Fines inclusion in a crushed limestone unbound aggregate base course material with 25.4-mm maximum particle size

Unbound aggregate base and subbase layers are the main load-bearing layers in a pavement structure. Size and shape properties of these aggregate materials should be controlled to ensure proper workability during construction and improved performance for pavement longevity. The effects of gradation, maximum particle size, fines content (percentage passing the No. 200 sieve), and dust ratio on the quality of aggregates were investigated by performing many soaked California bearing ratio tests on a crushed limestone material. The dust ratio represents the amount of fines content divided by the amount of minus No. 40 sieve material. The dust ratios studied were 0.4, 0.6, and 1.0. Two gradations commonly used in Illinois, with maximum particle sizes of 1 in. and 2 in., were studied to analyze the effect of fines content with respect to maximum particle size in the gradation. A typical range of fines contents (i.e., 5%, 8%, and 12%) was also considered. The results show that the gradation, dust ratio, and fines content should be taken into account in the selection of aggregate properties for stability requirements. Aggregates with larger maximum size particles provide high strength, and they are not affected as much as aggregates with smaller maximum size particles by an increase in fines content. The aggregates with smaller maximum size particles provide lower strength. It was also concluded that samples with a dust ratio of 1.0 do not necessarily result in an aggregate material with low strength.

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Mix Design of Cement-Stabilized Recycled Aggregate Base Course Material

Paving Materials and Pavement Analysis ◽

10.1061/41104(377)22 ◽

2010 ◽

Cited By ~ 3

Author(s):

Yijin Li ◽

Xinpeng Sun ◽

Jian Yin

Keyword(s):

Recycled Aggregate ◽

Mix Design ◽

Base Course Material ◽

Course Material ◽

Base Course ◽

Aggregate Base

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Research on Performance of Cement Stabilized Skeleton-Dense Structure Aggregate Base Course Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.1089 ◽

2011 ◽

Vol 194-196 ◽

pp. 1089-1094

Author(s):

Li Qun Hu ◽

Ai Min Sha

Keyword(s):

Cement Content ◽

Thermal Shrinkage ◽

Dry Density ◽

Maximum Dry Density ◽

Dense Structure ◽

Base Course Material ◽

Course Material ◽

Base Course ◽

Aggregate Base ◽

Shrinkage Coefficient

Laboratory tests were conducted to evaluate the performance of cement stabilized “skeleton-dense structure” aggregate and conventional “suspended-dense structure” aggregate. In this study, both of the aggregates above were stabilized by cement with different cement content (2%, 3%, 4%, 5% and 6%). Performances of the prepared specimens were studied in terms of compaction property, 7 day unconfined compressive strength (UCS), thermal shrinkage coefficient and 30 min erosion quantity. Results indicated that the maximum dry density of cement stabilized “skeleton-dense structure” aggregate is bigger than that of cement stabilized “suspended-dense structure” aggregate slightly. On the contrary, the optimum moisture content of the former is slightly smaller than that of the latter one. Along with the increase of cement content, the 7 day UCS and thermal shrinkage coefficient of cement stabilized two aggregates were all increase, and 30 min erosion quantity of cement stabilized two aggregates were all decrease. At the same cement content level, the 7 day UCS of cement stabilized “skeleton-dense structure” aggregate is greater than that of cement stabilized “suspended-dense structure” aggregate, and the thermal shrinkage coefficient and erosion quantity in 30 min of the former is smaller than that of the latter.

