Macadam Mixture Research Articles

Evaluation on the Crack Resistance of Cement-Stabilized Macadam Mixture with Crack-Resistant Interlocking Gap Gradation and Rubber Powder

Evaluation on the Crack Resistance of Cement-Stabilized Macadam Mixture with Crack-Resistant Interlocking Gap Gradation and Rubber Powder

Characteristics of the Warm Mix Asphalt with Emulsion as Additives in Engineering

The technology known as Warm Mix Asphalt (WMA), just unveiled in Europe, is becoming increasingly popular across the globe. By lowering the bitumen binder's viscosity, this cuttingedge technique makes asphalt mixtures more workable at lower temperatures between 30-40°C needed to generate conventional Hot Mix Asphalt (HMA). Reduced pollutants, energy savings, and a less offensive smell result from the lower mixing and compaction temperatures. More studies are necessary to evaluate its long-term performance. Based on MORTH requirements, this study examines the efficacy of bitumen emulsion as an addition in WMA samples of Stone Matrix Asphalt (SMA) and Dense Bituminous Macadam (DBM) mixtures. The combinations' binder contents varied from 4% to 7% of the aggregate weight. For the DBM and SMA mixes, cement and stone dust were utilized as fillers, and VG 30-grade bitumen was employed as the binder. For SMA and DBM mixtures, the ideal binder contents were determined to be 6.92% and 6.32%, respectively.

An Experimental Study on using RCA in Bituminous Mixtures to Create Sustainable Pavement Technique

Due of the extensive infrastructure development that India has been experiencing over the past thirty years, conventional stone aggregates are becoming scarcer and more expensive. However, there are plenty of wastes available, such as those from old concrete structures. Recycled concrete aggregate (RCA) wastes have already been the subject of numerous attempts to repurpose in a variety of building applications, including bituminous pavement layers. It's possible that not all bituminous binders that are frequently employed in Indian paving mixtures are compatible with RCA. The purpose of this experimental investigation is to examine how different types of binders affect the performance of densely graded bituminous mixtures in which RCA is used in place of the coarse portion of traditional stone aggregates. The primary goal of this project was to manufacture dense bituminous macadam (DBM) mixtures in accordance with pertinent Indian criteria. Traditional VG 30 and crumb rubber modified binder (CRMB), two forms of bituminous binders that are commonly used in India, were employed in this procedure. In accordance with the primary objective of this investigation, the blends were created and assessed about their technical attributes such as indirect tensile strength and moisture susceptibility traits like residual stability test and tensile strength ratio. The VG30 bitumen provides better and satisfactory results for combinations with an equal proportion of NA and RCA, taking into account all engineering properties evaluated.

Study on Improvement Measures for Construction Performance and Mechanical Properties of Cement Stabilized Porous Basalt

Abstract Cement stabilized porous basalt (CSPB) is prone to early agglomeration into lumps owing to the abundant pores and high moisture absorption of porous basalt, making it difficult to unload the mixture at construction sites in high temperatures and rainy areas. To study the construction performance of a CSPB mixture, a novel test method and a convenient device were proposed to test the workability of the cement stabilized macadam mixture, and the evaluation criteria and evaluation method of the workability were proposed based on the tilt angle test. The influencing factors of the workability of CSPB were investigated, and the results show that temperature, delay time, moisture absorption of aggregate, mixture proportion, and construction technology had significant influences on construction performance. Then measures were recommended to improve the construction performance of CSPB. Considering the influence of construction performance on mechanical strength, the effects of temperature, delay time, water reducer dosage, and cement dosage on the mechanical strength of CSPB were also investigated. The results show that temperature and delay time had significant influence on the mechanical strength. The results of this research are of great significance to the field construction of CSPB.

