Pavement Joints and Cracks

The U.S. Army Corps of Engineers’ design procedure for roller-compacted concrete (RCC) pavements assumes that no load transfer is achieved at RCC joints or cracks. This is in contrast to the Corps of Engineers’ rigid pavement design procedure for airfields, parking areas, and open storage areas, where a 25 percent load transfer is assumed for all joints and cracks. The no-load-transfer assumption for RCC pavements is conservative and is based upon limited data that indicated that RCC pavement joints did not achieve a 25 percent load transfer. The purpose of this study was to identify common types of RCC pavement joints and cracks, to determine the load transfer characteristics of these joint and crack types at 12 RCC pavement test sites using the falling weight deflectometer and to indicate the effect of incorporating these load transfer characteristics within the corps’ RCC pavement design procedure. Thirteen RCC pavement joint and crack types were identified. The mean load transfer achieved at these joints and cracks varied from 4 percent to 32 percent, and was no less than 10 percent for the most common joints and cracks found. In two design examples comparing the existing corps RCC pavement design procedure with a modified version incorporating 10–15 percent load transfer, the design RCC pavement thickness decreased 8–17 percent.

Load Transfer Characteristics of Roller-Compacted Concrete Pavement Joints and Cracks

The U.S. Army Corps of Engineers' design procedure for roller-compacted concrete (RCC) pavements assumes that no load transfer is achieved at RCC joints or cracks. This is in contrast to the Corps of Engineers' rigid pavement design procedure for airfields, parking areas, and open storage areas, where a 25 percent load transfer is assumed for all joints and cracks. The no-load-transfer assumption for RCC pavements is conservative and is based upon limited data that indicated that RCC pavement joints did not achieve a 25 percent load transfer. The purpose of this study was to identify common types of RCC pavement joints and cracks, to determine the load transfer characteristics of these joint and crack types at 12 RCC pavement test sites using the falling weight deflectome-ter and to indicate the effect of incorporating these load transfer characteristics within the corps' RCC pavement design procedure. Thirteen RCC pavement joint and crack types were identified. The mean load transfer achieved at these jo...

Factors Affecting Joint Efficiency of Roller-Compacted Concrete Pavement Joints and Cracks

The mechanism of joint efficiency for roller-compacted concrete (RCC) pavement joints and cracks is affected primarily by aggregate interlock or friction at the vertical interface of the joint. Current U.S. Army Corps of Engineers design procedures for RCC pavements make the conservative assumption that no joint efficiency is achieved at RCC pavement joints and cracks. The purpose of this study was to determine the degree of joint efficiency achieved at RCC pavement joints and cracks; to determine the factors that affect the joint efficiency, and to what degree; and to develop a regression model to predict the joint efficiency using those factors. The heavy weight deflectometer (HWD) and other devices were used to conduct nondestructive joint efficiency tests at 12 different RCC pavement sites around the United States. The joint efficiency results ranged from 22 percent to 89 percent, depending on the type of joint or crack tested. The joint efficiencies decreased significantly with increasing crack width...

Factors Affecting Joint Efficiency of Roller-Compacted Concrete Pavement Joints and Cracks

The mechanism of joint efficiency for roller-compacted concrete (RCC) pavement joints and cracks is affected primarily by aggregate interlock or friction at the vertical interface of the joint. Current U.S. Army Corps of Engineers design procedures for RCC pavements make the conservative assumption that no joint efficiency is achieved at RCC pavement joints and cracks. The purpose of this study was to determine the degree of joint efficiency achieved at RCC pavement joints and cracks; to determine the factors that affect the joint efficiency, and to what degree; and to develop a regression model to predict the joint efficiency using those factors. The heavy weight deflectometer (HWD) and other devices were used to conduct nondestructive joint efficiency tests at 12 different RCC pavement sites around the United States. The joint efficiency results ranged from 22 percent to 89 percent, depending on the type of joint or crack tested. The joint efficiencies decreased significantly with increasing crack width, crack spacing, and decreasing temperature. Cores were taken from some of the sites, and crack width measurements with depth indicated little evidence of crack skewing. The HWD load magnitude significantly affected the joint efficiency, and the individual effects of slab thickness and modulus of subgrade reaction did not appear to be significant from observation of the data. A regression was developed that predicts the joint efficiency of RCC pavement joints or cracks, with an R2 of 62 percent.

EFFECTS OF CLASSIFIED FLY ASH ON IMPROVING PERFORMANCE OF ROLLER COMPACTED CONCRETE PAVEMENTS

近年, 転圧コンクリート舗装 (RCCP) が注目されているが, 締固めと平坦性の確保の観点から1層施工の版厚が最大25cmに制限されている. このことが, RCCPを空港・港湾のような重荷重を対象とした舗装に適用していく上で大きな欠点となっている. この問題点に対処するため, 一般のコンクリートにおいてコンシステンシーの改善効果や耐久性向上の効果が認められている, 粒径20μm以下に分級されたフライアッシュが, RCCPの締固め特性の向上, 1層施工厚さの増大等の性能向上に及ぼす効果を検討した. 一連の室内実験, 試験舗装から, フライアッシュを混入することにより, (1) 必要締固めエネルギーが低減できる, (2) 単位水量が低減できる, (3) 舗装版の下層部分の強度が上昇する, 等の結果が得られ, 35cmの版厚を有するRCCPの1層施工が可能であることが確認できた.

Abstract of: State-of-the-Art Report on Roller Compacted Concrete Pavements

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流動化剤の後添加によるＲＣＣＰ用コンクリート供試体製造作業の省力化に関する実験的検討

It is a hard work to produce the bending strength test specimen of extremely stiff consistency concrete for roller compacted concrete pavement. The purpose of this study is to reduce the work time of the specimen production. In order to carry out this purpose, superplasticizer was added to the base concrete after mixing. The consistency was measured by a Swedish-type Vebe apparatus and the vibrating compaction value of the base concrete was 50±5 seconds.The suitable superplasticizer content was found to be 1.2% by cement content. By adding superplasticizer suitably to the base concrete, the vibrating compaction value and air content were decreased considerably and the compaction ratio was increased slightly. Furthermore, the surface vibrating compaction time to produce test specimens and the time to finish concrete surface by trowel could be reduced to half and one-eighth respectively, the surface finish condition was well and smooth enough, and the bending strength of the superplasticized concrete was equal to that of the base concrete at the age of 28 days. From these results, the work time to produce test specimens is reduced by adding superplasticizer.