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Effects of maximum particle size of coarse aggregates and steel fiber contents on the mechanical properties and impact resistance of recycled aggregate concrete

Advances in Structural Engineering ◽

10.1177/13694332211017998 ◽

2021 ◽

pp. 136943322110179

Author(s):

DongTao Xia ◽

ShaoJun Xie ◽

Min Fu ◽

Feng Zhu

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Steel Fiber ◽

Impact Resistance ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Aggregate Concrete ◽

Coarse Aggregates ◽

Maximum Particle Size ◽

Maximum Particle

Fiber reinforced recycled aggregate concrete has become a new type of green concrete material. The maximum particle size of coarse aggregates and steel fiber contents affect the mechanical properties and impact resistance of recycled aggregate concrete. However, such studies are rare in literature. The present paper shortens the gap through experimental study. A total of 144 specimens of 12 kinds of concrete mixtures were tested, which adopted different steel fiber volume admixtures (0%, 0.8%, 1.0%, 1.2%) and recycled coarse aggregates in different maximum particle sizes (9.5, 19, 31.5 mm) replacing 30% natural coarse aggregate. The compressive strength, splitting tensile strength, and impact resistance of the 12 concrete mixtures were tested. The results showed that the compressive strength, splitting tensile strength, and impact resistance of recycled aggregate concrete increased first and then decreased with the increase of the maximum particle size. The recycled aggregate concrete with the maximum particle size of 19 mm had the highest mechanical properties and impact resistance. Besides, with the increase of steel fiber content, the compressive strength, splitting tensile strength, and impact resistance of recycled aggregate concrete showed an increasing trend. Considering a large amount of experimental data and the coupling effect of steel fiber contents and the maximum particle size of coarse aggregates, the Weibull distribution function was introduced to analyze the impact test results and predict the number of resistance to impact under different failure probabilities. The results showed that the number of blows of the recycled aggregate concrete followed a two-parameter Weibull distribution, and the estimated value of the number of resistance to impact for failure increased with the increase of the failure probability.

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A study on the behaviour of soilgeotextile systems in filtration tests

Canadian Geotechnical Journal ◽

10.1139/t96-120 ◽

1996 ◽

Vol 33 (6) ◽

pp. 899-912 ◽

Cited By ~ 25

Author(s):

E M Palmeira ◽

R J Fannin ◽

Y P Vaid

Keyword(s):

Particle Size ◽

Soil Characteristics ◽

Retention Capacity ◽

Unidirectional Flow ◽

Maximum Particle Size ◽

Theoretical Predictions ◽

New Apparatus ◽

Maximum Particle ◽

Gradient Ratio ◽

Different Soils

The behaviour of soilgeotextile systems in filtration tests is reported for nonwoven geotextiles under unidirectional flow. A new apparatus was developed to preform filtration tests under an applied vertical stress, and tests were then conducted with different soils and nonwoven geotextiles in order to evaluate the clogging potential and retention capacity of these materials under rather severe combinations of geotextile and soil characteristics. Results show that the geotextiles perfomed well and that observed permeability losses were acceptable even for gradient ratios close to 3. No progressive piping was observed, and it is believed that the retention capacity of the geotextiles may be influenced by their manufacturing process. In general, theoretical predictions for the maximum particle size passing through the geotextile compared well with measurements. Key words: geotextiles, filtration, gradient ratio, permeability, soil retention, clogging.

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Performance Evaluation of Al2O3 Powder Dispersion by Bead and Ball Mills

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.682.32 ◽

2014 ◽

Vol 682 ◽

pp. 32-34 ◽

Cited By ~ 3

Author(s):

N.S. Belousova ◽

O.A. Goryaynova ◽

E.V. Melnikova

Keyword(s):

Particle Size ◽

Performance Evaluation ◽

Ball Mill ◽

Aqueous Suspension ◽

Ball Mills ◽

Powder Dispersion ◽

Maximum Particle Size ◽

Bead Mill ◽

Maximum Particle

In this paper the results of alumina aqueous suspension disaggregation with the help of bead and ball mills are shown. The changing of maximum particle size for50 wt. % and 90 wt. % of powder (from lowest to highest size) in suspension dispersed by a bead mill for one hour and ball mill for 48 hours was fixed. In order to achieve powder parameters given by the manufacturer disaggregating process sets was defined.

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