Laboratory assessment of the impact of modified asphalt binder on mechanical properties of grouted macadam mixtures under various performance conditions

ABSTRACT Grouted Macadam (GM) mixtures are used for pavement coatings due to their strong load-bearing capacity and rutting resistance. However, weak asphalt-cement interface bonding reduces crack resistance performance of these mixtures. This study aimed to enhance this adhesion through implementing TEGO Addibit L300 additive at concentrations of 0.2, 0.3, and 0.4% by weight of asphalt binder. Various tests assessed additive’s impact on asphalt binder properties, including penetration, softening point, and kinematic viscosity. Adhesion properties were evaluated through sessile drop and semi-circular bending bonding strength tests. Additionally, GM mixture performance was assessed with mechanical tests such as 3-point bending strength, indirect tensile strength, and Marshall stability, considering two conditions: samples tested immediately after a 28-day curing period (non pre-conditioned samples), and samples tested after the same period followed by exposure to 60 ℃ for 16 h (pre-conditioned samples). Results revealed that the adhesion capacity of the asphalt binder significantly affected GM mixture performance in both conditions. Addition of TEGO Addibit L300 enhanced ductility and fracture energy by 53.9% and 45.2%, respectively, in non pre-conditioned samples. In pre-conditioned samples, the additive increased indirect tensile strength by up to 12.1%. The optimal dosage for improving GM materials performance was determined to be 0.3%.

Study on the Performance of Recycled Cement-Stabilized Macadam Mixture Improved Using Alkali-Activated Lithium Slag–Fly Ash Composite

Study on the Performance of Recycled Cement-Stabilized Macadam Mixture Improved Using Alkali-Activated Lithium Slag–Fly Ash Composite

Municipal solid waste incineration bottom ash recycling assessment: Carbon emission analysis of bottom ash applied to pavement materials

Inspired by the concept of conserving resources, bottom ash has been increasingly utilized in road construction as a readily available waste material. This study sought to address this gap by quantifying the carbon benefits associated with bottom ash application. Through a comprehensive analysis grounded in life cycle theory, author evaluated the changes in energy consumption and carbon emissions before and after the integration of bottom ash into the road construction process. The analysis employed the raw material production stages of different pavement materials as the system boundary. By determining the optimal amount of bottom ash and calculating the associated values, the study proposed an efficient application scheme for utilizing bottom ash in urban engineering construction projects. The results showed that bottom ash had the least carbon reduction effect in permeable bricks, followed by cement concrete and cement stabilized macadam mixture. The most significant effect was observed in asphalt mixtures. However, energy consumption increased with the addition of bottom ash in asphalt mixtures, whereas it decreased in the other three products. The carbon reduction after applying bottom ash was predicted based on the annual growth rate of urban road construction. Under the premise of maintaining the non-destructive application performance of asphalt mixtures, the optimal carbon reduction benefit for a 20% addition of bottom ash was approximately 17,369.9 tons. In cement-stabilized crushed stone mixtures, the optimal carbon reduction benefit ws achieved with a bottom ash content of 30%, approximately 15,797.7 tons. The practice of utilizing bottom ash in road works was significant in terms of maximising the benefits of carbon reduction.

Laboratory mechanical properties and frost resistance of vibration-compacted cement–fly ash slurry and cement–fly ash-treated macadam mixtures

The objectives of this study were to characterize the compaction and mechanical characteristics and frost resistance of vibration-compacted cement–fly ash slurry (CFAS) and cement–fly ash-treated macadam (CFATM) mixtures and recommend the optimal ratio and dosage of cement–fly ash (CFA) based on laboratory compaction experiments, unconfined compressive testing, indirect tensile testing, and frost resistance testing. The effects of the CFA ratio and dosage, curing age, and gradation type on the mechanical strength and frost resistance were analyzed, and strength prediction equations were presented. Then, the optimal CFA ratio and dosage are recommended. The results show that the mechanical strength of CFAS and CFATM mixtures increased nonlinearly with increasing curing age. Gradation type, CFA ratio, and CFA dosage affected the conventional, initial, and ultimate mechanical strengths of these mixtures. A CFATM mixture cured for a longer duration with self-developed skeleton-dense gradation and the addition of less fly ash exhibited better frost resistance. To maximize the mechanical strength of CFAS and CFATM mixtures, the CFA ratio should not exceed 1:1 and 1:1–1:1.5, respectively. In addition, 3.5%–4.0% cement and 4.0%–7.0% fly ash should be used in the CFATM base or subbase to obtain optimal results. This paper provides a new option for the design of CFAS and CFATM mixes.

