Effects of Particle Size and Type of Aggregate on Mechanical Properties and Environmental Safety of Unbound Road Base and Subbase Materials: A Literature Review

Thai, Hong Nam; Kato, Akira; Nguyen, Hong Haï; Nguyễn, Tiến Dũng; Tong, Ton Kien; Nguyen, Van Tuan; Uchimura, Taro; Maki, Takeshi; Kawamoto, Ken

doi:10.21660/2021.78.gx281

Cited by 13 publications

(15 citation statements)

References 47 publications

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“…7a and b, NA had higher MDD than RCA regardless of D max and F c . This might be because NA is less porous and has higher particle density than RCA [7,11].…”

Section: Compaction Curves Of Tested Samplesmentioning

confidence: 99%

“…To maintain the performance and longevity of a road pavement structure, therefore, many studies have been done to characterize the mechanical properties of RCA such as compaction, California Bearing Ratio (CBR), shear strength, and resilience characteristics for application as unbound road base and subbase materials. For example, Thai et al [11] conducted an intensive review of the effects of particle size and type of aggregate on the mechanical properties of RCA. They reported that the mechanical indices [e.g., the maximum dry density (MDD) and CBR] depend highly on not only the type of aggregates, but also the nominal maximum particle size (D max ) of aggregates and fines content (F c , kg/kg in %; typically, the particle size of fines < 0.075 mm).…”

Section: Introductionmentioning

confidence: 99%

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Characterization of compaction and CBR properties of recycled concrete aggregates for unbound road base and subbase materials in Vietnam

Thai

Nguyễn

Nguyen

et al. 2021

J Mater Cycles Waste Manag

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Mechanical properties of recycled concrete aggregates (RCA) such as compaction and California bearing ratio (CBR) are important for application as unbound road base and subbase materials. Limited studies, however, have examined the effects of the nominal maximum particle diameter (D max ) of aggregates and fines content (F c ; < 0.075 mm). Also, particle rearrangement and breakage depend on water content (w) (i.e., water states of aggregates) under the compaction process. In this study, therefore, a series of compaction and CBR tests at different compaction energies (E c ) and w was carried in the laboratory using graded RCA with D max of 25 mm and 37.5 mm and four different F c ranging from 0 to 20%. The results showed that the compaction properties of RCA were controlled by E c and w. Based on the analysis of water states of aggregates, it can be understood that water existed in the capillary region for maximum dry density and existed at the boundary between capillary and hygroscopic regions for minimum dry density. The maximum measured CBR values were attained at F c = 5% for both D max of 25 mm and 37.5 mm. The breakage of samples became enhanced with increasing E c and weakened with increasing F c .

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“…7a and b, NA had higher MDD than RCA regardless of D max and F c . This might be because NA is less porous and has higher particle density than RCA [7,11].…”

Section: Compaction Curves Of Tested Samplesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization of compaction and CBR properties of recycled concrete aggregates for unbound road base and subbase materials in Vietnam

Thai

Nguyễn

Nguyen

et al. 2021

J Mater Cycles Waste Manag

Self Cite

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“…In China, the amount of coal mining waste (CMW) was 315 million tons for underground coal mining [3]. Therefore, the recycling of industrial wastes as construction materials has been interested in many countries to minimize the environmental impacts caused by the landfill area [4], as well as replacing the natural aggregates for the construction industry [3,[5][6][7][8][9][10][11][12]. Indranratna et.…”

Section: Introductionmentioning

confidence: 99%

“…These results are much lower than the MDD, or CBR of natural aggregates are usually 1.9-2.5 g/cm 3 and 25-180%. These properties mainly depend on the particle size (D max ), fines content, and type of aggregates [12]. However, the high MDD and CBR values will not be required for most pavements.…”