Laboratory evaluation of the effect of microfibers on the low-temperature cracking performance of grouted macadam mixtures

Grouted Macadam (GM) mixtures are a composite of bituminous and cementitious phases used as pavement semi-flexible overlays because of their high static bearing capacity and rutting resistance, good durability, and proper resistance to chemical attacks and fossil fuels. However, these mixtures do not have good performance at low temperatures. Reinforcement by fibers is a popular method to improve the performance of asphalt and concrete mixtures and has the potential to be used to reinforce GM mixtures. This study aims to reinforce both bituminous and cementitious phases of GM mixtures using glass based (Microcorta) and polypropylene based (PP) fibers, respectively. The bituminous phase of the first group of the GM mixtures was reinforced with 0.2, 0.4, and 0.6 vol% of glass microfibers (MC). In addition, 0.2, 0.3, and 0.4 vol% of PP fibers were used to produce the cement grout of the second group of GM mixtures. In the next step, the performance of each group was compared with that of the fiber-free samples using a three-point bending test (TPB) and low-temperature indirect tensile test (IDT). Based on the obtained results, GM mixtures’ best low-temperature performance in both IDT and TPB tests was obtained for mixtures containing the highest percentage of fibers (0.6% of MC and 0.4% of P.P fibers). Also, it was observed that the reinforcement of the bituminous phase increased the fracture strain tolerance (FST) in the TPB and IDT tests by 66.19% and 25.01%, respectively, compared to fiber-free samples. Moreover, using fiber-reinforced cement grout has been able to enhance the FST index in the TPB and IDT tests by 91.87% and 30.9%, respectively, compared to fiber-free samples. Overall, the results demonstrate that the reinforcement of both bituminous and cementitious phases of GM mixtures by microfibers can help improve their ability to resist low-temperature cracks.

Use of detoxified MSWI fly ash for cement stabilized macadam mixture: mechanism, mechanical and environmental considerations

Use of detoxified MSWI fly ash for cement stabilized macadam mixture: mechanism, mechanical and environmental considerations

Experimental evaluation of the effect of recycled cross-linked polyethylene on the performance of grouted macadam mixtures

ABSTRACT Grouted Macadam (GM) mixtures – recognized as semi-flexible pavement (SFP) materials – offer strong stability in high temperatures, good durability and high load-bearing capacity. However, these materials are prone to environmental and traffic-induced cracking. Cross-linked polyethylene (XLPE), a common high-voltage cable insulation, faces disposal challenges due to limited recycling technology, often leading to burning or burial of these waste materials. In this study, to enhance GM mixture crack resistance and mitigate the environmental impact of XLPE waste accumulation, XLPE material was used in GM mixtures in two methods. In the first group, 15%, 30%, and 45% of 4.75 to 9.5 mm natural aggregates were replaced in volume, with XLPE pseudo-aggregates of the same size. In the second group, XLPE pseudo-fibers (1.9–2.2 cm in length, 1.5 mm thickness) were incorporated as additives in 0.5, 0.7, and 1 volume percentages. The results of mechanical tests on treated GM mixtures showed that adding recycled XLPE improved durability, with a 24.5% and 29.9% enhancement in samples with the most pseudo-aggregates and pseudo-fibers contents. The fracture strain tolerance (FST) index in low-temperature bending tests also increased by 53.8% and 108.9% in mixtures containing XLPE, highlighting its potential to enhance GM mixture performance in various service conditions.

Performance of bituminous paving mixtures containing recycled concrete aggregate, fly ash and rice husk ash: A probabilistic approach

Due to the rapid increase in construction activities, the depletion of natural resources is accelerating. Extensive research has focused on finding alternative materials to conserve resources and minimize costs. This study explores the utilization of recycled concrete aggregate (RCA) as a substitute for coarse aggregate, along with waste materials like fly ash (FA) and rice husk ash (RHA) as fillers in bituminous paving mixtures. The aim is to address environmental concerns and waste disposal issues. The research evaluates the performance of different filler types in non-conventional bituminous mixtures using VG 30 grade bitumen as a binder, specifically for lower bituminous layers. A typical bitumen concentration of 5% by weight of dense bituminous macadam (DBM) mixtures is chosen based on existing literature. The study assesses various performance characteristics, including Marshall parameters, indirect tensile strength, and moisture susceptibility. A probabilistic approach is employed to determine the most suitable distribution model, focusing on retained stability (RS) as a measure of moisture susceptibility. For this, fifteen distribution functions were considered with three Goodness-of-fit (GOF) tests. To identify the best suitable function, 50 numbers of samples were prepared to find RS with two types of fillers and two types of coarse aggregate. Experimental results indicate that mixtures with natural aggregate exhibit slightly superior performance, but those with RCA meet all the requirements specified in relevant Indian codes and specifications. The probability analysis confirms that the Burr distribution best fits the experimental data, particularly for moisture susceptibility characteristics.

Sulfate-induced expansion of cement treated road base: Deterioration law of performance and air-void structure change under water-heat-salt coupling effect

The expansion and deterioration (E&D) of cement treated road base has become one of the common road problems in northwest and northern China, which seriously affected driving safety and increased road maintenance costs. In order to explore the influencing laws and mechanism of external salt on the expansion of cement treated road base in desert Gobi area with large temperature difference, based on the climate in Xinjiang and cement stabilized macadam (CSM) mixture, a laboratory accelerated simulation test under the coupling effect of water-heat-salt was designed to restore the working condition of the base course in Xinjiang. The expansion deformation and deterioration laws of CSM specimens under different gradation types, temperature, humidity and temperature-humidity cycle change were studied. Combined with MIP and computed tomography (CT), the air-void structure change, micro-pore morphology and accumulation of expansion products in the mixture were studied. The results showed that after 360-days’ coupling effect, the damage height of the specimen was SD (suspension-dense structure) > FP (frame-pore structure) > FD (frame-dense structure). The mass of the partially-immersed specimens increased first, and the mass loss began to appear at about day 120. After 360-days’ temperature and humidity cycle change, the mass loss rate of SD, FD and FP were 4.15 %, 2.4 % and 4.9 %, respectively, which were 2.75, 2.53 and 2.62 times of that at 25 °C. Moreover, the expansion rate increased by about 20 %, and the performance deterioration decreased by 24.9 %–30 %. Additionally, the MIP and CT test results indicated that the aggregate proportion had a significant effect on the spatial distribution of the air-voids and the change of pore structure with coupling ages. This study provides reference for the design of cement-based composites and the acknowledgement of cement-treated base expansion in desert Gobi area.

The influence of mixing technology on the uniformity and strength of cement stabilized macadam mixture

A comparison between the two strategies: secondary traditional mixing technology and secondary vibratory mixing technology is proposed based on aggregate sieving, cement EDTA titration and unconfined compressive strength tests to explore the influence of the uniformity and strength of cement stabilized macadam mixture in the paper. The results show that when the secondary vibratory mixing technology is adopted: (1) the standard deviations and coefficients of variation of the passing rates of key sieves of 19 mm, 13.2 mm, 9.5 mm, 4.75 mm and the cement dosage titration results decrease significantly, and the mixing uniformity of the mixture is significantly improved; (2) the 7-day and 28-day unconfined compressive strengths of the mixtures are significantly improved while the strength standard deviations and coefficients of variation are reduced, with an obvious trend along with the extension of the curing time (within 28 days).