Section: Introductionmentioning

confidence: 99%

Utilization of Recycled Coal Mining Waste for Road Foundation Layers in Vietnam

Kien¹

2021

GEOMATE

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Road foundation is commonly used crushed aggregates from natural stone or gravel, natural sand, or soil with natural gravel. However, nowadays the sources of natural materials have been increasingly exhausted. This promotes the search and utilization of other materials to replace these natural materials for road construction projects. Meanwhile, the total volume of coal mining waste (CMW) released from coal exploitation in Vietnam has reached 460 million m 3 /year. This waste is mainly the disposal of soil-rocky waste mountains at coal mining sites, which leads to waste natural resources and landfill areas. Therefore, this research on using CMW as recycled aggregates to replace natural aggregates. It is not only to minimize the consumption of natural resources and solve the shortage of raw materials for road construction but also to reduce the mammoth volume of CMW at coal mining fields. This paper focuses on compaction characteristics and California Bearing Ratio (CBR) of CMW recycled aggregates (RAs) for the subgrade and foundation layers application. The results show that the maximum dry density (MDD) of the recycled sand (D max =4.75mm) ranges from 1.695-1.912 g/cm 3 , the optimum moisture content (OMC) of 15.1-18.1%, and the CBR value reaches 33-44%. As for graded macadam (D max =25mm) has the MDD=2.091-2.307 g/cm 3 ; OMC=5.1-6.7% and CBR= 89-123%. These results proved that it is possible to use CMW as recycled sand to replace natural sand and macadam aggregate type II D max =25mm as bases and subbases pavement for sub-surface foundation layers in Vietnam.

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“…For example, compaction densities decreased mostly with increased proportions of clay brick aggregates [59,60], decreasing the bearing capacity [61]. The allowable limit of clay brick aggregates (and other types of aggregates such as reclaimed asphalt pavement and recycled glass) mixed with concrete aggregates should be examined fully when we apply the recycled aggregates made from dumped CDW to road construction as roadbed materials [62].…”

mentioning

confidence: 99%

Current Management Condition and Waste Composition Characteristics of Construction and Demolition Waste Landfills in Hanoi of Vietnam

Nguyen

Nghiem

et al. 2021

Sustainability

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This study collected basic information and conducted waste composition surveys to identify the present management condition of construction and demolition waste (CDW) landfills in Hanoi of Vietnam and to characterize waste composition and grain size distribution of CDW dumped at landfills. Basic information on seven CDW landfills under operation or closed/abandoned was collected, and the waste composition and the grain size distributions of dumped CDW at two landfills were investigated. Results showed that only one landfill site is currently under operation in Hanoi. Sanitary conditions of investigated landfills were relatively good without dumping of hazardous waste. Illegal dumping of domestic waste from residents, however, could be observed more or less at all sites due to an unclear boundary between dumping and surrounding areas. To improve current management of CDW landfills, a suitable recording system of accepted/dumped CDW and technical support for site managers are required as well as the implementation plan for developing and renovating landfills. Based on the results of the waste composition survey, the major components of dumped CDW were “Concrete”, “Clay bricks”, and “Soil-like”, and the sum of these materials reached >80% of the total. Grain size distributions of “Concrete” ranged from 10–600 mm and of “Clay bricks” ranged from 10–300 mm. Technical recommendations to examine a potential availability of dumped “Concrete” and “Clay bricks” as a base material in road construction are summarized from the viewpoints of segregation from “Soil-like” and impurities, grading of “Concrete” and “Clay bricks”, mechanical properties and environmental safety, and economic feasibility. The findings in this study raise challenges and perspectives to establish sound CDW management and to promote sustainable development of CDW recycling in Vietnam.

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Effects of Particle Size and Type of Aggregate on Mechanical Properties and Environmental Safety of Unbound Road Base and Subbase Materials: A Literature Review

Cited by 13 publications

References 47 publications

Characterization of compaction and CBR properties of recycled concrete aggregates for unbound road base and subbase materials in Vietnam

Characterization of compaction and CBR properties of recycled concrete aggregates for unbound road base and subbase materials in Vietnam

Utilization of Recycled Coal Mining Waste for Road Foundation Layers in Vietnam

Current Management Condition and Waste Composition Characteristics of Construction and Demolition Waste Landfills in Hanoi of Vietnam

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