Development of Improved Dense Graded Bituminous Macadam with Low Density polyethylene and High Density Polyethylene with Zykotherm Intermixing

The utilisation of leftover polythene in flexible road constructions is discussed in this paper. In flexible pavements, recovered polymer debris such as carry bags from supermarkets and water bottles, coldrink bottles (LDPE) and plastic bottle caps (HDPE) have been utilised as additives. We'll also use a fixed amount of Zykotherm in this experiment (ZycoTherm is an odourless ingredient that boosts moisture tolerance while decreasing blending and compaction temperatures by up to 65°F). The aforementioned components were chosen for two reasons: to use economically and environmentally undesirable trash and to build a superior material mixture to withstand higher traffic loads, temperature effects, and pressure, which results in fractures in the pavement surface. The polymer debris will be processed and reduced into a size that would flow through a 2-3mm filter in the research study utilizing a shredding machine. 
 In this investigation, a Dense Bituminous Macadam (DBM) mixture is being presented to be prepared utilizing pure bitumen as a control sample and bitumen blended with LDPE 2 percent and 4 percent & HDPE 2 percent, 3 percent, 4 percent, 5 percent by weight, with a specific amount of Zykotherm of 1.5 percent by weight. On control and modified DBM mixes, the Marshall Stability Test, Penetration Test, and Softening Point Test were performed.

Effect of fiber on mechanical properties of cement stabilized macadam mixture

In order to improve the crack resistance of semi-rigid base materials, polyester fiber (PET), polypropylene fiber (PP), polyacrylonitrile fiber (PAN) and polyvinyl alcohol fiber (PVA) were selected to prepare cement-stabilized crushed stone mixture. The mechanical properties of fiber-cement stabilized crushed stone mixture were studied by unconfined compressive strength, splitting strength and compressive rebound modulus tests. The results show that the fiber can effectively improve the compressive strength and splitting strength of cement-stabilized crushed stone mixture when the fiber content is 0.05%-0.11%, and both the compressive strength and splitting strength of the mixture increase with the increase of fiber content. The compressive strength and splitting strength of the mixture with the same fiber and dosage showed a trend of slow growth first, then rapid growth, and then gentle growth during the curing period of 90d. Adding PET, PP and PAN reduced the compressive resilience modulus of cement-stabilized macadam mixture, while adding PVA increased the compressive resilience modulus of cement-stabilized macadam mixture.

Comparative Research on Mechanical Properties and Void Distribution of Cement Stabilized Macadam Based on Static Pressure and Vibration Compaction

Cement stabilized macadam semi-rigid base materials are widely used in road construction in China. However, a traditional static molding method and heavy compaction method cannot guide the design and engineering application of cement stabilized macadam mixture because it often appears that the compaction degree exceeds 100% in the practical engineering. In view of this, this paper carried out the research of an indoor vibration compaction method of cement stabilized macadam mixture, and compared the mechanical properties and void distribution characteristics of two kinds of compositions of mixtures under the vibration compaction method as well as static pressure molding and heavy compaction method and on-site sample after 7 days curing period, which was combined with the physical engineering project of Yu-Song Expressway in Jilin Province, China. The research results show that the maximum dry density of mixture under vibration compaction is larger and the best moisture content is smaller, which has a heavy incomparable advantage on the simulation of on-site compaction. And the compressive strength and splitting strength indexes of vibration compacted specimens are close to those of an on-site sample, which are all larger than static pressure specimen. Moreover, the void distribution characteristics of vibration compacted specimens is much closer to those of the on-site sample and more universal, while static pressure specimens lack in uniformity. In addition, different results caused by the two gradation are compared. All of the above research results can verify that the vibration compaction method has more reliability and accuracy to simulate the actual properties of base material. This study provides a reference for the application of vibration compaction method in road engineering design.

Mechanical and Durability Properties of Cement-Stabilized Recycled Concrete Aggregate

This research investigates the effect of using recycled concrete aggregate (RCA) as a partial replacement of natural aggregate (NA) on the mechanical and durability-related properties of a cement-stabilized recycled concrete aggregate (CSR) mixture. In this case, mixtures were prepared with 0%, 40%, 70%, and 100% (by weight) RCA to replace NA, and cement contents of 4%, 5%, and 6% were used in this study. Test parameters included the replacement ratio, cement content, and curing time. Tests were carried out to establish the unconfined compressive strength (UCS), indirect tensile strength (ITS), drying shrinkage, and water loss ratio of each mix proportion. The preliminary results of UCS and ITS tests indicated that the incorporation of RCA resulted in a decrease of strength compared with a cement-stabilized macadam (CSM) mixture, but the seven-day strength of the CSR mixture met the related requirements of road bases. The increase in cement content and curing time had an obvious effect on strength improvement. The drying shrinkage test showed that the drying shrinkage properties of the CSR mixture were obviously reduced with a high replacement ratio. It is evident that the CSM mixture presented a better drying shrinkage performance than that of the CSR mixture.

Influence of binder type on performance of dense bituminous mixture prepared with coarse recycled concrete aggregate

Conventional stone aggregates are becoming scare and costly because of huge infrastructure activities going on since last three decades in India. On the other hand, wastes such as that resulting from old concrete constructions are abundantly available. Many attempts have already been made to utilise these wastes referred to as recycled concrete aggregate (RCA) in various constructions including in bituminous paving layers. All types of bituminous binders commonly used in paving mixes in India may not be compatible with RCA. This experimental study aims to study the influence of binder type on the performance of dense graded bituminous mixtures containing RCA replacing the coarse fraction of conventional stone aggregates. In order to achieve this main objective, dense bituminous macadam (DBM) mixtures as per the relevant Indian specifications were prepared using three different types of bituminous binders commonly used in India, namely conventional VG 30 and VG 40 bitumens, and crumb rubber modified binder (CRMB). Separate Marshall samples were prepared using RCA and natural aggregate (NA) and either of the above three binders. As per the main scope of this study, the mixtures thus prepared were evaluated in terms of their engineering properties such as Marshall characteristics, indirect tensile strength, moisture susceptibility characteristics, resilient modulus and rutting resistance. It is observed that all mixtures considered in this study, in general satisfy the requirements in terms of Marshall and moisture susceptibility characteristics. Considering all engineering properties studied, the CRMB/VG40 bitumen offer superior and satisfactory results for mixtures containing either NA or RCA, with NA showing slightly better result as compared with RCA in the mixtures.

Test Analysis on Drainage Base Mixture of Asphalt Pavement in Cold Area

Drainage base can effectively maintain the service performance of asphalt pavement structure in cold and humid areas, and improve its service durability. The void ratio of drainage base asphalt mixture shall be more than 20%, and the asphalt content is generally between 3.15% and 3.55%. Five kinds of open graded asphalt macadam mixtures were selected and tested for structural performance, water permeability, mechanical performance and water temperature stability. According to the test results, it is shown as follows. The water permeability coefficient of the five kinds of asphalt mixtures at 15°C was 0.10-0.19cm/s. The ratio of freeze-thaw splitting strength was 72.1%-92.3%. The compressive strength of uniaxial compression test was 4.53-8.91MPa. The compressive modulus of resilience was 794.79-1236.51MPa. The maximum bending tensile strain of beam was 3150-4977με. It has good structural strength, water stability and drainage performance. After 10-50 freeze-thaw cycles, the performance of structural performance index, tensile strain and mechanical index of asphalt mixture is well. The asphalt mixture can be used for drainage of asphalt pavement structure in high-latitude and low-altitude cold area. The recommended suitable layer is the upper base or lower layer of asphalt pavement structure.